TS file glitches cause audio loss

[zaldwaik]

I am having a problem with some recordings when a video or audio glitch happens to be in the file. While playback after the glitch the audio is gone unless I pause then play, or do a short skip. Otherwise the audio is gone indefinitely. PCH is not able to recover unless I intervene.

I have a strong signals for channels where this happens, so I cannot pin point the root cause. It could be my tuner getting old after 5 years, or something else causing the problem.

I tried running videoredo on recordings with limited success. Sometimes videoredo will introduce a glitch by fixing something else and the problem happens with the fixed file, but not the original. Sometimes it happens with both.

This appears to be a PCH issue as the problem happens outside NPVR too. I have not found much looking for answers on the PCH forum, I thought the folks here would have better insights (especially Martin) that might help me resolve the issue.

I am considering scripting tsmuxer to remux the file into a new one, but it looks like a lot of work to do compared to videoredo. Audio is AC3 and recordings are ATSC.

[mvallevand]

Are you using audio passthrough? The AC3 block is fairly long and checksumed so it is very prone to even the smallest stream error. Normally correcting the file won't even fix this. With analog out the PCH might be ok, its just PCM with a hiccup, but on passthrough it counts on your amp. In someways it is doing this to protect your speakers I expect the skip or pause causes the amp to reset too.

Rather than going to any bother, I'd be satisfied with the pause/play solution.

Martin

[zaldwaik]

It is pass-through. The play/pause solution works for me, but not the wife and children especially the little one while watching PBS kids. Is there a tool for fix AC3? Thanks.

[imilne]

You could maybe try something like Reclock and/or ac3filter and have them decode the audio, then re-encode it back to AC3. They might be able to handle the glitches, and ensure that a clean stream is sent to your amp.

[zaldwaik]

Thanks to Martin's tip, I decided to downmix AC3 on PCH instead of pass-through and the problem went away. A small price to pay for stability.

[leaded1]

Wow, thank you for this post! I've had this problem on my digital recordings with AC3 audio for a long time... Such a simple fix right under my nose the whole time.

[jksmurf]

"Thanks to Martin's tip, I decided to downmix AC3 on PCH instead of pass-through and the problem went away"
Can someone describe what the fix is exactly? What do I change, and where, and to what?

ta!

k.

[zaldwaik]

Change your PCH settings for AC3 under Audio/Video to analog (PCM) instead of raw or digital (pass- through)

[jksmurf]

OK Thanks for the info. They are already on that setting.
k.