Intermittent no-audio from Trailers with MPC-HC

[jwill 28]

I'm not sure if this belongs in the forum, or if it should be in the Plug-ins forum, but when in doubt, I'll choose the more general forum.

 

MBC Version 3.0.96.0 B11-19.1

Trailers version 1.0.5063.19267

MPC-HC version 1.7.1 (using built-in LAV filters 0.59.1.26)

WMC from Windows 7

 

The issue I am having is that there is, intermittently (randomly?) no audio playing when I play a trailer. The video plays fine, but the sound is missing. Sometimes the audio works on the trailers. Sometimes it does not. The issue does NOT appear to be random with every play of a trailer. Rather, it will randomly start, and then every trailer will play with no audio, but then sometime later, it will randomly go away and every trailer will play correctly with audio.

 

Note that it is ONLY on trailers. Whenever the no-audio issue would happen for a trailer, I would go and play one of my movies or TV shows and the audio would be fine on every one. Then I would go back and try to play a trailer, and the audio would still be missing. I could bounce back and forth between movies stored on my server, and trailers, and every single time the audio would be fine for my movies, but the trailer audio would still be missing. And then, for no apparent reason, the trailer audio would be back again.

 

Normally I would attribute this to a bug in MPC-HC and/or LAV Filters, but there is one more piece to this puzzle.

 

I tried going into the settings for Windows Media Center and turned off the WMC sound effects. Since doing that, I have not experienced the issue with trailers having no audio. It is too soon to say definitively that this workaround stopped it, but I would say about 80% sure that this workaround stopped it.

 

So, if that workaround can stop the issue, it seems like the likely culprit for the issue when WMC sound effects are turned on must be the Mediabrowser Classic client and/or the Trailers plug-in.

 

By the way, one more thing worth mentioning is that when a trailer is playing but the audio is not working, I am able to go into MPC-HC / filters / LAV audio decoder(internal) / Status and see the aac codec working in stereo (with the stereo level bars bouncing) and the output as PCM:

 

But despite that, I cannot hear the audio. The status box looks the same whether the audio is currently audible or not.

Edited December 1, 2013 by jwill

[ebr 14913]

There is no way MBC could be involved here.

 

Based on your description, I do think it is a problem with the codecs or MPC-HC.  

[jwill 28]

There is no way MBC could be involved here.

 

That is a bold statement.

 

How do you explain that disabling sound effects in WMC has apparently stopped the issue?

 

I think it is a problem with WMC and MBC not passing off the exclusive mode sound properly.

[ebr 14913]

All MBC does is start your player with a command line.  We don't enter into anything to do with how it handles video or audio.

 

It sounds to me like there is some sort of conflict between WMC's sounds and the codecs that MPC-HC is using.

[sydlexius 241]

EBR is right.  I have the same problem with playing aac-encoded files using MPC-HC and bitstreaming (I have LAV Codecs v 0.59.1).  The reason you get audio again after disabling navigation sounds is partially tied to allowing applications exclusive access to the soundcard, and the audio channel layout changing between WMC and whatever audio you're piping out from MPC-HC.  For most folks who bitstream, it's often easier to just disable navigation sounds.  There are other ways of mitigating the problem, but they either 1) cost money or 2) vary from OEM (ex: Sony) to OEM (ex: Onkyo).

 

Your best bet at getting resolution for lack of aac playback is to go to the LAV Filters forum.

[jwill 28]

Your best bet at getting resolution for lack of aac playback is to go to the LAV Filters forum.

 

If you have the same issue, and you (unlike me) are certain that LAV Filters is to blame, then have you reported the bug on the forum that you just linked to? I did a search on the LAV filters thread looking for a bug report about this issue, but I did not find anything. Could be my search terms were poorly chosen.

[ronvp 92]

If you use Re-clock, you may get audio issues with backdrop video's if you use MPC-HC to play those video's.. The same issue is with MBT and backdrop video's... Try without re-clock and see if the issue is gone. Also try without MAD-VR..

[jwill 28]

If you use Re-clock, you may get audio issues with backdrop video's if you use MPC-HC to play those video's.. The same issue is with MBT and backdrop video's... Try without re-clock and see if the issue is gone. Also try without MAD-VR..

I do not use re-clock.

 

What does madVR have to do with it?

[ronvp 92]

I have had audio issues with re-clock with background videos.  It maybe because the frequent and fast loading/unloading and synchronization that needs to happen. 

 

Disabling madVR is just a thing you can try. i.e.: madVR has the "Smooth" video option, and since it must be messing with the number of frames and possibly adjust the frame rate, it may also impact Audio sync. Just a thought.. I note that your comment on disabling MCE audio effects is well known issue. Also, there are some themes that have their own sound effects (Crystal) and need access to your sound hardware..maybe you need to look at these also..