static int flashsv_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; FlashSVContext *s = avctx->priv_data; int h_blocks, v_blocks, h_part, v_part, i, j; GetBitContext gb; /* no supplementary picture */ if (buf_size == 0) return 0; init_get_bits(&gb, buf, buf_size * 8); /* start to parse the bitstream */ s->block_width = 16* (get_bits(&gb, 4)+1); s->image_width = get_bits(&gb,12); s->block_height= 16* (get_bits(&gb, 4)+1); s->image_height= get_bits(&gb,12); /* calculate amount of blocks and the size of the border blocks */ h_blocks = s->image_width / s->block_width; h_part = s->image_width % s->block_width; v_blocks = s->image_height / s->block_height; v_part = s->image_height % s->block_height; /* the block size could change between frames, make sure the buffer * is large enough, if not, get a larger one */ if(s->block_size < s->block_width*s->block_height) { if (s->tmpblock != NULL) av_free(s->tmpblock); if ((s->tmpblock = av_malloc(3*s->block_width*s->block_height)) == NULL) { av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); } } s->block_size = s->block_width*s->block_height; /* init the image size once */ if((avctx->width==0) && (avctx->height==0)){ avctx->width = s->image_width; avctx->height = s->image_height; } /* check for changes of image width and image height */ if ((avctx->width != s->image_width) || (avctx->height != s->image_height)) { av_log(avctx, AV_LOG_ERROR, "Frame width or height differs from first frames!\n"); av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",avctx->height, avctx->width,s->image_height,s->image_width); } av_log(avctx, AV_LOG_DEBUG, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n", s->image_width, s->image_height, s->block_width, s->block_height, h_blocks, v_blocks, h_part, v_part); s->frame.reference = 1; s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; if(avctx->reget_buffer(avctx, &s->frame) < 0){ av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); } /* loop over all block columns */ for (j = 0; j < v_blocks + (v_part?1:0); j++) { int hp = j*s->block_height; // horiz position in frame int hs = (j<v_blocks)?s->block_height:v_part; // size of block /* loop over all block rows */ for (i = 0; i < h_blocks + (h_part?1:0); i++) { int wp = i*s->block_width; // vert position in frame int ws = (i<h_blocks)?s->block_width:h_part; // size of block /* get the size of the compressed zlib chunk */ int size = get_bits(&gb, 16); if (8 * size > get_bits_left(&gb)) { avctx->release_buffer(avctx, &s->frame); s->frame.data[0] = NULL; } if (size == 0) { /* no change, don't do anything */ } else { /* decompress block */ int ret = inflateReset(&(s->zstream)); if (ret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "error in decompression (reset) of block %dx%d\n", i, j); /* return -1; */ } s->zstream.next_in = buf+(get_bits_count(&gb)/8); s->zstream.avail_in = size; s->zstream.next_out = s->tmpblock; s->zstream.avail_out = s->block_size*3; ret = inflate(&(s->zstream), Z_FINISH); if (ret == Z_DATA_ERROR) { av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n"); inflateSync(&(s->zstream)); ret = inflate(&(s->zstream), Z_FINISH); } if ((ret != Z_OK) && (ret != Z_STREAM_END)) { av_log(avctx, AV_LOG_ERROR, "error in decompression of block %dx%d: %d\n", i, j, ret); /* return -1; */ } copy_region(s->tmpblock, s->frame.data[0], s->image_height-(hp+hs+1), wp, hs, ws, s->frame.linesize[0]); skip_bits_long(&gb, 8*size); /* skip the consumed bits */ } } } *data_size = sizeof(AVFrame); *(AVFrame*)data = s->frame; if ((get_bits_count(&gb)/8) != buf_size) av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n", buf_size, (get_bits_count(&gb)/8)); /* report that the buffer was completely consumed */ return buf_size; }