static int mimic_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; MimicContext *ctx = avctx->priv_data; GetByteContext gb; int is_pframe; int width, height; int quality, num_coeffs; int swap_buf_size = buf_size - MIMIC_HEADER_SIZE; if (buf_size <= MIMIC_HEADER_SIZE) { av_log(avctx, AV_LOG_ERROR, "insufficient data\n"); return -1; } bytestream2_init(&gb, buf, MIMIC_HEADER_SIZE); bytestream2_skip(&gb, 2); /* some constant (always 256) */ quality = bytestream2_get_le16u(&gb); width = bytestream2_get_le16u(&gb); height = bytestream2_get_le16u(&gb); bytestream2_skip(&gb, 4); /* some constant */ is_pframe = bytestream2_get_le32u(&gb); num_coeffs = bytestream2_get_byteu(&gb); bytestream2_skip(&gb, 3); /* some constant */ if(!ctx->avctx) { int i; if(!(width == 160 && height == 120) && !(width == 320 && height == 240)) { av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n"); return -1; } ctx->avctx = avctx; avctx->width = width; avctx->height = height; avctx->pix_fmt = PIX_FMT_YUV420P; for(i = 0; i < 3; i++) { ctx->num_vblocks[i] = -((-height) >> (3 + !!i)); ctx->num_hblocks[i] = width >> (3 + !!i) ; } } else if(width != ctx->avctx->width || height != ctx->avctx->height) { av_log(avctx, AV_LOG_ERROR, "resolution changing is not supported\n"); return -1; } if(is_pframe && !ctx->buf_ptrs[ctx->prev_index].data[0]) { av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n"); return -1; } ctx->buf_ptrs[ctx->cur_index].reference = 1; ctx->buf_ptrs[ctx->cur_index].pict_type = is_pframe ? AV_PICTURE_TYPE_P:AV_PICTURE_TYPE_I; if(ff_thread_get_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index])) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } ctx->next_prev_index = ctx->cur_index; ctx->next_cur_index = (ctx->cur_index - 1) & 15; prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index], (AVPicture*) &ctx->buf_ptrs[ctx->cur_index]); ff_thread_finish_setup(avctx); av_fast_malloc(&ctx->swap_buf, &ctx->swap_buf_size, swap_buf_size + FF_INPUT_BUFFER_PADDING_SIZE); if(!ctx->swap_buf) return AVERROR(ENOMEM); ctx->dsp.bswap_buf(ctx->swap_buf, (const uint32_t*) (buf + MIMIC_HEADER_SIZE), swap_buf_size>>2); init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3); if(!decode(ctx, quality, num_coeffs, !is_pframe)) { if (avctx->active_thread_type&FF_THREAD_FRAME) ff_thread_report_progress(&ctx->buf_ptrs[ctx->cur_index], INT_MAX, 0); else { ff_thread_release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]); return -1; } } *(AVFrame*)data = ctx->buf_ptrs[ctx->cur_index]; *data_size = sizeof(AVFrame); ctx->prev_index = ctx->next_prev_index; ctx->cur_index = ctx->next_cur_index; /* Only release frames that aren't used for backreferences anymore */ if(ctx->buf_ptrs[ctx->cur_index].data[0]) ff_thread_release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]); return buf_size; }