ape.c.svn-base

mediastreamer2是开源的网络传输媒体流的库

/*
 * Monkey's Audio APE demuxer
 * Copyright (c) 2007 Benjamin Zores <[e-mail]>
 *  based upon libdemac from Dave Chapman.
 *
 * 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 <stdio.h>

#include "avformat.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

/* APE tags */
#define APE_TAG_VERSION               2000
#define APE_TAG_FOOTER_BYTES          32
#define APE_TAG_FLAG_CONTAINS_HEADER  (1 << 31)
#define APE_TAG_FLAG_IS_HEADER        (1 << 29)

#define TAG(name, field)  {name, offsetof(AVFormatContext, field), sizeof(((AVFormatContext *)0)->field)}

static const struct {
    const char *name;
    int offset;
    int size;
} tags[] = {
    TAG("Title"    , title    ),
    TAG("Artist"   , author   ),
    TAG("Copyright", copyright),
    TAG("Comment"  , comment  ),
    TAG("Album"    , album    ),
    TAG("Year"     , year     ),
    TAG("Track"    , track    ),
    TAG("Genre"    , genre    ),
    { NULL }
};

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 void ape_tag_read_field(AVFormatContext *s)
{
    ByteIOContext *pb = s->pb;
    uint8_t buf[1024];
    uint32_t size;
    int i;

    memset(buf, 0, 1024);
    size = get_le32(pb);  /* field size */
    url_fskip(pb, 4);     /* skip field flags */

    for (i=0; pb->buf_ptr[i]!='0' && pb->buf_ptr[i]>=0x20 && pb->buf_ptr[i]<=0x7E; i++);

    get_buffer(pb, buf, FFMIN(i, 1024));
    url_fskip(pb, 1);

    for (i=0; tags[i].name; i++)
        if (!strcmp (buf, tags[i].name)) {
            if (tags[i].size == sizeof(int)) {
                char tmp[16];
                get_buffer(pb, tmp, FFMIN(sizeof(tmp), size));
                *(int *)(((char *)s)+tags[i].offset) = atoi(tmp);
            } else {
                get_buffer(pb, ((char *)s) + tags[i].offset,
                           FFMIN(tags[i].size, size));
            }
            break;
        }

    if (!tags[i].name)
        url_fskip(pb, size);
}

static void ape_parse_tag(AVFormatContext *s)
{
    ByteIOContext *pb = s->pb;
    int file_size = url_fsize(pb);
    uint32_t val, fields, tag_bytes;
    uint8_t buf[8];
    int i;

    if (file_size < APE_TAG_FOOTER_BYTES)
        return;

    url_fseek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);

    get_buffer(pb, buf, 8);    /* APETAGEX */
    if (strncmp(buf, "APETAGEX", 8)) {
        av_log(NULL, AV_LOG_ERROR, "Invalid APE Tags\n");
        return;
    }

    val = get_le32(pb);        /* APE tag version */
    if (val > APE_TAG_VERSION) {
        av_log(NULL, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
        return;
    }

    tag_bytes = get_le32(pb);  /* tag size */
    if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
        av_log(NULL, AV_LOG_ERROR, "Tag size is way too big\n");
        return;
    }

    fields = get_le32(pb);     /* number of fields */
    if (fields > 65536) {
        av_log(NULL, AV_LOG_ERROR, "Too many tag fields (%d)\n", fields);
        return;
    }

    val = get_le32(pb);        /* flags */
    if (val & APE_TAG_FLAG_IS_HEADER) {
        av_log(NULL, AV_LOG_ERROR, "APE Tag is a header\n");
        return;
    }

    if (val & APE_TAG_FLAG_CONTAINS_HEADER)
        tag_bytes += 2*APE_TAG_FOOTER_BYTES;

    url_fseek(pb, file_size - tag_bytes, SEEK_SET);

    for (i=0; i<fields; i++)
        ape_tag_read_field(s);

#if ENABLE_DEBUG
    av_log(NULL, AV_LOG_DEBUG, "\nAPE Tags:\n\n");
    av_log(NULL, AV_LOG_DEBUG, "title     = %s\n", s->title);
    av_log(NULL, AV_LOG_DEBUG, "author    = %s\n", s->author);
    av_log(NULL, AV_LOG_DEBUG, "copyright = %s\n", s->copyright);
    av_log(NULL, AV_LOG_DEBUG, "comment   = %s\n", s->comment);
    av_log(NULL, AV_LOG_DEBUG, "album     = %s\n", s->album);
    av_log(NULL, AV_LOG_DEBUG, "year      = %d\n", s->year);
    av_log(NULL, AV_LOG_DEBUG, "track     = %d\n", s->track);
    av_log(NULL, AV_LOG_DEBUG, "genre     = %s\n", s->genre);
#endif
}

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(APEContext * ape_ctx)
{
#if ENABLE_DEBUG
    int i;

    av_log(NULL, AV_LOG_DEBUG, "Descriptor Block:\n\n");
    av_log(NULL, 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(NULL, AV_LOG_DEBUG, "fileversion          = %d\n", ape_ctx->fileversion);
    av_log(NULL, AV_LOG_DEBUG, "descriptorlength     = %d\n", ape_ctx->descriptorlength);
    av_log(NULL, AV_LOG_DEBUG, "headerlength         = %d\n", ape_ctx->headerlength);
    av_log(NULL, AV_LOG_DEBUG, "seektablelength      = %d\n", ape_ctx->seektablelength);
    av_log(NULL, AV_LOG_DEBUG, "wavheaderlength      = %d\n", ape_ctx->wavheaderlength);
    av_log(NULL, AV_LOG_DEBUG, "audiodatalength      = %d\n", ape_ctx->audiodatalength);
    av_log(NULL, AV_LOG_DEBUG, "audiodatalength_high = %d\n", ape_ctx->audiodatalength_high);
    av_log(NULL, AV_LOG_DEBUG, "wavtaillength        = %d\n", ape_ctx->wavtaillength);
    av_log(NULL, AV_LOG_DEBUG, "md5                  = ");
    for (i = 0; i < 16; i++)
         av_log(NULL, AV_LOG_DEBUG, "%02x", ape_ctx->md5[i]);
    av_log(NULL, AV_LOG_DEBUG, "\n");

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

    av_log(NULL, AV_LOG_DEBUG, "compressiontype      = %d\n", ape_ctx->compressiontype);
    av_log(NULL, AV_LOG_DEBUG, "formatflags          = %d\n", ape_ctx->formatflags);
    av_log(NULL, AV_LOG_DEBUG, "blocksperframe       = %d\n", ape_ctx->blocksperframe);
    av_log(NULL, AV_LOG_DEBUG, "finalframeblocks     = %d\n", ape_ctx->finalframeblocks);
    av_log(NULL, AV_LOG_DEBUG, "totalframes          = %d\n", ape_ctx->totalframes);
    av_log(NULL, AV_LOG_DEBUG, "bps                  = %d\n", ape_ctx->bps);
    av_log(NULL, AV_LOG_DEBUG, "channels             = %d\n", ape_ctx->channels);
    av_log(NULL, AV_LOG_DEBUG, "samplerate           = %d\n", ape_ctx->samplerate);

    av_log(NULL, AV_LOG_DEBUG, "\nSeektable\n\n");
    if ((ape_ctx->seektablelength / sizeof(uint32_t)) != ape_ctx->totalframes) {
        av_log(NULL, 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(NULL, 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(NULL, AV_LOG_DEBUG, "%8d   %d\n", i, ape_ctx->seektable[i]);
            }
        }
    }

    av_log(NULL, AV_LOG_DEBUG, "\nFrames\n\n");
    for (i = 0; i < ape_ctx->totalframes; i++)
        av_log(NULL, 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);