static int bethsoftvid_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; BethsoftvidContext * vid = avctx->priv_data; char block_type; uint8_t * dst; uint8_t * frame_end; int remaining = avctx->width; // number of bytes remaining on a line const int wrap_to_next_line = vid->frame.linesize[0] - avctx->width; int code; int yoffset; if (avctx->reget_buffer(avctx, &vid->frame)) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return -1; } dst = vid->frame.data[0]; frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height; switch(block_type = *buf++){ case PALETTE_BLOCK: return set_palette(&vid->frame, buf, buf_size); case VIDEO_YOFF_P_FRAME: yoffset = bytestream_get_le16(&buf); if(yoffset >= avctx->height) return -1; dst += vid->frame.linesize[0] * yoffset; } // main code while((code = *buf++)){ int length = code & 0x7f; // copy any bytes starting at the current position, and ending at the frame width while(length > remaining){ if(code < 0x80) bytestream_get_buffer(&buf, dst, remaining); else if(block_type == VIDEO_I_FRAME) memset(dst, buf[0], remaining); length -= remaining; // decrement the number of bytes to be copied dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame remaining = avctx->width; if(dst == frame_end) goto end; } // copy any remaining bytes after / if line overflows if(code < 0x80) bytestream_get_buffer(&buf, dst, length); else if(block_type == VIDEO_I_FRAME) memset(dst, *buf++, length); remaining -= length; dst += length; } end: *data_size = sizeof(AVFrame); *(AVFrame*)data = vid->frame; return buf_size; }