[mythtv-users] getting video decode errors on ATSC subchannels

[Ian Evans]

On Thu, Feb 16, 2023 at 10:57 PM Ian Evans <dheianevans at gmail.com> wrote:
>
> On Thu, Feb 16, 2023 at 10:16 PM Gary Buhrmaster
> <gary.buhrmaster at gmail.com> wrote:
> >
> > On Fri, Feb 17, 2023 at 1:10 AM Ian Evans <dheianevans at gmail.com> wrote:
> >
> > > Any idea what I should be looking at?
> >
> > WAG's follows:
>
> That took me a second. LOL.
>
> >
> > What does mediainfo indicate about the recording?
> > There are a few locations where the non-primary
> > subchannel(s) is in a non-mpeg2 format[0] that one
> > may need different decoders (or hardware) to
> > decode.
>
> Even though there was a 300 MB .ts file, mediainfo wasn't able to read it.
>
> To clarify, this was just a test on a clean system, so completely new
> installation, nothing to upgrade. When I was testing jellyfin, their
> DVR was able to record them fine. But wow, did I miss the
> functionality of MythTV for TV. So I nuked all that. Looking at the
> logs, I do see a ton of lines about "Malformed NAL units" right after
> the subchannel recording started:
>
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: I CoreContext
> scheduler.cpp:717 (UpdateRecStatus) Updating status for Posse on
> cardid [3] (Tuning => Recording)
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: I TVRecEvent
> tv_rec.cpp:4146 (TuningNewRecorder) TVRec[3]: rec->GetPathname():
> '/media/disk2/15103_20230217032800.ts'
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: I TVRecEvent
> tv_rec.cpp:4179 (TuningNewRecorder) TVRec[3]: TuningNewRecorder -
> CreateRecorder()
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: E
> HDHRStreamHandler mpeg/AVCParser.cpp:410 (addBytes)
> AVCParser::addbytes: malformed NAL units
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: I TVRecEvent
> tv_rec.cpp:1648 (HandlePendingRecordings) TVRec[4]: ASK_RECORDING 4 0
> 0 0
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: E
> HDHRStreamHandler mpeg/AVCParser.cpp:410 (addBytes)
> AVCParser::addbytes: malformed NAL units
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: I TVRecEvent
> tv_rec.cpp:1648 (HandlePendingRecordings) TVRec[1]: ASK_RECORDING 1 0
> 0 0
> Feb 16 22:27:31 bhmf mythbackend: mythbackend[19718]: I TVRecEvent
> tv_rec.cpp:1648 (HandlePendingRecordings) TVRec[5]: ASK_RECORDING 5 0
> 0 0

[snip]

UPDATE: Ok, so it's not the subchannel, it's the multirec.

I went into program guide and started recording 7.2. That recorded
fine. A minute later I started recording 7.1. That exhibited the same
issue as before. I have two  tuners setup for the homerun and both are
set to eight max recordings. 32 has a different HDHomerun setup than I
had back in .27 so I'm not sure which other settings I need to look
at. Heading to bed, but can answer questions about the config on
Friday. Thanks!