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ffmpeg / libavformat / sierravmd.c @ 831ec935

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/*
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 * Sierra VMD Format Demuxer
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 * Copyright (c) 2004 The ffmpeg Project
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file sierravmd.c
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 * Sierra VMD file demuxer
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 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
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 * for more information on the Sierra VMD file format, visit:
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 *   http://www.pcisys.net/~melanson/codecs/
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 */
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#include "avformat.h"
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#define VMD_HEADER_SIZE 0x0330
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#define BYTES_PER_FRAME_RECORD 16
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typedef struct {
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  int stream_index;
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  offset_t frame_offset;
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  unsigned int frame_size;
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  int64_t pts;
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  int keyframe;
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  unsigned char frame_record[BYTES_PER_FRAME_RECORD];
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} vmd_frame_t;
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typedef struct VmdDemuxContext {
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    int video_stream_index;
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    int audio_stream_index;
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    unsigned int frame_count;
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    unsigned int frames_per_block;
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    vmd_frame_t *frame_table;
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    unsigned int current_frame;
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    int sample_rate;
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    int64_t audio_sample_counter;
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    int skiphdr;
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    unsigned char vmd_header[VMD_HEADER_SIZE];
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} VmdDemuxContext;
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static int vmd_probe(AVProbeData *p)
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{
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    /* check if the first 2 bytes of the file contain the appropriate size
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     * of a VMD header chunk */
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    if (AV_RL16(&p->buf[0]) != VMD_HEADER_SIZE - 2)
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        return 0;
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    /* only return half certainty since this check is a bit sketchy */
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    return AVPROBE_SCORE_MAX / 2;
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}
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static int vmd_read_header(AVFormatContext *s,
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                           AVFormatParameters *ap)
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{
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    VmdDemuxContext *vmd = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    AVStream *st = NULL, *vst;
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    unsigned int toc_offset;
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    unsigned char *raw_frame_table;
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    int raw_frame_table_size;
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    offset_t current_offset;
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    int i, j;
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    unsigned int total_frames;
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    int64_t pts_inc = 1;
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    int64_t current_video_pts = 0, current_audio_pts = 0;
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    unsigned char chunk[BYTES_PER_FRAME_RECORD];
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    int num, den;
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    int sound_buffers;
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    /* fetch the main header, including the 2 header length bytes */
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    url_fseek(pb, 0, SEEK_SET);
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    if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)
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        return AVERROR(EIO);
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    /* start up the decoders */
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    vst = av_new_stream(s, 0);
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    if (!vst)
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        return AVERROR(ENOMEM);
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    av_set_pts_info(vst, 33, 1, 10);
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    vmd->video_stream_index = vst->index;
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    vst->codec->codec_type = CODEC_TYPE_VIDEO;
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    vst->codec->codec_id = CODEC_ID_VMDVIDEO;
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    vst->codec->codec_tag = 0;  /* no fourcc */
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    vst->codec->width = AV_RL16(&vmd->vmd_header[12]);
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    vst->codec->height = AV_RL16(&vmd->vmd_header[14]);
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    vst->codec->extradata_size = VMD_HEADER_SIZE;
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    vst->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
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    memcpy(vst->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
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    /* if sample rate is 0, assume no audio */
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    vmd->sample_rate = AV_RL16(&vmd->vmd_header[804]);
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    if (vmd->sample_rate) {
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        st = av_new_stream(s, 0);
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        if (!st)
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            return AVERROR(ENOMEM);
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        vmd->audio_stream_index = st->index;
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        st->codec->codec_type = CODEC_TYPE_AUDIO;
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        st->codec->codec_id = CODEC_ID_VMDAUDIO;
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        st->codec->codec_tag = 0;  /* no fourcc */
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        st->codec->channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;
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        st->codec->sample_rate = vmd->sample_rate;
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        st->codec->block_align = AV_RL16(&vmd->vmd_header[806]);
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        if (st->codec->block_align & 0x8000) {
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            st->codec->bits_per_sample = 16;
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            st->codec->block_align = -(st->codec->block_align - 0x10000);
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        } else {
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            st->codec->bits_per_sample = 8;
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        }
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        st->codec->bit_rate = st->codec->sample_rate *
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            st->codec->bits_per_sample * st->codec->channels;
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        /* calculate pts */
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        num = st->codec->block_align;
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        den = st->codec->sample_rate * st->codec->channels;
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        av_reduce(&den, &num, den, num, (1UL<<31)-1);
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        av_set_pts_info(vst, 33, num, den);
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        av_set_pts_info(st, 33, num, den);
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        pts_inc = num;
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    }
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    toc_offset = AV_RL32(&vmd->vmd_header[812]);
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    vmd->frame_count = AV_RL16(&vmd->vmd_header[6]);
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    vmd->frames_per_block = AV_RL16(&vmd->vmd_header[18]);
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    url_fseek(pb, toc_offset, SEEK_SET);
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    raw_frame_table = NULL;
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    vmd->frame_table = NULL;
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    sound_buffers = AV_RL16(&vmd->vmd_header[808]);
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    raw_frame_table_size = vmd->frame_count * 6;
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    if(vmd->frame_count * vmd->frames_per_block  >= UINT_MAX / sizeof(vmd_frame_t)){
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        av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");
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        return -1;
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    }
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    raw_frame_table = av_malloc(raw_frame_table_size);
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    vmd->frame_table = av_malloc((vmd->frame_count * vmd->frames_per_block + sound_buffers) * sizeof(vmd_frame_t));
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    if (!raw_frame_table || !vmd->frame_table) {
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        av_free(raw_frame_table);
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        av_free(vmd->frame_table);
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        return AVERROR(ENOMEM);
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    }
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    if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=
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        raw_frame_table_size) {
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        av_free(raw_frame_table);
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        av_free(vmd->frame_table);
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        return AVERROR(EIO);
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    }
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    total_frames = 0;
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    for (i = 0; i < vmd->frame_count; i++) {
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        current_offset = AV_RL32(&raw_frame_table[6 * i + 2]);
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        /* handle each entry in index block */
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        for (j = 0; j < vmd->frames_per_block; j++) {
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            int type;
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            uint32_t size;
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            get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
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            type = chunk[0];
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            size = AV_RL32(&chunk[2]);
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            if(!size)
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                continue;
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            switch(type) {
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            case 1: /* Audio Chunk */
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                if (!st) break;
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                /* first audio chunk contains several audio buffers */
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                if(current_audio_pts){
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                    vmd->frame_table[total_frames].frame_offset = current_offset;
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                    vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
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                    vmd->frame_table[total_frames].frame_size = size;
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                    memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
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                    vmd->frame_table[total_frames].pts = current_audio_pts;
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                    total_frames++;
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                    current_audio_pts += pts_inc;
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                }else{
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                    uint32_t flags;
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                    int k;
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                    int noff;
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                    int64_t pos;
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                    pos = url_ftell(pb);
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                    url_fseek(pb, current_offset, SEEK_SET);
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                    flags = get_le32(pb);
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                    noff = 4;
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                    url_fseek(pb, pos, SEEK_SET);
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                    av_log(s, AV_LOG_DEBUG, "Sound mapping = %08X (%i bufs)\n", flags, sound_buffers);
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                    for(k = 0; k < sound_buffers - 1; k++){
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                        if(flags & 1) { /* silent block */
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                            vmd->frame_table[total_frames].frame_size = 0;
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                        }else{
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                            vmd->frame_table[total_frames].frame_size = st->codec->block_align + (st->codec->block_align & 1);
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                        }
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                        noff += vmd->frame_table[total_frames].frame_size;
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                        vmd->frame_table[total_frames].frame_offset = current_offset + noff;
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                        vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
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                        memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
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                        vmd->frame_table[total_frames].pts = current_audio_pts;
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                        total_frames++;
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                        current_audio_pts += pts_inc;
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                        flags >>= 1;
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                    }
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                }
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                break;
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            case 2: /* Video Chunk */
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                vmd->frame_table[total_frames].frame_offset = current_offset;
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                vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;
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                vmd->frame_table[total_frames].frame_size = size;
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                memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
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                vmd->frame_table[total_frames].pts = current_video_pts;
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                total_frames++;
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                break;
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            }
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            current_offset += size;
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        }
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        current_video_pts += pts_inc;
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    }
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    av_free(raw_frame_table);
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    vmd->current_frame = 0;
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    vmd->frame_count = total_frames;
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    return 0;
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}
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static int vmd_read_packet(AVFormatContext *s,
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                           AVPacket *pkt)
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{
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    VmdDemuxContext *vmd = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int ret = 0;
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    vmd_frame_t *frame;
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    if (vmd->current_frame >= vmd->frame_count)
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        return AVERROR(EIO);
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    frame = &vmd->frame_table[vmd->current_frame];
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    /* position the stream (will probably be there already) */
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    url_fseek(pb, frame->frame_offset, SEEK_SET);
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    if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))
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        return AVERROR(ENOMEM);
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    pkt->pos= url_ftell(pb);
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    memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);
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    ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,
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        frame->frame_size);
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    if (ret != frame->frame_size) {
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        av_free_packet(pkt);
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        ret = AVERROR(EIO);
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    }
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    pkt->stream_index = frame->stream_index;
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    pkt->pts = frame->pts;
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    av_log(NULL, AV_LOG_DEBUG, " dispatching %s frame with %d bytes and pts %"PRId64"\n",
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            (frame->frame_record[0] == 0x02) ? "video" : "audio",
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            frame->frame_size + BYTES_PER_FRAME_RECORD,
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            pkt->pts);
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    vmd->current_frame++;
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    return ret;
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}
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static int vmd_read_close(AVFormatContext *s)
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{
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    VmdDemuxContext *vmd = s->priv_data;
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    av_free(vmd->frame_table);
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    return 0;
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}
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AVInputFormat vmd_demuxer = {
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    "vmd",
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    NULL_IF_CONFIG_SMALL("Sierra VMD format"),
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    sizeof(VmdDemuxContext),
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    vmd_probe,
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    vmd_read_header,
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    vmd_read_packet,
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    vmd_read_close,
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};