PeerStreamer

/*

 * Monkey's Audio APE demuxer

 * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>

 *  based upon libdemac from Dave Chapman.

 *

 * 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 <stdio.h>

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#include "apetag.h"

#define ENABLE_DEBUG 0

/* The earliest and latest file formats supported by this library */

#define APE_MIN_VERSION 3950

#define APE_MAX_VERSION 3990

#define MAC_FORMAT_FLAG_8_BIT                 1 // is 8-bit [OBSOLETE]

#define MAC_FORMAT_FLAG_CRC                   2 // uses the new CRC32 error detection [OBSOLETE]

#define MAC_FORMAT_FLAG_HAS_PEAK_LEVEL        4 // uint32 nPeakLevel after the header [OBSOLETE]

#define MAC_FORMAT_FLAG_24_BIT                8 // is 24-bit [OBSOLETE]

#define MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS    16 // has the number of seek elements after the peak level

#define MAC_FORMAT_FLAG_CREATE_WAV_HEADER    32 // create the wave header on decompression (not stored)

#define MAC_SUBFRAME_SIZE 4608

#define APE_EXTRADATA_SIZE 6

typedef struct {

    int64_t pos;

    int nblocks;

    int size;

    int skip;

    int64_t pts;

} APEFrame;

typedef struct {

    /* Derived fields */

    uint32_t junklength;

    uint32_t firstframe;

    uint32_t totalsamples;

    int currentframe;

    APEFrame *frames;

    /* Info from Descriptor Block */

    char magic[4];

    int16_t fileversion;

    int16_t padding1;

    uint32_t descriptorlength;

    uint32_t headerlength;

    uint32_t seektablelength;

    uint32_t wavheaderlength;

    uint32_t audiodatalength;

    uint32_t audiodatalength_high;

    uint32_t wavtaillength;

    uint8_t md5[16];

    /* Info from Header Block */

    uint16_t compressiontype;

    uint16_t formatflags;

    uint32_t blocksperframe;

    uint32_t finalframeblocks;

    uint32_t totalframes;

    uint16_t bps;

    uint16_t channels;

    uint32_t samplerate;

    /* Seektable */

    uint32_t *seektable;

} APEContext;

static int ape_probe(AVProbeData * p)

{

    if (p->buf[0] == 'M' && p->buf[1] == 'A' && p->buf[2] == 'C' && p->buf[3] == ' ')

        return AVPROBE_SCORE_MAX;

    return 0;

}

static void ape_dumpinfo(AVFormatContext * s, APEContext * ape_ctx)

{

#if ENABLE_DEBUG

    int i;

    av_log(s, AV_LOG_DEBUG, "Descriptor Block:\n\n");

    av_log(s, AV_LOG_DEBUG, "magic                = \"%c%c%c%c\"\n", ape_ctx->magic[0], ape_ctx->magic[1], ape_ctx->magic[2], ape_ctx->magic[3]);

    av_log(s, AV_LOG_DEBUG, "fileversion          = %d\n", ape_ctx->fileversion);

    av_log(s, AV_LOG_DEBUG, "descriptorlength     = %d\n", ape_ctx->descriptorlength);

    av_log(s, AV_LOG_DEBUG, "headerlength         = %d\n", ape_ctx->headerlength);

    av_log(s, AV_LOG_DEBUG, "seektablelength      = %d\n", ape_ctx->seektablelength);

    av_log(s, AV_LOG_DEBUG, "wavheaderlength      = %d\n", ape_ctx->wavheaderlength);

    av_log(s, AV_LOG_DEBUG, "audiodatalength      = %d\n", ape_ctx->audiodatalength);

    av_log(s, AV_LOG_DEBUG, "audiodatalength_high = %d\n", ape_ctx->audiodatalength_high);

    av_log(s, AV_LOG_DEBUG, "wavtaillength        = %d\n", ape_ctx->wavtaillength);

    av_log(s, AV_LOG_DEBUG, "md5                  = ");

    for (i = 0; i < 16; i++)

         av_log(s, AV_LOG_DEBUG, "%02x", ape_ctx->md5[i]);

    av_log(s, AV_LOG_DEBUG, "\n");

    av_log(s, AV_LOG_DEBUG, "\nHeader Block:\n\n");

    av_log(s, AV_LOG_DEBUG, "compressiontype      = %d\n", ape_ctx->compressiontype);

    av_log(s, AV_LOG_DEBUG, "formatflags          = %d\n", ape_ctx->formatflags);

    av_log(s, AV_LOG_DEBUG, "blocksperframe       = %d\n", ape_ctx->blocksperframe);

    av_log(s, AV_LOG_DEBUG, "finalframeblocks     = %d\n", ape_ctx->finalframeblocks);

    av_log(s, AV_LOG_DEBUG, "totalframes          = %d\n", ape_ctx->totalframes);

    av_log(s, AV_LOG_DEBUG, "bps                  = %d\n", ape_ctx->bps);

    av_log(s, AV_LOG_DEBUG, "channels             = %d\n", ape_ctx->channels);

    av_log(s, AV_LOG_DEBUG, "samplerate           = %d\n", ape_ctx->samplerate);

    av_log(s, AV_LOG_DEBUG, "\nSeektable\n\n");

    if ((ape_ctx->seektablelength / sizeof(uint32_t)) != ape_ctx->totalframes) {

        av_log(s, AV_LOG_DEBUG, "No seektable\n");

    } else {

        for (i = 0; i < ape_ctx->seektablelength / sizeof(uint32_t); i++) {

            if (i < ape_ctx->totalframes - 1) {

                av_log(s, AV_LOG_DEBUG, "%8d   %d (%d bytes)\n", i, ape_ctx->seektable[i], ape_ctx->seektable[i + 1] - ape_ctx->seektable[i]);

            } else {

                av_log(s, AV_LOG_DEBUG, "%8d   %d\n", i, ape_ctx->seektable[i]);

            }

        }

    }

    av_log(s, AV_LOG_DEBUG, "\nFrames\n\n");

    for (i = 0; i < ape_ctx->totalframes; i++)

        av_log(s, AV_LOG_DEBUG, "%8d   %8lld %8d (%d samples)\n", i, ape_ctx->frames[i].pos, ape_ctx->frames[i].size, ape_ctx->frames[i].nblocks);

    av_log(s, AV_LOG_DEBUG, "\nCalculated information:\n\n");

    av_log(s, AV_LOG_DEBUG, "junklength           = %d\n", ape_ctx->junklength);

    av_log(s, AV_LOG_DEBUG, "firstframe           = %d\n", ape_ctx->firstframe);

    av_log(s, AV_LOG_DEBUG, "totalsamples         = %d\n", ape_ctx->totalsamples);

#endif

}

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

{

    AVIOContext *pb = s->pb;

    APEContext *ape = s->priv_data;

    AVStream *st;

    uint32_t tag;

    int i;

    int total_blocks;

    int64_t pts;

    /* TODO: Skip any leading junk such as id3v2 tags */

    ape->junklength = 0;

    tag = avio_rl32(pb);

    if (tag != MKTAG('M', 'A', 'C', ' '))

        return -1;

    ape->fileversion = avio_rl16(pb);

    if (ape->fileversion < APE_MIN_VERSION || ape->fileversion > APE_MAX_VERSION) {

        av_log(s, AV_LOG_ERROR, "Unsupported file version - %d.%02d\n", ape->fileversion / 1000, (ape->fileversion % 1000) / 10);

        return -1;

    }

    if (ape->fileversion >= 3980) {

        ape->padding1             = avio_rl16(pb);

        ape->descriptorlength     = avio_rl32(pb);

        ape->headerlength         = avio_rl32(pb);

        ape->seektablelength      = avio_rl32(pb);

        ape->wavheaderlength      = avio_rl32(pb);

        ape->audiodatalength      = avio_rl32(pb);

        ape->audiodatalength_high = avio_rl32(pb);

        ape->wavtaillength        = avio_rl32(pb);

        avio_read(pb, ape->md5, 16);

        /* Skip any unknown bytes at the end of the descriptor.

           This is for future compatibility */

        if (ape->descriptorlength > 52)

            avio_skip(pb, ape->descriptorlength - 52);

        /* Read header data */

        ape->compressiontype      = avio_rl16(pb);

        ape->formatflags          = avio_rl16(pb);

        ape->blocksperframe       = avio_rl32(pb);

        ape->finalframeblocks     = avio_rl32(pb);

        ape->totalframes          = avio_rl32(pb);

        ape->bps                  = avio_rl16(pb);

        ape->channels             = avio_rl16(pb);

        ape->samplerate           = avio_rl32(pb);

    } else {

        ape->descriptorlength = 0;

        ape->headerlength = 32;

        ape->compressiontype      = avio_rl16(pb);

        ape->formatflags          = avio_rl16(pb);

        ape->channels             = avio_rl16(pb);

        ape->samplerate           = avio_rl32(pb);

        ape->wavheaderlength      = avio_rl32(pb);

        ape->wavtaillength        = avio_rl32(pb);

        ape->totalframes          = avio_rl32(pb);

        ape->finalframeblocks     = avio_rl32(pb);

        if (ape->formatflags & MAC_FORMAT_FLAG_HAS_PEAK_LEVEL) {

            avio_skip(pb, 4); /* Skip the peak level */

            ape->headerlength += 4;

        }

        if (ape->formatflags & MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS) {

            ape->seektablelength = avio_rl32(pb);

            ape->headerlength += 4;

            ape->seektablelength *= sizeof(int32_t);

        } else

            ape->seektablelength = ape->totalframes * sizeof(int32_t);

        if (ape->formatflags & MAC_FORMAT_FLAG_8_BIT)

            ape->bps = 8;

        else if (ape->formatflags & MAC_FORMAT_FLAG_24_BIT)

            ape->bps = 24;

        else

            ape->bps = 16;

        if (ape->fileversion >= 3950)

            ape->blocksperframe = 73728 * 4;

        else if (ape->fileversion >= 3900 || (ape->fileversion >= 3800  && ape->compressiontype >= 4000))

            ape->blocksperframe = 73728;

        else

            ape->blocksperframe = 9216;

        /* Skip any stored wav header */

        if (!(ape->formatflags & MAC_FORMAT_FLAG_CREATE_WAV_HEADER))

            avio_skip(pb, ape->wavheaderlength);

    }

    if(!ape->totalframes){

        av_log(s, AV_LOG_ERROR, "No frames in the file!\n");

        return AVERROR(EINVAL);

    }

    if(ape->totalframes > UINT_MAX / sizeof(APEFrame)){

        av_log(s, AV_LOG_ERROR, "Too many frames: %d\n", ape->totalframes);

        return -1;

    }

    ape->frames       = av_malloc(ape->totalframes * sizeof(APEFrame));

    if(!ape->frames)

        return AVERROR(ENOMEM);

    ape->firstframe   = ape->junklength + ape->descriptorlength + ape->headerlength + ape->seektablelength + ape->wavheaderlength;

    ape->currentframe = 0;

    ape->totalsamples = ape->finalframeblocks;

    if (ape->totalframes > 1)

        ape->totalsamples += ape->blocksperframe * (ape->totalframes - 1);

    if (ape->seektablelength > 0) {

        ape->seektable = av_malloc(ape->seektablelength);

        for (i = 0; i < ape->seektablelength / sizeof(uint32_t); i++)

            ape->seektable[i] = avio_rl32(pb);

    }

    ape->frames[0].pos     = ape->firstframe;

    ape->frames[0].nblocks = ape->blocksperframe;

    ape->frames[0].skip    = 0;

    for (i = 1; i < ape->totalframes; i++) {

        ape->frames[i].pos      = ape->seektable[i]; //ape->frames[i-1].pos + ape->blocksperframe;

        ape->frames[i].nblocks  = ape->blocksperframe;

        ape->frames[i - 1].size = ape->frames[i].pos - ape->frames[i - 1].pos;

        ape->frames[i].skip     = (ape->frames[i].pos - ape->frames[0].pos) & 3;

    }

    ape->frames[ape->totalframes - 1].size    = ape->finalframeblocks * 4;

    ape->frames[ape->totalframes - 1].nblocks = ape->finalframeblocks;

    for (i = 0; i < ape->totalframes; i++) {

        if(ape->frames[i].skip){

            ape->frames[i].pos  -= ape->frames[i].skip;

            ape->frames[i].size += ape->frames[i].skip;

        }

        ape->frames[i].size = (ape->frames[i].size + 3) & ~3;

    }

    ape_dumpinfo(s, ape);

    /* try to read APE tags */

    if (!url_is_streamed(pb)) {

        ff_ape_parse_tag(s);

        avio_seek(pb, 0, SEEK_SET);

    }

    av_log(s, AV_LOG_DEBUG, "Decoding file - v%d.%02d, compression level %d\n", ape->fileversion / 1000, (ape->fileversion % 1000) / 10, ape->compressiontype);

    /* now we are ready: build format streams */

    st = av_new_stream(s, 0);

    if (!st)

        return -1;

    total_blocks = (ape->totalframes == 0) ? 0 : ((ape->totalframes - 1) * ape->blocksperframe) + ape->finalframeblocks;

    st->codec->codec_type      = AVMEDIA_TYPE_AUDIO;

    st->codec->codec_id        = CODEC_ID_APE;

    st->codec->codec_tag       = MKTAG('A', 'P', 'E', ' ');

    st->codec->channels        = ape->channels;

    st->codec->sample_rate     = ape->samplerate;

    st->codec->bits_per_coded_sample = ape->bps;

    st->codec->frame_size      = MAC_SUBFRAME_SIZE;

    st->nb_frames = ape->totalframes;

    st->start_time = 0;

    st->duration  = total_blocks / MAC_SUBFRAME_SIZE;

    av_set_pts_info(st, 64, MAC_SUBFRAME_SIZE, ape->samplerate);

    st->codec->extradata = av_malloc(APE_EXTRADATA_SIZE);

    st->codec->extradata_size = APE_EXTRADATA_SIZE;

    AV_WL16(st->codec->extradata + 0, ape->fileversion);

    AV_WL16(st->codec->extradata + 2, ape->compressiontype);

    AV_WL16(st->codec->extradata + 4, ape->formatflags);

    pts = 0;

    for (i = 0; i < ape->totalframes; i++) {

        ape->frames[i].pts = pts;

        av_add_index_entry(st, ape->frames[i].pos, ape->frames[i].pts, 0, 0, AVINDEX_KEYFRAME);

        pts += ape->blocksperframe / MAC_SUBFRAME_SIZE;

    }

    return 0;

}

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

{

    int ret;

    int nblocks;

    APEContext *ape = s->priv_data;

    uint32_t extra_size = 8;

    if (s->pb->eof_reached)

        return AVERROR(EIO);

    if (ape->currentframe > ape->totalframes)

        return AVERROR(EIO);

    avio_seek (s->pb, ape->frames[ape->currentframe].pos, SEEK_SET);

    /* Calculate how many blocks there are in this frame */

    if (ape->currentframe == (ape->totalframes - 1))

        nblocks = ape->finalframeblocks;

    else

        nblocks = ape->blocksperframe;

    if (av_new_packet(pkt,  ape->frames[ape->currentframe].size + extra_size) < 0)

        return AVERROR(ENOMEM);

    AV_WL32(pkt->data    , nblocks);

    AV_WL32(pkt->data + 4, ape->frames[ape->currentframe].skip);

    ret = avio_read(s->pb, pkt->data + extra_size, ape->frames[ape->currentframe].size);

    pkt->pts = ape->frames[ape->currentframe].pts;

    pkt->stream_index = 0;

    /* note: we need to modify the packet size here to handle the last

       packet */

    pkt->size = ret + extra_size;

    ape->currentframe++;

    return 0;

}

static int ape_read_close(AVFormatContext * s)

{

    APEContext *ape = s->priv_data;

    av_freep(&ape->frames);

    av_freep(&ape->seektable);

    return 0;

}

static int ape_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

{

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

    APEContext *ape = s->priv_data;

    int index = av_index_search_timestamp(st, timestamp, flags);

    if (index < 0)

        return -1;

    ape->currentframe = index;

    return 0;

}

AVInputFormat ff_ape_demuxer = {

    "ape",

    NULL_IF_CONFIG_SMALL("Monkey's Audio"),

    sizeof(APEContext),

    ape_probe,

    ape_read_header,

    ape_read_packet,

    ape_read_close,

    ape_read_seek,

    .extensions = "ape,apl,mac"

};