PeerStreamer

/*

 * AIFF/AIFF-C demuxer

 * Copyright (c) 2006  Patrick Guimond

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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.

 *

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

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

 */

#include "libavutil/intfloat_readwrite.h"

#include "avformat.h"

#include "pcm.h"

#include "aiff.h"

#define AIFF                    0

#define AIFF_C_VERSION1         0xA2805140

typedef struct {

    int64_t data_end;

} AIFFInputContext;

static enum CodecID aiff_codec_get_id(int bps)

{

    if (bps <= 8)

        return CODEC_ID_PCM_S8;

    if (bps <= 16)

        return CODEC_ID_PCM_S16BE;

    if (bps <= 24)

        return CODEC_ID_PCM_S24BE;

    if (bps <= 32)

        return CODEC_ID_PCM_S32BE;

    /* bigger than 32 isn't allowed  */

    return CODEC_ID_NONE;

}

/* returns the size of the found tag */

static int get_tag(AVIOContext *pb, uint32_t * tag)

{

    int size;

    if (url_feof(pb))

        return AVERROR(EIO);

    *tag = avio_rl32(pb);

    size = avio_rb32(pb);

    if (size < 0)

        size = 0x7fffffff;

    return size;

}

/* Metadata string read */

static void get_meta(AVFormatContext *s, const char *key, int size)

{

    uint8_t *str = av_malloc(size+1);

    int res;

    if (!str) {

        avio_seek(s->pb, size, SEEK_CUR);

        return;

    }

    res = avio_read(s->pb, str, size);

    if (res < 0)

        return;

    str[res] = 0;

    av_metadata_set2(&s->metadata, key, str, AV_METADATA_DONT_STRDUP_VAL);

}

/* Returns the number of sound data frames or negative on error */

static unsigned int get_aiff_header(AVIOContext *pb, AVCodecContext *codec,

                             int size, unsigned version)

{

    AVExtFloat ext;

    double sample_rate;

    unsigned int num_frames;

    if (size & 1)

        size++;

    codec->codec_type = AVMEDIA_TYPE_AUDIO;

    codec->channels = avio_rb16(pb);

    num_frames = avio_rb32(pb);

    codec->bits_per_coded_sample = avio_rb16(pb);

    avio_read(pb, (uint8_t*)&ext, sizeof(ext));/* Sample rate is in */

    sample_rate = av_ext2dbl(ext);          /* 80 bits BE IEEE extended float */

    codec->sample_rate = sample_rate;

    size -= 18;

    /* Got an AIFF-C? */

    if (version == AIFF_C_VERSION1) {

        codec->codec_tag = avio_rl32(pb);

        codec->codec_id  = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);

        switch (codec->codec_id) {

        case CODEC_ID_PCM_S16BE:

            codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);

            codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);

            break;

        case CODEC_ID_ADPCM_IMA_QT:

            codec->block_align = 34*codec->channels;

            codec->frame_size = 64;

            break;

        case CODEC_ID_MACE3:

            codec->block_align = 2*codec->channels;

            codec->frame_size = 6;

            break;

        case CODEC_ID_MACE6:

            codec->block_align = 1*codec->channels;

            codec->frame_size = 6;

            break;

        case CODEC_ID_GSM:

            codec->block_align = 33;

            codec->frame_size = 160;

            break;

        case CODEC_ID_QCELP:

            codec->block_align = 35;

            codec->frame_size= 160;

            break;

        default:

            break;

        }

        size -= 4;

    } else {

        /* Need the codec type */

        codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);

        codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);

    }

    /* Block align needs to be computed in all cases, as the definition

     * is specific to applications -> here we use the WAVE format definition */

    if (!codec->block_align)

        codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;

    codec->bit_rate = (codec->frame_size ? codec->sample_rate/codec->frame_size :

                       codec->sample_rate) * (codec->block_align << 3);

    /* Chunk is over */

    if (size)

        avio_seek(pb, size, SEEK_CUR);

    return num_frames;

}

static int aiff_probe(AVProbeData *p)

{

    /* check file header */

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

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

        p->buf[8] == 'A' && p->buf[9] == 'I' &&

        p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

/* aiff input */

static int aiff_read_header(AVFormatContext *s,

                            AVFormatParameters *ap)

{

    int size, filesize;

    int64_t offset = 0;

    uint32_t tag;

    unsigned version = AIFF_C_VERSION1;

    AVIOContext *pb = s->pb;

    AVStream * st;

    AIFFInputContext *aiff = s->priv_data;

    /* check FORM header */

    filesize = get_tag(pb, &tag);

    if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))

        return AVERROR_INVALIDDATA;

    /* AIFF data type */

    tag = avio_rl32(pb);

    if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */

        version = AIFF;

    else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */

        return AVERROR_INVALIDDATA;

    filesize -= 4;

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    while (filesize > 0) {

        /* parse different chunks */

        size = get_tag(pb, &tag);

        if (size < 0)

            return size;

        filesize -= size + 8;

        switch (tag) {

        case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */

            /* Then for the complete header info */

            st->nb_frames = get_aiff_header(pb, st->codec, size, version);

            if (st->nb_frames < 0)

                return st->nb_frames;

            if (offset > 0) // COMM is after SSND

                goto got_sound;

            break;

        case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */

            version = avio_rb32(pb);

            break;

        case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */

            get_meta(s, "title"    , size);

            break;

        case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */

            get_meta(s, "author"   , size);

            break;

        case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */

            get_meta(s, "copyright", size);

            break;

        case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */

            get_meta(s, "comment"  , size);

            break;

        case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */

            aiff->data_end = avio_tell(pb) + size;

            offset = avio_rb32(pb);      /* Offset of sound data */

            avio_rb32(pb);               /* BlockSize... don't care */

            offset += avio_tell(pb);    /* Compute absolute data offset */

            if (st->codec->block_align)    /* Assume COMM already parsed */

                goto got_sound;

            if (url_is_streamed(pb)) {

                av_log(s, AV_LOG_ERROR, "file is not seekable\n");

                return -1;

            }

            avio_seek(pb, size - 8, SEEK_CUR);

            break;

        case MKTAG('w', 'a', 'v', 'e'):

            if ((uint64_t)size > (1<<30))

                return -1;

            st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);

            if (!st->codec->extradata)

                return AVERROR(ENOMEM);

            st->codec->extradata_size = size;

            avio_read(pb, st->codec->extradata, size);

            break;

        default: /* Jump */

            if (size & 1)   /* Always even aligned */

                size++;

            avio_seek(pb, size, SEEK_CUR);

        }

    }

    if (!st->codec->block_align) {

        av_log(s, AV_LOG_ERROR, "could not find COMM tag\n");

        return -1;

    }

got_sound:

    /* Now positioned, get the sound data start and end */

    if (st->nb_frames)

        s->file_size = st->nb_frames * st->codec->block_align;

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

    st->start_time = 0;

    st->duration = st->codec->frame_size ?

        st->nb_frames * st->codec->frame_size : st->nb_frames;

    /* Position the stream at the first block */

    avio_seek(pb, offset, SEEK_SET);

    return 0;

}

#define MAX_SIZE 4096

static int aiff_read_packet(AVFormatContext *s,

                            AVPacket *pkt)

{

    AVStream *st = s->streams[0];

    AIFFInputContext *aiff = s->priv_data;

    int64_t max_size;

    int res, size;

    /* calculate size of remaining data */

    max_size = aiff->data_end - avio_tell(s->pb);

    if (max_size <= 0)

        return AVERROR_EOF;

    /* Now for that packet */

    if (st->codec->block_align >= 33) // GSM, QCLP, IMA4

        size = st->codec->block_align;

    else

        size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;

    size = FFMIN(max_size, size);

    res = av_get_packet(s->pb, pkt, size);

    if (res < 0)

        return res;

    /* Only one stream in an AIFF file */

    pkt->stream_index = 0;

    return 0;

}

AVInputFormat ff_aiff_demuxer = {

    "aiff",

    NULL_IF_CONFIG_SMALL("Audio IFF"),

    sizeof(AIFFInputContext),

    aiff_probe,

    aiff_read_header,

    aiff_read_packet,

    NULL,

    pcm_read_seek,

    .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},

};