PeerStreamer

/*

 * Yamaha SMAF format

 * Copyright (c) 2005 Vidar Madsen

 *

 * 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

 */

#include "avformat.h"

#include "avio_internal.h"

#include "pcm.h"

#include "riff.h"

typedef struct {

    int64_t atrpos, atsqpos, awapos;

    int64_t data_size;

} MMFContext;

static const int mmf_rates[] = { 4000, 8000, 11025, 22050, 44100 };

static int mmf_rate(int code)

{

    if((code < 0) || (code > 4))

        return -1;

    return mmf_rates[code];

}

#if CONFIG_MMF_MUXER

static int mmf_rate_code(int rate)

{

    int i;

    for(i = 0; i < 5; i++)

        if(mmf_rates[i] == rate)

            return i;

    return -1;

}

/* Copy of end_tag() from avienc.c, but for big-endian chunk size */

static void end_tag_be(AVIOContext *pb, int64_t start)

{

    int64_t pos;

    pos = avio_tell(pb);

    avio_seek(pb, start - 4, SEEK_SET);

    avio_wb32(pb, (uint32_t)(pos - start));

    avio_seek(pb, pos, SEEK_SET);

}

static int mmf_write_header(AVFormatContext *s)

{

    MMFContext *mmf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos;

    int rate;

    rate = mmf_rate_code(s->streams[0]->codec->sample_rate);

    if(rate < 0) {

        av_log(s, AV_LOG_ERROR, "Unsupported sample rate %d\n", s->streams[0]->codec->sample_rate);

        return -1;

    }

    ffio_wfourcc(pb, "MMMD");

    avio_wb32(pb, 0);

    pos = ff_start_tag(pb, "CNTI");

    avio_w8(pb, 0); /* class */

    avio_w8(pb, 0); /* type */

    avio_w8(pb, 0); /* code type */

    avio_w8(pb, 0); /* status */

    avio_w8(pb, 0); /* counts */

    avio_write(pb, "VN:libavcodec,", sizeof("VN:libavcodec,") -1); /* metadata ("ST:songtitle,VN:version,...") */

    end_tag_be(pb, pos);

    avio_write(pb, "ATR\x00", 4);

    avio_wb32(pb, 0);

    mmf->atrpos = avio_tell(pb);

    avio_w8(pb, 0); /* format type */

    avio_w8(pb, 0); /* sequence type */

    avio_w8(pb, (0 << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */

    avio_w8(pb, 0); /* wave base bit */

    avio_w8(pb, 2); /* time base d */

    avio_w8(pb, 2); /* time base g */

    ffio_wfourcc(pb, "Atsq");

    avio_wb32(pb, 16);

    mmf->atsqpos = avio_tell(pb);

    /* Will be filled on close */

    avio_write(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);

    mmf->awapos = ff_start_tag(pb, "Awa\x01");

    av_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);

    avio_flush(pb);

    return 0;

}

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

{

    AVIOContext *pb = s->pb;

    avio_write(pb, pkt->data, pkt->size);

    return 0;

}

/* Write a variable-length symbol */

static void put_varlength(AVIOContext *pb, int val)

{

    if(val < 128)

        avio_w8(pb, val);

    else {

        val -= 128;

        avio_w8(pb, 0x80 | val >> 7);

        avio_w8(pb, 0x7f & val);

    }

}

static int mmf_write_trailer(AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    MMFContext *mmf = s->priv_data;

    int64_t pos, size;

    int gatetime;

    if (s->pb->seekable) {

        /* Fill in length fields */

        end_tag_be(pb, mmf->awapos);

        end_tag_be(pb, mmf->atrpos);

        end_tag_be(pb, 8);

        pos = avio_tell(pb);

        size = pos - mmf->awapos;

        /* Fill Atsq chunk */

        avio_seek(pb, mmf->atsqpos, SEEK_SET);

        /* "play wav" */

        avio_w8(pb, 0); /* start time */

        avio_w8(pb, 1); /* (channel << 6) | wavenum */

        gatetime = size * 500 / s->streams[0]->codec->sample_rate;

        put_varlength(pb, gatetime); /* duration */

        /* "nop" */

        put_varlength(pb, gatetime); /* start time */

        avio_write(pb, "\xff\x00", 2); /* nop */

        /* "end of sequence" */

        avio_write(pb, "\x00\x00\x00\x00", 4);

        avio_seek(pb, pos, SEEK_SET);

        avio_flush(pb);

    }

    return 0;

}

#endif /* CONFIG_MMF_MUXER */

static int mmf_probe(AVProbeData *p)

{

    /* check file header */

    if (p->buf[0] == 'M' && p->buf[1] == 'M' &&

        p->buf[2] == 'M' && p->buf[3] == 'D' &&

        p->buf[8] == 'C' && p->buf[9] == 'N' &&

        p->buf[10] == 'T' && p->buf[11] == 'I')

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

/* mmf input */

static int mmf_read_header(AVFormatContext *s,

                           AVFormatParameters *ap)

{

    MMFContext *mmf = s->priv_data;

    unsigned int tag;

    AVIOContext *pb = s->pb;

    AVStream *st;

    int64_t file_size, size;

    int rate, params;

    tag = avio_rl32(pb);

    if (tag != MKTAG('M', 'M', 'M', 'D'))

        return -1;

    file_size = avio_rb32(pb);

    /* Skip some unused chunks that may or may not be present */

    for(;; avio_skip(pb, size)) {

        tag = avio_rl32(pb);

        size = avio_rb32(pb);

        if(tag == MKTAG('C','N','T','I')) continue;

        if(tag == MKTAG('O','P','D','A')) continue;

        break;

    }

    /* Tag = "ATRx", where "x" = track number */

    if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {

        av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");

        return -1;

    }

    if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {

        av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);

        return -1;

    }

    avio_r8(pb); /* format type */

    avio_r8(pb); /* sequence type */

    params = avio_r8(pb); /* (channel << 7) | (format << 4) | rate */

    rate = mmf_rate(params & 0x0f);

    if(rate  < 0) {

        av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");

        return -1;

    }

    avio_r8(pb); /* wave base bit */

    avio_r8(pb); /* time base d */

    avio_r8(pb); /* time base g */

    /* Skip some unused chunks that may or may not be present */

    for(;; avio_skip(pb, size)) {

        tag = avio_rl32(pb);

        size = avio_rb32(pb);

        if(tag == MKTAG('A','t','s','q')) continue;

        if(tag == MKTAG('A','s','p','I')) continue;

        break;

    }

    /* Make sure it's followed by an Awa chunk, aka wave data */

    if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {

        av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);

        return -1;

    }

    mmf->data_size = size;

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

    st->codec->codec_id = CODEC_ID_ADPCM_YAMAHA;

    st->codec->sample_rate = rate;

    st->codec->channels = 1;

    st->codec->bits_per_coded_sample = 4;

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

    av_set_pts_info(st, 64, 1, st->codec->sample_rate);

    return 0;

}

#define MAX_SIZE 4096

static int mmf_read_packet(AVFormatContext *s,

                           AVPacket *pkt)

{

    MMFContext *mmf = s->priv_data;

    AVStream *st;

    int ret, size;

    if (s->pb->eof_reached)

        return AVERROR(EIO);

    st = s->streams[0];

    size = MAX_SIZE;

    if(size > mmf->data_size)

        size = mmf->data_size;

    if(!size)

        return AVERROR(EIO);

    if (av_new_packet(pkt, size))

        return AVERROR(EIO);

    pkt->stream_index = 0;

    ret = avio_read(s->pb, pkt->data, pkt->size);

    if (ret < 0)

        av_free_packet(pkt);

    mmf->data_size -= ret;

    pkt->size = ret;

    return ret;

}

#if CONFIG_MMF_DEMUXER

AVInputFormat ff_mmf_demuxer = {

    "mmf",

    NULL_IF_CONFIG_SMALL("Yamaha SMAF"),

    sizeof(MMFContext),

    mmf_probe,

    mmf_read_header,

    mmf_read_packet,

    NULL,

    pcm_read_seek,

};

#endif

#if CONFIG_MMF_MUXER

AVOutputFormat ff_mmf_muxer = {

    "mmf",

    NULL_IF_CONFIG_SMALL("Yamaha SMAF"),

    "application/vnd.smaf",

    "mmf",

    sizeof(MMFContext),

    CODEC_ID_ADPCM_YAMAHA,

    CODEC_ID_NONE,

    mmf_write_header,

    mmf_write_packet,

    mmf_write_trailer,

};

#endif