Audio IMFTTransform:：ProcessOutput返回HE-AAC的MF_E_TRANSFORM_STREAM_CHANGE->；PCM 我尝试使用MediaFoundation转换将HE-AAC音频流（由LIVE55，RTP图书馆接收）转换成PCM（通过 WaveXXXX < /代码> Win32 API）播放。然而，目前我正在处理预先录制的数据包

当我调用

imfttransform:：ProcessOutput

时，它返回

MF\u E\u TRANSFORM\u STREAM\u CHANGE

。 中的文档表明，我应该确定正确的流类型，并再次调用

IMFTransform:：SetOutputType

但是，我无法确定

SetOutputType

的正确参数

作为参考，流的RTSP描述如下

m=audio 0 RTP/AVP 97
a=rtpmap:97 mpeg4-generic/16000/1
a=fmtp:97 streamtype=5; profile-level-id=15; mode=AAC-hbr; config=1408; 
  sizeLength=13; indexLength=3; indexDeltaLength=3; profile=1; bitrate=32000;

我的代码是（很抱歉长度太长；为简洁起见，错误处理已删除）

静态IMFMediaType*s_inputMediaType；
静态IMFMediaType*s_outputMediaType；
静态imf变换*s_变换；
静态DWORD s_输出采样；
静态void InitMFT（）
{
HRESULT res；
res=coinitializex（NULL，COINIT_APARTMENTTHREADED）；//可能应该在生产中使用threaded
#如果0
res=MFCreateMediaType（&inputMediaType）；
res=MFCreateMediaType（&outputMediaType）；
res=inputMediaType->SetGUID（MF\u MT\u MAJOR\u TYPE，MFMediaType\u Audio）；
res=inputMediaType->SetGUID（MF\u MT\u子类型，MFAudioFormat\u AAC）；
res=inputMediaType->SetUINT32（中频、音频、音频、电平指示，15）；
res=inputMediaType->SetUINT32（MF_MT_AAC_PAYLOAD_TYPE，1）；//音频数据传输流
res=outputMediaType->SetGUID（MF\u MT\u MAJOR\u TYPE，MFMediaType\u Audio）；
res=outputMediaType->SetGUID（MF\u MT\u子类型，MFAudioFormat\u PCM）；
res=outputMediaType->SetUINT32（MF\u MT\u样本大小，2）；
res=outputMediaType->SetUINT32（中频、音频、数字通道，2）；
res=outputMediaType->SetUINT32（每个采样的中频音频位，8*2）；
res=outputMediaType->SetUINT32（每秒音频采样数，8000）；
res=outputMediaType->SetUINT32（音频平均字节/秒，8000*2*2）；
#恩迪夫
CLSID*clsids=NULL；
UINT32 clsidCount=0；
MFT_寄存器_类型_信息输入类型={MFMediaType_音频，MEDIASUBTYPE_MPEG_HEAAC}；//无法搜索WAVE_格式_MPEG_HEAAC
MFT_寄存器_类型_信息输出类型={MFMediaType_音频，WAVE_格式_PCM}；//MEDIASUBTYPE_PCM不存在（但如果创建，可以搜索）
res=MFTEnum（MFT_类别_音频_解码器，0，
&输入类型，
NULL，//*&outputType，*///如果outputType不为NULL，则搜索失败
NULL，&clsids，&clsidCount）；
列表转码器（clsids、clsidCount）；
res=CoCreateInstance（clsids[0]，NULL，CLSCTX_ALL，IID_PPV_ARGS（&s_transform））；
/*GetStreamCount和GetStreamId始终返回E_NOTIMPL*/
DWORD输入计数；
DWORD输出计数；
res=s\u transform->GetStreamCount（&inputCount，&outputCount）；
DWORD inputIDs[16]；
DWORD输出[16]；
res=s_transform->getStreamId（inputCount，InputId，
输出计数，输出数）；
res=s_transform->GetInputAvailableType（0、0和s_inputMediaType）；
res=s_transform->SetInputType（0，s_inputMediaType，0）；
res=s_transform->GetOutputAvailableType（0，1，&s_outputMediaType）；//这里是因为PCM outputer是ListTranscoder中提供的第二个输出
res=s_transform->SetOutputType（0，s_outputMediaType，0）；
MFT_输出_流_信息输出流信息；
res=s_transform->GetOutputStreamInfo（0，&outputStreamInfo）；
s_outputSampleSize=outputStreamInfo.cbSize；
GUID输入编解码器；
GUID输出编解码器；
res=s\u inputMediaType->GetGUID（MF\u MT\u子类型和inputCodec）；
res=s\u outputMediaType->GetGUID（MF\u MT\u子类型和outputCodec）；
CoTaskMemFree（clsids）；
}
/*
http://msdn.microsoft.com/en-us/library/bb530106%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/bb530123%28v=vs.85%29.aspx
*/
void ProcessData（const void*inputData，DWORD inputSize，
void*outputData、DWORD和outputSize）
{
HRESULT res；
IMFSample*pSample；
IMFMediaBuffer*pBuffer；
字节*pData=NULL；
/****根据提供的数据创建输入样本缓冲区****/
res=MFCreateSample（&pSample）；
res=MFCreateMemoryBuffer（inputSize和pBuffer）；
res=pBuffer->Lock（&pData，NULL，NULL）；
memcpy_s（pData、inputSize、inputData、inputSize）；
res=pBuffer->SetCurrentLength（inputSize）；
res=pBuffer->Unlock（）；
res=pSample->AddBuffer（pBuffer）；
/****创建输出缓冲区****/
IMFSample*PUTPUTSAMPLE；
IMFMediaBuffer*pOutputBuffer；
res=MFCreateSample（&pOutputSample）；
res=MFCreateMemoryBuffer（s_outputSampleSize和pOutputBuffer）；
res=pOutputSample->AddBuffer（pOutputBuffer）；
MFT_OUTPUT_DATA_BUFFER outputDataBuffer；//可以是数组
outputDataBuffer.dwStreamID=0；
outputDataBuffer.pSample=pOutputSample；
outputDataBuffer.dwStatus=0；
outputDataBuffer.pEvents=NULL；
DWORD输出状态=0；
/***处理数据，并将其取回****/
res=s_transform->ProcessInput（0，pSample，0）；
res=s_transform->ProcessOutput（MFT_PROCESS_OUTPUT_DISCARD_当没有缓冲区时，
1、&outputDataBuffer、&outputStatus）；
if（res==MF\u E\u变换\u流\u变化）
{
// http://msdn.microsoft.com/en-us/library/windows/desktop/dd797815%28v=vs.85%29.aspx
//指示输出始终更改
//但不是怎么处理
/*GetStreamCount和GetStreamId始终返回E_NOTIMPL*/
DWORD输入计数；
DWORD输出计数；
res=s\u transform->GetStreamCount（&inputCount，&outputCount）；
DWORD inputIDs[16]；
DWORD输出[16]；
res=s_transform->getStreamId（inputCount，InputId，
输出计数，输出数）；
res=s_transform->GetInputAvailableType（0、0和s_inputMediaType）；
static IMFMediaType *s_inputMediaType;
static IMFMediaType *s_outputMediaType;
static IMFTransform *s_transform;
static DWORD         s_outputSampleSize;

static void InitMFT()
{
    HRESULT res;
    res = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED); // probably should use threaded in production
#if 0
    res = MFCreateMediaType(&inputMediaType);
    res = MFCreateMediaType(&outputMediaType);

    res = inputMediaType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Audio);
    res = inputMediaType->SetGUID(MF_MT_SUBTYPE, MFAudioFormat_AAC);
    res = inputMediaType->SetUINT32(MF_MT_AAC_AUDIO_PROFILE_LEVEL_INDICATION, 15);
    res = inputMediaType->SetUINT32(MF_MT_AAC_PAYLOAD_TYPE, 1); // Audio Data Transport Stream

    res = outputMediaType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Audio);
    res = outputMediaType->SetGUID(MF_MT_SUBTYPE, MFAudioFormat_PCM);
    res = outputMediaType->SetUINT32(MF_MT_SAMPLE_SIZE, 2);
    res = outputMediaType->SetUINT32(MF_MT_AUDIO_NUM_CHANNELS, 2);
    res = outputMediaType->SetUINT32(MF_MT_AUDIO_BITS_PER_SAMPLE, 8 * 2);
    res = outputMediaType->SetUINT32(MF_MT_AUDIO_SAMPLES_PER_SECOND, 8000);
    res = outputMediaType->SetUINT32(MF_MT_AUDIO_AVG_BYTES_PER_SECOND, 8000 * 2 *2);
#endif
    CLSID *clsids = NULL;
    UINT32 clsidCount=0;

    MFT_REGISTER_TYPE_INFO inputType  = {MFMediaType_Audio, MEDIASUBTYPE_MPEG_HEAAC}; // WAVE_FORMAT_MPEG_HEAAC can't be searched for
    MFT_REGISTER_TYPE_INFO outputType = {MFMediaType_Audio, WAVE_FORMAT_PCM};         // MEDIASUBTYPE_PCM doesn't exist (but can be search for if created)

    res = MFTEnum(MFT_CATEGORY_AUDIO_DECODER, 0,
                  &inputType,
                  NULL, /* &outputType, */ // search fails if outputType is not NULL
                  NULL, &clsids, &clsidCount);

    ListTranscoders(clsids, clsidCount);

    res = CoCreateInstance(clsids[0], NULL, CLSCTX_ALL, IID_PPV_ARGS(&s_transform));

    /* GetStreamCount and GetStreamIDs always return E_NOTIMPL */
    DWORD inputCount;
    DWORD outputCount;
    res = s_transform->GetStreamCount(&inputCount, &outputCount);

    DWORD inputIDs[16];
    DWORD outputIDs[16];

    res = s_transform->GetStreamIDs(inputCount, inputIDs,
                                  outputCount, outputIDs);

    res = s_transform->GetInputAvailableType(0, 0, &s_inputMediaType);
    res = s_transform->SetInputType(0, s_inputMediaType, 0);

    res = s_transform->GetOutputAvailableType(0, 1, &s_outputMediaType); // 1 here is because PCM outputer is the second output offered in ListTranscoders
    res = s_transform->SetOutputType(0, s_outputMediaType, 0);

    MFT_OUTPUT_STREAM_INFO outputStreamInfo;
    res = s_transform->GetOutputStreamInfo(0, &outputStreamInfo); 
    s_outputSampleSize = outputStreamInfo.cbSize;

    GUID inputCodec;
    GUID outputCodec;

    res = s_inputMediaType ->GetGUID(MF_MT_SUBTYPE, &inputCodec);
    res = s_outputMediaType->GetGUID(MF_MT_SUBTYPE, &outputCodec);

    CoTaskMemFree(clsids);
}

/*
http://msdn.microsoft.com/en-us/library/bb530106%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/bb530123%28v=vs.85%29.aspx
*/

void ProcessData(const void* inputData,  DWORD inputSize,
                       void* outputData, DWORD &outputSize)
{
    HRESULT         res;
    IMFSample      *pSample;
    IMFMediaBuffer *pBuffer;
    BYTE *pData = NULL;

    /**** Create an input sample buffer, from the supplied data ****/
    res = MFCreateSample(&pSample);
    res = MFCreateMemoryBuffer(inputSize, &pBuffer);
    res = pBuffer->Lock(&pData, NULL, NULL);
    memcpy_s(pData, inputSize, inputData, inputSize);
    res = pBuffer->SetCurrentLength(inputSize);
    res = pBuffer->Unlock();
    res = pSample->AddBuffer(pBuffer);

    /**** Create output buffer ****/
    IMFSample      *pOutputSample;
    IMFMediaBuffer *pOutputBuffer;

    res = MFCreateSample(&pOutputSample);
    res = MFCreateMemoryBuffer(s_outputSampleSize, &pOutputBuffer);
    res = pOutputSample->AddBuffer(pOutputBuffer);

    MFT_OUTPUT_DATA_BUFFER outputDataBuffer; // can be an array
    outputDataBuffer.dwStreamID=0;
    outputDataBuffer.pSample=pOutputSample;
    outputDataBuffer.dwStatus=0;
    outputDataBuffer.pEvents = NULL;

    DWORD outputStatus=0;

    /*** Process the data, and get it back ****/
    res = s_transform->ProcessInput(0, pSample, 0);
    res = s_transform->ProcessOutput( MFT_PROCESS_OUTPUT_DISCARD_WHEN_NO_BUFFER, 
                                   1, &outputDataBuffer, &outputStatus);


    if (res==MF_E_TRANSFORM_STREAM_CHANGE)
    {
        // http://msdn.microsoft.com/en-us/library/windows/desktop/dd797815%28v=vs.85%29.aspx
        // indicates that the output always changes
        // but not how to handle it

        /* GetStreamCount and GetStreamIDs always return E_NOTIMPL */

        DWORD inputCount;
        DWORD outputCount;
        res = s_transform->GetStreamCount(&inputCount, &outputCount);

        DWORD inputIDs[16];
        DWORD outputIDs[16];

        res = s_transform->GetStreamIDs(inputCount, inputIDs,
                                      outputCount, outputIDs);

        res = s_transform->GetInputAvailableType(0, 0, &s_inputMediaType);
        res = s_transform->SetInputType(0, s_inputMediaType, 0);

        res = s_transform->GetOutputAvailableType(0, 1, &s_outputMediaType); // 1 here is because PCM outputer is the second output offered
        res = s_transform->SetOutputType(0, s_outputMediaType, 0);
    }

    /**** Extract converted audio from the sample ****/
    DWORD dwNumOutputBuffers, i;
    res = outputDataBuffer.pSample->GetBufferCount(&dwNumOutputBuffers);

    for(i=0; i<dwNumOutputBuffers; i++)
    {
        IMFMediaBuffer *outputBuffer;
        res = outputDataBuffer.pSample->GetBufferByIndex(i, &outputBuffer);
        BYTE *outData;
        DWORD outDataLen = 0;

        res = outputBuffer->Lock(&outData, NULL, &outDataLen);

        memcpy(outputBuffer, outData, outDataLen);

        res = outputBuffer->Unlock();
    }

    /* TODO: Release any neccessery references */
}

res = s_transform->GetOutputAvailableType(0, 1, &s_outputMediaType); // 1 here is because PCM outputer is the second output offered
    GUID outputCodec;
    res = s_outputMediaType->GetGUID(MF_MT_SUBTYPE, &outputCodec);
    if (outputCodec == MFAudioFormat_PCM){
        printf("\nDecoder Output is expecting pcm format");                 
        res = s_transform->SetOutputType(0, s_outputMediaType, 0);//setting the type again

    }
    if (outputCodec == MFAudioFormat_Float){
        printf("\nDecoder Output is expecting float pcm format");
    }
    s_transform->ProcessMessage(MFT_MESSAGE_COMMAND_FLUSH,NULL);        

    return res;//no output coming get another input to process.