[mythtv-users] Anyone running MythTV 31 on 32-bit x86 with nVidia card?

[Stephen Worthington]

On Thu, 11 Feb 2021 09:49:59 -0500, you wrote:

>On 2/11/21, George Mari <george_mythusers at mari1938.org> wrote:
>> On 2/10/21 11:56 AM, Tom Dexter wrote:
>>> My trusty old frontend is a 32-bit x86 machine with a GT 430 nVidia card.
>>>
>>> Quite some time ago I upgraded to MythTV 30.0 but ended up reverting
>>> back to 29.1 because I had some issues with some (though not most)
>>> h264 videos. Specifically, some h264 videos would fail the VDPAU
>>> decode and fallback to software decoding. These were videos that used
>>> VDPAU with no issue in other players like xine, and also in MythTV
>>> 29.1. This was never resolved and was an issue that apparently
>>> couldn't be reproduced on 64 bit systems.
>>>
>>> My understanding is that the FFmpeg hardware acceleration code has
>>> been radically changed in version 31.
>>>
>>> As per the subject, if anyone is running MythTV 31 on 32-bit x86 and
>>> is using an nVidia GPU, it would help me enormously if they could test
>>> this example:
>>>
>>> http://jell.yfish.us/media/jellyfish-60-mbps-hd-h264.mkv
>>>
>>> ...and see if it uses VDPAU decoding, which can be determined during
>>> playback from the menu under Playback -> Playback Data.
>>>
>> I have a 64-bit Fedora installation with a GT 430 card - not exactly
>> what you are asking for, I know.
>>
>> But for me, the video Playback Data shows h.264 ffmpeg
>>
>
>Wow. So it's NOT using VDPAU, and that's with MythTV 31? That is
>really not good news at all. Do other h264 videos use VDPAU? That
>sounds like a significant bug to me. Even on my 32-bit system that
>video uses VDPAU without issues in xine, mpv, and in MythTV 29.1.
>
>When I was temporarily on 30.0 I posted comments about this on this
>(semi-related) bug, but at that time apparently nobody using 64-bit
>could duplicate this one:
>
>https://code.mythtv.org/trac/ticket/13223
>
>As noted there, the error that caused it to fallback to software
>decode was this:
>
>2019-05-17 10:37:09.222935 E [14504/28060] Decoder
>avformatdecoder.cpp:3785 (ProcessVideoPacket?) - AFD: video
>avcodec_send_packet error: Invalid data found when processing input
>(-1094995529) gotpicture:0
>
>I'm hesitant to update, though I'm going to have to soon, as (for a
>number of reasons) I can no longer compile MythTV 29.1 on my Gentoo
>system. What's worse is that, since I'm running 29.1 I can't very well
>log a bug or test any of this.
>
>I'd be interested to see what others find testing this...with 32 or 64
>bit. Thanks for the reply! That's significant for sure.
>
>Tom

That file is encoded using the H.264 High at L5 profile.  I am not sure
if a GT430 can play that profile, so that may be why it is dropping
back to using ffmpeg.  You only need High at L4.1 for playing BluRay, so
a lot of earlier Nvidia cards did not support higher than that, IIRC.
In v31 (using the new rendering code), when I play that file using
mythavtest on my GT1030, it plays using VDPAU.