在 ffplay 中獲得綠屏：使用 Live555 通過 RTP stream 將流式桌面（DirectX 表面）作為 H264 視頻

Question

I'm trying to stream the desktop(DirectX surface in NV12 format) as H264 video over RTP stream using Live555 & Windows media foundation's hardware encoder on Windows10, and expecting it to be rendered by ffplay (ffmpeg 4.2). 但只得到一個像下面這樣的綠屏，

我參考了 MFWebCamToRTP mediafoundation-sample & Encoding DirectX surface using hardware MFT來實現 live555 的 FramedSource 並將輸入源更改為 DirectX surface 而不是 webCam。

這是我對 Live555 的 doGetNextFrame 回調的實現的摘錄，以從 directX 表面提供輸入樣本：

virtual void doGetNextFrame()
{
    if (!_isInitialised)
    {
        if (!initialise()) {
            printf("Video device initialisation failed, stopping.");
            return;
        }
        else {
            _isInitialised = true;
        }
    }

    //if (!isCurrentlyAwaitingData()) return;

    DWORD processOutputStatus = 0;
    HRESULT mftProcessOutput = S_OK;
    MFT_OUTPUT_STREAM_INFO StreamInfo;
    IMFMediaBuffer *pBuffer = NULL;
    IMFSample *mftOutSample = NULL;
    DWORD mftOutFlags;
    bool frameSent = false;
    bool bTimeout = false;

    // Create sample
    CComPtr<IMFSample> videoSample = NULL;

    // Create buffer
    CComPtr<IMFMediaBuffer> inputBuffer;
    // Get next event
    CComPtr<IMFMediaEvent> event;
    HRESULT hr = eventGen->GetEvent(0, &event);
    CHECK_HR(hr, "Failed to get next event");

    MediaEventType eventType;
    hr = event->GetType(&eventType);
    CHECK_HR(hr, "Failed to get event type");


    switch (eventType)
    {
    case METransformNeedInput:
        {
            hr = MFCreateDXGISurfaceBuffer(__uuidof(ID3D11Texture2D), surface, 0, FALSE, &inputBuffer);
            CHECK_HR(hr, "Failed to create IMFMediaBuffer");

            hr = MFCreateSample(&videoSample);
            CHECK_HR(hr, "Failed to create IMFSample");
            hr = videoSample->AddBuffer(inputBuffer);
            CHECK_HR(hr, "Failed to add buffer to IMFSample");

            if (videoSample)
            {
                _frameCount++;

                CHECK_HR(videoSample->SetSampleTime(mTimeStamp), "Error setting the video sample time.\n");
                CHECK_HR(videoSample->SetSampleDuration(VIDEO_FRAME_DURATION), "Error getting video sample duration.\n");

                // Pass the video sample to the H.264 transform.

                hr = _pTransform->ProcessInput(inputStreamID, videoSample, 0);
                CHECK_HR(hr, "The resampler H264 ProcessInput call failed.\n");

                mTimeStamp += VIDEO_FRAME_DURATION;
            }
        }

        break;

    case METransformHaveOutput:

        {
            CHECK_HR(_pTransform->GetOutputStatus(&mftOutFlags), "H264 MFT GetOutputStatus failed.\n");

            if (mftOutFlags == MFT_OUTPUT_STATUS_SAMPLE_READY)
            {
                MFT_OUTPUT_DATA_BUFFER _outputDataBuffer;
                memset(&_outputDataBuffer, 0, sizeof _outputDataBuffer);
                _outputDataBuffer.dwStreamID = outputStreamID;
                _outputDataBuffer.dwStatus = 0;
                _outputDataBuffer.pEvents = NULL;
                _outputDataBuffer.pSample = nullptr;

                mftProcessOutput = _pTransform->ProcessOutput(0, 1, &_outputDataBuffer, &processOutputStatus);

                if (mftProcessOutput != MF_E_TRANSFORM_NEED_MORE_INPUT)
                {
                    if (_outputDataBuffer.pSample) {

                        //CHECK_HR(_outputDataBuffer.pSample->SetSampleTime(mTimeStamp), "Error setting MFT sample time.\n");
                        //CHECK_HR(_outputDataBuffer.pSample->SetSampleDuration(VIDEO_FRAME_DURATION), "Error setting MFT sample duration.\n");

                        IMFMediaBuffer *buf = NULL;
                        DWORD bufLength;
                        CHECK_HR(_outputDataBuffer.pSample->ConvertToContiguousBuffer(&buf), "ConvertToContiguousBuffer failed.\n");
                        CHECK_HR(buf->GetCurrentLength(&bufLength), "Get buffer length failed.\n");
                        BYTE * rawBuffer = NULL;

                        fFrameSize = bufLength;
                        fDurationInMicroseconds = 0;
                        gettimeofday(&fPresentationTime, NULL);

                        buf->Lock(&rawBuffer, NULL, NULL);
                        memmove(fTo, rawBuffer, fFrameSize);

                        FramedSource::afterGetting(this);

                        buf->Unlock();
                        SafeRelease(&buf);

                        frameSent = true;
                        _lastSendAt = GetTickCount();

                        _outputDataBuffer.pSample->Release();
                    }

                    if (_outputDataBuffer.pEvents)
                        _outputDataBuffer.pEvents->Release();
                }

                //SafeRelease(&pBuffer);
                //SafeRelease(&mftOutSample);

                break;
            }
        }

        break;
    }

    if (!frameSent)
    {
        envir().taskScheduler().triggerEvent(eventTriggerId, this);
    }

    return;

done:

    printf("MediaFoundationH264LiveSource doGetNextFrame failed.\n");
    envir().taskScheduler().triggerEvent(eventTriggerId, this);
}

初始化方法：

bool initialise()
{
    HRESULT hr;
    D3D11_TEXTURE2D_DESC desc = { 0 };

    HDESK CurrentDesktop = nullptr;
    CurrentDesktop = OpenInputDesktop(0, FALSE, GENERIC_ALL);
    if (!CurrentDesktop)
    {
        // We do not have access to the desktop so request a retry
        return false;
    }

    // Attach desktop to this thread
    bool DesktopAttached = SetThreadDesktop(CurrentDesktop) != 0;
    CloseDesktop(CurrentDesktop);
    CurrentDesktop = nullptr;
    if (!DesktopAttached)
    {
        printf("SetThreadDesktop failed\n");
    }

    UINT32 activateCount = 0;

    // h264 output
    MFT_REGISTER_TYPE_INFO info = { MFMediaType_Video, MFVideoFormat_H264 };

    UINT32 flags =
        MFT_ENUM_FLAG_HARDWARE |
        MFT_ENUM_FLAG_SORTANDFILTER;

    // ------------------------------------------------------------------------
    // Initialize D3D11
    // ------------------------------------------------------------------------

    // Driver types supported
    D3D_DRIVER_TYPE DriverTypes[] =
    {
        D3D_DRIVER_TYPE_HARDWARE,
        D3D_DRIVER_TYPE_WARP,
        D3D_DRIVER_TYPE_REFERENCE,
    };
    UINT NumDriverTypes = ARRAYSIZE(DriverTypes);

    // Feature levels supported
    D3D_FEATURE_LEVEL FeatureLevels[] =
    {
        D3D_FEATURE_LEVEL_11_0,
        D3D_FEATURE_LEVEL_10_1,
        D3D_FEATURE_LEVEL_10_0,
        D3D_FEATURE_LEVEL_9_1
    };
    UINT NumFeatureLevels = ARRAYSIZE(FeatureLevels);

    D3D_FEATURE_LEVEL FeatureLevel;

    // Create device
    for (UINT DriverTypeIndex = 0; DriverTypeIndex < NumDriverTypes; ++DriverTypeIndex)
    {
        hr = D3D11CreateDevice(nullptr, DriverTypes[DriverTypeIndex], nullptr,
            D3D11_CREATE_DEVICE_VIDEO_SUPPORT,
            FeatureLevels, NumFeatureLevels, D3D11_SDK_VERSION, &device, &FeatureLevel, &context);
        if (SUCCEEDED(hr))
        {
            // Device creation success, no need to loop anymore
            break;
        }
    }

    CHECK_HR(hr, "Failed to create device");

    // Create device manager
    UINT resetToken;
    hr = MFCreateDXGIDeviceManager(&resetToken, &deviceManager);
    CHECK_HR(hr, "Failed to create DXGIDeviceManager");

    hr = deviceManager->ResetDevice(device, resetToken);
    CHECK_HR(hr, "Failed to assign D3D device to device manager");


    // ------------------------------------------------------------------------
    // Create surface
    // ------------------------------------------------------------------------
    desc.Format = DXGI_FORMAT_NV12;
    desc.Width = surfaceWidth;
    desc.Height = surfaceHeight;
    desc.MipLevels = 1;
    desc.ArraySize = 1;
    desc.SampleDesc.Count = 1;

    hr = device->CreateTexture2D(&desc, NULL, &surface);
    CHECK_HR(hr, "Could not create surface");

    hr = MFTEnumEx(
        MFT_CATEGORY_VIDEO_ENCODER,
        flags,
        NULL,
        &info,
        &activateRaw,
        &activateCount
    );
    CHECK_HR(hr, "Failed to enumerate MFTs");

    CHECK(activateCount, "No MFTs found");

    // Choose the first available encoder
    activate = activateRaw[0];

    for (UINT32 i = 0; i < activateCount; i++)
        activateRaw[i]->Release();

    // Activate
    hr = activate->ActivateObject(IID_PPV_ARGS(&_pTransform));
    CHECK_HR(hr, "Failed to activate MFT");

    // Get attributes
    hr = _pTransform->GetAttributes(&attributes);
    CHECK_HR(hr, "Failed to get MFT attributes");

    // Unlock the transform for async use and get event generator
    hr = attributes->SetUINT32(MF_TRANSFORM_ASYNC_UNLOCK, TRUE);
    CHECK_HR(hr, "Failed to unlock MFT");

    eventGen = _pTransform;
    CHECK(eventGen, "Failed to QI for event generator");

    // Get stream IDs (expect 1 input and 1 output stream)
    hr = _pTransform->GetStreamIDs(1, &inputStreamID, 1, &outputStreamID);
    if (hr == E_NOTIMPL)
    {
        inputStreamID = 0;
        outputStreamID = 0;
        hr = S_OK;
    }
    CHECK_HR(hr, "Failed to get stream IDs");

     // ------------------------------------------------------------------------
    // Configure hardware encoder MFT
   // ------------------------------------------------------------------------
    CHECK_HR(_pTransform->ProcessMessage(MFT_MESSAGE_SET_D3D_MANAGER, reinterpret_cast<ULONG_PTR>(deviceManager.p)), "Failed to set device manager.\n");

    // Set low latency hint
    hr = attributes->SetUINT32(MF_LOW_LATENCY, TRUE);
    CHECK_HR(hr, "Failed to set MF_LOW_LATENCY");

    hr = MFCreateMediaType(&outputType);
    CHECK_HR(hr, "Failed to create media type");

    hr = outputType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video);
    CHECK_HR(hr, "Failed to set MF_MT_MAJOR_TYPE on H264 output media type");

    hr = outputType->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_H264);
    CHECK_HR(hr, "Failed to set MF_MT_SUBTYPE on H264 output media type");

    hr = outputType->SetUINT32(MF_MT_AVG_BITRATE, TARGET_AVERAGE_BIT_RATE);
    CHECK_HR(hr, "Failed to set average bit rate on H264 output media type");

    hr = MFSetAttributeSize(outputType, MF_MT_FRAME_SIZE, desc.Width, desc.Height);
    CHECK_HR(hr, "Failed to set frame size on H264 MFT out type");

    hr = MFSetAttributeRatio(outputType, MF_MT_FRAME_RATE, TARGET_FRAME_RATE, 1);
    CHECK_HR(hr, "Failed to set frame rate on H264 MFT out type");

    hr = outputType->SetUINT32(MF_MT_INTERLACE_MODE, 2);
    CHECK_HR(hr, "Failed to set MF_MT_INTERLACE_MODE on H.264 encoder MFT");

    hr = outputType->SetUINT32(MF_MT_ALL_SAMPLES_INDEPENDENT, TRUE);
    CHECK_HR(hr, "Failed to set MF_MT_ALL_SAMPLES_INDEPENDENT on H.264 encoder MFT");

    hr = _pTransform->SetOutputType(outputStreamID, outputType, 0);
    CHECK_HR(hr, "Failed to set output media type on H.264 encoder MFT");

    hr = MFCreateMediaType(&inputType);
    CHECK_HR(hr, "Failed to create media type");

    for (DWORD i = 0;; i++)
    {
        inputType = nullptr;
        hr = _pTransform->GetInputAvailableType(inputStreamID, i, &inputType);
        CHECK_HR(hr, "Failed to get input type");

        hr = inputType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video);
        CHECK_HR(hr, "Failed to set MF_MT_MAJOR_TYPE on H264 MFT input type");

        hr = inputType->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_NV12);
        CHECK_HR(hr, "Failed to set MF_MT_SUBTYPE on H264 MFT input type");

        hr = MFSetAttributeSize(inputType, MF_MT_FRAME_SIZE, desc.Width, desc.Height);
        CHECK_HR(hr, "Failed to set MF_MT_FRAME_SIZE on H264 MFT input type");

        hr = MFSetAttributeRatio(inputType, MF_MT_FRAME_RATE, TARGET_FRAME_RATE, 1);
        CHECK_HR(hr, "Failed to set MF_MT_FRAME_RATE on H264 MFT input type");

        hr = _pTransform->SetInputType(inputStreamID, inputType, 0);
        CHECK_HR(hr, "Failed to set input type");

        break;
    }

    CheckHardwareSupport();

    CHECK_HR(_pTransform->ProcessMessage(MFT_MESSAGE_COMMAND_FLUSH, NULL), "Failed to process FLUSH command on H.264 MFT.\n");
    CHECK_HR(_pTransform->ProcessMessage(MFT_MESSAGE_NOTIFY_BEGIN_STREAMING, NULL), "Failed to process BEGIN_STREAMING command on H.264 MFT.\n");
    CHECK_HR(_pTransform->ProcessMessage(MFT_MESSAGE_NOTIFY_START_OF_STREAM, NULL), "Failed to process START_OF_STREAM command on H.264 MFT.\n");

    return true;

done:

    printf("MediaFoundationH264LiveSource initialisation failed.\n");
    return false;
}


    HRESULT CheckHardwareSupport()
    {
        IMFAttributes *attributes;
        HRESULT hr = _pTransform->GetAttributes(&attributes);
        UINT32 dxva = 0;

        if (SUCCEEDED(hr))
        {
            hr = attributes->GetUINT32(MF_SA_D3D11_AWARE, &dxva);
        }

        if (SUCCEEDED(hr))
        {
            hr = attributes->SetUINT32(CODECAPI_AVDecVideoAcceleration_H264, TRUE);
        }

#if defined(CODECAPI_AVLowLatencyMode) // Win8 only

        hr = _pTransform->QueryInterface(IID_PPV_ARGS(&mpCodecAPI));

        if (SUCCEEDED(hr))
        {
            VARIANT var = { 0 };

            // FIXME: encoder only
            var.vt = VT_UI4;
            var.ulVal = 0;

            hr = mpCodecAPI->SetValue(&CODECAPI_AVEncMPVDefaultBPictureCount, &var);

            var.vt = VT_BOOL;
            var.boolVal = VARIANT_TRUE;
            hr = mpCodecAPI->SetValue(&CODECAPI_AVEncCommonLowLatency, &var);
            hr = mpCodecAPI->SetValue(&CODECAPI_AVEncCommonRealTime, &var);

            hr = attributes->SetUINT32(CODECAPI_AVLowLatencyMode, TRUE);

            if (SUCCEEDED(hr))
            {
                var.vt = VT_UI4;
                var.ulVal = eAVEncCommonRateControlMode_Quality;
                hr = mpCodecAPI->SetValue(&CODECAPI_AVEncCommonRateControlMode, &var);

                // This property controls the quality level when the encoder is not using a constrained bit rate. The AVEncCommonRateControlMode property determines whether the bit rate is constrained.
                VARIANT quality;
                InitVariantFromUInt32(50, &quality);
                hr = mpCodecAPI->SetValue(&CODECAPI_AVEncCommonQuality, &quality);
            }
        }
#endif

        return hr;
    }

ffplay 命令：

ffplay -protocol_whitelist file,udp,rtp -i test.sdp -x 800 -y 600 -profile:v baseline

發展規划署：

v=0
o=- 0 0 IN IP4 127.0.0.1
s=No Name
t=0 0
c=IN IP4 127.0.0.1
m=video 1234 RTP/AVP 96
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1

我不知道我錯過了什么，我已經嘗試解決這個問題將近一個星期沒有任何進展，並且嘗試了幾乎所有我能做的事情。 此外，用於將 DirectX 表面編碼為視頻的在線資源非常有限。

任何幫助，將不勝感激。

Answer 1

這比看起來更難。

如果你想像你一樣使用編碼器，通過直接調用IMFTransform接口，你必須將RGB幀轉換為NV12。 如果你想要好的性能，你應該在 GPU 上做。 可以使用像素着色器，渲染 2 幀，全尺寸一到 DXGI_FORMAT_R8_UNORM 渲染目標的亮度，半尺寸到 DXGI_FORMAT_R8G8_UNORM 目標的顏色，並寫入兩個像素着色器以產生 NV12 值。 兩個渲染目標都可以渲染到相同 NV12 紋理的 2 個平面中，但僅從 Windows 8 開始。

其他方法是使用sink writer 。 它可以同時托管多個 MFT，因此您可以在 VRAM 中提供 RGB 紋理，接收器寫入器將首先使用一個 MFT 將它們轉換為 NV12（這可能是由 GPU 驅動程序實現的專有硬件，就像編碼器一樣），然后傳遞給編碼器 MFT。 編碼成 mp4 文件相對容易，使用MFCreateSinkWriterFromURL API 來創建 writer。 但是，從接收器寫入器中獲取原始樣本要困難得多，您必須實現自定義媒體接收器，自定義 stream 接收器的視頻 stream 接收器，並調用MFCreateSinkWriterFromMediaSink來創建寫入器。

還有更多。

無論采用何種編碼方法，您都不能重用幀紋理。 從 DD 獲得的每一幀，都應該創建一個新紋理並將其傳遞給 MF。

視頻編碼器期望恆定的幀速率。 DD 不會給你那個，它每次屏幕上發生變化時都會給你一個框架。 如果您有游戲顯示器，則可以為 144 FPS，如果唯一的變化是閃爍 cursor，則可以為 2 FPS。 理想情況下，您應該以視頻媒體類型中指定的恆定幀速率向 MF 提交幀。

如果您想將 stream 聯網，通常您還必須提供參數集。 除非您使用的 Intel 硬件 h265 編碼器已損壞且 Intel 沒有評論，否則MF 通過調用 IMFMediaTypeHandler 接口上的 SetCurrentMediaType 為您提供媒體類型的MF_MT_MPEG_SEQUENCE_HEADER 屬性中的數據。 您可以實現該接口以獲得通知。 您只有在開始編碼后才能獲得該數據。 那就是如果您使用接收器編寫器，對於IMFTransform方法更容易，您應該從ProcessOutput方法獲取MF_E_TRANSFORM_STREAM_CHANGE代碼，然后調用GetOutputAvailableType以使用該魔法 blob 獲取更新的媒體類型。

Answer 2

由於ffplay抱怨 stream 參數，我認為它無法獲取 SPS/PPS。 您尚未在硬編碼的 SDP 中設置它們 - 請參閱RFC-3984並查找sprop-parameter-sets 。 來自 RFC 的一個示例：

m=視頻 49170 RTP/AVP 98
a=rtpmap:98 H264/90000
a=fmtp:98 profile-level-id=42A01E;sprop-parameter-sets=Z0IACpZTBYmI,aMljiA==

我強烈認為ffplay在 SDP 中期待這些。 我不記得如何從媒體基礎編碼器中獲取 SPS/PPS，但是它們都在示例有效負載中，您需要通過查找正確的 NAL 單元來提取它們，或者谷歌如何從編碼器 - 我得到的第一個打擊看起來很有希望。

Answer 3

Soonts 為您提供所有必要的東西來解決您的問題。

您需要做的第一件事是在 DXGI_FORMAT_B8G8R8A8_UNORM 和 MFVideoFormat_NV12 之間進行格式轉換：

格式轉換信息

我覺得最好用shader來做格式轉換，因為所有的貼圖都會留在GPU（性能更好）。

這是您需要做的第一步。 您將有其他人來改進您的程序。