[mythtv-users] HEVC/H.265 playback

[Stuart Auchterlonie]

On 26/04/2021 20:52, Leo Butler wrote:
> Stuart Auchterlonie <stuarta at squashedfrog.net> writes:
> 
>> On 21/04/2021 17:45, Leo Butler via mythtv-users wrote:
>>> Hi,
>>> I briefly did some experimenting with transcoding recordings using
>>> libx265+ffmpeg in an mpegts container.
>>> While the transcoding was fine and playback is fine over my lan
>>> using
>>> ffplay on my (old, slow) laptop, on my dedicated frontend only cartoons
>>> playback ok; other transcoded recordings have a lot of stutter and are
>>> unwatchable. I will guess that this is because the dedicated frontend is
>>> about 8 years old and has a slower cpu [*,**].
>>> I wonder if anyone has experience in these matters? Would a graphics
>>> card be an option (the frontend has a couple low profile pci-e slots
>>> available)? I am using ubuntu 20.04 and v0.31/fixes from the mythbuntu
>>> ppa, if that matters.
>>>
>>
>> Try transcoding to a format your existing hardware can accelerate.
> 
> Yes, I currently transcode to h264.
> 
>>
>> You didn't say what graphics card / video playback profile you are
>> using. You will need to look at that first, to determine
>> "what formats" it'll support.
>>
>> Given you are speculating about adding a graphics card, then I would
>> hazard a guess you have an embedded intel gpu. So try running `vainfo`
> 
> Thanks for the suggestion. You are right, I do not have a graphics card
> installed at the moment. My current hardware gives:
> 
> # vainfo
> error: XDG_RUNTIME_DIR not set in the environment.
> error: can't connect to X server!
> libva info: VA-API version 1.7.0
> libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/r600_drv_video.so
> libva info: Found init function __vaDriverInit_1_7
> libva info: va_openDriver() returns 0
> vainfo: VA-API version: 1.7 (libva 2.6.0)
> vainfo: Driver version: Mesa Gallium driver 20.2.6 for AMD SUMO (DRM 2.50.0 / 5.4.0-72-generic, LLVM 11.0.0)
> vainfo: Supported profile and entrypoints
>        VAProfileMPEG2Simple            :	VAEntrypointVLD
>        VAProfileMPEG2Main              :	VAEntrypointVLD
>        VAProfileVC1Simple              :	VAEntrypointVLD
>        VAProfileVC1Main                :	VAEntrypointVLD
>        VAProfileVC1Advanced            :	VAEntrypointVLD
>        VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
>        VAProfileH264Main               :	VAEntrypointVLD
>        VAProfileH264High               :	VAEntrypointVLD
>        VAProfileNone                   :	VAEntrypointVideoProc
> #
> 
> Leo
> 

So I was nearly correct, it's an AMD GPU exposed via vaapi.

That hardware has zero support for h265, so stick with h264 format
and use the hardware acceleration via VAAPI, if you want to achieve
decent playback without needing to add a video card.


Regards
Stuart