在ffplay中出现绿屏：使用Live555将桌面（DirectX表面）作为H264视频流传输到RTP流时。

Question

在ffplay中出现绿屏：使用Live555将桌面（DirectX表面）作为H264视频流传输到RTP流时。

ffmpegvideo-streamingdirectxh.264ms-media-foundation

10

我正在尝试使用Live555和Windows媒体基础架构的硬件编码器，在Windows10上以H264视频的形式通过RTP流来流式传输桌面（NV12格式的DirectX表面），并期望它能被ffplay（ffmpeg 4.2）渲染。但是只能得到如下所示的绿色屏幕。

我参考了MFWebCamToRTP媒体基础库示例和使用硬件MFT编码DirectX表面来实现Live555的FramedSource，并将输入源更改为DirectX表面而不是WebCam。

以下是我实现Live555的doGetNextFrame回调函数以从DirectX表面提供输入样本的摘录：

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

SDP:

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

我不知道我错过了什么，我已经尝试了将近一周的时间来修复它，但没有任何进展，并且几乎尝试了所有可能的方法。此外，有关将DirectX表面编码为视频的在线资源非常有限。

如果能得到任何帮助将不胜感激。

- iamrameshkumar

1

我认为你错误地期望在METransformNeedInput之后再次调用doGetNextFrame。也许你应该在其中循环，直到得到有效的ProcessOutput调用。 - VuVirt

hr = event->GetType(&eventType);switch(eventType) {....}如果没有发送帧，则使用envir().taskScheduler().triggerEvent(eventTriggerId, this);触发事件。以上两个块很好地处理了调用ProcessInput，直到我们从编码器获得输出。我已经验证过了。@VuVirt - iamrameshkumar

1

您可能需要检查是否从ProcessOutput接收到MF_E_TRANSFORM_STREAM_CHANGE，并相应地处理格式更改。 - VuVirt

这是否意味着编码器和渲染器正常工作，但问题可能出在图像源（DirectX表面）上？ - iamrameshkumar

是的，可以尝试解码并显示它。 - VuVirt

显示剩余3条评论

3个回答

1

我会尽力为您提供解决问题所需的一切。

首先，您需要进行DXGI_FORMAT_B8G8R8A8_UNORM和MFVideoFormat_NV12之间的格式转换：

格式转换信息

我认为使用着色器进行格式转换更好，因为所有纹理都将留在GPU中（对性能更好）。

这是你需要做的第一步。你会有其他方法来改进你的程序。

- mofo77

1

2x4图像在NV12格式下只占用12字节而不是24字节：由于该图只有1x2像素，比灰度图像小一倍，因此只需要4个字节来存储彩色信息，在这里你有8个亮度值，所以U和V分别需要2个字节。 - Soonts

是的，你说得对，我忽略了将 NV12 格式的下采样设置为 4:2:0。我会尝试制作一个更适合的图表。 - mofo77

1

由于ffplay抱怨流参数，我认为它无法捕获SPS/PPS。您没有在硬编码的SDP中设置它们-请参见RFC-3984并查找sprop-parameter-sets。来自RFC的示例：

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

我强烈认为 ffplay 期望在SDP中收到这些内容。我不记得如何从媒体基础编码器中获取SPS/PPS，但是它们可能在样本负载中，您需要通过查找正确的NAL单元来提取它们，或者搜索如何从编码器中提取额外数据 - 我得到的第一个 hit 看起来很有希望。

- Rudolfs Bundulis

这是一个有道理的观点。我也怀疑SPS/PPS。不过我还没有验证它。感谢您指引我到MSDN线程，给了我一些希望。 - iamrameshkumar

@Ram，有很大的可能性样本负载中包含SPS/PPS，所以我建议先检查一下。 - Rudolfs Bundulis

是的，我明白。当我尝试通过Mpeg4MediaSink将样本写入文件时，我已经掌握了直接从媒体基础编码器中检索和解析SPS/PPS的一些知识。我会朝着这个方向继续前进。 - iamrameshkumar

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Soonts · Accepted Answer

这比看起来要难。

如果您想像现在这样使用编码器，通过直接调用IMFTransform接口，您需要将RGB帧转换为NV12格式。如果您想要良好的性能，最好在GPU上进行转换。可以使用像素着色器完成此操作，将一个全尺寸带亮度的帧渲染到DXGI_FORMAT_R8_UNORM渲染目标中，将一个半尺寸带颜色的帧渲染到DXGI_FORMAT_R8G8_UNORM目标中，并编写两个像素着色器以生成NV12值。两个渲染目标都可以渲染到同一NV12纹理的2个平面上，但仅适用于Windows 8及以上版本。

另一种方法是使用 sink writer。它可以同时托管多个MFT，因此您可以在VRAM中提供RGB纹理，然后sink writer将首先使用一个MFT（很可能是由GPU驱动程序实现的专有硬件MFT，就像编码器一样）将其转换为NV12，然后传递给编码器MFT。相对而言，将其编码为mp4文件比较容易，使用 MFCreateSinkWriterFromURL API来创建writer。但是，从sink writer中获取原始样本要困难得多，您必须实现自定义媒体sink、自定义流sink来处理视频流，并调用 MFCreateSinkWriterFromMediaSink来创建writer。

还有更多。

无论采用哪种编码方法，都不能重复使用帧纹理。每次从DD获得的帧，您都应该创建一个新的纹理并将其传递给MF。

视频编码器需要恒定的帧率。DD 不能提供这一点，它只在屏幕上有变化时才给出一个帧。如果你有游戏显示器，帧率可以达到144 FPS；如果唯一的变化是闪烁的光标，则可能只有2 FPS。理想情况下，您应该以视频媒体类型中指定的恒定帧率提交帧到 MF。

如果您想要流式传输到网络，往往需要提供参数集。除非您使用的是英特尔硬件h265编码器，该编码器已经损坏且没有来自英特尔的评论，否则通过在IMFMediaTypeHandler接口上调用SetCurrentMediaType，MF会在媒体类型的MF_MT_MPEG_SEQUENCE_HEADER属性中提供该数据。您可以实现该接口以获得通知。只有在开始编码后才能获得这些数据。如果您使用的是sink writer，则对于IMFTransform方法更容易，您应该从ProcessOutput方法获得MF_E_TRANSFORM_STREAM_CHANGE代码，然后调用GetOutputAvailableType以获取带有该魔术 blob 的更新的媒体类型。