SkeyeRTSPLive高效转码之SkeyeVideoDecoder采用Intel集成显卡高效硬件解码解决方案 (1)

在我之前写的一篇文章《SkeyeRTSPLive传统视频监控互联网+实现利器解决方案》中提到RTSP转RTMP的转流过程，简化流程就是通过SkeyeRTSPClient拉RTSP流，获取音视频编码数据，然后再通过SkeyeRTMPPusher推出去，流程非常简单；然后再实际开发过程中，我们发现其实这个过程并没有想象中那么简单；首先，RTSP协议支持多种音视频编码格式，如音频支持AAC,G711，G726,等，视频支持H264，H625，MJPEG, MPEG等等各种格式，而SkeyeRTMP推流只支持H264（已扩展支持H265）格式，这时，音频我们可以通过SkeyeAACEncoder将音频转码成AAC格式，而视频我们可以通过SkeyeVideoDecoder解码成原始数据，然后再通过SkeyeVideoEncoder将原始数据转码成RTMP推送指定的格式，本文，我们将重点讲述SkeyeVideoDecoder基于Intel硬解码库的硬解码流程。

SkeyeVideoDecoder基于Intel硬解码库SkeyeIntelHardDecoder

SkeyeIntelHardDecoder库是基于Intel主板集成显卡的硬件解码程序，内部进行解码采用D3D进行显示，其解码效率比ffmpeg软件解码效率提到至少5-6倍；

1. 接口声明如下：

// Intel Media Hardware Codec SDK Interface [8/17/2016 SwordTwelve]

#ifndef INTELHARDCODEC_INTERFACE_H
#define INTELHARDCODEC_INTERFACE_H

#ifdef __cplusplus

#define HARDCODEC_MAKEFOURCC(A,B,C,D)    ((((int)A))+(((int)B)

2. SkeyeIntelHardDecoder解码库调用流程

• 第一步，初始化解码器
  首先，检查设备是否支持DXVA2，代码如下所示：

bool sSupportDxva2(HWND hwnd)
{
    HRESULT hr;
    mfxU32 adapterNum = 0;
    IDirect3D9*                 m_pD3D9 = NULL;
    IDirect3DDevice9*           m_pD3DD9 = NULL;
    IDirect3DDeviceManager9*    m_pDeviceManager9 = NULL;
    D3DPRESENT_PARAMETERS       m_D3DPP;

    m_pD3D9 = Direct3DCreate9(D3D_SDK_VERSION);
    if (!m_pD3D9)
        return false;

    ZeroMemory(&m_D3DPP, sizeof(m_D3DPP));
    m_D3DPP.Windowed = true;
    m_D3DPP.hDeviceWindow = hwnd;

    m_D3DPP.Flags                      = D3DPRESENTFLAG_VIDEO;
    m_D3DPP.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT;
    m_D3DPP.PresentationInterval       = D3DPRESENT_INTERVAL_ONE;
    m_D3DPP.BackBufferCount            = 1;
    m_D3DPP.BackBufferFormat           = D3DFMT_X8R8G8B8;

    m_D3DPP.BackBufferWidth  = GetSystemMetrics(SM_CXSCREEN);
    m_D3DPP.BackBufferHeight = GetSystemMetrics(SM_CYSCREEN);

    m_D3DPP.Flags |= D3DPRESENTFLAG_LOCKABLE_BACKBUFFER;


    m_D3DPP.SwapEffect = D3DSWAPEFFECT_DISCARD; // D3DSWAPEFFECT_OVERLAY

    hr = m_pD3D9->CreateDevice(
        adapterNum,
        D3DDEVTYPE_HAL,
        hwnd,
        D3DCREATE_SOFTWARE_VERTEXPROCESSING | D3DCREATE_MULTITHREADED | D3DCREATE_FPU_PRESERVE,
        &m_D3DPP,
        &m_pD3DD9);
    if (FAILED(hr))
    {
        m_pD3D9->Release();
        return false;
    }
    hr = m_pD3DD9->Reset(&m_D3DPP);
    if (FAILED(hr))
        return false;
    hr = m_pD3DD9->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
    if (FAILED(hr))
    {
        m_pD3DD9->Release();
        m_pD3D9->Release();
        return false;
    }

    UINT resetToken = 0;

    hr = DXVA2CreateDirect3DDeviceManager9(&resetToken, &m_pDeviceManager9);
    if (FAILED(hr))
    {
        m_pD3DD9->Release();
        m_pD3D9->Release();
        return false;
    }
    m_pDeviceManager9->Release();
    m_pD3DD9->Release();
    m_pD3D9->Release();
    return true;
}

然后，初始化解码器，代码如下：

int    Init(HWND hWnd, bool bDxv2Show, bool bShowToScale, int mode )
{
    //检测是否支持硬件解码
    bool bUseIntelSdk = isSupportDxva2(hWnd);
    if (!bUseIntelSdk)
    {
        return -1;
    }
    m_bDxv2Show = bDxv2Show;
    m_bShowToScale = bShowToScale;
    m_hWnd = hWnd;
    ::GetClientRect(m_hWnd,&m_WndRect);

    m_pD3dRender = new CDecodeD3DRender();
    m_pD3dRender->Init(hWnd);

    mfxStatus sts = MFX_ERR_NONE;
//    mfxVersion version = {MFX_VERSION_MINOR, MFX_VERSION_MAJOR};
    mfxVersion version = {0, 1};

    if (mode == 1)
    {
        if (MFX_ERR_NONE != m_mfxSession.Init(MFX_IMPL_HARDWARE_ANY, &version))
            sts = m_mfxSession.Init(MFX_IMPL_HARDWARE, &version);
        if(sts != MFX_ERR_NONE)
            sts = m_mfxSession.Init(MFX_IMPL_SOFTWARE, &version);
    }
    else
    {
        sts = m_mfxSession.Init(MFX_IMPL_SOFTWARE, &version);
    }

    MSDK_CHECK_RESULT(sts, MFX_ERR_NONE, sts);

    // create decoder
    m_pmfxDEC = new MFXVideoDECODE(m_mfxSession);
    MSDK_CHECK_POINTER(m_pmfxDEC, MFX_ERR_MEMORY_ALLOC);

    // set video type in parameters
    m_mfxVideoParams.mfx.CodecId = MFX_CODEC_AVC;
    m_mfxVideoParams.AsyncDepth = 1;
    //  [12/6/2016 dingshuai]
    m_mfxVideoParams.mfx.FrameInfo.FourCC = MFX_FOURCC_NV12;//MFX_FOURCC_YV12;


    // set memory type
    m_bd3dAlloc = true;

    memset(&m_mfxBS, 0, sizeof(m_mfxBS));

    sts = InitMfxBitstream(&m_mfxBS, 1024*1024*2);
    return sts;
}

• 第二步，调用解码函数
  解码器是异步工作的，所以在解码函数调用后，我们需要从缓冲区内把数据取出进行D3D显示或者回调到上层显示，代码如下所示：

mfxStatus CIntelMediaDecode::h264DecPacket(unsigned char * p_data, int len, unsigned char* p_yuvData)
{
    mfxSyncPoint    syncp;
    mfxStatus        sts = MFX_ERR_NONE;
    mfxU16             nIndex = 0; // index of free surface

    //while (MFX_ERR_NONE  (m_mfxBS.MaxLength - m_mfxBS.DataLength))
        {
            //    sts = ExtendMfxBitstream(&m_mfxBS, m_mfxBS.MaxLength * 2);
            //    MSDK_CHECK_RESULT(sts, MFX_ERR_NONE, sts);
            m_mfxBS.DataOffset = 0;
            m_mfxBS.DataLength = 0;
        }

        if (len > 0)
        {
            memmove(m_mfxBS.Data, m_mfxBS.Data+m_mfxBS.DataOffset, m_mfxBS.DataLength);
            m_mfxBS.DataOffset = 0;

            memcpy(m_mfxBS.Data+m_mfxBS.DataLength, p_data, len);
            m_mfxBS.DataLength += len;
        }

        if (m_mfxBS.DataLength DecodeFrameAsync(&m_mfxBS, &(m_pmfxSurfaces[nIndex]), &m_pmfxOutSurface, &syncp);
        if (MFX_ERR_DEVICE_LOST == sts || MFX_ERR_DEVICE_FAILED == sts)
            return sts;
        m_sPrevState = sts;

        // ignore warnings if output is available,
        // if no output and no action required just repeat the same call
        if (MFX_ERR_NONE linesize[0] = m_pmfxOutSurface->Data.Pitch;
                picture->linesize[1] = m_pmfxOutSurface->Data.Pitch;
                picture->linesize[2] = 0;

                picture->data[0] = m_pmfxOutSurface->Data.Y;
                picture->data[1] = m_pmfxOutSurface->Data.UV;
                picture->data[2] = 0;

                int ret = SetSnapFrameData(picture);
                if (ret > 0)
                {
                    m_nSnapShotDataReady = 1;
                }
                m_nSnapShotRequest = 0;
            }
#endif

#if 1
            if (m_bExternalAlloc)
            {
                sts = m_pMFXAllocator->Lock(m_pMFXAllocator->pthis, m_pmfxOutSurface->Data.MemId, &(m_pmfxOutSurface->Data));
                MSDK_CHECK_RESULT(sts, MFX_ERR_NONE, sts);
            }
#endif

            ++m_nFrameIndex;

            int nYUVSize = m_nSrcWidth*m_nSrcHeight;
            //YUV数据拷贝
            if (p_yuvData)//YUV420
            {
                memcpy(p_yuvData, m_pmfxOutSurface->Data.Y, nYUVSize);
                memcpy(p_yuvData+m_nSrcWidth*m_nSrcHeight, m_pmfxOutSurface->Data.UV, m_nSrcWidth*m_nSrcHeight>>1);

                // 硬件编码出来是NV12，外部为了显示方便应该转成I420 [12/6/2016 dingshuai]
#if 0
                int i = 0;
                int yuvDely = nYUVSize*5/4;
                int nHelfYUVSize = nYUVSize/2;
                // Write Cb
                for(int idx = 0; idx Data.UV[idx];
                    *(p_yuvData+yuvDely +i) = m_pmfxOutSurface->Data.UV[idx+1];
                    i++;
                }
#endif

            }

#if 1
            if (m_bExternalAlloc)
            {
                sts = m_pMFXAllocator->Unlock(m_pMFXAllocator->pthis, m_pmfxOutSurface->Data.MemId, &(m_pmfxOutSurface->Data));
                MSDK_CHECK_RESULT(sts, MFX_ERR_NONE, sts);
            }
#endif
            if (m_bDxv2Show)
            {
                ::GetClientRect(m_hWnd, &m_WndRect);
                sts = m_pD3dRender->RenderFrame(m_pmfxOutSurface, m_pMFXAllocator,
                    m_WndRect, m_DisplayTitle, m_bEndedDrag, m_bShowToScale, &m_TargetRect);
                if (sts == MFX_ERR_NULL_PTR)
                    sts = MFX_ERR_NONE;
            }
        }
    }
    return sts;
}

• 第三步，关闭解码器

void Close()
{
    WipeMfxBitstream(&m_mfxBS);
    MSDK_SAFE_DELETE(m_pmfxDEC);
    MSDK_SAFE_DELETE(m_pD3dRender);

    if (m_bIntelSystemInitFinish != true)
        return;

    m_bIntelSystemInitFinish = false;

    DeleteFrames();

    // allocator if used as external for MediaSDK must be deleted after decoder
    DeleteAllocator();

    m_mfxSession.Close();

    if (NULL != m_pSnapShotBuf)
    {
        free(m_pSnapShotBuf);
        m_pSnapShotBuf = NULL;
    }
}

至此，我们已经完成了对Intel集显解码器的封装，通过阅读[SkeyeRTSPPlayer]的代码可以对该库的调用流程有一个系统的认识；此外，目前集成的Intel集显解码库是比较旧的版本，目前尚不支持H265解码，有兴趣的朋友可以下载最新的Intel集显编解码库Demo自行封装解码库，相信现在的版本会更加的易用和高效。

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