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3044 Discussions

Unexpected MFX_ERR_NOT_ENOUGH_BUFFER error during h.264 encoding



We use Media SDK to do software h.264 video encoding.

We switched from Media SDK 2012 R2 to Media SDK 2014 R2. Long run tests revealed a problem: after a period (several hours, not constant), encoding stops working, no more video frames are encoded.
After investigations, we found that the function MFXVideoENCODE::EncodeFrameAsync(...) returns -5, i.e. MFX_ERR_NOT_ENOUGH_BUFFER

The documentation stipulates that this error happens when: The bitstream buffer size is insufficient.

We have output the state of the bitstream buffer when the error occurred and here are some:
- Encoding Error: -5 - encode buffer state: max: 9375000, current: 1041, offset: 0    
- Encoding Error: -5 - encode buffer state: max: 9375000, current: 585, offset: 0    
- Encoding Error: -5 - encode buffer state: max: 9375000, current: 1284, offset: 0    
- Encoding Error: -5 - encode buffer state: max: 9375000, current: 1024, offset: 0    
- Encoding Error: -5 - encode buffer state: max: 9375000, current: 81, offset: 0    
- Encoding Error: -5 - encode buffer state: max: 9375000, current: 859, offset: 0    

As you can see, the bitstream buffer seems large enough to handle a new frame. Our code doesn't change and it worked perfectly with Media SDK 2012.

We have currently a workaround which consist to destroy and re-create the bitstream buffer and reinitialize the buffer data length with: (mfxVideoParam)m_MFXEncParams.mfx.BufferSizeInKB * 1000
However it doesn't seem to be an expected behavior, so I would like to know if it is something that has already been remarked?

Here is our initialization code and the code added to skirt the problem:

Init parameters:

    m_MFXEncParams.mfx.CodecId                    = MFX_CODEC_AVC;
    m_MFXEncParams.mfx.TargetUsage                = MFX_TARGETUSAGE_BEST_SPEED ;
    m_MFXEncParams.mfx.RateControlMethod        = MFX_RATECONTROL_VBR;
    m_MFXEncParams.mfx.GopRefDist                = 1;
    m_MFXEncParams.AsyncDepth                    = 1;
    m_MFXEncParams.mfx.FrameInfo.FourCC            = MFX_FOURCC_NV12;
    m_MFXEncParams.mfx.FrameInfo.ChromaFormat    = MFX_CHROMAFORMAT_YUV420;

    // specify memory type

    /*Initializing Extcoding options with msxdecframebuffering = 1 to reduce decode latency*/
    mfxExtBuffer *extBuffersInit[1];
    mfxExtCodingOption extCO;
    memset( &extCO, 0, sizeof( extCO)) ;
    extCO.Header.BufferId = MFX_EXTBUFF_CODING_OPTION;
    extCO.Header.BufferSz = sizeof(mfxExtCodingOption);
    extCO.MaxDecFrameBuffering = 1;
    extBuffersInit[0] = reinterpret_cast<mfxExtBuffer*>(&extCO);
    m_MFXEncParams.NumExtParam = 1;
    m_MFXEncParams.ExtParam = extBuffersInit;
    m_MFXEncParams.mfx.NumRefFrame  = 1;

    //Initialization of the specific encoding params
    m_MFXEncParams.mfx.FrameInfo.Width  = ALIGN_16(m_StreamFormat.GetWidth()) ;
    m_MFXEncParams.mfx.FrameInfo.Height = ALIGN_16(m_StreamFormat.GetHeight()) ;

    m_MFXEncParams.mfx.FrameInfo.CropX = 0;
    m_MFXEncParams.mfx.FrameInfo.CropY = 0;
    m_MFXEncParams.mfx.FrameInfo.CropW = m_StreamFormat.GetWidth() ;
    m_MFXEncParams.mfx.FrameInfo.CropH = m_StreamFormat.GetHeight() ;

    m_MFXEncParams.mfx.TargetKbps                = (mfxU16)m_StreamFormat.GetBitrate() ; // in Kbps
    m_MFXEncParams.mfx.FrameInfo.FrameRateExtN    = (mfxU32)m_StreamFormat.GetFps() ;
    m_MFXEncParams.mfx.FrameInfo.FrameRateExtD    = 1 ;
    m_MFXEncParams.mfx.GopPicSize                = m_MFXEncParams.mfx.FrameInfo.FrameRateExtN*2 ;

    m_MFXEncParams.mfx.FrameInfo.PicStruct        = MFX_PICSTRUCT_PROGRESSIVE;


        mfxError = m_MFXEncoder->EncodeFrameAsync( FKFC, surface, &m_MFXEncodedBs, &sp);
        if (mfxError == MFX_ERR_NONE)
            break ;

        if (mfxError == MFX_WRN_DEVICE_BUSY)
            Sleep(1) ;
            CStdString dbgStr ;

            dbgStr.Format( L"- Encoding Err: %d - encode buffer state: max: %d, current: %d, offset: %d\n", mfxError, m_MFXEncodedBs.MaxLength, m_MFXEncodedBs.DataLength, m_MFXEncodedBs.DataOffset) ;
            OutputDebugString( dbgStr.GetString()) ;

            if (mfxError == MFX_ERR_NOT_ENOUGH_BUFFER)
                //resize the buffer to the needed size
                delete [] m_MFXEncodedBs.Data ;
                memset( &m_MFXEncodedBs, 0, sizeof( m_MFXEncodedBs)) ;
                m_MFXEncodedBs.Data = new unsigned char[m_MFXEncParams.mfx.BufferSizeInKB * 1000] ;
                m_MFXEncodedBs.MaxLength = m_MFXEncParams.mfx.BufferSizeInKB * 1000;
            return errEncode ;
    while (true) ;
    CPU: Intel Core i7-2600
    OS: Windows 7 Pro 64 bits
    Graphic Drivers: latest
    SDK Library version used: 32 bits
Thank you,



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4 Replies


Can you update to MSDK 2015  new version API 1.13 which is available as part of INDE now from Also if you can send us the logs from System analyzer and tracer which will help us further look into the issue of buffer reset. Also are you running a 4k video? As I see HW is a 2nd generation SKU.  Logs from the tools will provide us more information.


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Hi Harsh,

Thanks for your fast answer! I will download the new SDK and try to reproduce with it. If I succeeded, I will use the system analyzer and tracer to create logs. 

The video resolution is only 640x480.

Have a good day,


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Hi Harsh,

I have updated to the new version of the MSDK (1.13) from Inde and performed several days of testing without modifying the code.

And it works! I have never seen again the 'not enough' buffer error. It seems that there was probably a problem with the 2014R2 version of MSDK.

Thanks for your time,


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Yes, with every new release of MSDK API, we have fixes and new implementaion. Glad to know you don't see the issue.


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