PeerStreamer

/*

 * Sega FILM Format (CPK) Demuxer

 * Copyright (c) 2003 The ffmpeg Project

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file segafilm.c

 * Sega FILM (.cpk) file demuxer

 * by Mike Melanson (melanson@pcisys.net)

 * For more information regarding the Sega FILM file format, visit:

 *   http://www.pcisys.net/~melanson/codecs/

 */

#include "avformat.h"

#define FILM_TAG MKBETAG('F', 'I', 'L', 'M')

#define FDSC_TAG MKBETAG('F', 'D', 'S', 'C')

#define STAB_TAG MKBETAG('S', 'T', 'A', 'B')

#define CVID_TAG MKBETAG('c', 'v', 'i', 'd')

typedef struct {

  int stream;

  offset_t sample_offset;

  unsigned int sample_size;

  int64_t pts;

  int keyframe;

} film_sample_t;

typedef struct FilmDemuxContext {

    int video_stream_index;

    int audio_stream_index;

    unsigned int audio_type;

    unsigned int audio_samplerate;

    unsigned int audio_bits;

    unsigned int audio_channels;

    unsigned int video_type;

    unsigned int sample_count;

    film_sample_t *sample_table;

    unsigned int current_sample;

    unsigned int base_clock;

    unsigned int version;

    int cvid_extra_bytes;  /* the number of bytes thrown into the Cinepak

                            * chunk header to throw off decoders */

    /* buffer used for interleaving stereo PCM data */

    unsigned char *stereo_buffer;

    int stereo_buffer_size;

} FilmDemuxContext;

static int film_probe(AVProbeData *p)

{

    if (p->buf_size < 4)

        return 0;

    if (BE_32(&p->buf[0]) != FILM_TAG)

        return 0;

    return AVPROBE_SCORE_MAX;

}

static int film_read_header(AVFormatContext *s,

                            AVFormatParameters *ap)

{

    FilmDemuxContext *film = (FilmDemuxContext *)s->priv_data;

    ByteIOContext *pb = &s->pb;

    AVStream *st;

    unsigned char scratch[256];

    int i;

    unsigned int data_offset;

    unsigned int audio_frame_counter;

    film->sample_table = NULL;

    film->stereo_buffer = NULL;

    film->stereo_buffer_size = 0;

    /* load the main FILM header */

    if (get_buffer(pb, scratch, 16) != 16)

        return AVERROR_IO;

    data_offset = BE_32(&scratch[4]);

    film->version = BE_32(&scratch[8]);

    /* load the FDSC chunk */

    if (film->version == 0) {

        /* special case for Lemmings .film files; 20-byte header */

        if (get_buffer(pb, scratch, 20) != 20)

            return AVERROR_IO;

        /* make some assumptions about the audio parameters */

        film->audio_type = CODEC_ID_PCM_S8;

        film->audio_samplerate = 22050;

        film->audio_channels = 1;

        film->audio_bits = 8;

    } else {

        /* normal Saturn .cpk files; 32-byte header */

        if (get_buffer(pb, scratch, 32) != 32)

            return AVERROR_IO;

        film->audio_samplerate = BE_16(&scratch[24]);;

        film->audio_channels = scratch[21];

        film->audio_bits = scratch[22];

        if (film->audio_bits == 8)

            film->audio_type = CODEC_ID_PCM_S8;

        else if (film->audio_bits == 16)

            film->audio_type = CODEC_ID_PCM_S16BE;

        else

            film->audio_type = 0;

    }

    if (BE_32(&scratch[0]) != FDSC_TAG)

        return AVERROR_INVALIDDATA;

    film->cvid_extra_bytes = 0;

    if (BE_32(&scratch[8]) == CVID_TAG) {

        film->video_type = CODEC_ID_CINEPAK;

        if (film->version)

            film->cvid_extra_bytes = 2;

        else

            film->cvid_extra_bytes = 6;  /* Lemmings 3DO case */

    } else

        film->video_type = 0;

    /* initialize the decoder streams */

    if (film->video_type) {

        st = av_new_stream(s, 0);

        if (!st)

            return AVERROR_NOMEM;

        film->video_stream_index = st->index;

        st->codec->codec_type = CODEC_TYPE_VIDEO;

        st->codec->codec_id = film->video_type;

        st->codec->codec_tag = 0;  /* no fourcc */

        st->codec->width = BE_32(&scratch[16]);

        st->codec->height = BE_32(&scratch[12]);

    }

    if (film->audio_type) {

        st = av_new_stream(s, 0);

        if (!st)

            return AVERROR_NOMEM;

        film->audio_stream_index = st->index;

        st->codec->codec_type = CODEC_TYPE_AUDIO;

        st->codec->codec_id = film->audio_type;

        st->codec->codec_tag = 1;

        st->codec->channels = film->audio_channels;

        st->codec->bits_per_sample = film->audio_bits;

        st->codec->sample_rate = film->audio_samplerate;

        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *

            st->codec->bits_per_sample;

        st->codec->block_align = st->codec->channels *

            st->codec->bits_per_sample / 8;

    }

    /* load the sample table */

    if (get_buffer(pb, scratch, 16) != 16)

        return AVERROR_IO;

    if (BE_32(&scratch[0]) != STAB_TAG)

        return AVERROR_INVALIDDATA;

    film->base_clock = BE_32(&scratch[8]);

    film->sample_count = BE_32(&scratch[12]);

    if(film->sample_count >= UINT_MAX / sizeof(film_sample_t))

        return -1;

    film->sample_table = av_malloc(film->sample_count * sizeof(film_sample_t));

    for(i=0; i<s->nb_streams; i++)

        av_set_pts_info(s->streams[i], 33, 1, film->base_clock);

    audio_frame_counter = 0;

    for (i = 0; i < film->sample_count; i++) {

        /* load the next sample record and transfer it to an internal struct */

        if (get_buffer(pb, scratch, 16) != 16) {

            av_free(film->sample_table);

            return AVERROR_IO;

        }

        film->sample_table[i].sample_offset =

            data_offset + BE_32(&scratch[0]);

        film->sample_table[i].sample_size = BE_32(&scratch[4]);

        if (BE_32(&scratch[8]) == 0xFFFFFFFF) {

            film->sample_table[i].stream = film->audio_stream_index;

            film->sample_table[i].pts = audio_frame_counter;

            film->sample_table[i].pts *= film->base_clock;

            film->sample_table[i].pts /= film->audio_samplerate;

            audio_frame_counter += (film->sample_table[i].sample_size /

                (film->audio_channels * film->audio_bits / 8));

        } else {

            film->sample_table[i].stream = film->video_stream_index;

            film->sample_table[i].pts = BE_32(&scratch[8]) & 0x7FFFFFFF;

            film->sample_table[i].keyframe = (scratch[8] & 0x80) ? 0 : 1;

        }

    }

    film->current_sample = 0;

    return 0;

}

static int film_read_packet(AVFormatContext *s,

                            AVPacket *pkt)

{

    FilmDemuxContext *film = (FilmDemuxContext *)s->priv_data;

    ByteIOContext *pb = &s->pb;

    film_sample_t *sample;

    int ret = 0;

    int i;

    int left, right;

    if (film->current_sample >= film->sample_count)

        return AVERROR_IO;

    sample = &film->sample_table[film->current_sample];

    /* position the stream (will probably be there anyway) */

    url_fseek(pb, sample->sample_offset, SEEK_SET);

    /* do a special song and dance when loading FILM Cinepak chunks */

    if ((sample->stream == film->video_stream_index) &&

        (film->video_type == CODEC_ID_CINEPAK)) {

        if (av_new_packet(pkt, sample->sample_size - film->cvid_extra_bytes))

            return AVERROR_NOMEM;

        if(pkt->size < 10)

            return -1;

        pkt->pos= url_ftell(pb);

        ret = get_buffer(pb, pkt->data, 10);

        /* skip the non-spec CVID bytes */

        url_fseek(pb, film->cvid_extra_bytes, SEEK_CUR);

        ret += get_buffer(pb, pkt->data + 10,

            sample->sample_size - 10 - film->cvid_extra_bytes);

        if (ret != sample->sample_size - film->cvid_extra_bytes)

            ret = AVERROR_IO;

    } else if ((sample->stream == film->audio_stream_index) &&

        (film->audio_channels == 2)) {

        /* stereo PCM needs to be interleaved */

        if (av_new_packet(pkt, sample->sample_size))

            return AVERROR_NOMEM;

        /* make sure the interleave buffer is large enough */

        if (sample->sample_size > film->stereo_buffer_size) {

            av_free(film->stereo_buffer);

            film->stereo_buffer_size = sample->sample_size;

            film->stereo_buffer = av_malloc(film->stereo_buffer_size);

        }

        pkt->pos= url_ftell(pb);

        ret = get_buffer(pb, film->stereo_buffer, sample->sample_size);

        if (ret != sample->sample_size)

            ret = AVERROR_IO;

        left = 0;

        right = sample->sample_size / 2;

        for (i = 0; i < sample->sample_size; ) {

            if (film->audio_bits == 8) {

                pkt->data[i++] = film->stereo_buffer[left++];

                pkt->data[i++] = film->stereo_buffer[right++];

            } else {

                pkt->data[i++] = film->stereo_buffer[left++];

                pkt->data[i++] = film->stereo_buffer[left++];

                pkt->data[i++] = film->stereo_buffer[right++];

                pkt->data[i++] = film->stereo_buffer[right++];

            }

        }

    } else {

        ret= av_get_packet(pb, pkt, sample->sample_size);

        if (ret != sample->sample_size)

            ret = AVERROR_IO;

    }

    pkt->stream_index = sample->stream;

    pkt->pts = sample->pts;

    film->current_sample++;

    return ret;

}

static int film_read_close(AVFormatContext *s)

{

    FilmDemuxContext *film = (FilmDemuxContext *)s->priv_data;

    av_free(film->sample_table);

    av_free(film->stereo_buffer);

    return 0;

}

static AVInputFormat film_iformat = {

    "film_cpk",

    "Sega FILM/CPK format",

    sizeof(FilmDemuxContext),

    film_probe,

    film_read_header,

    film_read_packet,

    film_read_close,

};

int film_init(void)

{

    av_register_input_format(&film_iformat);

    return 0;

}