Bug in the H.264 Hardware Decoder

Bug in the H.264 Hardware Decoder

There seems to be a bug in the H.264 hardware decoder.

The sample file is here:

When I run this command I get good looking YUV output:

sample_decode.exe h264 -i wowzamedia.h264 -o wowzamedia_sf.yuv

When I run this command I get bad looking YUV output (blocky artifacts in many frames):

sample_decode.exe -hw h264 -i wowzamedia.h264 -o wowzamedia_hw.yuv

Here are the environment details:
Intel Media SDK:

Processor: Sandy Bridge, 2600K
Driver version: Intel Corporation, 1/7/2011,
Motherboard: ASUS, P8H67-MEVO

The source file was encoded using x264 with this command line:

ffmpeg -i wowzamedia.ts -strict experimental -pass 1 -s 1280x720 -y -an -vcodec libx264 -vpre default -vpre hq -vpre main -g 150 -b 3000k -bt 3000k -threads 64 wowzamedia.mov
ffmpeg -i wowzamedia.ts -strict experimental -pass 2 -s 1280x720 -y -acodec aac -ab 128k -ac 2 -ar 48000 -vcodec libx264 -vpre default -vpre hq -vpre main -g 150 -b 3000k -bt 3000k -threads 64 wowzamedia.mov

Let me know if you need any further information.


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Sorry for the delay Charile, We will look into this.


Hi Charlie,we have reproduced the issue. Investigation is ongoing, we'll get back to as soon as we know more.In the meantime, if needed, to circumvent the issue please try different ffmpeg encoder options.I experimented with ffmpeg (0.5.7) using similar options as you referred to in your report but was not able to produce a H264 stream resulting HW decode issues.Regards,Petter

BTW, the version of FFmpeg that I used to create this file is:

It is from this site:


Hi Charlie,The issue has been resolved in Media SDK HW encode path. We expect the fix to be part of the 15.22 production build of the platform Graphics Driver (including Intel Media SDK HW implementation) in ww14 (end of March).Thanks for helping us improve Intel Media SDK/Intel Quick Sync Technology.Let me know if you have any questions.Regards,Petter

Best Reply

You guys rock!

Thanks a ton,
Charlie Good
Wowza Media Systems

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