VAAPI transcoding problem? am I using wrong version?

Evren Yurtesen · 2019-11-09T22:00:48+00:00

I have "HTS Tvheadend 4.2.9~pre+201910311127-0~built201910311332~gitcfa450e~ubuntu19.10.1" installed from mamarley/stable repository. I am able to use VAAPI...

Evren Yurtesen

You say encoding to HEVC works. Does it preserve Aspect Ratio? Because I am able to encode using FFMPEG from command line but aspect ratio gets screwed for some channels which has special AR setting. Seems to be a known bug with VAAPI hardware encoding using FFMPEG.

M A Ben Amara

Evren Yurtesen wrote:

> You say encoding to HEVC works. Does it preserve Aspect Ratio? Because I am able to encode using FFMPEG from command line but aspect ratio gets screwed for some channels which has special AR setting. Seems to be a known bug with VAAPI hardware encoding using FFMPEG.

if you mean me, yes, attached a sample, aspect is also as it should be.

Evren Yurtesen

Yes @"M A BEN Amara". VLC does not seem to be showing all the media information. I tested the following file with VLC and it does not show the aspect ratio. (although it should)
https://drive.google.com/file/d/1-IDAYhfj93aPJPizWKttpfGV-KVPKKSx/view

If I open it with MPC-HC I see the aspect ratio printed in media info. See my screenshot on the left is original video and on the right is VAAPI encoded to h264.

Perhaps the problem is more difficult to see with FullHD broadcast as the SD broadcast here is 720x576 and it looks like a box (roughly ~ 4:3) without the correct aspect ratio. But FullHD is 1920x1080 and it is natively 16:9 so it will look the same even with this information is lost via VAAPI. Try a channel with more square resolution :)

See this ticket for more information. There is link to encoded version of the same video and ffmpeg encoding information:

https://trac.ffmpeg.org/ticket/8376

Obviously the issue in this case is ffmpeg and different than my original issue with transcoding/tvheadend (because tvheadend transcoding does not work at all.). But it would be interesting to see if tvheadend has the same problem or not.

M A Ben Amara

i tested ~ 30 channels, all where good, also 4:3 shows ... actually i only use h264 source and no more 576i mpeg2 sources, didnt tested them, if i may find some time i can add such a channel and look if thats also working here.

about VLC not showing the aspect ratio, yes, but the display switches to the fitting screen, i know that "morphed" behavior from early days when i made some wrong settings in encoding ...

and as you said i have different issues with hevc decoding so im wrong here

Evren Yurtesen

@"M A Ben Amara" It is interesting. Anyway, this issue is irrelevant to my problem. But if you want you can test from command line using ffmpeg/vaapi as described here with given small sample files.
https://trac.ffmpeg.org/ticket/8376

M A Ben Amara

i made some small samples, when u want take a look ... onedrive

https://1drv.ms/u/s!ApY1s9BRY-iSqEOFPmSbWsKuXuV7?e=cwn2Ox

sources are still all europe streams, also added 2 x 4:3 aspect ratio streams, all encoded to hevc 720 (see attachement),

and im too lazy to add mpeg2 576i streams as source, so all are based on h264 sources ...

i look now further with my issue with hw decoding hevc and this crap error
vaapi: decode: unsupported pixel format: yuv420p10le

Evren Yurtesen

@"M A Ben Amara" You did not record 4:3 streams. All your recordings in your drive are 1280x720, therefore 16:9 natively.
You are lucky that your channels are streaming like that. In my case the stream resolution is 720x 576 but with 16:9 aspect ratio.
You should really see the files I uploaded to that bug report and re-encode them using ffmpeg to see what happens :)

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