Media (Intel® oneAPI Video Processing Library, Intel Media SDK)
Access community support with transcoding, decoding, and encoding in applications using media tools from Intel. This includes Intel® oneAPI Video Processing Library and Intel® Media SDK.
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Errors when using several encoding applications

New Contributor III


Customers often wish to fully utilize processor resources for decoding/encoding (of live/realtime video streams).
I.e. to run multiple imsdk applications: some of them utilize gpu/hw, and some - cpu/sw.

And it is normally that number of applications can be changed from time to time.
Or, alternative approach: one (multithreaded) apllication/service, which can change number of handled streams on-the-fly.
E.g. computer transcodes 5 iptv streams today and will transcode 7 streams tomorrow. And, 5 running already streams shouldn't be interrupted during start of 2 additional streams.

But intel media sdk library has well-known bug, which has not been fixed for years.
Start/stop of mfx session may cause errors inside another running sessions.
I think the reason is lack of synchronization primitives somewhere inside imsdk libraries.

I saw such errors on different processors, different windows versions, etc.
Issue can be easily reproduced using standart imsdk samples.

Steps to reproduce a bug with sw-library on windows:

1. Download latest samples (today it is
2. Take \_bin\win32\sample_encode.exe from it.
3. Employ latest imsdk library (MediaSDK2019R1.exe, libmfxsw32.dll).
4. Take some uncompessed video file. I use this one _input.nv12:
5. Download two scripts (sample_encode_1.bat and sample_encode_N.bat) attached to this message and put them beside sample_encode.exe.
6. Start sample_encode_N.bat. It will run in infinite loop four sample_encode.exe instances.
7. Wait several days (or less), and you'll see error messages at sample_encode consoles.

This bug has already been published years ago. But it is still not fixed. Here you can find detailed discussions:

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21 Replies

yes that's true I got your review useful to sort it out