Commit message: avcodec/h264: use subsample factors of the used pixel format

Fixes out of array read
Fixes: 1cb91c36c4e55463f14aacb9bdf55b38-asan_heap-oob_106cbce_5617_cov_11212800_h264_mmx_chroma_intra_lf.mp4
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
CVE: None
CWE: CWE-703
Vulnerability description: None

Project: FFmpeg
File: h264.c

static int h264_frame_start(H264Context *h)
{
    Picture *pic;
    int i, ret;
    const int pixel_shift = h->pixel_shift;
    int c[4] = {
        1<<(h->sps.bit_depth_luma-1),
        1<<(h->sps.bit_depth_chroma-1),
        1<<(h->sps.bit_depth_chroma-1),
        -1
    };

    if (!ff_thread_can_start_frame(h->avctx)) {
        av_log(h->avctx, AV_LOG_ERROR, "Attempt to start a frame outside SETUP state\n");
        return -1;
    }

    release_unused_pictures(h, 1);
    h->cur_pic_ptr = NULL;

    i = find_unused_picture(h);
    if (i < 0) {
        av_log(h->avctx, AV_LOG_ERROR, "no frame buffer available\n");
        return i;
    }
    pic = &h->DPB[i];

    pic->reference              = h->droppable ? 0 : h->picture_structure;
    pic->f.coded_picture_number = h->coded_picture_number++;
    pic->field_picture          = h->picture_structure != PICT_FRAME;

    /*
     * Zero key_frame here; IDR markings per slice in frame or fields are ORed
     * in later.
     * See decode_nal_units().
     */
    pic->f.key_frame = 0;
    pic->mmco_reset  = 0;
    pic->recovered   = 0;

    if ((ret = alloc_picture(h, pic)) < 0)
        return ret;
    if(!h->frame_recovered && !h->avctx->hwaccel &&
       !(h->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU))
        avpriv_color_frame(&pic->f, c);

    h->cur_pic_ptr = pic;
    unref_picture(h, &h->cur_pic);
    if (CONFIG_ERROR_RESILIENCE) {
        h->er.cur_pic = NULL;
    }

    if ((ret = ref_picture(h, &h->cur_pic, h->cur_pic_ptr)) < 0)
        return ret;

    if (CONFIG_ERROR_RESILIENCE) {
        ff_er_frame_start(&h->er);
        h->er.last_pic =
        h->er.next_pic = NULL;
    }

    assert(h->linesize && h->uvlinesize);

    for (i = 0; i < 16; i++) {
        h->block_offset[i]           = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 4 * h->linesize * ((scan8[i] - scan8[0]) >> 3);
        h->block_offset[48 + i]      = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 8 * h->linesize * ((scan8[i] - scan8[0]) >> 3);
    }
    for (i = 0; i < 16; i++) {
        h->block_offset[16 + i]      =
        h->block_offset[32 + i]      = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 4 * h->uvlinesize * ((scan8[i] - scan8[0]) >> 3);
        h->block_offset[48 + 16 + i] =
        h->block_offset[48 + 32 + i] = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 8 * h->uvlinesize * ((scan8[i] - scan8[0]) >> 3);
    }

    // s->decode = (h->flags & CODEC_FLAG_PSNR) || !s->encoding ||
    //             h->cur_pic.reference /* || h->contains_intra */ || 1;

    /* We mark the current picture as non-reference after allocating it, so
     * that if we break out due to an error it can be released automatically
     * in the next ff_MPV_frame_start().
     */
    h->cur_pic_ptr->reference = 0;

    h->cur_pic_ptr->field_poc[0] = h->cur_pic_ptr->field_poc[1] = INT_MAX;

    h->next_output_pic = NULL;

    assert(h->cur_pic_ptr->long_ref == 0);

    return 0;
}

Project: FFmpeg
File: h264.c

static int ref_picture(H264Context *h, Picture *dst, Picture *src)
{
    int ret, i;

    av_assert0(!dst->f.buf[0]);
    av_assert0(src->f.buf[0]);

    src->tf.f = &src->f;
    dst->tf.f = &dst->f;
    ret = ff_thread_ref_frame(&dst->tf, &src->tf);
    if (ret < 0)
        goto fail;

    dst->qscale_table_buf = av_buffer_ref(src->qscale_table_buf);
    dst->mb_type_buf      = av_buffer_ref(src->mb_type_buf);
    if (!dst->qscale_table_buf || !dst->mb_type_buf)
        goto fail;
    dst->qscale_table = src->qscale_table;
    dst->mb_type      = src->mb_type;

    for (i = 0; i < 2; i++) {
        dst->motion_val_buf[i] = av_buffer_ref(src->motion_val_buf[i]);
        dst->ref_index_buf[i]  = av_buffer_ref(src->ref_index_buf[i]);
        if (!dst->motion_val_buf[i] || !dst->ref_index_buf[i])
            goto fail;
        dst->motion_val[i] = src->motion_val[i];
        dst->ref_index[i]  = src->ref_index[i];
    }

    if (src->hwaccel_picture_private) {
        dst->hwaccel_priv_buf = av_buffer_ref(src->hwaccel_priv_buf);
        if (!dst->hwaccel_priv_buf)
            goto fail;
        dst->hwaccel_picture_private = dst->hwaccel_priv_buf->data;
    }

    for (i = 0; i < 2; i++)
        dst->field_poc[i] = src->field_poc[i];

    memcpy(dst->ref_poc,   src->ref_poc,   sizeof(src->ref_poc));
    memcpy(dst->ref_count, src->ref_count, sizeof(src->ref_count));

    dst->poc           = src->poc;
    dst->frame_num     = src->frame_num;
    dst->mmco_reset    = src->mmco_reset;
    dst->pic_id        = src->pic_id;
    dst->long_ref      = src->long_ref;
    dst->mbaff         = src->mbaff;
    dst->field_picture = src->field_picture;
    dst->needs_realloc = src->needs_realloc;
    dst->reference     = src->reference;
    dst->crop          = src->crop;
    dst->crop_left     = src->crop_left;
    dst->crop_top      = src->crop_top;
    dst->recovered     = src->recovered;

    return 0;
fail:
    unref_picture(h, dst);
    return ret;
}

Project: FFmpeg
File: h264.c

static int decode_update_thread_context(AVCodecContext *dst,
                                        const AVCodecContext *src)
{
    H264Context *h = dst->priv_data, *h1 = src->priv_data;
    int inited = h->context_initialized, err = 0;
    int context_reinitialized = 0;
    int i, ret;

    if (dst == src)
        return 0;

    if (inited &&
        (h->width                 != h1->width                 ||
         h->height                != h1->height                ||
         h->mb_width              != h1->mb_width              ||
         h->mb_height             != h1->mb_height             ||
         h->sps.bit_depth_luma    != h1->sps.bit_depth_luma    ||
         h->sps.chroma_format_idc != h1->sps.chroma_format_idc ||
         h->sps.colorspace        != h1->sps.colorspace)) {

        /* set bits_per_raw_sample to the previous value. the check for changed
         * bit depth in h264_set_parameter_from_sps() uses it and sets it to
         * the current value */
        h->avctx->bits_per_raw_sample = h->sps.bit_depth_luma;

        av_freep(&h->bipred_scratchpad);

        h->width     = h1->width;
        h->height    = h1->height;
        h->mb_height = h1->mb_height;
        h->mb_width  = h1->mb_width;
        h->mb_num    = h1->mb_num;
        h->mb_stride = h1->mb_stride;
        h->b_stride  = h1->b_stride;
        // SPS/PPS
        if ((ret = copy_parameter_set((void **)h->sps_buffers,
                                      (void **)h1->sps_buffers,
                                      MAX_SPS_COUNT, sizeof(SPS))) < 0)
            return ret;
        h->sps = h1->sps;
        if ((ret = copy_parameter_set((void **)h->pps_buffers,
                                      (void **)h1->pps_buffers,
                                      MAX_PPS_COUNT, sizeof(PPS))) < 0)
            return ret;
        h->pps = h1->pps;

        if ((err = h264_slice_header_init(h, 1)) < 0) {
            av_log(h->avctx, AV_LOG_ERROR, "h264_slice_header_init() failed");
            return err;
        }
        context_reinitialized = 1;

#if 0
        h264_set_parameter_from_sps(h);
        //Note we set context_reinitialized which will cause h264_set_parameter_from_sps to be reexecuted
        h->cur_chroma_format_idc = h1->cur_chroma_format_idc;
#endif
    }
    /* update linesize on resize for h264. The h264 decoder doesn't
     * necessarily call ff_MPV_frame_start in the new thread */
    h->linesize   = h1->linesize;
    h->uvlinesize = h1->uvlinesize;

    /* copy block_offset since frame_start may not be called */
    memcpy(h->block_offset, h1->block_offset, sizeof(h->block_offset));

    if (!inited) {
        for (i = 0; i < MAX_SPS_COUNT; i++)
            av_freep(h->sps_buffers + i);

        for (i = 0; i < MAX_PPS_COUNT; i++)
            av_freep(h->pps_buffers + i);

        av_freep(&h->rbsp_buffer[0]);
        av_freep(&h->rbsp_buffer[1]);
        memcpy(h, h1, offsetof(H264Context, intra_pcm_ptr));
        memcpy(&h->cabac, &h1->cabac,
               sizeof(H264Context) - offsetof(H264Context, cabac));
        av_assert0((void*)&h->cabac == &h->mb_padding + 1);

        memset(h->sps_buffers, 0, sizeof(h->sps_buffers));
        memset(h->pps_buffers, 0, sizeof(h->pps_buffers));

        memset(&h->er, 0, sizeof(h->er));
        memset(&h->me, 0, sizeof(h->me));
        memset(&h->mb, 0, sizeof(h->mb));
        memset(&h->mb_luma_dc, 0, sizeof(h->mb_luma_dc));
        memset(&h->mb_padding, 0, sizeof(h->mb_padding));

        h->avctx             = dst;
        h->DPB               = NULL;
        h->qscale_table_pool = NULL;
        h->mb_type_pool      = NULL;
        h->ref_index_pool    = NULL;
        h->motion_val_pool   = NULL;
        for (i = 0; i < 2; i++) {
            h->rbsp_buffer[i] = NULL;
            h->rbsp_buffer_size[i] = 0;
        }

        if (h1->context_initialized) {
        h->context_initialized = 0;

        memset(&h->cur_pic, 0, sizeof(h->cur_pic));
        av_frame_unref(&h->cur_pic.f);
        h->cur_pic.tf.f = &h->cur_pic.f;

        ret = ff_h264_alloc_tables(h);
        if (ret < 0) {
            av_log(dst, AV_LOG_ERROR, "Could not allocate memory\n");
            return ret;
        }
        ret = context_init(h);
        if (ret < 0) {
            av_log(dst, AV_LOG_ERROR, "context_init() failed.\n");
            return ret;
        }
        }

        h->bipred_scratchpad = NULL;
        h->edge_emu_buffer   = NULL;

        h->thread_context[0] = h;
        h->context_initialized = h1->context_initialized;
    }

    h->avctx->coded_height  = h1->avctx->coded_height;
    h->avctx->coded_width   = h1->avctx->coded_width;
    h->avctx->width         = h1->avctx->width;
    h->avctx->height        = h1->avctx->height;
    h->coded_picture_number = h1->coded_picture_number;
    h->first_field          = h1->first_field;
    h->picture_structure    = h1->picture_structure;
    h->qscale               = h1->qscale;
    h->droppable            = h1->droppable;
    h->low_delay            = h1->low_delay;

    for (i = 0; h->DPB && i < MAX_PICTURE_COUNT; i++) {
        unref_picture(h, &h->DPB[i]);
        if (h1->DPB && h1->DPB[i].f.buf[0] &&
            (ret = ref_picture(h, &h->DPB[i], &h1->DPB[i])) < 0)
            return ret;
    }

    h->cur_pic_ptr = REBASE_PICTURE(h1->cur_pic_ptr, h, h1);
    unref_picture(h, &h->cur_pic);
    if (h1->cur_pic.f.buf[0] && (ret = ref_picture(h, &h->cur_pic, &h1->cur_pic)) < 0)
        return ret;

    h->workaround_bugs = h1->workaround_bugs;
    h->low_delay       = h1->low_delay;
    h->droppable       = h1->droppable;

    // extradata/NAL handling
    h->is_avc = h1->is_avc;

    // SPS/PPS
    if ((ret = copy_parameter_set((void **)h->sps_buffers,
                                  (void **)h1->sps_buffers,
                                  MAX_SPS_COUNT, sizeof(SPS))) < 0)
        return ret;
    h->sps = h1->sps;
    if ((ret = copy_parameter_set((void **)h->pps_buffers,
                                  (void **)h1->pps_buffers,
                                  MAX_PPS_COUNT, sizeof(PPS))) < 0)
        return ret;
    h->pps = h1->pps;

    // Dequantization matrices
    // FIXME these are big - can they be only copied when PPS changes?
    copy_fields(h, h1, dequant4_buffer, dequant4_coeff);

    for (i = 0; i < 6; i++)
        h->dequant4_coeff[i] = h->dequant4_buffer[0] +
                               (h1->dequant4_coeff[i] - h1->dequant4_buffer[0]);

    for (i = 0; i < 6; i++)
        h->dequant8_coeff[i] = h->dequant8_buffer[0] +
                               (h1->dequant8_coeff[i] - h1->dequant8_buffer[0]);

    h->dequant_coeff_pps = h1->dequant_coeff_pps;

    // POC timing
    copy_fields(h, h1, poc_lsb, redundant_pic_count);

    // reference lists
    copy_fields(h, h1, short_ref, cabac_init_idc);

    copy_picture_range(h->short_ref, h1->short_ref, 32, h, h1);
    copy_picture_range(h->long_ref, h1->long_ref, 32, h, h1);
    copy_picture_range(h->delayed_pic, h1->delayed_pic,
                       MAX_DELAYED_PIC_COUNT + 2, h, h1);

    h->frame_recovered       = h1->frame_recovered;

    if (context_reinitialized)
        h264_set_parameter_from_sps(h);

    if (!h->cur_pic_ptr)
        return 0;

    if (!h->droppable) {
        err = ff_h264_execute_ref_pic_marking(h, h->mmco, h->mmco_index);
        h->prev_poc_msb = h->poc_msb;
        h->prev_poc_lsb = h->poc_lsb;
    }
    h->prev_frame_num_offset = h->frame_num_offset;
    h->prev_frame_num        = h->frame_num;
    h->outputed_poc          = h->next_outputed_poc;

    h->recovery_frame        = h1->recovery_frame;

    return err;
}

Project: FFmpeg
File: h264.c

static int decode_slice(struct AVCodecContext *avctx, void *arg)
{
    H264Context *h = *(void **)arg;
    int lf_x_start = h->mb_x;

    h->mb_skip_run = -1;

    av_assert0(h->block_offset[15] == (4 * ((scan8[15] - scan8[0]) & 7) << h->pixel_shift) + 4 * h->linesize * ((scan8[15] - scan8[0]) >> 3));

    h->is_complex = FRAME_MBAFF(h) || h->picture_structure != PICT_FRAME ||
                    avctx->codec_id != AV_CODEC_ID_H264 ||
                    (CONFIG_GRAY && (h->flags & CODEC_FLAG_GRAY));

    if (!(h->avctx->active_thread_type & FF_THREAD_SLICE) && h->picture_structure == PICT_FRAME && h->er.error_status_table) {
        const int start_i  = av_clip(h->resync_mb_x + h->resync_mb_y * h->mb_width, 0, h->mb_num - 1);
        if (start_i) {
            int prev_status = h->er.error_status_table[h->er.mb_index2xy[start_i - 1]];
            prev_status &= ~ VP_START;
            if (prev_status != (ER_MV_END | ER_DC_END | ER_AC_END))
                h->er.error_occurred = 1;
        }
    }

    if (h->pps.cabac) {
        /* realign */
        align_get_bits(&h->gb);

        /* init cabac */
        ff_init_cabac_decoder(&h->cabac,
                              h->gb.buffer + get_bits_count(&h->gb) / 8,
                              (get_bits_left(&h->gb) + 7) / 8);

        ff_h264_init_cabac_states(h);

        for (;;) {
            // START_TIMER
            int ret = ff_h264_decode_mb_cabac(h);
            int eos;
            // STOP_TIMER("decode_mb_cabac")

            if (ret >= 0)
                ff_h264_hl_decode_mb(h);

            // FIXME optimal? or let mb_decode decode 16x32 ?
            if (ret >= 0 && FRAME_MBAFF(h)) {
                h->mb_y++;

                ret = ff_h264_decode_mb_cabac(h);

                if (ret >= 0)
                    ff_h264_hl_decode_mb(h);
                h->mb_y--;
            }
            eos = get_cabac_terminate(&h->cabac);

            if ((h->workaround_bugs & FF_BUG_TRUNCATED) &&
                h->cabac.bytestream > h->cabac.bytestream_end + 2) {
                er_add_slice(h, h->resync_mb_x, h->resync_mb_y, h->mb_x - 1,
                             h->mb_y, ER_MB_END);
                if (h->mb_x >= lf_x_start)
                    loop_filter(h, lf_x_start, h->mb_x + 1);
                return 0;
            }
            if (h->cabac.bytestream > h->cabac.bytestream_end + 2 )
                av_log(h->avctx, AV_LOG_DEBUG, "bytestream overread %td\n", h->cabac.bytestream_end - h->cabac.bytestream);
            if (ret < 0 || h->cabac.bytestream > h->cabac.bytestream_end + 4) {
                av_log(h->avctx, AV_LOG_ERROR,
                       "error while decoding MB %d %d, bytestream %td\n",
                       h->mb_x, h->mb_y,
                       h->cabac.bytestream_end - h->cabac.bytestream);
                er_add_slice(h, h->resync_mb_x, h->resync_mb_y, h->mb_x,
                             h->mb_y, ER_MB_ERROR);
                return AVERROR_INVALIDDATA;
            }

            if (++h->mb_x >= h->mb_width) {
                loop_filter(h, lf_x_start, h->mb_x);
                h->mb_x = lf_x_start = 0;
                decode_finish_row(h);
                ++h->mb_y;
                if (FIELD_OR_MBAFF_PICTURE(h)) {
                    ++h->mb_y;
                    if (FRAME_MBAFF(h) && h->mb_y < h->mb_height)
                        predict_field_decoding_flag(h);
                }
            }

            if (eos || h->mb_y >= h->mb_height) {
                tprintf(h->avctx, "slice end %d %d\n",
                        get_bits_count(&h->gb), h->gb.size_in_bits);
                er_add_slice(h, h->resync_mb_x, h->resync_mb_y, h->mb_x - 1,
                             h->mb_y, ER_MB_END);
                if (h->mb_x > lf_x_start)
                    loop_filter(h, lf_x_start, h->mb_x);
                return 0;
            }
        }
    } else {
        for (;;) {
            int ret = ff_h264_decode_mb_cavlc(h);

            if (ret >= 0)
                ff_h264_hl_decode_mb(h);

            // FIXME optimal? or let mb_decode decode 16x32 ?
            if (ret >= 0 && FRAME_MBAFF(h)) {
                h->mb_y++;
                ret = ff_h264_decode_mb_cavlc(h);

                if (ret >= 0)
                    ff_h264_hl_decode_mb(h);
                h->mb_y--;
            }

            if (ret < 0) {
                av_log(h->avctx, AV_LOG_ERROR,
                       "error while decoding MB %d %d\n", h->mb_x, h->mb_y);
                er_add_slice(h, h->resync_mb_x, h->resync_mb_y, h->mb_x,
                             h->mb_y, ER_MB_ERROR);
                return ret;
            }

            if (++h->mb_x >= h->mb_width) {
                loop_filter(h, lf_x_start, h->mb_x);
                h->mb_x = lf_x_start = 0;
                decode_finish_row(h);
                ++h->mb_y;
                if (FIELD_OR_MBAFF_PICTURE(h)) {
                    ++h->mb_y;
                    if (FRAME_MBAFF(h) && h->mb_y < h->mb_height)
                        predict_field_decoding_flag(h);
                }
                if (h->mb_y >= h->mb_height) {
                    tprintf(h->avctx, "slice end %d %d\n",
                            get_bits_count(&h->gb), h->gb.size_in_bits);

                    if (   get_bits_left(&h->gb) == 0
                        || get_bits_left(&h->gb) > 0 && !(h->avctx->err_recognition & AV_EF_AGGRESSIVE)) {
                        er_add_slice(h, h->resync_mb_x, h->resync_mb_y,
                                     h->mb_x - 1, h->mb_y,
                                     ER_MB_END);

                        return 0;
                    } else {
                        er_add_slice(h, h->resync_mb_x, h->resync_mb_y,
                                     h->mb_x, h->mb_y,
                                     ER_MB_END);

                        return AVERROR_INVALIDDATA;
                    }
                }
            }

            if (get_bits_left(&h->gb) <= 0 && h->mb_skip_run <= 0) {
                tprintf(h->avctx, "slice end %d %d\n",
                        get_bits_count(&h->gb), h->gb.size_in_bits);

                if (get_bits_left(&h->gb) == 0) {
                    er_add_slice(h, h->resync_mb_x, h->resync_mb_y,
                                 h->mb_x - 1, h->mb_y,
                                 ER_MB_END);
                    if (h->mb_x > lf_x_start)
                        loop_filter(h, lf_x_start, h->mb_x);

                    return 0;
                } else {
                    er_add_slice(h, h->resync_mb_x, h->resync_mb_y, h->mb_x,
                                 h->mb_y, ER_MB_ERROR);

                    return AVERROR_INVALIDDATA;
                }
            }
        }
    }
}

Project: FFmpeg
File: h264.c

int ff_h264_decode_extradata(H264Context *h, const uint8_t *buf, int size)
{
    AVCodecContext *avctx = h->avctx;
    int ret;

    if (!buf || size <= 0)
        return -1;

    if (buf[0] == 1) {
        int i, cnt, nalsize;
        const unsigned char *p = buf;

        h->is_avc = 1;

        if (size < 7) {
            av_log(avctx, AV_LOG_ERROR,
                   "avcC %d too short\n", size);
            return AVERROR_INVALIDDATA;
        }
        /* sps and pps in the avcC always have length coded with 2 bytes,
         * so put a fake nal_length_size = 2 while parsing them */
        h->nal_length_size = 2;
        // Decode sps from avcC
        cnt = *(p + 5) & 0x1f; // Number of sps
        p  += 6;
        for (i = 0; i < cnt; i++) {
            nalsize = AV_RB16(p) + 2;
            if(nalsize > size - (p-buf))
                return AVERROR_INVALIDDATA;
            ret = decode_nal_units(h, p, nalsize, 1);
            if (ret < 0) {
                av_log(avctx, AV_LOG_ERROR,
                       "Decoding sps %d from avcC failed\n", i);
                return ret;
            }
            p += nalsize;
        }
        // Decode pps from avcC
        cnt = *(p++); // Number of pps
        for (i = 0; i < cnt; i++) {
            nalsize = AV_RB16(p) + 2;
            if(nalsize > size - (p-buf))
                return AVERROR_INVALIDDATA;
            ret = decode_nal_units(h, p, nalsize, 1);
            if (ret < 0) {
                av_log(avctx, AV_LOG_ERROR,
                       "Decoding pps %d from avcC failed\n", i);
                return ret;
            }
            p += nalsize;
        }
        // Now store right nal length size, that will be used to parse all other nals
        h->nal_length_size = (buf[4] & 0x03) + 1;
    } else {
        h->is_avc = 0;
        ret = decode_nal_units(h, buf, size, 1);
        if (ret < 0)
            return ret;
    }
    return size;
}

Project: FFmpeg
File: h264.c

static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size,
                            int parse_extradata)
{
    AVCodecContext *const avctx = h->avctx;
    H264Context *hx; ///< thread context
    int buf_index;
    unsigned context_count;
    int next_avc;
    int pass = !(avctx->active_thread_type & FF_THREAD_FRAME);
    int nals_needed = 0; ///< number of NALs that need decoding before the next frame thread starts
    int nal_index;
    int idr_cleared=0;
    int first_slice = 0;
    int ret = 0;

    h->nal_unit_type= 0;

    if(!h->slice_context_count)
         h->slice_context_count= 1;
    h->max_contexts = h->slice_context_count;
    if (!(avctx->flags2 & CODEC_FLAG2_CHUNKS)) {
        h->current_slice = 0;
        if (!h->first_field)
            h->cur_pic_ptr = NULL;
        ff_h264_reset_sei(h);
    }

    if (h->nal_length_size == 4) {
        if (buf_size > 8 && AV_RB32(buf) == 1 && AV_RB32(buf+5) > (unsigned)buf_size) {
            h->is_avc = 0;
        }else if(buf_size > 3 && AV_RB32(buf) > 1 && AV_RB32(buf) <= (unsigned)buf_size)
            h->is_avc = 1;
    }

    for (; pass <= 1; pass++) {
        buf_index     = 0;
        context_count = 0;
        next_avc      = h->is_avc ? 0 : buf_size;
        nal_index     = 0;
        for (;;) {
            int consumed;
            int dst_length;
            int bit_length;
            const uint8_t *ptr;
            int i, nalsize = 0;
            int err;

            if (buf_index >= next_avc) {
                if (buf_index >= buf_size - h->nal_length_size)
                    break;
                nalsize = 0;
                for (i = 0; i < h->nal_length_size; i++)
                    nalsize = (nalsize << 8) | buf[buf_index++];
                if (nalsize <= 0 || nalsize > buf_size - buf_index) {
                    av_log(h->avctx, AV_LOG_ERROR,
                           "AVC: nal size %d\n", nalsize);
                    break;
                }
                next_avc = buf_index + nalsize;
            } else {
                // start code prefix search
                for (; buf_index + 3 < next_avc; buf_index++)
                    // This should always succeed in the first iteration.
                    if (buf[buf_index]     == 0 &&
                        buf[buf_index + 1] == 0 &&
                        buf[buf_index + 2] == 1)
                        break;

                if (buf_index + 3 >= buf_size) {
                    buf_index = buf_size;
                    break;
                }

                buf_index += 3;
                if (buf_index >= next_avc)
                    continue;
            }

            hx = h->thread_context[context_count];

            ptr = ff_h264_decode_nal(hx, buf + buf_index, &dst_length,
                                     &consumed, next_avc - buf_index);
            if (ptr == NULL || dst_length < 0) {
                ret = -1;
                goto end;
            }
            i = buf_index + consumed;
            if ((h->workaround_bugs & FF_BUG_AUTODETECT) && i + 3 < next_avc &&
                buf[i]     == 0x00 && buf[i + 1] == 0x00 &&
                buf[i + 2] == 0x01 && buf[i + 3] == 0xE0)
                h->workaround_bugs |= FF_BUG_TRUNCATED;

            if (!(h->workaround_bugs & FF_BUG_TRUNCATED))
                while (dst_length > 0 && ptr[dst_length - 1] == 0)
                    dst_length--;
            bit_length = !dst_length ? 0
                                     : (8 * dst_length -
                                        decode_rbsp_trailing(h, ptr + dst_length - 1));

            if (h->avctx->debug & FF_DEBUG_STARTCODE)
                av_log(h->avctx, AV_LOG_DEBUG,
                       "NAL %d/%d at %d/%d length %d pass %d\n",
                       hx->nal_unit_type, hx->nal_ref_idc, buf_index, buf_size, dst_length, pass);

            if (h->is_avc && (nalsize != consumed) && nalsize)
                av_log(h->avctx, AV_LOG_DEBUG,
                       "AVC: Consumed only %d bytes instead of %d\n",
                       consumed, nalsize);

            buf_index += consumed;
            nal_index++;

            if (pass == 0) {
                /* packets can sometimes contain multiple PPS/SPS,
                 * e.g. two PAFF field pictures in one packet, or a demuxer
                 * which splits NALs strangely if so, when frame threading we
                 * can't start the next thread until we've read all of them */
                switch (hx->nal_unit_type) {
                case NAL_SPS:
                case NAL_PPS:
                    nals_needed = nal_index;
                    break;
                case NAL_DPA:
                case NAL_IDR_SLICE:
                case NAL_SLICE:
                    init_get_bits(&hx->gb, ptr, bit_length);
                    if (!get_ue_golomb(&hx->gb) || !first_slice)
                        nals_needed = nal_index;
                    if (!first_slice)
                        first_slice = hx->nal_unit_type;
                }
                continue;
            }

            if (!first_slice)
                switch (hx->nal_unit_type) {
                case NAL_DPA:
                case NAL_IDR_SLICE:
                case NAL_SLICE:
                    first_slice = hx->nal_unit_type;
                }

            if (avctx->skip_frame >= AVDISCARD_NONREF &&
                h->nal_ref_idc == 0 &&
                h->nal_unit_type != NAL_SEI)
                continue;

again:
            if (   !(avctx->active_thread_type & FF_THREAD_FRAME)
                || nals_needed >= nal_index)
                h->au_pps_id = -1;
            /* Ignore per frame NAL unit type during extradata
             * parsing. Decoding slices is not possible in codec init
             * with frame-mt */
            if (parse_extradata) {
                switch (hx->nal_unit_type) {
                case NAL_IDR_SLICE:
                case NAL_SLICE:
                case NAL_DPA:
                case NAL_DPB:
                case NAL_DPC:
                    av_log(h->avctx, AV_LOG_WARNING,
                           "Ignoring NAL %d in global header/extradata\n",
                           hx->nal_unit_type);
                    // fall through to next case
                case NAL_AUXILIARY_SLICE:
                    hx->nal_unit_type = NAL_FF_IGNORE;
                }
            }

            err = 0;

            switch (hx->nal_unit_type) {
            case NAL_IDR_SLICE:
                if (first_slice != NAL_IDR_SLICE) {
                    av_log(h->avctx, AV_LOG_ERROR,
                           "Invalid mix of idr and non-idr slices\n");
                    ret = -1;
                    goto end;
                }
                if(!idr_cleared)
                    idr(h); // FIXME ensure we don't lose some frames if there is reordering
                idr_cleared = 1;
            case NAL_SLICE:
                init_get_bits(&hx->gb, ptr, bit_length);
                hx->intra_gb_ptr      =
                hx->inter_gb_ptr      = &hx->gb;
                hx->data_partitioning = 0;

                if ((err = decode_slice_header(hx, h)))
                    break;

                if (h->sei_recovery_frame_cnt >= 0) {
                    if (h->frame_num != h->sei_recovery_frame_cnt || hx->slice_type_nos != AV_PICTURE_TYPE_I)
                        h->valid_recovery_point = 1;

                    if (   h->recovery_frame < 0
                        || ((h->recovery_frame - h->frame_num) & ((1 << h->sps.log2_max_frame_num)-1)) > h->sei_recovery_frame_cnt) {
                        h->recovery_frame = (h->frame_num + h->sei_recovery_frame_cnt) &
                                            ((1 << h->sps.log2_max_frame_num) - 1);

                        if (!h->valid_recovery_point)
                            h->recovery_frame = h->frame_num;
                    }
                }

                h->cur_pic_ptr->f.key_frame |=
                    (hx->nal_unit_type == NAL_IDR_SLICE);

                if (hx->nal_unit_type == NAL_IDR_SLICE ||
                    h->recovery_frame == h->frame_num) {
                    h->recovery_frame         = -1;
                    h->cur_pic_ptr->recovered = 1;
                }
                // If we have an IDR, all frames after it in decoded order are
                // "recovered".
                if (hx->nal_unit_type == NAL_IDR_SLICE)
                    h->frame_recovered |= FRAME_RECOVERED_IDR;
                h->frame_recovered |= 3*!!(avctx->flags2 & CODEC_FLAG2_SHOW_ALL);
                h->frame_recovered |= 3*!!(avctx->flags & CODEC_FLAG_OUTPUT_CORRUPT);
#if 1
                h->cur_pic_ptr->recovered |= h->frame_recovered;
#else
                h->cur_pic_ptr->recovered |= !!(h->frame_recovered & FRAME_RECOVERED_IDR);
#endif

                if (h->current_slice == 1) {
                    if (!(avctx->flags2 & CODEC_FLAG2_CHUNKS))
                        decode_postinit(h, nal_index >= nals_needed);

                    if (h->avctx->hwaccel &&
                        (ret = h->avctx->hwaccel->start_frame(h->avctx, NULL, 0)) < 0)
                        return ret;
                    if (CONFIG_H264_VDPAU_DECODER &&
                        h->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)
                        ff_vdpau_h264_picture_start(h);
                }

                if (hx->redundant_pic_count == 0 &&
                    (avctx->skip_frame < AVDISCARD_NONREF ||
                     hx->nal_ref_idc) &&
                    (avctx->skip_frame < AVDISCARD_BIDIR  ||
                     hx->slice_type_nos != AV_PICTURE_TYPE_B) &&
                    (avctx->skip_frame < AVDISCARD_NONKEY ||
                     hx->slice_type_nos == AV_PICTURE_TYPE_I) &&
                    avctx->skip_frame < AVDISCARD_ALL) {
                    if (avctx->hwaccel) {
                        ret = avctx->hwaccel->decode_slice(avctx,
                                                           &buf[buf_index - consumed],
                                                           consumed);
                        if (ret < 0)
                            return ret;
                    } else if (CONFIG_H264_VDPAU_DECODER &&
                               h->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU) {
                        ff_vdpau_add_data_chunk(h->cur_pic_ptr->f.data[0],
                                                start_code,
                                                sizeof(start_code));
                        ff_vdpau_add_data_chunk(h->cur_pic_ptr->f.data[0],
                                                &buf[buf_index - consumed],
                                                consumed);
                    } else
                        context_count++;
                }
                break;
            case NAL_DPA:
                if (h->avctx->flags & CODEC_FLAG2_CHUNKS) {
                    av_log(h->avctx, AV_LOG_ERROR,
                           "Decoding in chunks is not supported for "
                           "partitioned slices.\n");
                    return AVERROR(ENOSYS);
                }

                init_get_bits(&hx->gb, ptr, bit_length);
                hx->intra_gb_ptr =
                hx->inter_gb_ptr = NULL;

                if ((err = decode_slice_header(hx, h)) < 0) {
                    /* make sure data_partitioning is cleared if it was set
                     * before, so we don't try decoding a slice without a valid
                     * slice header later */
                    h->data_partitioning = 0;
                    break;
                }

                hx->data_partitioning = 1;
                break;
            case NAL_DPB:
                init_get_bits(&hx->intra_gb, ptr, bit_length);
                hx->intra_gb_ptr = &hx->intra_gb;
                break;
            case NAL_DPC:
                init_get_bits(&hx->inter_gb, ptr, bit_length);
                hx->inter_gb_ptr = &hx->inter_gb;

                av_log(h->avctx, AV_LOG_ERROR, "Partitioned H.264 support is incomplete\n");
                break;

                if (hx->redundant_pic_count == 0 &&
                    hx->intra_gb_ptr &&
                    hx->data_partitioning &&
                    h->cur_pic_ptr && h->context_initialized &&
                    (avctx->skip_frame < AVDISCARD_NONREF || hx->nal_ref_idc) &&
                    (avctx->skip_frame < AVDISCARD_BIDIR  ||
                     hx->slice_type_nos != AV_PICTURE_TYPE_B) &&
                    (avctx->skip_frame < AVDISCARD_NONKEY ||
                     hx->slice_type_nos == AV_PICTURE_TYPE_I) &&
                    avctx->skip_frame < AVDISCARD_ALL)
                    context_count++;
                break;
            case NAL_SEI:
                init_get_bits(&h->gb, ptr, bit_length);
                ff_h264_decode_sei(h);
                break;
            case NAL_SPS:
                init_get_bits(&h->gb, ptr, bit_length);
                if (ff_h264_decode_seq_parameter_set(h) < 0 && (h->is_avc ? nalsize : 1)) {
                    av_log(h->avctx, AV_LOG_DEBUG,
                           "SPS decoding failure, trying again with the complete NAL\n");
                    if (h->is_avc)
                        av_assert0(next_avc - buf_index + consumed == nalsize);
                    if ((next_avc - buf_index + consumed - 1) >= INT_MAX/8)
                        break;
                    init_get_bits(&h->gb, &buf[buf_index + 1 - consumed],
                                  8*(next_avc - buf_index + consumed - 1));
                    ff_h264_decode_seq_parameter_set(h);
                }

                break;
            case NAL_PPS:
                init_get_bits(&h->gb, ptr, bit_length);
                ff_h264_decode_picture_parameter_set(h, bit_length);
                break;
            case NAL_AUD:
            case NAL_END_SEQUENCE:
            case NAL_END_STREAM:
            case NAL_FILLER_DATA:
            case NAL_SPS_EXT:
            case NAL_AUXILIARY_SLICE:
                break;
            case NAL_FF_IGNORE:
                break;
            default:
                av_log(avctx, AV_LOG_DEBUG, "Unknown NAL code: %d (%d bits)\n",
                       hx->nal_unit_type, bit_length);
            }

            if (context_count == h->max_contexts) {
                execute_decode_slices(h, context_count);
                context_count = 0;
            }

            if (err < 0) {
                av_log(h->avctx, AV_LOG_ERROR, "decode_slice_header error\n");
                h->ref_count[0] = h->ref_count[1] = h->list_count = 0;
            } else if (err == 1) {
                /* Slice could not be decoded in parallel mode, copy down
                 * NAL unit stuff to context 0 and restart. Note that
                 * rbsp_buffer is not transferred, but since we no longer
                 * run in parallel mode this should not be an issue. */
                h->nal_unit_type = hx->nal_unit_type;
                h->nal_ref_idc   = hx->nal_ref_idc;
                hx               = h;
                goto again;
            }
        }
    }
    if (context_count)
        execute_decode_slices(h, context_count);

end:
    /* clean up */
    if (h->cur_pic_ptr && !h->droppable) {
        ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                  h->picture_structure == PICT_BOTTOM_FIELD);
    }

    return (ret < 0) ? ret : buf_index;
}

Project: FFmpeg
File: h264.c

static int h264_set_parameter_from_sps(H264Context *h)
{
    if (h->flags & CODEC_FLAG_LOW_DELAY ||
        (h->sps.bitstream_restriction_flag &&
         !h->sps.num_reorder_frames)) {
        if (h->avctx->has_b_frames > 1 || h->delayed_pic[0])
            av_log(h->avctx, AV_LOG_WARNING, "Delayed frames seen. "
                   "Reenabling low delay requires a codec flush.\n");
        else
            h->low_delay = 1;
    }

    if (h->avctx->has_b_frames < 2)
        h->avctx->has_b_frames = !h->low_delay;

    if (h->avctx->bits_per_raw_sample != h->sps.bit_depth_luma ||
        h->cur_chroma_format_idc      != h->sps.chroma_format_idc) {
        if (h->avctx->codec &&
            h->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU &&
            (h->sps.bit_depth_luma != 8 || h->sps.chroma_format_idc > 1)) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "VDPAU decoding does not support video colorspace.\n");
            return AVERROR_INVALIDDATA;
        }
        if (h->sps.bit_depth_luma >= 8 && h->sps.bit_depth_luma <= 14 &&
            h->sps.bit_depth_luma != 11 && h->sps.bit_depth_luma != 13) {
            h->avctx->bits_per_raw_sample = h->sps.bit_depth_luma;
            h->cur_chroma_format_idc      = h->sps.chroma_format_idc;
            h->pixel_shift                = h->sps.bit_depth_luma > 8;

            ff_h264dsp_init(&h->h264dsp, h->sps.bit_depth_luma,
                            h->sps.chroma_format_idc);
            ff_h264chroma_init(&h->h264chroma, h->sps.bit_depth_chroma);
            ff_h264qpel_init(&h->h264qpel, h->sps.bit_depth_luma);
            ff_h264_pred_init(&h->hpc, h->avctx->codec_id, h->sps.bit_depth_luma,
                              h->sps.chroma_format_idc);

            if (CONFIG_ERROR_RESILIENCE)
                ff_dsputil_init(&h->dsp, h->avctx);
            ff_videodsp_init(&h->vdsp, h->sps.bit_depth_luma);
        } else {
            av_log(h->avctx, AV_LOG_ERROR, "Unsupported bit depth %d\n",
                   h->sps.bit_depth_luma);
            return AVERROR_INVALIDDATA;
        }
    }
    return 0;
}

Project: FFmpeg
File: h264.c

static void decode_postinit(H264Context *h, int setup_finished)
{
    Picture *out = h->cur_pic_ptr;
    Picture *cur = h->cur_pic_ptr;
    int i, pics, out_of_order, out_idx;

    h->cur_pic_ptr->f.pict_type = h->pict_type;

    if (h->next_output_pic)
        return;

    if (cur->field_poc[0] == INT_MAX || cur->field_poc[1] == INT_MAX) {
        /* FIXME: if we have two PAFF fields in one packet, we can't start
         * the next thread here. If we have one field per packet, we can.
         * The check in decode_nal_units() is not good enough to find this
         * yet, so we assume the worst for now. */
        // if (setup_finished)
        //    ff_thread_finish_setup(h->avctx);
        return;
    }

    cur->f.interlaced_frame = 0;
    cur->f.repeat_pict      = 0;

    /* Signal interlacing information externally. */
    /* Prioritize picture timing SEI information over used
     * decoding process if it exists. */

    if (h->sps.pic_struct_present_flag) {
        switch (h->sei_pic_struct) {
        case SEI_PIC_STRUCT_FRAME:
            break;
        case SEI_PIC_STRUCT_TOP_FIELD:
        case SEI_PIC_STRUCT_BOTTOM_FIELD:
            cur->f.interlaced_frame = 1;
            break;
        case SEI_PIC_STRUCT_TOP_BOTTOM:
        case SEI_PIC_STRUCT_BOTTOM_TOP:
            if (FIELD_OR_MBAFF_PICTURE(h))
                cur->f.interlaced_frame = 1;
            else
                // try to flag soft telecine progressive
                cur->f.interlaced_frame = h->prev_interlaced_frame;
            break;
        case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
        case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
            /* Signal the possibility of telecined film externally
             * (pic_struct 5,6). From these hints, let the applications
             * decide if they apply deinterlacing. */
            cur->f.repeat_pict = 1;
            break;
        case SEI_PIC_STRUCT_FRAME_DOUBLING:
            cur->f.repeat_pict = 2;
            break;
        case SEI_PIC_STRUCT_FRAME_TRIPLING:
            cur->f.repeat_pict = 4;
            break;
        }

        if ((h->sei_ct_type & 3) &&
            h->sei_pic_struct <= SEI_PIC_STRUCT_BOTTOM_TOP)
            cur->f.interlaced_frame = (h->sei_ct_type & (1 << 1)) != 0;
    } else {
        /* Derive interlacing flag from used decoding process. */
        cur->f.interlaced_frame = FIELD_OR_MBAFF_PICTURE(h);
    }
    h->prev_interlaced_frame = cur->f.interlaced_frame;

    if (cur->field_poc[0] != cur->field_poc[1]) {
        /* Derive top_field_first from field pocs. */
        cur->f.top_field_first = cur->field_poc[0] < cur->field_poc[1];
    } else {
        if (cur->f.interlaced_frame || h->sps.pic_struct_present_flag) {
            /* Use picture timing SEI information. Even if it is a
             * information of a past frame, better than nothing. */
            if (h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM ||
                h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM_TOP)
                cur->f.top_field_first = 1;
            else
                cur->f.top_field_first = 0;
        } else {
            /* Most likely progressive */
            cur->f.top_field_first = 0;
        }
    }

    if (h->sei_frame_packing_present &&
        h->frame_packing_arrangement_type >= 0 &&
        h->frame_packing_arrangement_type <= 6 &&
        h->content_interpretation_type > 0 &&
        h->content_interpretation_type < 3) {
        AVStereo3D *stereo = av_stereo3d_create_side_data(&cur->f);
        if (!stereo)
            return;

        switch (h->frame_packing_arrangement_type) {
        case 0:
            stereo->type = AV_STEREO3D_CHECKERBOARD;
            break;
        case 1:
            stereo->type = AV_STEREO3D_LINES;
            break;
        case 2:
            stereo->type = AV_STEREO3D_COLUMNS;
            break;
        case 3:
            if (h->quincunx_subsampling)
                stereo->type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
            else
                stereo->type = AV_STEREO3D_SIDEBYSIDE;
            break;
        case 4:
            stereo->type = AV_STEREO3D_TOPBOTTOM;
            break;
        case 5:
            stereo->type = AV_STEREO3D_FRAMESEQUENCE;
            break;
        case 6:
            stereo->type = AV_STEREO3D_2D;
            break;
        }

        if (h->content_interpretation_type == 2)
            stereo->flags = AV_STEREO3D_FLAG_INVERT;
    }

    cur->mmco_reset = h->mmco_reset;
    h->mmco_reset = 0;

    // FIXME do something with unavailable reference frames

    /* Sort B-frames into display order */

    if (h->sps.bitstream_restriction_flag &&
        h->avctx->has_b_frames < h->sps.num_reorder_frames) {
        h->avctx->has_b_frames = h->sps.num_reorder_frames;
        h->low_delay           = 0;
    }

    if (h->avctx->strict_std_compliance >= FF_COMPLIANCE_STRICT &&
        !h->sps.bitstream_restriction_flag) {
        h->avctx->has_b_frames = MAX_DELAYED_PIC_COUNT - 1;
        h->low_delay           = 0;
    }

    for (i = 0; 1; i++) {
        if(i == MAX_DELAYED_PIC_COUNT || cur->poc < h->last_pocs[i]){
            if(i)
                h->last_pocs[i-1] = cur->poc;
            break;
        } else if(i) {
            h->last_pocs[i-1]= h->last_pocs[i];
        }
    }
    out_of_order = MAX_DELAYED_PIC_COUNT - i;
    if(   cur->f.pict_type == AV_PICTURE_TYPE_B
       || (h->last_pocs[MAX_DELAYED_PIC_COUNT-2] > INT_MIN && h->last_pocs[MAX_DELAYED_PIC_COUNT-1] - h->last_pocs[MAX_DELAYED_PIC_COUNT-2] > 2))
        out_of_order = FFMAX(out_of_order, 1);
    if (out_of_order == MAX_DELAYED_PIC_COUNT) {
        av_log(h->avctx, AV_LOG_VERBOSE, "Invalid POC %d<%d\n", cur->poc, h->last_pocs[0]);
        for (i = 1; i < MAX_DELAYED_PIC_COUNT; i++)
            h->last_pocs[i] = INT_MIN;
        h->last_pocs[0] = cur->poc;
        cur->mmco_reset = 1;
    } else if(h->avctx->has_b_frames < out_of_order && !h->sps.bitstream_restriction_flag){
        av_log(h->avctx, AV_LOG_VERBOSE, "Increasing reorder buffer to %d\n", out_of_order);
        h->avctx->has_b_frames = out_of_order;
        h->low_delay = 0;
    }

    pics = 0;
    while (h->delayed_pic[pics])
        pics++;

    av_assert0(pics <= MAX_DELAYED_PIC_COUNT);

    h->delayed_pic[pics++] = cur;
    if (cur->reference == 0)
        cur->reference = DELAYED_PIC_REF;

    out     = h->delayed_pic[0];
    out_idx = 0;
    for (i = 1; h->delayed_pic[i] &&
                !h->delayed_pic[i]->f.key_frame &&
                !h->delayed_pic[i]->mmco_reset;
         i++)
        if (h->delayed_pic[i]->poc < out->poc) {
            out     = h->delayed_pic[i];
            out_idx = i;
        }
    if (h->avctx->has_b_frames == 0 &&
        (h->delayed_pic[0]->f.key_frame || h->delayed_pic[0]->mmco_reset))
        h->next_outputed_poc = INT_MIN;
    out_of_order = out->poc < h->next_outputed_poc;

    if (out_of_order || pics > h->avctx->has_b_frames) {
        out->reference &= ~DELAYED_PIC_REF;
        // for frame threading, the owner must be the second field's thread or
        // else the first thread can release the picture and reuse it unsafely
        for (i = out_idx; h->delayed_pic[i]; i++)
            h->delayed_pic[i] = h->delayed_pic[i + 1];
    }
    if (!out_of_order && pics > h->avctx->has_b_frames) {
        h->next_output_pic = out;
        if (out_idx == 0 && h->delayed_pic[0] && (h->delayed_pic[0]->f.key_frame || h->delayed_pic[0]->mmco_reset)) {
            h->next_outputed_poc = INT_MIN;
        } else
            h->next_outputed_poc = out->poc;
    } else {
        av_log(h->avctx, AV_LOG_DEBUG, "no picture %s\n", out_of_order ? "ooo" : "");
    }

    if (h->next_output_pic) {
        if (h->next_output_pic->recovered) {
            // We have reached an recovery point and all frames after it in
            // display order are "recovered".
            h->frame_recovered |= FRAME_RECOVERED_SEI;
        }
        h->next_output_pic->recovered |= !!(h->frame_recovered & FRAME_RECOVERED_SEI);
    }

    if (setup_finished && !h->avctx->hwaccel)
        ff_thread_finish_setup(h->avctx);
}

Project: FFmpeg
File: h264.c

av_cold int ff_h264_decode_init(AVCodecContext *avctx)
{
    H264Context *h = avctx->priv_data;
    int i;
    int ret;

    h->avctx = avctx;

    h->bit_depth_luma    = 8;
    h->chroma_format_idc = 1;

    h->avctx->bits_per_raw_sample = 8;
    h->cur_chroma_format_idc = 1;

    ff_h264dsp_init(&h->h264dsp, 8, 1);
    av_assert0(h->sps.bit_depth_chroma == 0);
    ff_h264chroma_init(&h->h264chroma, h->sps.bit_depth_chroma);
    ff_h264qpel_init(&h->h264qpel, 8);
    ff_h264_pred_init(&h->hpc, h->avctx->codec_id, 8, 1);

    h->dequant_coeff_pps = -1;
    h->current_sps_id = -1;

    /* needed so that IDCT permutation is known early */
    if (CONFIG_ERROR_RESILIENCE)
        ff_dsputil_init(&h->dsp, h->avctx);
    ff_videodsp_init(&h->vdsp, 8);

    memset(h->pps.scaling_matrix4, 16, 6 * 16 * sizeof(uint8_t));
    memset(h->pps.scaling_matrix8, 16, 2 * 64 * sizeof(uint8_t));

    h->picture_structure   = PICT_FRAME;
    h->slice_context_count = 1;
    h->workaround_bugs     = avctx->workaround_bugs;
    h->flags               = avctx->flags;

    /* set defaults */
    // s->decode_mb = ff_h263_decode_mb;
    if (!avctx->has_b_frames)
        h->low_delay = 1;

    avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;

    ff_h264_decode_init_vlc();

    ff_init_cabac_states();

    h->pixel_shift        = 0;
    h->sps.bit_depth_luma = avctx->bits_per_raw_sample = 8;

    h->thread_context[0] = h;
    h->outputed_poc      = h->next_outputed_poc = INT_MIN;
    for (i = 0; i < MAX_DELAYED_PIC_COUNT; i++)
        h->last_pocs[i] = INT_MIN;
    h->prev_poc_msb = 1 << 16;
    h->prev_frame_num = -1;
    h->x264_build   = -1;
    h->sei_fpa.frame_packing_arrangement_cancel_flag = -1;
    ff_h264_reset_sei(h);
    if (avctx->codec_id == AV_CODEC_ID_H264) {
        if (avctx->ticks_per_frame == 1) {
            if(h->avctx->time_base.den < INT_MAX/2) {
                h->avctx->time_base.den *= 2;
            } else
                h->avctx->time_base.num /= 2;
        }
        avctx->ticks_per_frame = 2;
    }

    if (avctx->extradata_size > 0 && avctx->extradata) {
        ret = ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size);
        if (ret < 0) {
            ff_h264_free_context(h);
            return ret;
        }
    }

    if (h->sps.bitstream_restriction_flag &&
        h->avctx->has_b_frames < h->sps.num_reorder_frames) {
        h->avctx->has_b_frames = h->sps.num_reorder_frames;
        h->low_delay           = 0;
    }

    avctx->internal->allocate_progress = 1;

    flush_change(h);

    return 0;
}

Project: FFmpeg
File: h264.c

int ff_set_ref_count(H264Context *h)
{
    int ref_count[2], list_count;
    int num_ref_idx_active_override_flag;

    // set defaults, might be overridden a few lines later
    ref_count[0] = h->pps.ref_count[0];
    ref_count[1] = h->pps.ref_count[1];

    if (h->slice_type_nos != AV_PICTURE_TYPE_I) {
        unsigned max[2];
        max[0] = max[1] = h->picture_structure == PICT_FRAME ? 15 : 31;

        if (h->slice_type_nos == AV_PICTURE_TYPE_B)
            h->direct_spatial_mv_pred = get_bits1(&h->gb);
        num_ref_idx_active_override_flag = get_bits1(&h->gb);

        if (num_ref_idx_active_override_flag) {
            ref_count[0] = get_ue_golomb(&h->gb) + 1;
            if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
                ref_count[1] = get_ue_golomb(&h->gb) + 1;
            } else
                // full range is spec-ok in this case, even for frames
                ref_count[1] = 1;
        }

        if (ref_count[0]-1 > max[0] || ref_count[1]-1 > max[1]){
            av_log(h->avctx, AV_LOG_ERROR, "reference overflow %u > %u or %u > %u\n", ref_count[0]-1, max[0], ref_count[1]-1, max[1]);
            h->ref_count[0] = h->ref_count[1] = 0;
            h->list_count   = 0;
            return AVERROR_INVALIDDATA;
        }

        if (h->slice_type_nos == AV_PICTURE_TYPE_B)
            list_count = 2;
        else
            list_count = 1;
    } else {
        list_count   = 0;
        ref_count[0] = ref_count[1] = 0;
    }

    if (list_count != h->list_count ||
        ref_count[0] != h->ref_count[0] ||
        ref_count[1] != h->ref_count[1]) {
        h->ref_count[0] = ref_count[0];
        h->ref_count[1] = ref_count[1];
        h->list_count   = list_count;
        return 1;
    }

    return 0;
}

Project: FFmpeg
File: h264.c

static void init_dequant_tables(H264Context *h)
{
    int i, x;
    init_dequant4_coeff_table(h);
    memset(h->dequant8_coeff, 0, sizeof(h->dequant8_coeff));

    if (h->pps.transform_8x8_mode)
        init_dequant8_coeff_table(h);
    if (h->sps.transform_bypass) {
        for (i = 0; i < 6; i++)
            for (x = 0; x < 16; x++)
                h->dequant4_coeff[i][0][x] = 1 << 6;
        if (h->pps.transform_8x8_mode)
            for (i = 0; i < 6; i++)
                for (x = 0; x < 64; x++)
                    h->dequant8_coeff[i][0][x] = 1 << 6;
    }
}

Project: FFmpeg

static int output_frame(H264Context *h, AVFrame *dst, Picture *srcp)
{
    AVFrame *src = &srcp->f;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(src->format);
    int i;
    int ret = av_frame_ref(dst, src);
    if (ret < 0)
        return ret;

    av_dict_set(&dst->metadata, "stereo_mode", ff_h264_sei_stereo_mode(h), 0);

    if (!srcp->crop)
        return 0;

    for (i = 0; i < desc->nb_components; i++) {
        int hshift = (i > 0) ? desc->log2_chroma_w : 0;
        int vshift = (i > 0) ? desc->log2_chroma_h : 0;
        int off    = ((srcp->crop_left >> hshift) << h->pixel_shift) +
                      (srcp->crop_top  >> vshift) * dst->linesize[i];
        dst->data[i] += off;
    }
    return 0;
}

Project: FFmpeg
File: h264.c

static enum AVPixelFormat get_pixel_format(H264Context *h, int force_callback)
{
    switch (h->sps.bit_depth_luma) {
    case 9:
        if (CHROMA444(h)) {
            if (h->avctx->colorspace == AVCOL_SPC_RGB) {
                return AV_PIX_FMT_GBRP9;
            } else
                return AV_PIX_FMT_YUV444P9;
        } else if (CHROMA422(h))
            return AV_PIX_FMT_YUV422P9;
        else
            return AV_PIX_FMT_YUV420P9;
        break;
    case 10:
        if (CHROMA444(h)) {
            if (h->avctx->colorspace == AVCOL_SPC_RGB) {
                return AV_PIX_FMT_GBRP10;
            } else
                return AV_PIX_FMT_YUV444P10;
        } else if (CHROMA422(h))
            return AV_PIX_FMT_YUV422P10;
        else
            return AV_PIX_FMT_YUV420P10;
        break;
    case 12:
        if (CHROMA444(h)) {
            if (h->avctx->colorspace == AVCOL_SPC_RGB) {
                return AV_PIX_FMT_GBRP12;
            } else
                return AV_PIX_FMT_YUV444P12;
        } else if (CHROMA422(h))
            return AV_PIX_FMT_YUV422P12;
        else
            return AV_PIX_FMT_YUV420P12;
        break;
    case 14:
        if (CHROMA444(h)) {
            if (h->avctx->colorspace == AVCOL_SPC_RGB) {
                return AV_PIX_FMT_GBRP14;
            } else
                return AV_PIX_FMT_YUV444P14;
        } else if (CHROMA422(h))
            return AV_PIX_FMT_YUV422P14;
        else
            return AV_PIX_FMT_YUV420P14;
        break;
    case 8:
        if (CHROMA444(h)) {
            if (h->avctx->colorspace == AVCOL_SPC_RGB) {
                av_log(h->avctx, AV_LOG_DEBUG, "Detected GBR colorspace.\n");
                return AV_PIX_FMT_GBR24P;
            } else if (h->avctx->colorspace == AVCOL_SPC_YCGCO) {
                av_log(h->avctx, AV_LOG_WARNING, "Detected unsupported YCgCo colorspace.\n");
            }
            return h->avctx->color_range == AVCOL_RANGE_JPEG ? AV_PIX_FMT_YUVJ444P
                                                                : AV_PIX_FMT_YUV444P;
        } else if (CHROMA422(h)) {
            return h->avctx->color_range == AVCOL_RANGE_JPEG ? AV_PIX_FMT_YUVJ422P
                                                             : AV_PIX_FMT_YUV422P;
        } else {
            int i;
            const enum AVPixelFormat * fmt = h->avctx->codec->pix_fmts ?
                                        h->avctx->codec->pix_fmts :
                                        h->avctx->color_range == AVCOL_RANGE_JPEG ?
                                        h264_hwaccel_pixfmt_list_jpeg_420 :
                                        h264_hwaccel_pixfmt_list_420;

            for (i=0; fmt[i] != AV_PIX_FMT_NONE; i++)
                if (fmt[i] == h->avctx->pix_fmt && !force_callback)
                    return fmt[i];
            return ff_thread_get_format(h->avctx, fmt);
        }
        break;
    default:
        av_log(h->avctx, AV_LOG_ERROR,
               "Unsupported bit depth %d\n", h->sps.bit_depth_luma);
        return AVERROR_INVALIDDATA;
    }
}

Project: FFmpeg
File: h264.c

static int execute_decode_slices(H264Context *h, unsigned context_count)
{
    AVCodecContext *const avctx = h->avctx;
    H264Context *hx;
    int i;

    av_assert0(h->mb_y < h->mb_height);

    if (h->avctx->hwaccel ||
        h->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)
        return 0;
    if (context_count == 1) {
        return decode_slice(avctx, &h);
    } else {
        av_assert0(context_count > 0);
        for (i = 1; i < context_count; i++) {
            hx                 = h->thread_context[i];
            if (CONFIG_ERROR_RESILIENCE) {
                hx->er.error_count = 0;
            }
            hx->x264_build     = h->x264_build;
        }

        avctx->execute(avctx, decode_slice, h->thread_context,
                       NULL, context_count, sizeof(void *));

        /* pull back stuff from slices to master context */
        hx                   = h->thread_context[context_count - 1];
        h->mb_x              = hx->mb_x;
        h->mb_y              = hx->mb_y;
        h->droppable         = hx->droppable;
        h->picture_structure = hx->picture_structure;
        if (CONFIG_ERROR_RESILIENCE) {
            for (i = 1; i < context_count; i++)
                h->er.error_count += h->thread_context[i]->er.error_count;
        }
    }

    return 0;
}

Project: FFmpeg
File: h264.c

int ff_h264_alloc_tables(H264Context *h)
{
    const int big_mb_num = h->mb_stride * (h->mb_height + 1);
    const int row_mb_num = 2*h->mb_stride*FFMAX(h->avctx->thread_count, 1);
    int x, y, i;

    FF_ALLOCZ_OR_GOTO(h->avctx, h->intra4x4_pred_mode,
                      row_mb_num * 8 * sizeof(uint8_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->non_zero_count,
                      big_mb_num * 48 * sizeof(uint8_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->slice_table_base,
                      (big_mb_num + h->mb_stride) * sizeof(*h->slice_table_base), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->cbp_table,
                      big_mb_num * sizeof(uint16_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->chroma_pred_mode_table,
                      big_mb_num * sizeof(uint8_t), fail)
    FF_ALLOCZ_OR_GOTO(h->avctx, h->mvd_table[0],
                      16 * row_mb_num * sizeof(uint8_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->mvd_table[1],
                      16 * row_mb_num * sizeof(uint8_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->direct_table,
                      4 * big_mb_num * sizeof(uint8_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->list_counts,
                      big_mb_num * sizeof(uint8_t), fail)

    memset(h->slice_table_base, -1,
           (big_mb_num + h->mb_stride) * sizeof(*h->slice_table_base));
    h->slice_table = h->slice_table_base + h->mb_stride * 2 + 1;

    FF_ALLOCZ_OR_GOTO(h->avctx, h->mb2b_xy,
                      big_mb_num * sizeof(uint32_t), fail);
    FF_ALLOCZ_OR_GOTO(h->avctx, h->mb2br_xy,
                      big_mb_num * sizeof(uint32_t), fail);
    for (y = 0; y < h->mb_height; y++)
        for (x = 0; x < h->mb_width; x++) {
            const int mb_xy = x + y * h->mb_stride;
            const int b_xy  = 4 * x + 4 * y * h->b_stride;

            h->mb2b_xy[mb_xy]  = b_xy;
            h->mb2br_xy[mb_xy] = 8 * (FMO ? mb_xy : (mb_xy % (2 * h->mb_stride)));
        }

    if (!h->dequant4_coeff[0])
        init_dequant_tables(h);

    if (!h->DPB) {
        h->DPB = av_mallocz_array(MAX_PICTURE_COUNT, sizeof(*h->DPB));
        if (!h->DPB)
            return AVERROR(ENOMEM);
        for (i = 0; i < MAX_PICTURE_COUNT; i++)
            av_frame_unref(&h->DPB[i].f);
        av_frame_unref(&h->cur_pic.f);
    }

    return 0;

fail:
    free_tables(h, 1);
    return AVERROR(ENOMEM);
}

Project: FFmpeg

static int decode_slice_header(H264Context *h, H264Context *h0)
{
    unsigned int first_mb_in_slice;
    unsigned int pps_id;
    int ret;
    unsigned int slice_type, tmp, i, j;
    int last_pic_structure, last_pic_droppable;
    int must_reinit;
    int needs_reinit = 0;
    int field_pic_flag, bottom_field_flag;

    h->me.qpel_put = h->h264qpel.put_h264_qpel_pixels_tab;
    h->me.qpel_avg = h->h264qpel.avg_h264_qpel_pixels_tab;

    first_mb_in_slice = get_ue_golomb_long(&h->gb);

    if (first_mb_in_slice == 0) { // FIXME better field boundary detection
        if (h0->current_slice && h->cur_pic_ptr && FIELD_PICTURE(h)) {
            field_end(h, 1);
        }

        h0->current_slice = 0;
        if (!h0->first_field) {
            if (h->cur_pic_ptr && !h->droppable) {
                ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                          h->picture_structure == PICT_BOTTOM_FIELD);
            }
            h->cur_pic_ptr = NULL;
        }
    }

    slice_type = get_ue_golomb_31(&h->gb);
    if (slice_type > 9) {
        av_log(h->avctx, AV_LOG_ERROR,
               "slice type %d too large at %d %d\n",
               slice_type, h->mb_x, h->mb_y);
        return AVERROR_INVALIDDATA;
    }
    if (slice_type > 4) {
        slice_type -= 5;
        h->slice_type_fixed = 1;
    } else
        h->slice_type_fixed = 0;

    slice_type = golomb_to_pict_type[slice_type];
    h->slice_type     = slice_type;
    h->slice_type_nos = slice_type & 3;

    if (h->nal_unit_type  == NAL_IDR_SLICE &&
        h->slice_type_nos != AV_PICTURE_TYPE_I) {
        av_log(h->avctx, AV_LOG_ERROR, "A non-intra slice in an IDR NAL unit.\n");
        return AVERROR_INVALIDDATA;
    }

    // to make a few old functions happy, it's wrong though
    h->pict_type = h->slice_type;

    pps_id = get_ue_golomb(&h->gb);
    if (pps_id >= MAX_PPS_COUNT) {
        av_log(h->avctx, AV_LOG_ERROR, "pps_id %u out of range\n", pps_id);
        return AVERROR_INVALIDDATA;
    }
    if (!h0->pps_buffers[pps_id]) {
        av_log(h->avctx, AV_LOG_ERROR,
               "non-existing PPS %u referenced\n",
               pps_id);
        return AVERROR_INVALIDDATA;
    }
    if (h0->au_pps_id >= 0 && pps_id != h0->au_pps_id) {
        av_log(h->avctx, AV_LOG_ERROR,
               "PPS change from %d to %d forbidden\n",
               h0->au_pps_id, pps_id);
        return AVERROR_INVALIDDATA;
    }
    h->pps = *h0->pps_buffers[pps_id];

    if (!h0->sps_buffers[h->pps.sps_id]) {
        av_log(h->avctx, AV_LOG_ERROR,
               "non-existing SPS %u referenced\n",
               h->pps.sps_id);
        return AVERROR_INVALIDDATA;
    }

    if (h->pps.sps_id != h->sps.sps_id ||
        h->pps.sps_id != h->current_sps_id ||
        h0->sps_buffers[h->pps.sps_id]->new) {

        h->sps = *h0->sps_buffers[h->pps.sps_id];

        if (h->mb_width  != h->sps.mb_width ||
            h->mb_height != h->sps.mb_height * (2 - h->sps.frame_mbs_only_flag) ||
            h->avctx->bits_per_raw_sample != h->sps.bit_depth_luma ||
            h->cur_chroma_format_idc != h->sps.chroma_format_idc
        )
            needs_reinit = 1;

        if (h->bit_depth_luma    != h->sps.bit_depth_luma ||
            h->chroma_format_idc != h->sps.chroma_format_idc) {
            h->bit_depth_luma    = h->sps.bit_depth_luma;
            h->chroma_format_idc = h->sps.chroma_format_idc;
            needs_reinit         = 1;
        }
        if ((ret = h264_set_parameter_from_sps(h)) < 0)
            return ret;
    }

    h->avctx->profile = ff_h264_get_profile(&h->sps);
    h->avctx->level   = h->sps.level_idc;
    h->avctx->refs    = h->sps.ref_frame_count;

    must_reinit = (h->context_initialized &&
                    (   16*h->sps.mb_width != h->avctx->coded_width
                     || 16*h->sps.mb_height * (2 - h->sps.frame_mbs_only_flag) != h->avctx->coded_height
                     || h->avctx->bits_per_raw_sample != h->sps.bit_depth_luma
                     || h->cur_chroma_format_idc != h->sps.chroma_format_idc
                     || av_cmp_q(h->sps.sar, h->avctx->sample_aspect_ratio)
                     || h->mb_width  != h->sps.mb_width
                     || h->mb_height != h->sps.mb_height * (2 - h->sps.frame_mbs_only_flag)
                    ));
    if (h0->avctx->pix_fmt != get_pixel_format(h0, 0))
        must_reinit = 1;

    h->mb_width  = h->sps.mb_width;
    h->mb_height = h->sps.mb_height * (2 - h->sps.frame_mbs_only_flag);
    h->mb_num    = h->mb_width * h->mb_height;
    h->mb_stride = h->mb_width + 1;

    h->b_stride = h->mb_width * 4;

    h->chroma_y_shift = h->sps.chroma_format_idc <= 1; // 400 uses yuv420p

    h->width  = 16 * h->mb_width;
    h->height = 16 * h->mb_height;

    ret = init_dimensions(h);
    if (ret < 0)
        return ret;

    if (h->sps.video_signal_type_present_flag) {
        h->avctx->color_range = h->sps.full_range>0 ? AVCOL_RANGE_JPEG
                                                    : AVCOL_RANGE_MPEG;
        if (h->sps.colour_description_present_flag) {
            if (h->avctx->colorspace != h->sps.colorspace)
                needs_reinit = 1;
            h->avctx->color_primaries = h->sps.color_primaries;
            h->avctx->color_trc       = h->sps.color_trc;
            h->avctx->colorspace      = h->sps.colorspace;
        }
    }

    if (h->context_initialized &&
        (h->width  != h->avctx->coded_width   ||
         h->height != h->avctx->coded_height  ||
         must_reinit ||
         needs_reinit)) {
        if (h != h0) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "changing width %d -> %d / height %d -> %d on "
                   "slice %d\n",
                   h->width, h->avctx->coded_width,
                   h->height, h->avctx->coded_height,
                   h0->current_slice + 1);
            return AVERROR_INVALIDDATA;
        }

        flush_change(h);

        if ((ret = get_pixel_format(h, 1)) < 0)
            return ret;
        h->avctx->pix_fmt = ret;

        av_log(h->avctx, AV_LOG_INFO, "Reinit context to %dx%d, "
               "pix_fmt: %s\n", h->width, h->height, av_get_pix_fmt_name(h->avctx->pix_fmt));

        if ((ret = h264_slice_header_init(h, 1)) < 0) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "h264_slice_header_init() failed\n");
            return ret;
        }
    }
    if (!h->context_initialized) {
        if (h != h0) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "Cannot (re-)initialize context during parallel decoding.\n");
            return AVERROR_PATCHWELCOME;
        }

        if ((ret = get_pixel_format(h, 1)) < 0)
            return ret;
        h->avctx->pix_fmt = ret;

        if ((ret = h264_slice_header_init(h, 0)) < 0) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "h264_slice_header_init() failed\n");
            return ret;
        }
    }

    if (h == h0 && h->dequant_coeff_pps != pps_id) {
        h->dequant_coeff_pps = pps_id;
        init_dequant_tables(h);
    }

    h->frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num);

    h->mb_mbaff        = 0;
    h->mb_aff_frame    = 0;
    last_pic_structure = h0->picture_structure;
    last_pic_droppable = h0->droppable;
    h->droppable       = h->nal_ref_idc == 0;
    if (h->sps.frame_mbs_only_flag) {
        h->picture_structure = PICT_FRAME;
    } else {
        if (!h->sps.direct_8x8_inference_flag && slice_type == AV_PICTURE_TYPE_B) {
            av_log(h->avctx, AV_LOG_ERROR, "This stream was generated by a broken encoder, invalid 8x8 inference\n");
            return -1;
        }
        field_pic_flag = get_bits1(&h->gb);
        if (field_pic_flag) {
            bottom_field_flag = get_bits1(&h->gb);
            h->picture_structure = PICT_TOP_FIELD + bottom_field_flag;
        } else {
            h->picture_structure = PICT_FRAME;
            h->mb_aff_frame      = h->sps.mb_aff;
        }
    }
    h->mb_field_decoding_flag = h->picture_structure != PICT_FRAME;

    if (h0->current_slice != 0) {
        if (last_pic_structure != h->picture_structure ||
            last_pic_droppable != h->droppable) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "Changing field mode (%d -> %d) between slices is not allowed\n",
                   last_pic_structure, h->picture_structure);
            h->picture_structure = last_pic_structure;
            h->droppable         = last_pic_droppable;
            return AVERROR_INVALIDDATA;
        } else if (!h0->cur_pic_ptr) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "unset cur_pic_ptr on slice %d\n",
                   h0->current_slice + 1);
            return AVERROR_INVALIDDATA;
        }
    } else {
        /* Shorten frame num gaps so we don't have to allocate reference
         * frames just to throw them away */
        if (h->frame_num != h->prev_frame_num) {
            int unwrap_prev_frame_num = h->prev_frame_num;
            int max_frame_num         = 1 << h->sps.log2_max_frame_num;

            if (unwrap_prev_frame_num > h->frame_num)
                unwrap_prev_frame_num -= max_frame_num;

            if ((h->frame_num - unwrap_prev_frame_num) > h->sps.ref_frame_count) {
                unwrap_prev_frame_num = (h->frame_num - h->sps.ref_frame_count) - 1;
                if (unwrap_prev_frame_num < 0)
                    unwrap_prev_frame_num += max_frame_num;

                h->prev_frame_num = unwrap_prev_frame_num;
            }
        }

        /* See if we have a decoded first field looking for a pair...
         * Here, we're using that to see if we should mark previously
         * decode frames as "finished".
         * We have to do that before the "dummy" in-between frame allocation,
         * since that can modify h->cur_pic_ptr. */
        if (h0->first_field) {
            assert(h0->cur_pic_ptr);
            assert(h0->cur_pic_ptr->f.buf[0]);
            assert(h0->cur_pic_ptr->reference != DELAYED_PIC_REF);

            /* Mark old field/frame as completed */
            if (h0->cur_pic_ptr->tf.owner == h0->avctx) {
                ff_thread_report_progress(&h0->cur_pic_ptr->tf, INT_MAX,
                                          last_pic_structure == PICT_BOTTOM_FIELD);
            }

            /* figure out if we have a complementary field pair */
            if (!FIELD_PICTURE(h) || h->picture_structure == last_pic_structure) {
                /* Previous field is unmatched. Don't display it, but let it
                 * remain for reference if marked as such. */
                if (last_pic_structure != PICT_FRAME) {
                    ff_thread_report_progress(&h0->cur_pic_ptr->tf, INT_MAX,
                                              last_pic_structure == PICT_TOP_FIELD);
                }
            } else {
                if (h0->cur_pic_ptr->frame_num != h->frame_num) {
                    /* This and previous field were reference, but had
                     * different frame_nums. Consider this field first in
                     * pair. Throw away previous field except for reference
                     * purposes. */
                    if (last_pic_structure != PICT_FRAME) {
                        ff_thread_report_progress(&h0->cur_pic_ptr->tf, INT_MAX,
                                                  last_pic_structure == PICT_TOP_FIELD);
                    }
                } else {
                    /* Second field in complementary pair */
                    if (!((last_pic_structure   == PICT_TOP_FIELD &&
                           h->picture_structure == PICT_BOTTOM_FIELD) ||
                          (last_pic_structure   == PICT_BOTTOM_FIELD &&
                           h->picture_structure == PICT_TOP_FIELD))) {
                        av_log(h->avctx, AV_LOG_ERROR,
                               "Invalid field mode combination %d/%d\n",
                               last_pic_structure, h->picture_structure);
                        h->picture_structure = last_pic_structure;
                        h->droppable         = last_pic_droppable;
                        return AVERROR_INVALIDDATA;
                    } else if (last_pic_droppable != h->droppable) {
                        avpriv_request_sample(h->avctx,
                                              "Found reference and non-reference fields in the same frame, which");
                        h->picture_structure = last_pic_structure;
                        h->droppable         = last_pic_droppable;
                        return AVERROR_PATCHWELCOME;
                    }
                }
            }
        }

        while (h->frame_num != h->prev_frame_num && !h0->first_field &&
               h->frame_num != (h->prev_frame_num + 1) % (1 << h->sps.log2_max_frame_num)) {
            Picture *prev = h->short_ref_count ? h->short_ref[0] : NULL;
            av_log(h->avctx, AV_LOG_DEBUG, "Frame num gap %d %d\n",
                   h->frame_num, h->prev_frame_num);
            if (!h->sps.gaps_in_frame_num_allowed_flag)
                for(i=0; i<FF_ARRAY_ELEMS(h->last_pocs); i++)
                    h->last_pocs[i] = INT_MIN;
            ret = h264_frame_start(h);
            if (ret < 0) {
                h0->first_field = 0;
                return ret;
            }

            h->prev_frame_num++;
            h->prev_frame_num        %= 1 << h->sps.log2_max_frame_num;
            h->cur_pic_ptr->frame_num = h->prev_frame_num;
            ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX, 0);
            ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX, 1);
            ret = ff_generate_sliding_window_mmcos(h, 1);
            if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
                return ret;
            ret = ff_h264_execute_ref_pic_marking(h, h->mmco, h->mmco_index);
            if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
                return ret;
            /* Error concealment: If a ref is missing, copy the previous ref
             * in its place.
             * FIXME: Avoiding a memcpy would be nice, but ref handling makes
             * many assumptions about there being no actual duplicates.
             * FIXME: This does not copy padding for out-of-frame motion
             * vectors.  Given we are concealing a lost frame, this probably
             * is not noticeable by comparison, but it should be fixed. */
            if (h->short_ref_count) {
                if (prev) {
                    av_image_copy(h->short_ref[0]->f.data,
                                  h->short_ref[0]->f.linesize,
                                  (const uint8_t **)prev->f.data,
                                  prev->f.linesize,
                                  h->avctx->pix_fmt,
                                  h->mb_width  * 16,
                                  h->mb_height * 16);
                    h->short_ref[0]->poc = prev->poc + 2;
                }
                h->short_ref[0]->frame_num = h->prev_frame_num;
            }
        }

        /* See if we have a decoded first field looking for a pair...
         * We're using that to see whether to continue decoding in that
         * frame, or to allocate a new one. */
        if (h0->first_field) {
            assert(h0->cur_pic_ptr);
            assert(h0->cur_pic_ptr->f.buf[0]);
            assert(h0->cur_pic_ptr->reference != DELAYED_PIC_REF);

            /* figure out if we have a complementary field pair */
            if (!FIELD_PICTURE(h) || h->picture_structure == last_pic_structure) {
                /* Previous field is unmatched. Don't display it, but let it
                 * remain for reference if marked as such. */
                h0->cur_pic_ptr = NULL;
                h0->first_field = FIELD_PICTURE(h);
            } else {
                if (h0->cur_pic_ptr->frame_num != h->frame_num) {
                    ff_thread_report_progress(&h0->cur_pic_ptr->tf, INT_MAX,
                                              h0->picture_structure==PICT_BOTTOM_FIELD);
                    /* This and the previous field had different frame_nums.
                     * Consider this field first in pair. Throw away previous
                     * one except for reference purposes. */
                    h0->first_field = 1;
                    h0->cur_pic_ptr = NULL;
                } else {
                    /* Second field in complementary pair */
                    h0->first_field = 0;
                }
            }
        } else {
            /* Frame or first field in a potentially complementary pair */
            h0->first_field = FIELD_PICTURE(h);
        }

        if (!FIELD_PICTURE(h) || h0->first_field) {
            if (h264_frame_start(h) < 0) {
                h0->first_field = 0;
                return AVERROR_INVALIDDATA;
            }
        } else {
            release_unused_pictures(h, 0);
        }
        /* Some macroblocks can be accessed before they're available in case
        * of lost slices, MBAFF or threading. */
        if (FIELD_PICTURE(h)) {
            for(i = (h->picture_structure == PICT_BOTTOM_FIELD); i<h->mb_height; i++)
                memset(h->slice_table + i*h->mb_stride, -1, (h->mb_stride - (i+1==h->mb_height)) * sizeof(*h->slice_table));
        } else {
            memset(h->slice_table, -1,
                (h->mb_height * h->mb_stride - 1) * sizeof(*h->slice_table));
        }
        h0->last_slice_type = -1;
    }
    if (h != h0 && (ret = clone_slice(h, h0)) < 0)
        return ret;

    /* can't be in alloc_tables because linesize isn't known there.
     * FIXME: redo bipred weight to not require extra buffer? */
    for (i = 0; i < h->slice_context_count; i++)
        if (h->thread_context[i]) {
            ret = alloc_scratch_buffers(h->thread_context[i], h->linesize);
            if (ret < 0)
                return ret;
        }

    h->cur_pic_ptr->frame_num = h->frame_num; // FIXME frame_num cleanup

    av_assert1(h->mb_num == h->mb_width * h->mb_height);
    if (first_mb_in_slice << FIELD_OR_MBAFF_PICTURE(h) >= h->mb_num ||
        first_mb_in_slice >= h->mb_num) {
        av_log(h->avctx, AV_LOG_ERROR, "first_mb_in_slice overflow\n");
        return AVERROR_INVALIDDATA;
    }
    h->resync_mb_x = h->mb_x =  first_mb_in_slice % h->mb_width;
    h->resync_mb_y = h->mb_y = (first_mb_in_slice / h->mb_width) <<
                               FIELD_OR_MBAFF_PICTURE(h);
    if (h->picture_structure == PICT_BOTTOM_FIELD)
        h->resync_mb_y = h->mb_y = h->mb_y + 1;
    av_assert1(h->mb_y < h->mb_height);

    if (h->picture_structure == PICT_FRAME) {
        h->curr_pic_num = h->frame_num;
        h->max_pic_num  = 1 << h->sps.log2_max_frame_num;
    } else {
        h->curr_pic_num = 2 * h->frame_num + 1;
        h->max_pic_num  = 1 << (h->sps.log2_max_frame_num + 1);
    }

    if (h->nal_unit_type == NAL_IDR_SLICE)
        get_ue_golomb(&h->gb); /* idr_pic_id */

    if (h->sps.poc_type == 0) {
        h->poc_lsb = get_bits(&h->gb, h->sps.log2_max_poc_lsb);

        if (h->pps.pic_order_present == 1 && h->picture_structure == PICT_FRAME)
            h->delta_poc_bottom = get_se_golomb(&h->gb);
    }

    if (h->sps.poc_type == 1 && !h->sps.delta_pic_order_always_zero_flag) {
        h->delta_poc[0] = get_se_golomb(&h->gb);

        if (h->pps.pic_order_present == 1 && h->picture_structure == PICT_FRAME)
            h->delta_poc[1] = get_se_golomb(&h->gb);
    }

    ff_init_poc(h, h->cur_pic_ptr->field_poc, &h->cur_pic_ptr->poc);

    if (h->pps.redundant_pic_cnt_present)
        h->redundant_pic_count = get_ue_golomb(&h->gb);

    ret = ff_set_ref_count(h);
    if (ret < 0)
        return ret;

    if (slice_type != AV_PICTURE_TYPE_I &&
        (h0->current_slice == 0 ||
         slice_type != h0->last_slice_type ||
         memcmp(h0->last_ref_count, h0->ref_count, sizeof(h0->ref_count)))) {

        ff_h264_fill_default_ref_list(h);
    }

    if (h->slice_type_nos != AV_PICTURE_TYPE_I) {
       ret = ff_h264_decode_ref_pic_list_reordering(h);
       if (ret < 0) {
           h->ref_count[1] = h->ref_count[0] = 0;
           return ret;
       }
    }

    if ((h->pps.weighted_pred && h->slice_type_nos == AV_PICTURE_TYPE_P) ||
        (h->pps.weighted_bipred_idc == 1 &&
         h->slice_type_nos == AV_PICTURE_TYPE_B))
        ff_pred_weight_table(h);
    else if (h->pps.weighted_bipred_idc == 2 &&
             h->slice_type_nos == AV_PICTURE_TYPE_B) {
        implicit_weight_table(h, -1);
    } else {
        h->use_weight = 0;
        for (i = 0; i < 2; i++) {
            h->luma_weight_flag[i]   = 0;
            h->chroma_weight_flag[i] = 0;
        }
    }

    // If frame-mt is enabled, only update mmco tables for the first slice
    // in a field. Subsequent slices can temporarily clobber h->mmco_index
    // or h->mmco, which will cause ref list mix-ups and decoding errors
    // further down the line. This may break decoding if the first slice is
    // corrupt, thus we only do this if frame-mt is enabled.
    if (h->nal_ref_idc) {
        ret = ff_h264_decode_ref_pic_marking(h0, &h->gb,
                                             !(h->avctx->active_thread_type & FF_THREAD_FRAME) ||
                                             h0->current_slice == 0);
        if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
            return AVERROR_INVALIDDATA;
    }

    if (FRAME_MBAFF(h)) {
        ff_h264_fill_mbaff_ref_list(h);

        if (h->pps.weighted_bipred_idc == 2 && h->slice_type_nos == AV_PICTURE_TYPE_B) {
            implicit_weight_table(h, 0);
            implicit_weight_table(h, 1);
        }
    }

    if (h->slice_type_nos == AV_PICTURE_TYPE_B && !h->direct_spatial_mv_pred)
        ff_h264_direct_dist_scale_factor(h);
    ff_h264_direct_ref_list_init(h);

    if (h->slice_type_nos != AV_PICTURE_TYPE_I && h->pps.cabac) {
        tmp = get_ue_golomb_31(&h->gb);
        if (tmp > 2) {
            av_log(h->avctx, AV_LOG_ERROR, "cabac_init_idc %u overflow\n", tmp);
            return AVERROR_INVALIDDATA;
        }
        h->cabac_init_idc = tmp;
    }

    h->last_qscale_diff = 0;
    tmp = h->pps.init_qp + get_se_golomb(&h->gb);
    if (tmp > 51 + 6 * (h->sps.bit_depth_luma - 8)) {
        av_log(h->avctx, AV_LOG_ERROR, "QP %u out of range\n", tmp);
        return AVERROR_INVALIDDATA;
    }
    h->qscale       = tmp;
    h->chroma_qp[0] = get_chroma_qp(h, 0, h->qscale);
    h->chroma_qp[1] = get_chroma_qp(h, 1, h->qscale);
    // FIXME qscale / qp ... stuff
    if (h->slice_type == AV_PICTURE_TYPE_SP)
        get_bits1(&h->gb); /* sp_for_switch_flag */
    if (h->slice_type == AV_PICTURE_TYPE_SP ||
        h->slice_type == AV_PICTURE_TYPE_SI)
        get_se_golomb(&h->gb); /* slice_qs_delta */

    h->deblocking_filter     = 1;
    h->slice_alpha_c0_offset = 0;
    h->slice_beta_offset     = 0;
    if (h->pps.deblocking_filter_parameters_present) {
        tmp = get_ue_golomb_31(&h->gb);
        if (tmp > 2) {
            av_log(h->avctx, AV_LOG_ERROR,
                   "deblocking_filter_idc %u out of range\n", tmp);
            return AVERROR_INVALIDDATA;
        }
        h->deblocking_filter = tmp;
        if (h->deblocking_filter < 2)
            h->deblocking_filter ^= 1;  // 1<->0

        if (h->deblocking_filter) {
            h->slice_alpha_c0_offset = get_se_golomb(&h->gb) * 2;
            h->slice_beta_offset     = get_se_golomb(&h->gb) * 2;
            if (h->slice_alpha_c0_offset >  12 ||
                h->slice_alpha_c0_offset < -12 ||
                h->slice_beta_offset >  12     ||
                h->slice_beta_offset < -12) {
                av_log(h->avctx, AV_LOG_ERROR,
                       "deblocking filter parameters %d %d out of range\n",
                       h->slice_alpha_c0_offset, h->slice_beta_offset);
                return AVERROR_INVALIDDATA;
            }
        }
    }

    if (h->avctx->skip_loop_filter >= AVDISCARD_ALL ||
        (h->avctx->skip_loop_filter >= AVDISCARD_NONKEY &&
         h->slice_type_nos != AV_PICTURE_TYPE_I) ||
        (h->avctx->skip_loop_filter >= AVDISCARD_BIDIR  &&
         h->slice_type_nos == AV_PICTURE_TYPE_B) ||
        (h->avctx->skip_loop_filter >= AVDISCARD_NONREF &&
         h->nal_ref_idc == 0))
        h->deblocking_filter = 0;

    if (h->deblocking_filter == 1 && h0->max_contexts > 1) {
        if (h->avctx->flags2 & CODEC_FLAG2_FAST) {
            /* Cheat slightly for speed:
             * Do not bother to deblock across slices. */
            h->deblocking_filter = 2;
        } else {
            h0->max_contexts = 1;
            if (!h0->single_decode_warning) {
                av_log(h->avctx, AV_LOG_INFO,
                       "Cannot parallelize deblocking type 1, decoding such frames in sequential order\n");
                h0->single_decode_warning = 1;
            }
            if (h != h0) {
                av_log(h->avctx, AV_LOG_ERROR,
                       "Deblocking switched inside frame.\n");
                return 1;
            }
        }
    }
    h->qp_thresh = 15 -
                   FFMIN(h->slice_alpha_c0_offset, h->slice_beta_offset) -
                   FFMAX3(0,
                          h->pps.chroma_qp_index_offset[0],
                          h->pps.chroma_qp_index_offset[1]) +
                   6 * (h->sps.bit_depth_luma - 8);

    h0->last_slice_type = slice_type;
    memcpy(h0->last_ref_count, h0->ref_count, sizeof(h0->last_ref_count));
    h->slice_num        = ++h0->current_slice;

    if (h->slice_num)
        h0->slice_row[(h->slice_num-1)&(MAX_SLICES-1)]= h->resync_mb_y;
    if (   h0->slice_row[h->slice_num&(MAX_SLICES-1)] + 3 >= h->resync_mb_y
        && h0->slice_row[h->slice_num&(MAX_SLICES-1)] <= h->resync_mb_y
        && h->slice_num >= MAX_SLICES) {
        //in case of ASO this check needs to be updated depending on how we decide to assign slice numbers in this case
        av_log(h->avctx, AV_LOG_WARNING, "Possibly too many slices (%d >= %d), increase MAX_SLICES and recompile if there are artifacts\n", h->slice_num, MAX_SLICES);
    }

    for (j = 0; j < 2; j++) {
        int id_list[16];
        int *ref2frm = h->ref2frm[h->slice_num & (MAX_SLICES - 1)][j];
        for (i = 0; i < 16; i++) {
            id_list[i] = 60;
            if (j < h->list_count && i < h->ref_count[j] &&
                h->ref_list[j][i].f.buf[0]) {
                int k;
                AVBuffer *buf = h->ref_list[j][i].f.buf[0]->buffer;
                for (k = 0; k < h->short_ref_count; k++)
                    if (h->short_ref[k]->f.buf[0]->buffer == buf) {
                        id_list[i] = k;
                        break;
                    }
                for (k = 0; k < h->long_ref_count; k++)
                    if (h->long_ref[k] && h->long_ref[k]->f.buf[0]->buffer == buf) {
                        id_list[i] = h->short_ref_count + k;
                        break;
                    }
            }
        }

        ref2frm[0] =
        ref2frm[1] = -1;
        for (i = 0; i < 16; i++)
            ref2frm[i + 2] = 4 * id_list[i] + (h->ref_list[j][i].reference & 3);
        ref2frm[18 + 0] =
        ref2frm[18 + 1] = -1;
        for (i = 16; i < 48; i++)
            ref2frm[i + 4] = 4 * id_list[(i - 16) >> 1] +
                             (h->ref_list[j][i].reference & 3);
    }

    if (h->ref_count[0]) h->er.last_pic = &h->ref_list[0][0];
    if (h->ref_count[1]) h->er.next_pic = &h->ref_list[1][0];
    h->er.ref_count = h->ref_count[0];
    h0->au_pps_id = pps_id;
    h->sps.new =
    h0->sps_buffers[h->pps.sps_id]->new = 0;
    h->current_sps_id = h->pps.sps_id;

    if (h->avctx->debug & FF_DEBUG_PICT_INFO) {
        av_log(h->avctx, AV_LOG_DEBUG,
               "slice:%d %s mb:%d %c%s%s pps:%u frame:%d poc:%d/%d ref:%d/%d qp:%d loop:%d:%d:%d weight:%d%s %s\n",
               h->slice_num,
               (h->picture_structure == PICT_FRAME ? "F" : h->picture_structure == PICT_TOP_FIELD ? "T" : "B"),
               first_mb_in_slice,
               av_get_picture_type_char(h->slice_type),
               h->slice_type_fixed ? " fix" : "",
               h->nal_unit_type == NAL_IDR_SLICE ? " IDR" : "",
               pps_id, h->frame_num,
               h->cur_pic_ptr->field_poc[0],
               h->cur_pic_ptr->field_poc[1],
               h->ref_count[0], h->ref_count[1],
               h->qscale,
               h->deblocking_filter,
               h->slice_alpha_c0_offset, h->slice_beta_offset,
               h->use_weight,
               h->use_weight == 1 && h->use_weight_chroma ? "c" : "",
               h->slice_type == AV_PICTURE_TYPE_B ? (h->direct_spatial_mv_pred ? "SPAT" : "TEMP") : "");
    }

    return 0;
}

Project: FFmpeg
File: h264.c

static void flush_change(H264Context *h)
{
    int i, j;

    h->outputed_poc          = h->next_outputed_poc = INT_MIN;
    h->prev_interlaced_frame = 1;
    idr(h);

    h->prev_frame_num = -1;
    if (h->cur_pic_ptr) {
        h->cur_pic_ptr->reference = 0;
        for (j=i=0; h->delayed_pic[i]; i++)
            if (h->delayed_pic[i] != h->cur_pic_ptr)
                h->delayed_pic[j++] = h->delayed_pic[i];
        h->delayed_pic[j] = NULL;
    }
    h->first_field = 0;
    memset(h->ref_list[0], 0, sizeof(h->ref_list[0]));
    memset(h->ref_list[1], 0, sizeof(h->ref_list[1]));
    memset(h->default_ref_list[0], 0, sizeof(h->default_ref_list[0]));
    memset(h->default_ref_list[1], 0, sizeof(h->default_ref_list[1]));
    ff_h264_reset_sei(h);
    h->recovery_frame = -1;
    h->frame_recovered = 0;
    h->list_count = 0;
    h->current_slice = 0;
    h->mmco_reset = 1;
}

Project: FFmpeg
File: h264.c

const uint8_t *ff_h264_decode_nal(H264Context *h, const uint8_t *src,
                                  int *dst_length, int *consumed, int length)
{
    int i, si, di;
    uint8_t *dst;
    int bufidx;

    // src[0]&0x80; // forbidden bit
    h->nal_ref_idc   = src[0] >> 5;
    h->nal_unit_type = src[0] & 0x1F;

    src++;
    length--;

#define STARTCODE_TEST                                                  \
    if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) {         \
        if (src[i + 2] != 3) {                                          \
            /* startcode, so we must be past the end */                 \
            length = i;                                                 \
        }                                                               \
        break;                                                          \
    }

#if HAVE_FAST_UNALIGNED
#define FIND_FIRST_ZERO                                                 \
    if (i > 0 && !src[i])                                               \
        i--;                                                            \
    while (src[i])                                                      \
        i++

#if HAVE_FAST_64BIT
    for (i = 0; i + 1 < length; i += 9) {
        if (!((~AV_RN64A(src + i) &
               (AV_RN64A(src + i) - 0x0100010001000101ULL)) &
              0x8000800080008080ULL))
            continue;
        FIND_FIRST_ZERO;
        STARTCODE_TEST;
        i -= 7;
    }
#else
    for (i = 0; i + 1 < length; i += 5) {
        if (!((~AV_RN32A(src + i) &
               (AV_RN32A(src + i) - 0x01000101U)) &
              0x80008080U))
            continue;
        FIND_FIRST_ZERO;
        STARTCODE_TEST;
        i -= 3;
    }
#endif
#else
    for (i = 0; i + 1 < length; i += 2) {
        if (src[i])
            continue;
        if (i > 0 && src[i - 1] == 0)
            i--;
        STARTCODE_TEST;
    }
#endif

    // use second escape buffer for inter data
    bufidx = h->nal_unit_type == NAL_DPC ? 1 : 0;

    si = h->rbsp_buffer_size[bufidx];
    av_fast_padded_malloc(&h->rbsp_buffer[bufidx], &h->rbsp_buffer_size[bufidx], length+MAX_MBPAIR_SIZE);
    dst = h->rbsp_buffer[bufidx];

    if (dst == NULL)
        return NULL;

    if(i>=length-1){ //no escaped 0
        *dst_length= length;
        *consumed= length+1; //+1 for the header
        if(h->avctx->flags2 & CODEC_FLAG2_FAST){
            return src;
        }else{
            memcpy(dst, src, length);
            return dst;
        }
    }

    memcpy(dst, src, i);
    si = di = i;
    while (si + 2 < length) {
        // remove escapes (very rare 1:2^22)
        if (src[si + 2] > 3) {
            dst[di++] = src[si++];
            dst[di++] = src[si++];
        } else if (src[si] == 0 && src[si + 1] == 0) {
            if (src[si + 2] == 3) { // escape
                dst[di++]  = 0;
                dst[di++]  = 0;
                si        += 3;
                continue;
            } else // next start code
                goto nsc;
        }

        dst[di++] = src[si++];
    }
    while (si < length)
        dst[di++] = src[si++];

nsc:
    memset(dst + di, 0, FF_INPUT_BUFFER_PADDING_SIZE);

    *dst_length = di;
    *consumed   = si + 1; // +1 for the header
    /* FIXME store exact number of bits in the getbitcontext
     * (it is needed for decoding) */
    return dst;
}

Project: FFmpeg
File: h264.c

static int h264_slice_header_init(H264Context *h, int reinit)
{
    int nb_slices = (HAVE_THREADS &&
                     h->avctx->active_thread_type & FF_THREAD_SLICE) ?
                    h->avctx->thread_count : 1;
    int i, ret;

    h->avctx->sample_aspect_ratio = h->sps.sar;
    av_assert0(h->avctx->sample_aspect_ratio.den);
    av_pix_fmt_get_chroma_sub_sample(h->avctx->pix_fmt,
                                     &h->chroma_x_shift, &h->chroma_y_shift);

    if (h->sps.timing_info_present_flag) {
        int64_t den = h->sps.time_scale;
        if (h->x264_build < 44U)
            den *= 2;
        av_reduce(&h->avctx->time_base.num, &h->avctx->time_base.den,
                  h->sps.num_units_in_tick, den, 1 << 30);
    }

    h->avctx->hwaccel = ff_find_hwaccel(h->avctx);

    if (reinit)
        free_tables(h, 0);
    h->first_field           = 0;
    h->prev_interlaced_frame = 1;

    init_scan_tables(h);
    ret = ff_h264_alloc_tables(h);
    if (ret < 0) {
        av_log(h->avctx, AV_LOG_ERROR, "Could not allocate memory\n");
        return ret;
    }

    if (nb_slices > MAX_THREADS || (nb_slices > h->mb_height && h->mb_height)) {
        int max_slices;
        if (h->mb_height)
            max_slices = FFMIN(MAX_THREADS, h->mb_height);
        else
            max_slices = MAX_THREADS;
        av_log(h->avctx, AV_LOG_WARNING, "too many threads/slices %d,"
               " reducing to %d\n", nb_slices, max_slices);
        nb_slices = max_slices;
    }
    h->slice_context_count = nb_slices;

    if (!HAVE_THREADS || !(h->avctx->active_thread_type & FF_THREAD_SLICE)) {
        ret = context_init(h);
        if (ret < 0) {
            av_log(h->avctx, AV_LOG_ERROR, "context_init() failed.\n");
            return ret;
        }
    } else {
        for (i = 1; i < h->slice_context_count; i++) {
            H264Context *c;
            c                    = h->thread_context[i] = av_mallocz(sizeof(H264Context));
            if (!c)
                return AVERROR(ENOMEM);
            c->avctx             = h->avctx;
            if (CONFIG_ERROR_RESILIENCE) {
                c->dsp               = h->dsp;
            }
            c->vdsp              = h->vdsp;
            c->h264dsp           = h->h264dsp;
            c->h264qpel          = h->h264qpel;
            c->h264chroma        = h->h264chroma;
            c->sps               = h->sps;
            c->pps               = h->pps;
            c->pixel_shift       = h->pixel_shift;
            c->cur_chroma_format_idc = h->cur_chroma_format_idc;
            c->width             = h->width;
            c->height            = h->height;
            c->linesize          = h->linesize;
            c->uvlinesize        = h->uvlinesize;
            c->chroma_x_shift    = h->chroma_x_shift;
            c->chroma_y_shift    = h->chroma_y_shift;
            c->qscale            = h->qscale;
            c->droppable         = h->droppable;
            c->data_partitioning = h->data_partitioning;
            c->low_delay         = h->low_delay;
            c->mb_width          = h->mb_width;
            c->mb_height         = h->mb_height;
            c->mb_stride         = h->mb_stride;
            c->mb_num            = h->mb_num;
            c->flags             = h->flags;
            c->workaround_bugs   = h->workaround_bugs;
            c->pict_type         = h->pict_type;

            init_scan_tables(c);
            clone_tables(c, h, i);
            c->context_initialized = 1;
        }

        for (i = 0; i < h->slice_context_count; i++)
            if ((ret = context_init(h->thread_context[i])) < 0) {
                av_log(h->avctx, AV_LOG_ERROR, "context_init() failed.\n");
                return ret;
            }
    }

    h->context_initialized = 1;

    return 0;
}

Project: FFmpeg
File: h264.c

static int h264_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size       = avpkt->size;
    H264Context *h     = avctx->priv_data;
    AVFrame *pict      = data;
    int buf_index      = 0;
    Picture *out;
    int i, out_idx;
    int ret;

    h->flags = avctx->flags;
    /* reset data partitioning here, to ensure GetBitContexts from previous
     * packets do not get used. */
    h->data_partitioning = 0;

    /* end of stream, output what is still in the buffers */
    if (buf_size == 0) {
 out:

        h->cur_pic_ptr = NULL;
        h->first_field = 0;

        // FIXME factorize this with the output code below
        out     = h->delayed_pic[0];
        out_idx = 0;
        for (i = 1;
             h->delayed_pic[i] &&
             !h->delayed_pic[i]->f.key_frame &&
             !h->delayed_pic[i]->mmco_reset;
             i++)
            if (h->delayed_pic[i]->poc < out->poc) {
                out     = h->delayed_pic[i];
                out_idx = i;
            }

        for (i = out_idx; h->delayed_pic[i]; i++)
            h->delayed_pic[i] = h->delayed_pic[i + 1];

        if (out) {
            out->reference &= ~DELAYED_PIC_REF;
            ret = output_frame(h, pict, out);
            if (ret < 0)
                return ret;
            *got_frame = 1;
        }

        return buf_index;
    }
    if(h->is_avc && buf_size >= 9 && buf[0]==1 && buf[2]==0 && (buf[4]&0xFC)==0xFC && (buf[5]&0x1F) && buf[8]==0x67){
        int cnt= buf[5]&0x1f;
        const uint8_t *p= buf+6;
        while(cnt--){
            int nalsize= AV_RB16(p) + 2;
            if(nalsize > buf_size - (p-buf) || p[2]!=0x67)
                goto not_extra;
            p += nalsize;
        }
        cnt = *(p++);
        if(!cnt)
            goto not_extra;
        while(cnt--){
            int nalsize= AV_RB16(p) + 2;
            if(nalsize > buf_size - (p-buf) || p[2]!=0x68)
                goto not_extra;
            p += nalsize;
        }

        return ff_h264_decode_extradata(h, buf, buf_size);
    }
not_extra:

    buf_index = decode_nal_units(h, buf, buf_size, 0);
    if (buf_index < 0)
        return AVERROR_INVALIDDATA;

    if (!h->cur_pic_ptr && h->nal_unit_type == NAL_END_SEQUENCE) {
        av_assert0(buf_index <= buf_size);
        goto out;
    }

    if (!(avctx->flags2 & CODEC_FLAG2_CHUNKS) && !h->cur_pic_ptr) {
        if (avctx->skip_frame >= AVDISCARD_NONREF ||
            buf_size >= 4 && !memcmp("Q264", buf, 4))
            return buf_size;
        av_log(avctx, AV_LOG_ERROR, "no frame!\n");
        return AVERROR_INVALIDDATA;
    }

    if (!(avctx->flags2 & CODEC_FLAG2_CHUNKS) ||
        (h->mb_y >= h->mb_height && h->mb_height)) {
        if (avctx->flags2 & CODEC_FLAG2_CHUNKS)
            decode_postinit(h, 1);

        field_end(h, 0);

        /* Wait for second field. */
        *got_frame = 0;
        if (h->next_output_pic && (
                                   h->next_output_pic->recovered)) {
            if (!h->next_output_pic->recovered)
                h->next_output_pic->f.flags |= AV_FRAME_FLAG_CORRUPT;

            ret = output_frame(h, pict, h->next_output_pic);
            if (ret < 0)
                return ret;
            *got_frame = 1;
            if (CONFIG_MPEGVIDEO) {
                ff_print_debug_info2(h->avctx, h->next_output_pic, pict, h->er.mbskip_table,
                                    &h->low_delay,
                                    h->mb_width, h->mb_height, h->mb_stride, 1);
            }
        }
    }

    assert(pict->buf[0] || !*got_frame);

    return get_consumed_bytes(buf_index, buf_size);
}

Project: FFmpeg
File: h264.c

static void flush_dpb(AVCodecContext *avctx)
{
    H264Context *h = avctx->priv_data;
    int i;

    for (i = 0; i <= MAX_DELAYED_PIC_COUNT; i++) {
        if (h->delayed_pic[i])
            h->delayed_pic[i]->reference = 0;
        h->delayed_pic[i] = NULL;
    }

    flush_change(h);

    if (h->DPB)
        for (i = 0; i < MAX_PICTURE_COUNT; i++)
            unref_picture(h, &h->DPB[i]);
    h->cur_pic_ptr = NULL;
    unref_picture(h, &h->cur_pic);

    h->mb_x = h->mb_y = 0;

    h->parse_context.state             = -1;
    h->parse_context.frame_start_found = 0;
    h->parse_context.overread          = 0;
    h->parse_context.overread_index    = 0;
    h->parse_context.index             = 0;
    h->parse_context.last_index        = 0;

    free_tables(h, 1);
    h->context_initialized = 0;
}