movenc.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

/*
 * MOV, 3GP, MP4 muxer
 * Copyright (c) 2003 Thomas Raivio.
 * Copyright (c) 2004 Gildas Bazin <gbazin at videolan dot org>.
 *
 * 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 "avformat.h"
#include "riff.h"
#include "avio.h"
#include "isom.h"

#undef NDEBUG
#include <assert.h>

#define MOV_INDEX_CLUSTER_SIZE 16384
#define globalTimescale 1000

#define MODE_MP4 0
#define MODE_MOV 1
#define MODE_3GP 2
#define MODE_PSP 3 // example working PSP command line:
// ffmpeg -i testinput.avi  -f psp -r 14.985 -s 320x240 -b 768 -ar 24000 -ab 32 M4V00001.MP4
#define MODE_3G2 4

typedef struct MOVIentry {
    unsigned int flags, size;
    uint64_t     pos;
    unsigned int samplesInChunk;
    char         key_frame;
    unsigned int entries;
    int64_t      cts;
    int64_t      dts;
} MOVIentry;

typedef struct MOVIndex {
    int         mode;
    int         entry;
    long        timescale;
    long        time;
    int64_t     trackDuration;
    long        sampleCount;
    long        sampleSize;
    int         hasKeyframes;
    int         hasBframes;
    int         language;
    int         trackID;
    int         tag;
    AVCodecContext *enc;

    int         vosLen;
    uint8_t     *vosData;
    MOVIentry   *cluster;
    int         audio_vbr;
} MOVTrack;

typedef struct MOVContext {
    int     mode;
    int64_t time;
    int     nb_streams;
    offset_t mdat_pos;
    uint64_t mdat_size;
    long    timescale;
    MOVTrack tracks[MAX_STREAMS];
} MOVContext;

//FIXME support 64 bit variant with wide placeholders
static offset_t updateSize (ByteIOContext *pb, offset_t pos)
{
    offset_t curpos = url_ftell(pb);
    url_fseek(pb, pos, SEEK_SET);
    put_be32(pb, curpos - pos); /* rewrite size */
    url_fseek(pb, curpos, SEEK_SET);

    return curpos - pos;
}

/* Chunk offset atom */
static int mov_write_stco_tag(ByteIOContext *pb, MOVTrack* track)
{
    int i;
    int mode64 = 0; //   use 32 bit size variant if possible
    offset_t pos = url_ftell(pb);
    put_be32(pb, 0); /* size */
    if (pos > UINT32_MAX) {
        mode64 = 1;
        put_tag(pb, "co64");
    } else
        put_tag(pb, "stco");
    put_be32(pb, 0); /* version & flags */
    put_be32(pb, track->entry); /* entry count */
    for (i=0; i<track->entry; i++) {
        if(mode64 == 1)
            put_be64(pb, track->cluster[i].pos);
        else
            put_be32(pb, track->cluster[i].pos);
    }
    return updateSize (pb, pos);
}

/* Sample size atom */
static int mov_write_stsz_tag(ByteIOContext *pb, MOVTrack* track)
{
    int equalChunks = 1;
    int i, j, entries = 0, tst = -1, oldtst = -1;

    offset_t pos = url_ftell(pb);
    put_be32(pb, 0); /* size */
    put_tag(pb, "stsz");
    put_be32(pb, 0); /* version & flags */

    for (i=0; i<track->entry; i++) {
        tst = track->cluster[i].size/track->cluster[i].entries;
        if(oldtst != -1 && tst != oldtst) {
            equalChunks = 0;
        }
        oldtst = tst;
        entries += track->cluster[i].entries;
    }
    if (equalChunks) {
        int sSize = track->cluster[0].size/track->cluster[0].entries;
        put_be32(pb, sSize); // sample size
        put_be32(pb, entries); // sample count
    }
    else {
        put_be32(pb, 0); // sample size
        put_be32(pb, entries); // sample count
        for (i=0; i<track->entry; i++) {
            for ( j=0; j<track->cluster[i].entries; j++) {
                put_be32(pb, track->cluster[i].size /
                         track->cluster[i].entries);
            }
        }
    }
    return updateSize (pb, pos);
}

/* Sample to chunk atom */
static int mov_write_stsc_tag(ByteIOContext *pb, MOVTrack* track)
{
    int index = 0, oldval = -1, i;
    offset_t entryPos, curpos;

    offset_t pos = url_ftell(pb);
    put_be32(pb, 0); /* size */
    put_tag(pb, "stsc");
    put_be32(pb, 0); // version & flags
    entryPos = url_ftell(pb);
    put_be32(pb, track->entry); // entry count
    for (i=0; i<track->entry; i++) {
        if(oldval != track->cluster[i].samplesInChunk)
        {
            put_be32(pb, i+1); // first chunk
            put_be32(pb, track->cluster[i].samplesInChunk); // samples per chunk
            put_be32(pb, 0x1); // sample description index
            oldval = track->cluster[i].samplesInChunk;
            index++;
        }
    }
    curpos = url_ftell(pb);
    url_fseek(pb, entryPos, SEEK_SET);
    put_be32(pb, index); // rewrite size
    url_fseek(pb, curpos, SEEK_SET);

    return updateSize (pb, pos);
}

/* Sync sample atom */
static int mov_write_stss_tag(ByteIOContext *pb, MOVTrack* track)
{
    offset_t curpos, entryPos;
    int i, index = 0;
    offset_t pos = url_ftell(pb);
    put_be32(pb, 0); // size
    put_tag(pb, "stss");
    put_be32(pb, 0); // version & flags
    entryPos = url_ftell(pb);
    put_be32(pb, track->entry); // entry count
    for (i=0; i<track->entry; i++) {
        if(track->cluster[i].key_frame == 1) {
            put_be32(pb, i+1);
            index++;
        }
    }
    curpos = url_ftell(pb);
    url_fseek(pb, entryPos, SEEK_SET);
    put_be32(pb, index); // rewrite size
    url_fseek(pb, curpos, SEEK_SET);
    return updateSize (pb, pos);
}

static int mov_write_amr_tag(ByteIOContext *pb, MOVTrack *track)
{
    put_be32(pb, 0x11); /* size */
    if (track->mode == MODE_MOV) put_tag(pb, "samr");
    else                         put_tag(pb, "damr");
    put_tag(pb, "FFMP");
    put_byte(pb, 0); /* decoder version */

    put_be16(pb, 0x81FF); /* Mode set (all modes for AMR_NB) */
    put_byte(pb, 0x00); /* Mode change period (no restriction) */
    put_byte(pb, 0x01); /* Frames per sample */
    return 0x11;
}

static int mov_write_enda_tag(ByteIOContext *pb)
{
    put_be32(pb, 10);
    put_tag(pb, "enda");
    put_be16(pb, 1); /* little endian */
    return 10;
}

static unsigned int descrLength(unsigned int len)
{
    int i;
    for(i=1; len>>(7*i); i++);
    return len + 1 + i;
}

static void putDescr(ByteIOContext *pb, int tag, unsigned int size)
{
    int i= descrLength(size) - size - 2;
    put_byte(pb, tag);
    for(; i>0; i--)
        put_byte(pb, (size>>(7*i)) | 0x80);
    put_byte(pb, size & 0x7F);
}

static int mov_write_esds_tag(ByteIOContext *pb, MOVTrack* track) // Basic
{
    offset_t pos = url_ftell(pb);
    int decoderSpecificInfoLen = track->vosLen ? descrLength(track->vosLen):0;

    put_be32(pb, 0);               // size
    put_tag(pb, "esds");
    put_be32(pb, 0);               // Version

    // ES descriptor
    putDescr(pb, 0x03, 3 + descrLength(13 + decoderSpecificInfoLen) +
             descrLength(1));
    put_be16(pb, track->trackID);
    put_byte(pb, 0x00);            // flags (= no flags)

    // DecoderConfig descriptor
    putDescr(pb, 0x04, 13 + decoderSpecificInfoLen);

    // Object type indication
    put_byte(pb, codec_get_tag(ff_mp4_obj_type, track->enc->codec_id));

    // the following fields is made of 6 bits to identify the streamtype (4 for video, 5 for audio)
    // plus 1 bit to indicate upstream and 1 bit set to 1 (reserved)
    if(track->enc->codec_type == CODEC_TYPE_AUDIO)
        put_byte(pb, 0x15);            // flags (= Audiostream)
    else
        put_byte(pb, 0x11);            // flags (= Visualstream)

    put_byte(pb,  track->enc->rc_buffer_size>>(3+16));             // Buffersize DB (24 bits)
    put_be16(pb, (track->enc->rc_buffer_size>>3)&0xFFFF);          // Buffersize DB

    put_be32(pb, FFMAX(track->enc->bit_rate, track->enc->rc_max_rate));     // maxbitrate  (FIXME should be max rate in any 1 sec window)
    if(track->enc->rc_max_rate != track->enc->rc_min_rate || track->enc->rc_min_rate==0)
        put_be32(pb, 0);     // vbr
    else
        put_be32(pb, track->enc->rc_max_rate);     // avg bitrate

    if (track->vosLen)
    {
        // DecoderSpecific info descriptor
        putDescr(pb, 0x05, track->vosLen);
        put_buffer(pb, track->vosData, track->vosLen);
    }


    // SL descriptor
    putDescr(pb, 0x06, 1);
    put_byte(pb, 0x02);
    return updateSize (pb, pos);
}

static int mov_write_wave_tag(ByteIOContext *pb, MOVTrack* track)
{
    offset_t pos = url_ftell(pb);

    put_be32(pb, 0);     /* size */
    put_tag(pb, "wave");

    put_be32(pb, 12);    /* size */
    put_tag(pb, "frma");
    put_le32(pb, track->tag);

    if (track->enc->codec_id == CODEC_ID_AAC) {
        /* useless atom needed by mplayer, ipod, not needed by quicktime */
        put_be32(pb, 12); /* size */
        put_tag(pb, "mp4a");
        put_be32(pb, 0);
        mov_write_esds_tag(pb, track);
    } else if (track->enc->codec_id == CODEC_ID_PCM_S24LE ||
               track->enc->codec_id == CODEC_ID_PCM_S32LE) {
        mov_write_enda_tag(pb);
    } else if (track->enc->codec_id == CODEC_ID_AMR_NB) {
        mov_write_amr_tag(pb, track);
    }

    put_be32(pb, 8);     /* size */
    put_be32(pb, 0);     /* null tag */

    return updateSize (pb, pos);
}

static int mov_write_audio_tag(ByteIOContext *pb, MOVTrack* track)
{
    offset_t pos = url_ftell(pb);
    int version = track->mode == MODE_MOV &&
        (track->audio_vbr ||
         track->enc->codec_id == CODEC_ID_PCM_S32LE ||
         track->enc->codec_id == CODEC_ID_PCM_S24LE);

    put_be32(pb, 0); /* size */
    put_le32(pb, track->tag); // store it byteswapped
    put_be32(pb, 0); /* Reserved */
    put_be16(pb, 0); /* Reserved */
    put_be16(pb, 1); /* Data-reference index, XXX  == 1 */

    /* SoundDescription */
    put_be16(pb, version); /* Version */
    put_be16(pb, 0); /* Revision level */
    put_be32(pb, 0); /* Reserved */

    if (track->mode == MODE_MOV) {
        put_be16(pb, track->enc->channels);
        if (track->enc->codec_id == CODEC_ID_PCM_U8 ||
            track->enc->codec_id == CODEC_ID_PCM_S8)
            put_be16(pb, 8); /* bits per sample */
        else
            put_be16(pb, 16);
        put_be16(pb, track->audio_vbr ? -2 : 0); /* compression ID */
    } else { /* reserved for mp4/3gp */
        put_be16(pb, 2);
        put_be16(pb, 16);
        put_be16(pb, 0);
    }

    put_be16(pb, 0); /* packet size (= 0) */
    put_be16(pb, track->timescale); /* Time scale */
    put_be16(pb, 0); /* Reserved */

    if(version == 1) { /* SoundDescription V1 extended info */
        put_be32(pb, track->enc->frame_size); /* Samples per packet */
        put_be32(pb, track->sampleSize / track->enc->channels); /* Bytes per packet */
        put_be32(pb, track->sampleSize); /* Bytes per frame */
        put_be32(pb, 2); /* Bytes per sample */
    }

    if(track->mode == MODE_MOV &&
       (track->enc->codec_id == CODEC_ID_AAC ||
        track->enc->codec_id == CODEC_ID_AMR_NB ||
        track->enc->codec_id == CODEC_ID_PCM_S24LE ||
        track->enc->codec_id == CODEC_ID_PCM_S32LE))
        mov_write_wave_tag(pb, track);
    else if(track->enc->codec_id == CODEC_ID_AAC)
        mov_write_esds_tag(pb, track);
    else if(track->enc->codec_id == CODEC_ID_AMR_NB)
        mov_write_amr_tag(pb, track);

    return updateSize (pb, pos);
}

static int mov_write_d263_tag(ByteIOContext *pb)
{
    put_be32(pb, 0xf); /* size */
    put_tag(pb, "d263");
    put_tag(pb, "FFMP");
    put_byte(pb, 0); /* decoder version */
    /* FIXME use AVCodecContext level/profile, when encoder will set values */
    put_byte(pb, 0xa); /* level */
    put_byte(pb, 0); /* profile */
    return 0xf;
}

/* TODO: No idea about these values */
static int mov_write_svq3_tag(ByteIOContext *pb)
{
    put_be32(pb, 0x15);
    put_tag(pb, "SMI ");
    put_tag(pb, "SEQH");
    put_be32(pb, 0x5);
    put_be32(pb, 0xe2c0211d);
    put_be32(pb, 0xc0000000);
    put_byte(pb, 0);
    return 0x15;
}

static uint8_t *avc_find_startcode( uint8_t *p, uint8_t *end )
{
    uint8_t *a = p + 4 - ((long)p & 3);

    for( end -= 3; p < a && p < end; p++ ) {
        if( p[0] == 0 && p[1] == 0 && p[2] == 1 )
            return p;
    }

    for( end -= 3; p < end; p += 4 ) {
        uint32_t x = *(uint32_t*)p;
//      if( (x - 0x01000100) & (~x) & 0x80008000 ) // little endian
//      if( (x - 0x00010001) & (~x) & 0x00800080 ) // big endian
        if( (x - 0x01010101) & (~x) & 0x80808080 ) { // generic
            if( p[1] == 0 ) {
                if( p[0] == 0 && p[2] == 1 )
                    return p-1;
                if( p[2] == 0 && p[3] == 1 )
                    return p;
            }