mp4file.cpp

AAC编解码源码

    pInteger32Property->SetValue(timeScale ? timeScale : 1000);

    // now have enough to create MP4Track object
    MP4Track* pTrack = NULL;
    if (!strcmp(normType, MP4_HINT_TRACK_TYPE)) {
        pTrack = new MP4RtpHintTrack(this, pTrakAtom);
    } else {
        pTrack = new MP4Track(this, pTrakAtom);
    }
    m_pTracks.Add(pTrack);

    // mark non-hint tracks as enabled
    if (strcmp(normType, MP4_HINT_TRACK_TYPE)) {
        SetTrackIntegerProperty(trackId, "tkhd.flags", 1);
    }

    // mark track as contained in this file
    // LATER will provide option for external data references
    AddDataReference(trackId, NULL);

    return trackId;
}

void MP4File::AddTrackToIod(MP4TrackId trackId)
{
    MP4DescriptorProperty* pDescriptorProperty = NULL;
    m_pRootAtom->FindProperty("moov.iods.esIds",
        (MP4Property**)&pDescriptorProperty);
    ASSERT(pDescriptorProperty);

    MP4Descriptor* pDescriptor =
        pDescriptorProperty->AddDescriptor(MP4ESIDIncDescrTag);
    ASSERT(pDescriptor);

    MP4Integer32Property* pIdProperty = NULL;
    pDescriptor->FindProperty("id",
        (MP4Property**)&pIdProperty);
    ASSERT(pIdProperty);

    pIdProperty->SetValue(trackId);
}

void MP4File::RemoveTrackFromIod(MP4TrackId trackId)
{
    MP4DescriptorProperty* pDescriptorProperty = NULL;
    m_pRootAtom->FindProperty("moov.iods.esIds",
        (MP4Property**)&pDescriptorProperty);
    ASSERT(pDescriptorProperty);

    for (u_int32_t i = 0; i < pDescriptorProperty->GetCount(); i++) {
        static char name[32];
        snprintf(name, sizeof(name), "esIds[%u].id", i);

        MP4Integer32Property* pIdProperty = NULL;
        pDescriptorProperty->FindProperty(name,
            (MP4Property**)&pIdProperty);
        ASSERT(pIdProperty);

        if (pIdProperty->GetValue() == trackId) {
            pDescriptorProperty->DeleteDescriptor(i);
            break;
        }
    }
}

void MP4File::AddTrackToOd(MP4TrackId trackId)
{
    if (!m_odTrackId) {
        return;
    }

    AddTrackReference(MakeTrackName(m_odTrackId, "tref.mpod"), trackId);
}

void MP4File::RemoveTrackFromOd(MP4TrackId trackId)
{
    if (!m_odTrackId) {
        return;
    }

    RemoveTrackReference(MakeTrackName(m_odTrackId, "tref.mpod"), trackId);
}

void MP4File::GetTrackReferenceProperties(const char* trefName,
    MP4Property** ppCountProperty, MP4Property** ppTrackIdProperty)
{
    char propName[1024];

    snprintf(propName, sizeof(propName), "%s.%s", trefName, "entryCount");
    m_pRootAtom->FindProperty(propName, ppCountProperty);
    ASSERT(*ppCountProperty);

    snprintf(propName, sizeof(propName), "%s.%s", trefName, "entries.trackId");
    m_pRootAtom->FindProperty(propName, ppTrackIdProperty);
    ASSERT(*ppTrackIdProperty);
}

void MP4File::AddTrackReference(const char* trefName, MP4TrackId refTrackId)
{
    MP4Integer32Property* pCountProperty = NULL;
    MP4Integer32Property* pTrackIdProperty = NULL;

    GetTrackReferenceProperties(trefName,
        (MP4Property**)&pCountProperty,
        (MP4Property**)&pTrackIdProperty);

    pTrackIdProperty->AddValue(refTrackId);
    pCountProperty->IncrementValue();
}

u_int32_t MP4File::FindTrackReference(const char* trefName,
    MP4TrackId refTrackId)
{
    MP4Integer32Property* pCountProperty = NULL;
    MP4Integer32Property* pTrackIdProperty = NULL;

    GetTrackReferenceProperties(trefName,
        (MP4Property**)&pCountProperty,
        (MP4Property**)&pTrackIdProperty);

    for (u_int32_t i = 0; i < pCountProperty->GetValue(); i++) {
        if (refTrackId == pTrackIdProperty->GetValue(i)) {
            return i + 1;   // N.B. 1 not 0 based index
        }
    }
    return 0;
}

void MP4File::RemoveTrackReference(const char* trefName, MP4TrackId refTrackId)
{
    MP4Integer32Property* pCountProperty = NULL;
    MP4Integer32Property* pTrackIdProperty = NULL;

    GetTrackReferenceProperties(trefName,
        (MP4Property**)&pCountProperty,
        (MP4Property**)&pTrackIdProperty);

    for (u_int32_t i = 0; i < pCountProperty->GetValue(); i++) {
        if (refTrackId == pTrackIdProperty->GetValue(i)) {
            pTrackIdProperty->DeleteValue(i);
            pCountProperty->IncrementValue(-1);
        }
    }
}

void MP4File::AddDataReference(MP4TrackId trackId, const char* url)
{
    MP4Atom* pDrefAtom =
        FindAtom(MakeTrackName(trackId, "mdia.minf.dinf.dref"));
    ASSERT(pDrefAtom);

    MP4Integer32Property* pCountProperty = NULL;
    pDrefAtom->FindProperty("dref.entryCount",
        (MP4Property**)&pCountProperty);
    ASSERT(pCountProperty);
    pCountProperty->IncrementValue();

    MP4Atom* pUrlAtom = AddChildAtom(pDrefAtom, "url ");

    if (url && url[0] != '\0') {
        pUrlAtom->SetFlags(pUrlAtom->GetFlags() & 0xFFFFFE);

        MP4StringProperty* pUrlProperty = NULL;
        pUrlAtom->FindProperty("url .location",
            (MP4Property**)&pUrlProperty);
        ASSERT(pUrlProperty);
        pUrlProperty->SetValue(url);
    } else {
        pUrlAtom->SetFlags(pUrlAtom->GetFlags() | 1);
    }
}

MP4TrackId MP4File::AddSystemsTrack(const char* type)
{
    const char* normType = MP4Track::NormalizeTrackType(type);

    // TBD if user type, fix name to four chars, and warn

    MP4TrackId trackId = AddTrack(type, MP4_MSECS_TIME_SCALE);

    InsertChildAtom(MakeTrackName(trackId, "mdia.minf"), "nmhd", 0);

    AddChildAtom(MakeTrackName(trackId, "mdia.minf.stbl.stsd"), "mp4s");

    // stsd is a unique beast in that it has a count of the number
    // of child atoms that needs to be incremented after we add the mp4s atom
    MP4Integer32Property* pStsdCountProperty;
    FindIntegerProperty(
        MakeTrackName(trackId, "mdia.minf.stbl.stsd.entryCount"),
        (MP4Property**)&pStsdCountProperty);
    pStsdCountProperty->IncrementValue();

    SetTrackIntegerProperty(trackId,
                "mdia.minf.stbl.stsd.mp4s.esds.ESID",
#if 0
                // note - for a file, these values need to
                // be 0 - wmay - 04/16/2003
                trackId
#else
                0
#endif
                );

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4s.esds.decConfigDescr.objectTypeId",
        MP4SystemsV1ObjectType);

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4s.esds.decConfigDescr.streamType",
        ConvertTrackTypeToStreamType(normType));

    return trackId;
}

MP4TrackId MP4File::AddODTrack()
{
    // until a demonstrated need emerges
    // we limit ourselves to one object description track
    if (m_odTrackId != MP4_INVALID_TRACK_ID) {
        throw new MP4Error("object description track already exists",
            "AddObjectDescriptionTrack");
    }

    m_odTrackId = AddSystemsTrack(MP4_OD_TRACK_TYPE);

    AddTrackToIod(m_odTrackId);

    AddDescendantAtoms(MakeTrackName(m_odTrackId, NULL), "tref.mpod");

    return m_odTrackId;
}

MP4TrackId MP4File::AddSceneTrack()
{
    MP4TrackId trackId = AddSystemsTrack(MP4_SCENE_TRACK_TYPE);

    AddTrackToIod(trackId);
    AddTrackToOd(trackId);

    return trackId;
}

MP4TrackId MP4File::AddAudioTrack(
    u_int32_t timeScale,
    MP4Duration sampleDuration,
    u_int8_t audioType)
{
    MP4TrackId trackId = AddTrack(MP4_AUDIO_TRACK_TYPE, timeScale);

    AddTrackToOd(trackId);

    SetTrackFloatProperty(trackId, "tkhd.volume", 1.0);

    InsertChildAtom(MakeTrackName(trackId, "mdia.minf"), "smhd", 0);

    AddChildAtom(MakeTrackName(trackId, "mdia.minf.stbl.stsd"), "mp4a");

    // stsd is a unique beast in that it has a count of the number
    // of child atoms that needs to be incremented after we add the mp4a atom
    MP4Integer32Property* pStsdCountProperty;
    FindIntegerProperty(
        MakeTrackName(trackId, "mdia.minf.stbl.stsd.entryCount"),
        (MP4Property**)&pStsdCountProperty);
    pStsdCountProperty->IncrementValue();

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4a.timeScale", timeScale);

    SetTrackIntegerProperty(trackId,
                "mdia.minf.stbl.stsd.mp4a.esds.ESID",
#if 0
                // note - for a file, these values need to
                // be 0 - wmay - 04/16/2003
                trackId
#else
                0
#endif
                );

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4a.esds.decConfigDescr.objectTypeId",
        audioType);

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4a.esds.decConfigDescr.streamType",
        MP4AudioStreamType);

    m_pTracks[FindTrackIndex(trackId)]->
        SetFixedSampleDuration(sampleDuration);

    return trackId;
}

MP4TrackId MP4File::AddEncAudioTrack(u_int32_t timeScale,
                     MP4Duration sampleDuration,
                     u_int8_t audioType)
{
  MP4TrackId trackId = AddTrack(MP4_AUDIO_TRACK_TYPE, timeScale);

  AddTrackToOd(trackId);

  SetTrackFloatProperty(trackId, "tkhd.volume", 1.0);

  InsertChildAtom(MakeTrackName(trackId, "mdia.minf"), "smhd", 0);

  AddChildAtom(MakeTrackName(trackId, "mdia.minf.stbl.stsd"), "enca");

  // stsd is a unique beast in that it has a count of the number
  // of child atoms that needs to be incremented after we add the enca atom
  MP4Integer32Property* pStsdCountProperty;
  FindIntegerProperty(
              MakeTrackName(trackId, "mdia.minf.stbl.stsd.entryCount"),
              (MP4Property**)&pStsdCountProperty);
  pStsdCountProperty->IncrementValue();

  SetTrackIntegerProperty(trackId,
              "mdia.minf.stbl.stsd.enca.timeScale", timeScale);

  SetTrackIntegerProperty(trackId,
              "mdia.minf.stbl.stsd.enca.esds.ESID",
#if 0
              // note - for a file, these values need to
              // be 0 - wmay - 04/16/2003
              trackId
#else
              0
#endif
              );

  SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.enca.esds.decConfigDescr.objectTypeId",
              audioType);

  SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.enca.esds.decConfigDescr.streamType",
              MP4AudioStreamType);

  m_pTracks[FindTrackIndex(trackId)]->
    SetFixedSampleDuration(sampleDuration);

  return trackId;
}

MP4TrackId MP4File::AddVideoTrack(
    u_int32_t timeScale,
    MP4Duration sampleDuration,
    u_int16_t width,
    u_int16_t height,
    u_int8_t videoType)
{
    MP4TrackId trackId = AddTrack(MP4_VIDEO_TRACK_TYPE, timeScale);

    AddTrackToOd(trackId);

    SetTrackFloatProperty(trackId, "tkhd.width", width);
    SetTrackFloatProperty(trackId, "tkhd.height", height);

    InsertChildAtom(MakeTrackName(trackId, "mdia.minf"), "vmhd", 0);

    AddChildAtom(MakeTrackName(trackId, "mdia.minf.stbl.stsd"), "mp4v");

    // stsd is a unique beast in that it has a count of the number
    // of child atoms that needs to be incremented after we add the mp4v atom
    MP4Integer32Property* pStsdCountProperty;
    FindIntegerProperty(
        MakeTrackName(trackId, "mdia.minf.stbl.stsd.entryCount"),
        (MP4Property**)&pStsdCountProperty);
    pStsdCountProperty->IncrementValue();

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4v.width", width);
    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4v.height", height);

    SetTrackIntegerProperty(trackId,
                "mdia.minf.stbl.stsd.mp4v.esds.ESID",
#if 0
                // note - for a file, these values need to
                // be 0 - wmay - 04/16/2003
                trackId
#else
                0
#endif
                );

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4v.esds.decConfigDescr.objectTypeId",
        videoType);

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4v.esds.decConfigDescr.streamType",
        MP4VisualStreamType);

    SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsz.sampleSize", sampleDuration);

    m_pTracks[FindTrackIndex(trackId)]->
        SetFixedSampleDuration(sampleDuration);

    return trackId;
}

MP4TrackId MP4File::AddEncVideoTrack(u_int32_t timeScale,
                     MP4Duration sampleDuration,
                     u_int16_t width,
                     u_int16_t height,
                     u_int8_t videoType)
{
  MP4TrackId trackId = AddTrack(MP4_VIDEO_TRACK_TYPE, timeScale);

  AddTrackToOd(trackId);

  SetTrackFloatProperty(trackId, "tkhd.width", width);
  SetTrackFloatProperty(trackId, "tkhd.height", height);

  InsertChildAtom(MakeTrackName(trackId, "mdia.minf"), "vmhd", 0);

  AddChildAtom(MakeTrackName(trackId, "mdia.minf.stbl.stsd"), "encv");

  // stsd is a unique beast in that it has a count of the number
  // of child atoms that needs to be incremented after we add the encv atom
  MP4Integer32Property* pStsdCountProperty;
  FindIntegerProperty(
              MakeTrackName(trackId, "mdia.minf.stbl.stsd.entryCount"),
              (MP4Property**)&pStsdCountProperty);
  pStsdCountProperty->IncrementValue();

  SetTrackIntegerProperty(trackId,
              "mdia.minf.stbl.stsd.encv.width", width);
  SetTrackIntegerProperty(trackId,
              "mdia.minf.stbl.stsd.encv.height", height);

  SetTrackIntegerProperty(trackId,
              "mdia.minf.stbl.stsd.encv.esds.ESID",
#if 0
              // note - for a file, these values need to
              // be 0 - wmay - 04/16/2003
              trackId
#else
              0
#endif
              );

  SetTrackIntegerProperty(trackId,
          "mdia.minf.stbl.stsd.encv.esds.decConfigDescr.objectTypeId",
              videoType);

  SetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.encv.esds.decConfigDescr.streamType",
              MP4VisualStreamType);