static int encode_bitstream(FlashSVContext *s, const AVFrame *p, uint8_t *buf, int buf_size, int block_width, int block_height, uint8_t *previous_frame, int *I_frame) { PutBitContext pb; int h_blocks, v_blocks, h_part, v_part, i, j; int buf_pos, res; int pred_blocks = 0; init_put_bits(&pb, buf, buf_size * 8); put_bits(&pb, 4, block_width / 16 - 1); put_bits(&pb, 12, s->image_width); put_bits(&pb, 4, block_height / 16 - 1); put_bits(&pb, 12, s->image_height); flush_put_bits(&pb); buf_pos = 4; h_blocks = s->image_width / block_width; h_part = s->image_width % block_width; v_blocks = s->image_height / block_height; v_part = s->image_height % block_height; /* loop over all block columns */ for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) { int y_pos = j * block_height; // vertical position in frame int cur_blk_height = (j < v_blocks) ? block_height : v_part; /* loop over all block rows */ for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) { int x_pos = i * block_width; // horizontal position in frame int cur_blk_width = (i < h_blocks) ? block_width : h_part; int ret = Z_OK; uint8_t *ptr = buf + buf_pos; /* copy the block to the temp buffer before compression * (if it differs from the previous frame's block) */ res = copy_region_enc(p->data[0], s->tmpblock, s->image_height - (y_pos + cur_blk_height + 1), x_pos, cur_blk_height, cur_blk_width, p->linesize[0], previous_frame); if (res || *I_frame) { unsigned long zsize = 3 * block_width * block_height; ret = compress2(ptr + 2, &zsize, s->tmpblock, 3 * cur_blk_width * cur_blk_height, 9); //ret = deflateReset(&s->zstream); if (ret != Z_OK) av_log(s->avctx, AV_LOG_ERROR, "error while compressing block %dx%d\n", i, j); bytestream_put_be16(&ptr, zsize); buf_pos += zsize + 2; av_dlog(s->avctx, "buf_pos = %d\n", buf_pos); } else { pred_blocks++; bytestream_put_be16(&ptr, 0); buf_pos += 2; } } } if (pred_blocks) *I_frame = 0; else *I_frame = 1; return buf_pos; }