static int read_frame(BVID_DemuxContext *vid, AVIOContext *pb, AVPacket *pkt, uint8_t block_type, AVFormatContext *s) { uint8_t * vidbuf_start = NULL; int vidbuf_nbytes = 0; int code; int bytes_copied = 0; int position, duration, npixels; unsigned int vidbuf_capacity; int ret = 0; AVStream *st; if (vid->video_index < 0) { st = avformat_new_stream(s, NULL); if (!st) return AVERROR(ENOMEM); vid->video_index = st->index; if (vid->audio_index < 0) { av_log_ask_for_sample(s, "No audio packet before first video " "packet. Using default video time base.\n"); } avpriv_set_pts_info(st, 64, 185, vid->sample_rate); st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = AV_CODEC_ID_BETHSOFTVID; st->codec->width = vid->width; st->codec->height = vid->height; } st = s->streams[vid->video_index]; npixels = st->codec->width * st->codec->height; vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE); if(!vidbuf_start) return AVERROR(ENOMEM); // save the file position for the packet, include block type position = avio_tell(pb) - 1; vidbuf_start[vidbuf_nbytes++] = block_type; // get the current packet duration duration = vid->bethsoft_global_delay + avio_rl16(pb); // set the y offset if it exists (decoder header data should be in data section) if(block_type == VIDEO_YOFF_P_FRAME){ if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) { ret = AVERROR(EIO); goto fail; } vidbuf_nbytes += 2; } do{ vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE); if(!vidbuf_start) return AVERROR(ENOMEM); code = avio_r8(pb); vidbuf_start[vidbuf_nbytes++] = code; if(code >= 0x80){ // rle sequence if(block_type == VIDEO_I_FRAME) vidbuf_start[vidbuf_nbytes++] = avio_r8(pb); } else if(code){ // plain sequence if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], code) != code) { ret = AVERROR(EIO); goto fail; } vidbuf_nbytes += code; } bytes_copied += code & 0x7F; if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied // may contain a 0 byte even if read all pixels if(avio_r8(pb)) avio_seek(pb, -1, SEEK_CUR); break; } if (bytes_copied > npixels) { ret = AVERROR_INVALIDDATA; goto fail; } } while(code); // copy data into packet if ((ret = av_new_packet(pkt, vidbuf_nbytes)) < 0) goto fail; memcpy(pkt->data, vidbuf_start, vidbuf_nbytes); av_free(vidbuf_start); pkt->pos = position; pkt->stream_index = vid->video_index; pkt->duration = duration; if (block_type == VIDEO_I_FRAME) pkt->flags |= AV_PKT_FLAG_KEY; /* if there is a new palette available, add it to packet side data */ if (vid->palette) { uint8_t *pdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, BVID_PALETTE_SIZE); memcpy(pdata, vid->palette, BVID_PALETTE_SIZE); av_freep(&vid->palette); } vid->nframes--; // used to check if all the frames were read return 0; fail: av_free(vidbuf_start); return ret; }