mp4file.cpp

AAC编解码源码

    SetSessionSdp(newSdpString);
    MP4Free(newSdpString);
}


// track level convenience functions

MP4SampleId MP4File::GetTrackNumberOfSamples(MP4TrackId trackId)
{
    return m_pTracks[FindTrackIndex(trackId)]->GetNumberOfSamples();
}

const char* MP4File::GetTrackType(MP4TrackId trackId)
{
    return m_pTracks[FindTrackIndex(trackId)]->GetType();
}

u_int32_t MP4File::GetTrackTimeScale(MP4TrackId trackId)
{
    return m_pTracks[FindTrackIndex(trackId)]->GetTimeScale();
}

void MP4File::SetTrackTimeScale(MP4TrackId trackId, u_int32_t value)
{
    if (value == 0) {
        throw new MP4Error("invalid value", "SetTrackTimeScale");
    }
    SetTrackIntegerProperty(trackId, "mdia.mdhd.timeScale", value);
}

MP4Duration MP4File::GetTrackDuration(MP4TrackId trackId)
{
    return GetTrackIntegerProperty(trackId, "mdia.mdhd.duration");
}

// now GetTrackEsdsObjectTypeId
u_int8_t MP4File::GetTrackAudioType(MP4TrackId trackId)
{
        return GetTrackIntegerProperty(trackId,
                "mdia.minf.stbl.stsd.mp4a.esds.decConfigDescr.objectTypeId");
}

u_int8_t MP4File::GetTrackEsdsObjectTypeId(MP4TrackId trackId)
{
    // changed mp4a to * to handle enca case
    return GetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.*.esds.decConfigDescr.objectTypeId");
}

u_int8_t MP4File::GetTrackAudioMpeg4Type(MP4TrackId trackId)
{
    // verify that track is an MPEG-4 audio track
    if (GetTrackEsdsObjectTypeId(trackId) != MP4_MPEG4_AUDIO_TYPE) {
        return MP4_MPEG4_INVALID_AUDIO_TYPE;
    }

    u_int8_t* pEsConfig = NULL;
    u_int32_t esConfigSize;

    // The Mpeg4 audio type (AAC, CELP, HXVC, ...)
    // is the first 5 bits of the ES configuration

    GetTrackESConfiguration(trackId, &pEsConfig, &esConfigSize);

    if (esConfigSize < 1) {
        return MP4_MPEG4_INVALID_AUDIO_TYPE;
    }

    u_int8_t mpeg4Type = (pEsConfig[0] >> 3);

    free(pEsConfig);

    return mpeg4Type;
}

// replaced with GetTrackEsdsObjectTypeId
u_int8_t MP4File::GetTrackVideoType(MP4TrackId trackId)
{
    return GetTrackIntegerProperty(trackId,
        "mdia.minf.stbl.stsd.mp4v.esds.decConfigDescr.objectTypeId");
}

MP4Duration MP4File::GetTrackFixedSampleDuration(MP4TrackId trackId)
{
    return m_pTracks[FindTrackIndex(trackId)]->GetFixedSampleDuration();
}

float MP4File::GetTrackVideoFrameRate(MP4TrackId trackId)
{
    MP4SampleId numSamples =
        GetTrackNumberOfSamples(trackId);
    u_int64_t
        msDuration =
        ConvertFromTrackDuration(trackId,
            GetTrackDuration(trackId), MP4_MSECS_TIME_SCALE);

    if (msDuration == 0) {
        return 0.0;
    }

    return ((double)numSamples / UINT64_TO_DOUBLE(msDuration)) * MP4_MSECS_TIME_SCALE;
}

void MP4File::GetTrackESConfiguration(MP4TrackId trackId,
    u_int8_t** ppConfig, u_int32_t* pConfigSize)
{
    GetTrackBytesProperty(trackId,
        "mdia.minf.stbl.stsd.*[0].esds.decConfigDescr.decSpecificInfo[0].info",
        ppConfig, pConfigSize);
}

void MP4File::SetTrackESConfiguration(MP4TrackId trackId,
    const u_int8_t* pConfig, u_int32_t configSize)
{
    // get a handle on the track decoder config descriptor
    MP4DescriptorProperty* pConfigDescrProperty = NULL;
    FindProperty(MakeTrackName(trackId,
        "mdia.minf.stbl.stsd.*[0].esds.decConfigDescr.decSpecificInfo"),
        (MP4Property**)&pConfigDescrProperty);

    if (pConfigDescrProperty == NULL) {
        // probably trackId refers to a hint track
        throw new MP4Error("no such property", "MP4SetTrackESConfiguration");
    }

    // lookup the property to store the configuration
    MP4BytesProperty* pInfoProperty = NULL;
    pConfigDescrProperty->FindProperty("decSpecificInfo[0].info",
        (MP4Property**)&pInfoProperty);

    // configuration being set for the first time
    if (pInfoProperty == NULL) {
        // need to create a new descriptor to hold it
        MP4Descriptor* pConfigDescr =
            pConfigDescrProperty->AddDescriptor(MP4DecSpecificDescrTag);
        pConfigDescr->Generate();

        pConfigDescrProperty->FindProperty(
            "decSpecificInfo[0].info",
            (MP4Property**)&pInfoProperty);
        ASSERT(pInfoProperty);
    }

    // set the value
    pInfoProperty->SetValue(pConfig, configSize);
}

const char* MP4File::GetHintTrackSdp(MP4TrackId hintTrackId)
{
    return GetTrackStringProperty(hintTrackId, "udta.hnti.sdp .sdpText");
}

void MP4File::SetHintTrackSdp(MP4TrackId hintTrackId, const char* sdpString)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4SetHintTrackSdp");
    }

    AddDescendantAtoms(
        MakeTrackName(hintTrackId, NULL), "udta.hnti.sdp ");

    SetTrackStringProperty(hintTrackId, "udta.hnti.sdp .sdpText", sdpString);
}

void MP4File::AppendHintTrackSdp(MP4TrackId hintTrackId,
    const char* sdpFragment)
{
    const char* oldSdpString = NULL;
    try {
        oldSdpString = GetHintTrackSdp(hintTrackId);
    }
    catch (MP4Error* e) {
        delete e;
        SetHintTrackSdp(hintTrackId, sdpFragment);
        return;
    }

    char* newSdpString =
        (char*)MP4Malloc(strlen(oldSdpString) + strlen(sdpFragment) + 1);
    strcpy(newSdpString, oldSdpString);
    strcat(newSdpString, sdpFragment);
    SetHintTrackSdp(hintTrackId, newSdpString);
    MP4Free(newSdpString);
}

void MP4File::GetHintTrackRtpPayload(
    MP4TrackId hintTrackId,
    char** ppPayloadName,
    u_int8_t* pPayloadNumber,
    u_int16_t* pMaxPayloadSize,
    char **ppEncodingParams)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4GetHintTrackRtpPayload");
    }

    ((MP4RtpHintTrack*)pTrack)->GetPayload(
        ppPayloadName, pPayloadNumber, pMaxPayloadSize, ppEncodingParams);
}

void MP4File::SetHintTrackRtpPayload(MP4TrackId hintTrackId,
    const char* payloadName, u_int8_t* pPayloadNumber, u_int16_t maxPayloadSize,
                     const char *encoding_params,
                     bool include_rtp_map,
                     bool include_mpeg4_esid)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4SetHintTrackRtpPayload");
    }

    u_int8_t payloadNumber;
    if (pPayloadNumber && *pPayloadNumber != MP4_SET_DYNAMIC_PAYLOAD) {
        payloadNumber = *pPayloadNumber;
    } else {
        payloadNumber = AllocRtpPayloadNumber();
        if (pPayloadNumber) {
            *pPayloadNumber = payloadNumber;
        }
    }

    ((MP4RtpHintTrack*)pTrack)->SetPayload(
        payloadName, payloadNumber, maxPayloadSize, encoding_params,
        include_rtp_map, include_mpeg4_esid);
}

u_int8_t MP4File::AllocRtpPayloadNumber()
{
    MP4Integer32Array usedPayloads;
    u_int32_t i;

    // collect rtp payload numbers in use by existing tracks
    for (i = 0; i < m_pTracks.Size(); i++) {
        MP4Atom* pTrakAtom = m_pTracks[i]->GetTrakAtom();

        MP4Integer32Property* pPayloadProperty = NULL;
        pTrakAtom->FindProperty("trak.udta.hinf.payt.payloadNumber",
            (MP4Property**)&pPayloadProperty);

        if (pPayloadProperty) {
            usedPayloads.Add(pPayloadProperty->GetValue());
        }
    }

    // search dynamic payload range for an available slot
    u_int8_t payload;
    for (payload = 96; payload < 128; payload++) {
        for (i = 0; i < usedPayloads.Size(); i++) {
            if (payload == usedPayloads[i]) {
                break;
            }
        }
        if (i == usedPayloads.Size()) {
            break;
        }
    }

    if (payload >= 128) {
        throw new MP4Error("no more available rtp payload numbers",
            "AllocRtpPayloadNumber");
    }

    return payload;
}

MP4TrackId MP4File::GetHintTrackReferenceTrackId(
    MP4TrackId hintTrackId)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4GetHintTrackReferenceTrackId");
    }

    MP4Track* pRefTrack = ((MP4RtpHintTrack*)pTrack)->GetRefTrack();

    if (pRefTrack == NULL) {
        return MP4_INVALID_TRACK_ID;
    }
    return pRefTrack->GetId();
}

void MP4File::ReadRtpHint(
    MP4TrackId hintTrackId,
    MP4SampleId hintSampleId,
    u_int16_t* pNumPackets)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track", "MP4ReadRtpHint");
    }
    ((MP4RtpHintTrack*)pTrack)->
        ReadHint(hintSampleId, pNumPackets);
}

u_int16_t MP4File::GetRtpHintNumberOfPackets(
    MP4TrackId hintTrackId)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4GetRtpHintNumberOfPackets");
    }
    return ((MP4RtpHintTrack*)pTrack)->GetHintNumberOfPackets();
}

int8_t MP4File::GetRtpPacketBFrame(
    MP4TrackId hintTrackId,
    u_int16_t packetIndex)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4GetRtpHintBFrame");
    }
    return ((MP4RtpHintTrack*)pTrack)->GetPacketBFrame(packetIndex);
}

int32_t MP4File::GetRtpPacketTransmitOffset(
    MP4TrackId hintTrackId,
    u_int16_t packetIndex)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4GetRtpPacketTransmitOffset");
    }
    return ((MP4RtpHintTrack*)pTrack)->GetPacketTransmitOffset(packetIndex);
}

void MP4File::ReadRtpPacket(
    MP4TrackId hintTrackId,
    u_int16_t packetIndex,
    u_int8_t** ppBytes,
    u_int32_t* pNumBytes,
    u_int32_t ssrc,
    bool includeHeader,
    bool includePayload)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track", "MP4ReadPacket");
    }
    ((MP4RtpHintTrack*)pTrack)->ReadPacket(
        packetIndex, ppBytes, pNumBytes,
        ssrc, includeHeader, includePayload);
}

MP4Timestamp MP4File::GetRtpTimestampStart(
    MP4TrackId hintTrackId)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4GetRtpTimestampStart");
    }
    return ((MP4RtpHintTrack*)pTrack)->GetRtpTimestampStart();
}

void MP4File::SetRtpTimestampStart(
    MP4TrackId hintTrackId,
    MP4Timestamp rtpStart)
{
    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4SetRtpTimestampStart");
    }
    ((MP4RtpHintTrack*)pTrack)->SetRtpTimestampStart(rtpStart);
}

void MP4File::AddRtpHint(MP4TrackId hintTrackId,
    bool isBframe, u_int32_t timestampOffset)
{
    ProtectWriteOperation("MP4AddRtpHint");

    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track", "MP4AddRtpHint");
    }
    ((MP4RtpHintTrack*)pTrack)->AddHint(isBframe, timestampOffset);
}

void MP4File::AddRtpPacket(
    MP4TrackId hintTrackId, bool setMbit, int32_t transmitOffset)
{
    ProtectWriteOperation("MP4AddRtpPacket");

    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track", "MP4AddRtpPacket");
    }
    ((MP4RtpHintTrack*)pTrack)->AddPacket(setMbit, transmitOffset);
}

void MP4File::AddRtpImmediateData(MP4TrackId hintTrackId,
    const u_int8_t* pBytes, u_int32_t numBytes)
{
    ProtectWriteOperation("MP4AddRtpImmediateData");

    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4AddRtpImmediateData");
    }
    ((MP4RtpHintTrack*)pTrack)->AddImmediateData(pBytes, numBytes);
}

void MP4File::AddRtpSampleData(MP4TrackId hintTrackId,
    MP4SampleId sampleId, u_int32_t dataOffset, u_int32_t dataLength)
{
    ProtectWriteOperation("MP4AddRtpSampleData");

    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetType(), MP4_HINT_TRACK_TYPE)) {
        throw new MP4Error("track is not a hint track",
            "MP4AddRtpSampleData");
    }
    ((MP4RtpHintTrack*)pTrack)->AddSampleData(
        sampleId, dataOffset, dataLength);
}

void MP4File::AddRtpESConfigurationPacket(MP4TrackId hintTrackId)
{
    ProtectWriteOperation("MP4AddRtpESConfigurationPacket");

    MP4Track* pTrack = m_pTracks[FindTrackIndex(hintTrackId)];

    if (strcmp(pTrack->GetT