PeerStreamer

/*

 * Tiertex Limited SEQ File Demuxer

 * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)

 *

 * This file is part of Libav.

 *

 * Libav 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 2.1 of the License, or (at your option) any later version.

 *

 * Libav 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 Libav; if not, write to the Free Software

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

 */

/**

 * @file

 * Tiertex Limited SEQ file demuxer

 */

#include "avformat.h"

#define SEQ_FRAME_SIZE         6144

#define SEQ_FRAME_W            256

#define SEQ_FRAME_H            128

#define SEQ_NUM_FRAME_BUFFERS  30

#define SEQ_AUDIO_BUFFER_SIZE  882

#define SEQ_SAMPLE_RATE        22050

#define SEQ_FRAME_RATE         25

typedef struct TiertexSeqFrameBuffer {

    int fill_size;

    int data_size;

    unsigned char *data;

} TiertexSeqFrameBuffer;

typedef struct SeqDemuxContext {

    int audio_stream_index;

    int video_stream_index;

    int current_frame_pts;

    int current_frame_offs;

    TiertexSeqFrameBuffer frame_buffers[SEQ_NUM_FRAME_BUFFERS];

    int frame_buffers_count;

    unsigned int current_audio_data_size;

    unsigned int current_audio_data_offs;

    unsigned int current_pal_data_size;

    unsigned int current_pal_data_offs;

    unsigned int current_video_data_size;

    unsigned char *current_video_data_ptr;

    int audio_buffer_full;

} SeqDemuxContext;

static int seq_probe(AVProbeData *p)

{

    int i;

    if (p->buf_size < 258)

        return 0;

    /* there's no real header in a .seq file, the only thing they have in common */

    /* is the first 256 bytes of the file which are always filled with 0 */

    for (i = 0; i < 256; i++)

        if (p->buf[i])

            return 0;

    if(p->buf[256]==0 && p->buf[257]==0)

        return 0;

    /* only one fourth of the score since the previous check is too naive */

    return AVPROBE_SCORE_MAX / 4;

}

static int seq_init_frame_buffers(SeqDemuxContext *seq, AVIOContext *pb)

{

    int i, sz;

    TiertexSeqFrameBuffer *seq_buffer;

    avio_seek(pb, 256, SEEK_SET);

    for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++) {

        sz = avio_rl16(pb);

        if (sz == 0)

            break;

        else {

            seq_buffer = &seq->frame_buffers[i];

            seq_buffer->fill_size = 0;

            seq_buffer->data_size = sz;

            seq_buffer->data = av_malloc(sz);

            if (!seq_buffer->data)

                return AVERROR(ENOMEM);

        }

    }

    seq->frame_buffers_count = i;

    return 0;

}

static int seq_fill_buffer(SeqDemuxContext *seq, AVIOContext *pb, int buffer_num, unsigned int data_offs, int data_size)

{

    TiertexSeqFrameBuffer *seq_buffer;

    if (buffer_num >= SEQ_NUM_FRAME_BUFFERS)

        return AVERROR_INVALIDDATA;

    seq_buffer = &seq->frame_buffers[buffer_num];

    if (seq_buffer->fill_size + data_size > seq_buffer->data_size || data_size <= 0)

        return AVERROR_INVALIDDATA;

    avio_seek(pb, seq->current_frame_offs + data_offs, SEEK_SET);

    if (avio_read(pb, seq_buffer->data + seq_buffer->fill_size, data_size) != data_size)

        return AVERROR(EIO);

    seq_buffer->fill_size += data_size;

    return 0;

}

static int seq_parse_frame_data(SeqDemuxContext *seq, AVIOContext *pb)

{

    unsigned int offset_table[4], buffer_num[4];

    TiertexSeqFrameBuffer *seq_buffer;

    int i, e, err;

    seq->current_frame_offs += SEQ_FRAME_SIZE;

    avio_seek(pb, seq->current_frame_offs, SEEK_SET);

    /* sound data */

    seq->current_audio_data_offs = avio_rl16(pb);

    if (seq->current_audio_data_offs) {

        seq->current_audio_data_size = SEQ_AUDIO_BUFFER_SIZE * 2;

    } else {

        seq->current_audio_data_size = 0;

    }

    /* palette data */

    seq->current_pal_data_offs = avio_rl16(pb);

    if (seq->current_pal_data_offs) {

        seq->current_pal_data_size = 768;

    } else {

        seq->current_pal_data_size = 0;

    }

    /* video data */

    for (i = 0; i < 4; i++)

        buffer_num[i] = avio_r8(pb);

    for (i = 0; i < 4; i++)

        offset_table[i] = avio_rl16(pb);

    for (i = 0; i < 3; i++) {

        if (offset_table[i]) {

            for (e = i + 1; e < 3 && offset_table[e] == 0; e++);

            err = seq_fill_buffer(seq, pb, buffer_num[1 + i],

              offset_table[i],

              offset_table[e] - offset_table[i]);

            if (err)

                return err;

        }

    }

    if (buffer_num[0] != 255) {

        if (buffer_num[0] >= SEQ_NUM_FRAME_BUFFERS)

            return AVERROR_INVALIDDATA;

        seq_buffer = &seq->frame_buffers[buffer_num[0]];

        seq->current_video_data_size = seq_buffer->fill_size;

        seq->current_video_data_ptr  = seq_buffer->data;

        seq_buffer->fill_size = 0;

    } else {

        seq->current_video_data_size = 0;

        seq->current_video_data_ptr  = 0;

    }

    return 0;

}

static int seq_read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    int i, rc;

    SeqDemuxContext *seq = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st;

    /* init internal buffers */

    rc = seq_init_frame_buffers(seq, pb);

    if (rc)

        return rc;

    seq->current_frame_offs = 0;

    /* preload (no audio data, just buffer operations related data) */

    for (i = 1; i <= 100; i++) {

        rc = seq_parse_frame_data(seq, pb);

        if (rc)

            return rc;

    }

    seq->current_frame_pts = 0;

    seq->audio_buffer_full = 0;

    /* initialize the video decoder stream */

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    av_set_pts_info(st, 32, 1, SEQ_FRAME_RATE);

    seq->video_stream_index = st->index;

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codec->codec_id = CODEC_ID_TIERTEXSEQVIDEO;

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

    st->codec->width = SEQ_FRAME_W;

    st->codec->height = SEQ_FRAME_H;

    /* initialize the audio decoder stream */

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    av_set_pts_info(st, 32, 1, SEQ_SAMPLE_RATE);

    seq->audio_stream_index = st->index;

    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

    st->codec->codec_id = CODEC_ID_PCM_S16BE;

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

    st->codec->channels = 1;

    st->codec->sample_rate = SEQ_SAMPLE_RATE;

    st->codec->bits_per_coded_sample = 16;

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

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

    return 0;

}

static int seq_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    int rc;

    SeqDemuxContext *seq = s->priv_data;

    AVIOContext *pb = s->pb;

    if (!seq->audio_buffer_full) {

        rc = seq_parse_frame_data(seq, pb);

        if (rc)

            return rc;

        /* video packet */

        if (seq->current_pal_data_size + seq->current_video_data_size != 0) {

            if (av_new_packet(pkt, 1 + seq->current_pal_data_size + seq->current_video_data_size))

                return AVERROR(ENOMEM);

            pkt->data[0] = 0;

            if (seq->current_pal_data_size) {

                pkt->data[0] |= 1;

                avio_seek(pb, seq->current_frame_offs + seq->current_pal_data_offs, SEEK_SET);

                if (avio_read(pb, &pkt->data[1], seq->current_pal_data_size) != seq->current_pal_data_size)

                    return AVERROR(EIO);

            }

            if (seq->current_video_data_size) {

                pkt->data[0] |= 2;

                memcpy(&pkt->data[1 + seq->current_pal_data_size],

                  seq->current_video_data_ptr,

                  seq->current_video_data_size);

            }

            pkt->stream_index = seq->video_stream_index;

            pkt->pts = seq->current_frame_pts;

            /* sound buffer will be processed on next read_packet() call */

            seq->audio_buffer_full = 1;

            return 0;

       }

    }

    /* audio packet */

    if (seq->current_audio_data_offs == 0) /* end of data reached */

        return AVERROR(EIO);

    avio_seek(pb, seq->current_frame_offs + seq->current_audio_data_offs, SEEK_SET);

    rc = av_get_packet(pb, pkt, seq->current_audio_data_size);

    if (rc < 0)

        return rc;

    pkt->stream_index = seq->audio_stream_index;

    seq->current_frame_pts++;

    seq->audio_buffer_full = 0;

    return 0;

}

static int seq_read_close(AVFormatContext *s)

{

    int i;

    SeqDemuxContext *seq = s->priv_data;

    for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++)

        av_free(seq->frame_buffers[i].data);

    return 0;

}

AVInputFormat ff_tiertexseq_demuxer = {

    "tiertexseq",

    NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ format"),

    sizeof(SeqDemuxContext),

    seq_probe,

    seq_read_header,

    seq_read_packet,

    seq_read_close,

};