Missing Audio - Switching from MPEG-1 to AC3 and vice versa

[NumberFive]

Hello,

Since migrating to a new (faster) machine I am experiencing a bug in 4.2.5 when changing between channels with MPEG-1 and AC3 audio.  I get the overlay "Missing Audio.  You don't have <...> decoder selected." message.

The thing is, I do have working decoders selected.  If I tune to either channel from scratch from the TV Guide, they work perfectly.  If I change from one channel to the other, I get the overlay and no audio.  Seems to be the same bug as here:

https://forums.nextpvr.com/showthread.ph...388&page=2

and here:

https://forums.nextpvr.com/showthread.php?tid=58260

Recordings playback fine.

I know that V4 is no longer developed, but was there a fix to this?  Sorry I've tried to forum search and Google and I'm not finding one.


Thank you.


(the good news is, I now have a spare machine to try migrating to V5!)

[NumberFive]

Update with an observation...

On my old PC I had DVB-T tuners and one DVB-T2 tuner. The DVB-T2 tuner only had DVB-T2 muxes on it, no DVB-T ones. Thus, if changing from a channel with AC3 audio to one with MPEG audio, this usually means changing tuners.

On my new PC, all the channels are tuned to all tuners, so when changing channel you remain on the same tuner. This means frequently changing from AC3 to MPEG audio and vice versa. Plus the new tuner is noticeably snappier at changing channels.

Where this falls apart is that there are some MPEG audio channels on DVB-T2, and when changing between those on the old machine there's no problem. But it's also much slower at doing so.

Could it be that this is time related? Something to do with the time needed to build a filter graph?

Just pondering. Any thoughts much appreciated.

[NumberFive]

Here's logs of the issue.

Start off on BBC1 - MPEG1 audio, fine.
Move to BBC2 HD - AAC audio, fine (unusually).
Move to RTE1 HD - MPEG1 audio, says:

Code:

2021-04-27 23:27:38.770 [DEBUG][1] Audio renderer not found. Warning user...

However it's clear the MPEG1 decoder is there as it has been using it previously.  

[mvallevand]

Have you tried LAV? The MS decoder might not decode MPEG in all situations.

Martin

[NumberFive]

Hi Martin,

I've tried various combinations of decoders, including all Microsoft, all LAV and mixes of both and others. It doesn't seem to make any difference.

If I tune to a channel from scratch (i.e. no live TV running) it always works. Recordings also always work. It's only the case of when changing from one channel to another with a different audio type that brings up the error.

[mvallevand]

Sounds like it could be time to re-think your decision not to upgrade to V5 when you upgraded the PC.

Martin

[NumberFive]

I do intend to upgrade to V5, however I decided to upgrade in 2017 and have spent the last number of years working with various equipment vendors to sort out bugs in their firmware and drivers. For example the Intel graphics flickering OSD overlay glitch.

This is a bug that has seemingly existed for a while (the two linked threads above). I'm not looking for a new fix to V4, I'm just wondering if there is a known fix out there.

I'll get a look into V5 migration soon.

[mvallevand]

Sorry I didn't understand your "new" machine was made in 2017. What many people don't know is sub probably started v5 in late 2018 or early 2019 since we got the first pre release in March 2019. I expect there would have been very little investigation into v4 issues in the second half of 2018. I don't see the problem magically fixing itself but it would be good to see the logs in v5.

Martin

[NumberFive]

Sounds like it could be time to re-think your decision not to upgrade to V5 when you upgraded the PC.

Martin

Seems to also manifest in V5 - https://forums.nextpvr.com/showthread.php?tid=62578

[sub]

Sounds like it could be time to re-think your decision not to upgrade to V5 when you upgraded the PC.

Martin

Seems to also manifest in V5 - https://forums.nextpvr.com/showthread.php?tid=62578

The difference is that I'll look take the time to look into it with v5