Intel VAAPI and Hardware mpeg2video decoding

**heitbaum** · December 6, 2020 at 11:22 AM

I have been chasing the errors in my kodi.log for a while now. As you would know I think I have made all Intel Generic current or head in the build tree.

Code

2020-12-06 21:48:28.754 T:5314    ERROR <general>: VAAPI output: Postproc preinit failed
2020-12-06 21:48:28.787 T:5314    ERROR <general>: VAAPI/vpp vaCreateConfig error: the requested VAProfile is not supported (12)

This occurs when playing ISOs (DVD) or mpeg2video as the video stream in a MKV.

I have believe that the that Intel chip is suppose to suppose this decoding. As per the details at VAProfile is not supported (12) With MPEG2 playback · Issue #477 · intel/libva · GitHub VAProfileMPEG2Main is supported.

The media details itself are:

Code

Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg, progressive), 720x576 [SAR 16:15 DAR 4:3], 25 fps, 25 tbr, 90k tbn, 50 tbc

The full ffprobe output of the ISO is at - http://ix.io/2GQe

I added vadumpcaps to my build tree - vadumpcaps: add vadumpcaps to show all capabilities of a VAAPI device… · heitbaum/LibreELEC.tv@821ea50 · GitHub and from that it seems like Kodi/.... is incorrectly mapping the media type to 12 (which is JPEG.) - full output at http://ix.io/2GQl

So by my reading of vadumpcaps - VAProfile should be 1 for this media? Is this right / or am I chasing the wrong thing?

Code

        {
            "profile": 1,
            "name": "MPEG2Main",
            "description": "MPEG-2 Main Profile",
....
        {
            "profile": 12,
            "name": "JPEGBaseline",
            "description": "JPEG",

**heitbaum** · December 6, 2020 at 11:55 AM

Checking with ffmpeg it definitely decodes, but I can’t tell if it is using the hwaccel? And why/what the profile it has mapped the .ISO (mpeg2video) to.

Code

ffmpeg -vaapi_device /dev/dri/renderD128 -hwaccel vaapi -i a.iso -pix_fmt yuv420p a.yuv

HWAccelIntro – FFmpeg

#6668 (MPEG2 decoding failed with FFMPEG-VAAPI) – FFmpeg

Based on the above post - moeg2video HW decoding was suppose to be fixed in Jan 2020 and in the following ffmpeg branches - master n4.4-dev n4.3.1 n4.3

Kenneth · December 15, 2020 at 9:57 AM

MPEG-2 is easy to CPU decode compared to the other codecs like VC1 or H.264, even for 1920x1080 video. Does it really matter if it's hardware accelerated? MCDVOICE

**heitbaum** · December 20, 2020 at 7:05 AM

The issue is more the logs and the why. We have identified why now - deinterlacing settings in the vaapi. Next steps will be to perform some tests and get to an end state.

See the bug an pull request.

[BUG] Intel VAAPI and Hardware mpeg2video decoding not working · Issue #4732 · LibreELEC/LibreELEC.tv · GitHub

media-driver: enable VAAPI deinterlacers at X11 by mglae · Pull Request #4771 · LibreELEC/LibreELEC.tv · GitHub

**CvH** · December 20, 2020 at 10:00 AM Official Post

Quote from Kenneth

Does it really matter if it's hardware accelerated?

usually with HW acceleration there are better scalers/filters etc could be used, so in a ideal world you would always want HW decode

but currently we have no idea if this translates at all to real world, because its very likely that intel didn't put too much effort in such an old codec.