[mythtv-users] Help with playback issue on recordings from a single channel

[John Pilkington]

On 30/12/2021 00:08, Vincent Poore via mythtv-users wrote:
> Thanks Barry
> 
> I have an AMD A10-5800K APU 3.8Ghz 4 Core Processor with 
> integrated Trinity Radeon HD 7660D graphics.
> 
> I'm running Ubuntu 20.04 which has AMDGPU open source drivers to support 
> both VDPAU and VAAPI acceleration protocols.
> 
> I might try VAAPI to see what happens but my experience also matches Don 
> Brett's advice in that it plays perfectly in Open GL.   Thanks for 
> sharing that insight.
> 
> 
> On Wednesday, December 29, 2021, 08:13:57 AM MST, Barry Martin 
> <barry3martin at gmail.com> wrote:
> 
> 
> 
> Vincent:
> 
>> I've been living with and frustrated by a problem with recordings from
>> my local CBS broadcast channel.
>>
>> It all started when my local station added a new digital sub-channel.
>>   I know this because my problem started on March 1st and a call to the
>> station engineer confirmed changes were made to the broadcast signal
>> early that Sunday morning. He says, "Everything in this encoding scheme
>> is industry standard, so I wouldn't expect there to be any problem
>> decoding it with commercial equipment." I'm not technical enough to
>> determine what has changed that would give mythtv so much trouble.
> 
> It appears the CBS network does a few things differently from other 
> networks.  Not necessarily wrong, just different.  With the local CBS 
> channel and watching via television (not via MythTV) if the Closed 
> Captioning is set for one of the settings other than CC1 (I've forgotten 
> which one) a big black box will overlay most of the screen.  This does 
> not occur with any of the other networks/stations (I tested for 'fun').
> 
> Not really of any specific help but I'm wondering if perhaps you have a 
> Closed Captioning option set?  The overlay does not appear on all CBS 
> programmes.
> 
> Also, IIRC VDPAU is for nVidia video cards -- so check correct and 
> up-to-date.  Also found this old note which could explain your VDPAU issues:
> 
> <start quote>
> 
>     7. Re: HD Hiomerun works better in HDHomeRun viewer than MythTV (Don
>     Brett)
> 
> 
>     Subject: Re: [mythtv-users] HD Hiomerun works better in HDHomeRun
>     viewer than MythTV
> 
>     From: Don Brett <dlbrett at zoominternet.net>
>     <mailto:dlbrett at zoominternet.net>
> 
>     Date: 1/25/19, 11:17
> 
> 
>     There is a bug with VDPAU rendering. Certain channels in the USA are
>     using MPEG2 in a way that overloads VDPAU and causes pixellation
>     every few seconds. This is nothing to do with HDHomerun, it happens
>     with any type of equipment. The solution is to change to software
>     decode and OpenGL Rendering for mpeg2 streams. If you are not using
>     VDPAU ignore this email.
>     Peter
> 
> 
> 
> 
>     Subject: Re: [mythtv-users] HD Hiomerun works better in HDHomeRun
>     viewer than MythTV
> 
>     From: Peter Bennett <pb.mythtv at gmail.com> <mailto:pb.mythtv at gmail.com>
> 
>     Date: 1/25/19, 11:48
> 
> 
>     I suggest change your profile to one of the OpenGL ones (try OpenGL
>     Slim) instead of "VDPAU High quality". If that solves your problem
>     you can customize a profile that uses OpenGL for mpeg2 and OpenGL
>     for others, or you can just leave it using OpenGL Slim.
> 
> 
> 
>     *Mythfrontend > Setup > Video > Playback (3/8): *
> 
> 
> 
>     Subject: Re: [mythtv-users] HD Hiomerun works better in HDHomeRun
>     viewer than MythTV
> 
>     From: Don Brett <dlbrett at zoominternet.net>
>     <mailto:dlbrett at zoominternet.net>
> 
>     Date: 1/25/19, 14:24
> 
> 
>     Just tried it, but when I played an existing recording, the audio
>     played and mythfrontend exited to the desktop...audio continued to
>     play until I rebooted.  Is there a library I need to install?
> 
> 
> 
>     Subject: Re: [mythtv-users] HD Hiomerun works better in HDHomeRun
>     viewer than MythTV
> 
>     From: Peter Bennett <pb.mythtv at gmail.com> <mailto:pb.mythtv at gmail.com>
> 
>     Date: 1/25/19, 14:41
> 
> 
>     Make sure that the Theme Painter is set to opengl2 in
>     Settings->Appearance. If that does not work you may have a broken
>     opengl system.
> 
> <end quote>
> 
> Barry
> 

Now that you have said what the hardware actually is, it's clear that it 
should easily be able to handle that material with software decoding. 
So some of my comments won't apply.  But I do have the one multiplex for 
which the apparent frame rate halves after an ffmpeg demux/remux using 
the timestamp-regenerating command line that I quoted earlier.  Might be 
worth following up.

John