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ffmpeg / libavformat / segafilm.c @ 5a757507

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/*
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 * Sega FILM Format (CPK) Demuxer
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 * Copyright (c) 2003 The ffmpeg Project
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 *
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 * This library 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 of the License, or (at your option) any later version.
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 *
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 * This library 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 this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
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/**
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 * @file segafilm.c
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 * Sega FILM (.cpk) file demuxer
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 * by Mike Melanson (melanson@pcisys.net)
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 * For more information regarding the Sega FILM 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 FILM_TAG MKBETAG('F', 'I', 'L', 'M')
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#define FDSC_TAG MKBETAG('F', 'D', 'S', 'C')
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#define STAB_TAG MKBETAG('S', 'T', 'A', 'B')
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#define CVID_TAG MKBETAG('c', 'v', 'i', 'd')
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typedef struct {
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  int stream;
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  offset_t sample_offset;
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  unsigned int sample_size;
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  int64_t pts;
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  int keyframe;
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} film_sample_t;
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typedef struct FilmDemuxContext {
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    int video_stream_index;
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    int audio_stream_index;
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    unsigned int audio_type;
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    unsigned int audio_samplerate;
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    unsigned int audio_bits;
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    unsigned int audio_channels;
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    unsigned int video_type;
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    unsigned int sample_count;
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    film_sample_t *sample_table;
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    unsigned int current_sample;
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    unsigned int base_clock;
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    unsigned int version;
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    int cvid_extra_bytes;  /* the number of bytes thrown into the Cinepak
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                            * chunk header to throw off decoders */
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    /* buffer used for interleaving stereo PCM data */
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    unsigned char *stereo_buffer;
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    int stereo_buffer_size;
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} FilmDemuxContext;
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static int film_probe(AVProbeData *p)
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{
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    if (p->buf_size < 4)
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        return 0;
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    if (BE_32(&p->buf[0]) != FILM_TAG)
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        return 0;
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    return AVPROBE_SCORE_MAX;
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}
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static int film_read_header(AVFormatContext *s,
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                            AVFormatParameters *ap)
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{
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    FilmDemuxContext *film = (FilmDemuxContext *)s->priv_data;
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    ByteIOContext *pb = &s->pb;
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    AVStream *st;
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    unsigned char scratch[256];
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    int i;
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    unsigned int data_offset;
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    unsigned int audio_frame_counter;
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    film->sample_table = NULL;
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    film->stereo_buffer = NULL;
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    film->stereo_buffer_size = 0;
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    /* load the main FILM header */
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    if (get_buffer(pb, scratch, 16) != 16)
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        return -EIO;
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    data_offset = BE_32(&scratch[4]);
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    film->version = BE_32(&scratch[8]);
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    /* load the FDSC chunk */
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    if (film->version == 0) {
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        /* special case for Lemmings .film files; 20-byte header */
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        if (get_buffer(pb, scratch, 20) != 20)
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            return -EIO;
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        /* make some assumptions about the audio parameters */
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        film->audio_type = CODEC_ID_PCM_S8;
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        film->audio_samplerate = 22050;
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        film->audio_channels = 1;
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        film->audio_bits = 8;
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    } else {
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        /* normal Saturn .cpk files; 32-byte header */
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        if (get_buffer(pb, scratch, 32) != 32)
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            return -EIO;
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        film->audio_samplerate = BE_16(&scratch[24]);;
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        film->audio_channels = scratch[21];
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        film->audio_bits = scratch[22];
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        if (film->audio_bits == 8)
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            film->audio_type = CODEC_ID_PCM_S8;
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        else if (film->audio_bits == 16)
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            film->audio_type = CODEC_ID_PCM_S16BE;
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        else
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            film->audio_type = 0;
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    }
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    if (BE_32(&scratch[0]) != FDSC_TAG)
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        return AVERROR_INVALIDDATA;
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    film->cvid_extra_bytes = 0;
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    if (BE_32(&scratch[8]) == CVID_TAG) {
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        film->video_type = CODEC_ID_CINEPAK;
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        if (film->version)
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            film->cvid_extra_bytes = 2;
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        else
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            film->cvid_extra_bytes = 6;  /* Lemmings 3DO case */
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    } else
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        film->video_type = 0;
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    /* initialize the decoder streams */
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    if (film->video_type) {
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        st = av_new_stream(s, 0);
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        if (!st)
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            return AVERROR_NOMEM;
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        film->video_stream_index = st->index;
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        st->codec.codec_type = CODEC_TYPE_VIDEO;
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        st->codec.codec_id = film->video_type;
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        st->codec.codec_tag = 0;  /* no fourcc */
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        st->codec.width = BE_32(&scratch[16]);
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        st->codec.height = BE_32(&scratch[12]);
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    }
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    if (film->audio_type) {
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        st = av_new_stream(s, 0);
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        if (!st)
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            return AVERROR_NOMEM;
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        film->audio_stream_index = st->index;
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        st->codec.codec_type = CODEC_TYPE_AUDIO;
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        st->codec.codec_id = film->audio_type;
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        st->codec.codec_tag = 1;
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        st->codec.channels = film->audio_channels;
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        st->codec.bits_per_sample = film->audio_bits;
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        st->codec.sample_rate = film->audio_samplerate;
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        st->codec.bit_rate = st->codec.channels * st->codec.sample_rate *
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            st->codec.bits_per_sample;
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        st->codec.block_align = st->codec.channels * 
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            st->codec.bits_per_sample / 8;
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    }
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    /* load the sample table */
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    if (get_buffer(pb, scratch, 16) != 16)
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        return -EIO;
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    if (BE_32(&scratch[0]) != STAB_TAG)
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        return AVERROR_INVALIDDATA;
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    film->base_clock = BE_32(&scratch[8]);
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    film->sample_count = BE_32(&scratch[12]);
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    film->sample_table = av_malloc(film->sample_count * sizeof(film_sample_t));
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    audio_frame_counter = 0;
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    for (i = 0; i < film->sample_count; i++) {
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        /* load the next sample record and transfer it to an internal struct */
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        if (get_buffer(pb, scratch, 16) != 16) {
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            av_free(film->sample_table);
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            return -EIO;
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        }
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        film->sample_table[i].sample_offset = 
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            data_offset + BE_32(&scratch[0]);
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        film->sample_table[i].sample_size = BE_32(&scratch[4]);
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        if (BE_32(&scratch[8]) == 0xFFFFFFFF) {
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            film->sample_table[i].stream = film->audio_stream_index;
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            film->sample_table[i].pts = audio_frame_counter;
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            film->sample_table[i].pts *= film->base_clock;
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            film->sample_table[i].pts /= film->audio_samplerate;
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            audio_frame_counter += (film->sample_table[i].sample_size /
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                (film->audio_channels * film->audio_bits / 8));
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        } else {
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            film->sample_table[i].stream = film->video_stream_index;
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            film->sample_table[i].pts = BE_32(&scratch[8]) & 0x7FFFFFFF;
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            film->sample_table[i].keyframe = (scratch[8] & 0x80) ? 0 : 1;
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        }
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    }
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    film->current_sample = 0;
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    /* set the pts reference to match the tick rate of the file */
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    s->pts_num = 1;
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    s->pts_den = film->base_clock;
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    return 0;
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}
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static int film_read_packet(AVFormatContext *s,
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                            AVPacket *pkt)
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{
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    FilmDemuxContext *film = (FilmDemuxContext *)s->priv_data;
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    ByteIOContext *pb = &s->pb;
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    film_sample_t *sample;
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    int ret = 0;
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    int i;
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    int left, right;
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    if (film->current_sample >= film->sample_count)
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        return -EIO;
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    sample = &film->sample_table[film->current_sample];
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    /* position the stream (will probably be there anyway) */
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    url_fseek(pb, sample->sample_offset, SEEK_SET);
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    /* do a special song and dance when loading FILM Cinepak chunks */
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    if ((sample->stream == film->video_stream_index) && 
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        (film->video_type == CODEC_ID_CINEPAK)) {
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        if (av_new_packet(pkt, sample->sample_size - film->cvid_extra_bytes))
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            return AVERROR_NOMEM;
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        ret = get_buffer(pb, pkt->data, 10);
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        /* skip the non-spec CVID bytes */
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        url_fseek(pb, film->cvid_extra_bytes, SEEK_CUR);
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        ret += get_buffer(pb, pkt->data + 10, 
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            sample->sample_size - 10 - film->cvid_extra_bytes);
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        if (ret != sample->sample_size - film->cvid_extra_bytes)
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            ret = -EIO;
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    } else if ((sample->stream == film->audio_stream_index) &&
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        (film->audio_channels == 2)) {
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        /* stereo PCM needs to be interleaved */
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        if (av_new_packet(pkt, sample->sample_size))
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            return AVERROR_NOMEM;
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        /* make sure the interleave buffer is large enough */
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        if (sample->sample_size > film->stereo_buffer_size) {
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            av_free(film->stereo_buffer);
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            film->stereo_buffer_size = sample->sample_size;
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            film->stereo_buffer = av_malloc(film->stereo_buffer_size);
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        }
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        ret = get_buffer(pb, film->stereo_buffer, sample->sample_size);
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        if (ret != sample->sample_size)
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            ret = -EIO;
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        left = 0;
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        right = sample->sample_size / 2;
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        for (i = 0; i < sample->sample_size; ) {
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            if (film->audio_bits == 8) {
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                pkt->data[i++] = film->stereo_buffer[left++];
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                pkt->data[i++] = film->stereo_buffer[right++];
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            } else {
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                pkt->data[i++] = film->stereo_buffer[left++];
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                pkt->data[i++] = film->stereo_buffer[left++];
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                pkt->data[i++] = film->stereo_buffer[right++];
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                pkt->data[i++] = film->stereo_buffer[right++];
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            }
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        }
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    } else {
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        if (av_new_packet(pkt, sample->sample_size))
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            return AVERROR_NOMEM;
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        ret = get_buffer(pb, pkt->data, sample->sample_size);
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        if (ret != sample->sample_size)
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            ret = -EIO;
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    }
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    pkt->stream_index = sample->stream;
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    pkt->pts = sample->pts;
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    film->current_sample++;
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    return ret;
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}
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static int film_read_close(AVFormatContext *s)
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{
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    FilmDemuxContext *film = (FilmDemuxContext *)s->priv_data;
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    av_free(film->sample_table);
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    av_free(film->stereo_buffer);
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    return 0;
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}
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static AVInputFormat film_iformat = {
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    "film_cpk",
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    "Sega FILM/CPK format",
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    sizeof(FilmDemuxContext),
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    film_probe,
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    film_read_header,
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    film_read_packet,
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    film_read_close,
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};
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int film_init(void)
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{
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    av_register_input_format(&film_iformat);
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    return 0;
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}