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

[Ian Evans]

On Fri, Feb 17, 2023, 8:10 AM Ian Evans, <dheianevans at gmail.com> wrote:

> On Fri, Feb 17, 2023, 7:43 AM Ian Evans, <dheianevans at gmail.com> wrote:
>
>> On Fri, Feb 17, 2023 at 2:40 AM Klaas de Waal <klaas.de.waal at gmail.com>
>> wrote:
>> >
>> >
>> >
>> > On Fri, 17 Feb 2023 at 05:31, Ian Evans <dheianevans at gmail.com> wrote:
>> >>
>> >> 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:
>> >> >
>> >> [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!
>> >>
>> > MythTV 27 uses static tuner assignment and that means the HDHR cannot
>> be shared with other devices.
>> > MythTV 32 (30+ IIRC) uses a dynamic allocation scheme that allows
>> sharing the HDHR with other devices that have implemented the dynamic
>> allocation scheme.
>> > So if you want to use the new version 32 system make sure the old
>> version 27 system is disconnected. Note that "not recording" can mean it is
>> still doing EIT.
>> >
>> > You might want to check the software version of the HDHR and possibly
>> do an update of the software. This can be done with the hdhomerun-config or
>> the hdhomerun-config-gui app. The source code of this can be downloaded
>> from the Silicon Dust website.
>> > It could be that the software in the HDHR is too old and that it does
>> not yet (or does not properly) implement the dynamic allocation.
>> >
>> > Everything you always wanted to know about tuner configuration and
>> channel scanning can be found here
>> https://www.mythtv.org/wiki/Channel_Scanning and especially for the HDHR
>> there is this paragraph
>> https://www.mythtv.org/wiki/Channel_Scanning#Scanning_with_HDHomeRun_tuners
>> >
>>
>> Just to further clarify further, this is a brand new install miles
>> away from my .27 system at home. So there is no conflict there. :-)
>> Just wanted to mess around with 32 while I was here and before I do it
>> at home. The hdhomerun firmware is from December 20221205.
>>
>> I can record on both tuners. I just can't record additional channels
>> on the same frequencies . That is, I can record 7.1 and 2.1 at the
>> same time but cannot also record 2.4 and 7.2. Will mess around further
>> today.
>>
>
> Just realized what the issue probably is. The homerun here is the Extend
> model. Just checked and transcoding is on. Will turn that off and will try
> MythTV later.
>

As per my realization this morning, the errors were due to the Extend's
transcode being on. Working now.

Thanks.

>
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