[mythtv-users] Playback Video Stutters & Audio Quits on one Frontend

[John Pilkington]

On 09/08/2020 22:45, Craig Huff wrote:
> On Wed, Aug 5, 2020 at 9:05 PM jam <jam at tigger.ws 
> <mailto:jam at tigger.ws>> wrote:
> 
> 
> 
>      > On 5 Aug 2020, at 8:09 am, Craig Huff <huffcslists at gmail.com
>     <mailto:huffcslists at gmail.com>> wrote:
>      >
>      > I'm stumped and need help.  I've been trying to understand why
>     some video files work fine and others give me grief.  If I play a
>     "bad" file on my BE/FE, it plays just fine.  If I play the same file
>     on the remote FE, it will play ok for a second or two, but then the
>     audio quits and the video will stutter like it's in slow motion.  If
>     I play a "good" file, it works just fine anywhere.
>      >
>      > A "bad" file is one of my older recordings that has a file type
>     description of:
>      >           "MPEG sequence, v2, program multiplex"
>      > (using the 'file' command in an xterm).
>      > A "good" file is one of the newer ones with a description of:
>      >           "MPEG transport stream data".
>      >
>      > The BE/FE is based on an ASRock Z77 Extreme4 motherboard with an
>     Intel Core i3-3250 CPU @ 3.50GHz, integrated HD Graphics 2500 and
>     16GB of RAM.  The video connection is DVI-D.
>      >
>      > The remote FE is based on an ASRock A785GM-LE motherboard with an
>     AMD Phenom II X4 965 CPU @3.4GHz, Nvidia GT710 PCI-E 2.0 Graphics
>     adapter, and 4GB of RAM.  The video connection is HDMI (with 5.1
>     Audio via the HDMI cable).
>      >
>      > The ethernet connection is 1GB/second rated, not tested.
>      >
>      > I fiddled around with various audio options and the pre-defined
>     VDPAU profiles (made things worse! -- audio would drop out faster)
>     vs. the High Quality profile.  I tried tweaking processor settings
>     with cpufrequtils and only managed to get it running so hot it would
>     freeze up until I forced it to shutdown and waited for it to cool
>     off again.
>      >
>      > Short of transcoding the problem files to a format that works, or
>     getting completely new hardware for the remote FE, I'd appreciate
>     any suggestions for what I might have missed to try and get this to
>     work.
>      >
>      > I'd also appreciate any advice on how to transcode the files into
>     a format that will not cause this problem, preferably using
>     Handbrake, Avidemux, and/or ffmpeg.
> 
>     I’d be very interested too!
>     One of my FE is a wireless laptop. Most movies play just fine
>     (including HD), but every now and then is a movie that is always
>     stuttery
> 
>     James
> 
> 
> Sadly, rebuilding seek tables didn't change anything.  I believe the 
> problem is with SD recordings captured using PVR-500 tuners that I'm 
> trying to play back on an HD TV via HDMI on a remote FE.  They play 
> successfully on the BE/FE connected to a digital monitor via DVI.  
> ffprobe describes the couple I'm focusing on as:
>          Video: mpeg2video (Main), yuv420p(tv, top first), 720x480 [SAR 
> 8:9 DAR 4:3], 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
>          Audio: mp2, 48000 Hz, stereo, s16p, 384 kb/s
> 
> I will try to see what I can come up with to transcode them to MP4 or 
> h.264 and see if that helps.  Any suggestions from the peanut gallery 
> gratefully appreciated.

That probe result looks like any DVB-T recording of mine, apart from the 
30 Hz frame rate, the higher audio sample rate and the lack of subtitle 
or alternative audio tracks.  My max audio rate is usually 256 kb/s. 
It's stereo which you are trying to play as 5.1, and I wonder if that's 
the problem.

I would try frontend setup > Setup Wizard > Next > and try options 
there.  Tests in the Setup > Audio page fail for me.  GT 710 / HDMI

John P