MFT编码器（h264）CPU利用率高

Question

我能够使用媒体基础设施转换（MFT）成功地对数据进行H264编码，但不幸的是，我的CPU占用率非常高（当我在程序中注释调用此函数时，CPU占用率较低）。由于获取编码的步骤很少，我无法做任何改进。有什么想法可以帮忙吗？

    HRESULT MFTransform::EncodeSample(IMFSample *videosample, LONGLONG llVideoTimeStamp, MFT_OUTPUT_STREAM_INFO &StreamInfo, MFT_OUTPUT_DATA_BUFFER &encDataBuffer)
{
    HRESULT hr;
    LONGLONG llSampleDuration;
    DWORD mftEncFlags, processOutputStatus;
    //used to set the output sample
    IMFSample *mftEncodedSample;
    //used to set the output sample
    IMFMediaBuffer *mftEncodedBuffer = NULL;
    memset(&encDataBuffer, 0, sizeof encDataBuffer);
    if (videosample)
    {
        //1=set the time stamp for the sample
        hr = videosample->SetSampleTime(llVideoTimeStamp);
        #ifdef _DEBUG
        printf("Passing sample to the H264 encoder with sample time %i.\n", llVideoTimeStamp);
        #endif
        if (SUCCEEDED(hr))
        {
            hr = MFT_encoder->ProcessInput(0, videosample, 0);
        }
        if (SUCCEEDED(hr))
        {
            MFT_encoder->GetOutputStatus(&mftEncFlags);
        }
        if (mftEncFlags == MFT_OUTPUT_STATUS_SAMPLE_READY)
        {
            hr = MFT_encoder->GetOutputStreamInfo(0, &StreamInfo);

            //create empty encoded sample
            if (SUCCEEDED(hr))
            {
                hr = MFCreateSample(&mftEncodedSample);
            }
            if (SUCCEEDED(hr))
            {
                hr = MFCreateMemoryBuffer(StreamInfo.cbSize, &mftEncodedBuffer);
            }
            if (SUCCEEDED(hr))
            {
                hr = mftEncodedSample->AddBuffer(mftEncodedBuffer);
            }
            if (SUCCEEDED(hr))
            {
                encDataBuffer.dwStatus = 0;
                encDataBuffer.pEvents = 0;
                encDataBuffer.dwStreamID = 0;
                //Two shall after this step points on the same address
                encDataBuffer.pSample = mftEncodedSample;
                hr = MFT_encoder->ProcessOutput(0, 1, &encDataBuffer, &processOutputStatus);


            }
        }
    }
    SafeRelease(&mftEncodedBuffer);

    return hr;
}

- tulipe

---

需要高CPU使用率是合理的。你想实时编码吗？你如何配置编码器（配置文件、比特率等）？ - Anton Angelov

@AntonAngelov 帧率（33帧/秒）...比特率（400kbps）...分辨率（640x480）....是的编码器可以实时工作。 - tulipe

Answer 1

首要任务是确保你已经使用MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS配置好了sink。我还设置了MF_LOW_LATENCY属性。

// error checking omitted for brevity
hr = attributes->SetUINT32(MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, TRUE);
hr = attributes->SetUINT32(MF_SINK_WRITER_DISABLE_THROTTLING, TRUE);
hr = attributes->SetUINT32(MF_LOW_LATENCY, TRUE);

另一个关键点是确保选择源输出的本地格式，否则您将非常失望。我在这里详细描述了这一点。

我还应该提到，您应该考虑在开始时创建转换示例和内存缓冲区，而不是在每次接收样本时重新创建它们。

祝你好运。希望这可以帮助到你。

- Jeff