Different AVC low power encoding quality on free and non-free media drivers

[dvrogozh]

Following the article https://github.com/Intel-Media-SDK/MediaSDK/wiki/Intel-media-stack-on-Ubuntu, let's compare AVC low power encoding outputs from free and non-free drivers:

wget https://fate-suite.libav.org/h264-conformance/AUD_MW_E.264
/usr/share/mfx/samples/sample_decode h264 -i AUD_MW_E.264 -o AUD_MW_E.yuv -i420

# free driver:
apt-get install intel-media-va-driver
/usr/share/mfx/samples/sample_encode h264   -w 176 -h 144 -f 30 -cqp -qpi 30 -qpp 30 -qpb 30 -qsv-ff    -i AUD_MW_E.yuv -o encoded_free_AUD_MW_E.264

# non-free driver:
apt-get install intel-media-va-driver-non-free
/usr/share/mfx/samples/sample_encode h264   -w 176 -h 144 -f 30 -cqp -qpi 30 -qpp 30 -qpb 30 -qsv-ff    -i AUD_MW_E.yuv -o encoded_nonfree_AUD_MW_E.264

sha1sum encoded*
2d4baa6a75e9ae5c7f1e57d4127cd8849360dc29  encoded_free_AUD_MW_E.264
52c1b787b16f51c7ba30eebb67deec8cf35a5354  encoded_nonfree_AUD_MW_E.264

Why free/non-free drivers output differs?

Above results obtained under Ubuntu 19.10 running on SKL.

[dvrogozh]

That's likely media driver bug, but free/nonfree drivers return different caps and potentially mediasdk might do something different after reading caps. So, I suggest to investigate from mediasdk side.

[dmitryermilov]

On which platform did you find the issue?

[dvrogozh]

SKL

[AntonGrishin]

Issue reproduced with latest media-driver master.
By driver dumps:
With free driver sets TU = 7 by default, instead of TU = 4 w/ non-free.
I found that with -DENABLE_NONFREE_KERNELS=OFF, also enables flag _FULL_OPEN_SOURCE.

This code is cause of issue:

#ifdef _FULL_OPEN_SOURCE
    if (!GFX_IS_PRODUCT(m_encodeCtx->pMediaCtx->platform, IGFX_ICELAKE_LP))
    {
        if (m_encodeCtx->targetUsage >= 1 && m_encodeCtx->targetUsage <= 2)
        {
            m_encodeCtx->targetUsage = 4;
        }
        else if (m_encodeCtx->targetUsage >= 3 &&m_encodeCtx->targetUsage <= 5)
        {
            m_encodeCtx->targetUsage = 7;
        }
    }
#endif

I checked with m_encodeCtx->targetUsage = 4; in second else if block. Files w/ free/non-free drivers are bit match.

So, problem is on driver side.

[dmitryermilov]

@AntonGrishin , thanks! Indeed. it doesn't make sense why VDENC in CQP mode behaves differently for free and non free build. Can you please submit issue against media driver?

[egorovdanil]

Not reproduced with latest media-driver master.

52c1b787b16f51c7ba30eebb67deec8cf35a5354  encoded_free_AUD_MW_E.264
52c1b787b16f51c7ba30eebb67deec8cf35a5354  encoded_nonfree_AUD_MW_E.264

[daleksan]

Hi @dvrogozh can we close this issue?