Audio out of sync (1 Viewer)

[beatnut88]

Okie dokie. Here are the new logs. Honestly cannot see what the digital audio could have to do with it though - my reading of the tea leaves is that something global like that would affect all playback. I am also uploading the media info on the two files. I love a challenge - except when I don't! Tommy-1 is the one that ain't working. Can upload a clip of it if that helps.

 

[mm1352000]

Here are the new logs.

Thanks. The media info is also a great idea.

Honestly cannot see what the digital audio could have to do with it though - my reading of the tea leaves is that something global like that would affect all playback.

I can understand why you'd think that.

Without taking all day to explain it, the reason why I pointed out the configuration issue is because it was causing MP to have both LAV audio and AC3Filter codecs in the playback graph.

I hear you say: so what?
Well, the playback graph timing/synchronisation/clocking is strongly coupled to the audio decoding path. I was thinking that two audio codecs in the graph may be messing with the sync.

I hear you say: okay, but something like that should affect all playback, right?
Well, no, because the configuration issue only affected videos with one or more Dolby Digital (AC-3), Dolby Digital Plus (E-AC3), Dolby TrueHD or DTS audio tracks. This is where your choice of videos for the log files is fortuitous; they illustrate perfectly. If you look at the media info you'll see that "Film_2016_-_8. TVC.mp4" only has one stereo AAC LC audio track, and therefore it wouldn't have been affected. "Tommy-1.mp4" also has a stereo AAC LC audio track... and a 5.1 channel Dolby Digital track, so it would have been affected.


Anyhow...
The latest log files show that MP is now only using LAV audio for both videos as you've configured it to do. You've said that there's no difference in result. Therefore the problem must lie elsewhere. The question becomes: where (?). In short, my answer is: I don't know. From an MP perspective, for all money it looks like both videos are played fine. This might lead me to deduce that the problem is deeper in the playback chain. Perhaps within the splitter or codecs. I don't have any insight into that because those are third party components. All I can say is that the enhanced video renderer (EVR) log doesn't show any significant frame dropping.

 

[beatnut88]

Oh, well thanks for your efforts. I did find a clip I had extracted of Tommy and was HandBraked without the DTS soundtrack. It plays fine. So obviously MP - unlike VLC - cannot cope with the digital soundtrack and still maintain sync - for reasons neither of us can fathom. The workaround is obvious while the problem persists.
Neil

 

[mm1352000]

Neil, from your response I have the impression you've completely misunderstood.

I did find a clip I had extracted of Tommy and was HandBraked without the DTS soundtrack.

I assume when you say DTS you mean Dolby Digital.

So obviously MP - unlike VLC - cannot cope with the digital soundtrack and still maintain sync...

Respectfully, this statement appears to show a gross misunderstanding of the situation.

First, all audio that MP deals with is digital. You've said that MP can play 90% of your videos with no trouble. Therefore to say that MP cannot cope with digital audio and still maintain sync is simply false. Let me try to explain this "digital" thing again. The mistake that you made was that you had enabled bit-streaming (which is digital output from the PC) while using an analog PC output. That's like trying to use a postage stamp to send an email, or trying to put petrol in an electric car. It makes no sense; they're incompatible. This advice applies to VLC as much as it does to MP.

Second, to blame MP for failure to maintain sync is to misunderstand how playback in MP works. In your configuration which does not use the MP Audio Renderer, no MP component is responsible for the synchronisation. This is the point I was trying to convey towards the end of my previous reply. Synchronisation is controlled by the splitter and codec filters that you've configured MP to use. In your case those are [third party] LAV components. If you're unsatisfied with the job those components are doing, change them. In other words: try a different splitter and/or codecs.

I hope this has helped to clarify.

 

[mm1352000]

One more note for clarity...
You've compared MP and VLC. One of the primary differences between MP and VLC that almost certainly explains the difference in result is that they are not using the same splitter and codecs. This is why I've suggested that you try configuring MP to use a different splitter and/or codecs. Please remember that those are third party components, so it's quite unfair to blame MP for their short-comings and failings.

 

[beatnut88]

You're over-reacting. But the difference between VLC and MP is that in VLC you can select the audio track (on this case stereo) - an option unavailable in MP from what I can see. Whether you regard this as a failing or a feature is all in the eye of the beholder. As said the simple solution is to re-Handbrake the original DVD (in this particular case) so there is only one audio track (stereo).
Neil

 

[mm1352000]

But the difference between VLC and MP is that in VLC you can select the audio track (on this case stereo) - an option unavailable in MP from what I can see.

For videos that have multiple audio tracks you can:

• select the audio track to play using the context menu (press F9 or right click), OR...
• use the 'a' key to toggle between tracks

Additionally, you're able to configure which audio language MP should select by default:
http://wiki.team-mediaportal.com/1_...n/MediaPortal_Configuration/2_Videos#Language


...but putting that aside, I don't understand how the ability to select the audio track is relevant to the problem at hand. Can you please elaborate?

Whether you regard this as a failing or a feature is all in the eye of the beholder.

In my opinion, the inability to select the audio track would be a missing feature. I don't know how that feature would be relevant to the problem at hand... but happily MP is not missing the feature.

In my opinion, the inability to play a video with correct video-to-audio synchronisation is a failure. As I've previously attempted to explain, MP is not responsible for that failure. Whether you choose to follow up on my previous recommendation to try other splitters and/or codecs is up to you.

As said the simple solution is to re-Handbrake the original DVD...

When you said "the workaround is obvious", I thought the workaround you were referring to was to use VLC instead of MP to play these videos. This reinforced my impression that you consider(ed) MP to be at fault and/or responsible for the synchronisation problem. That's why I've repeatedly emphasized that your chosen splitter and codecs are responsible for synchronisation.

...so there is only one audio track (stereo).

In my opinion encoding with only one audio track should be unnecessary. In general MP is able to play videos that have multiple audio tracks with correct video-to-audio synchronisation, regardless of which audio track is selected.

Further, I don't understand how encoding with one audio track would be an effective workaround. You haven't said that the 10% of videos that have synchronisation problems all have multiple audio tracks, and the 90% that play fine have only one audio track. If you had said that, I'd obviously understand, but since you haven't, I just don't see the connection at this point.

 

[beatnut88]

By changing to auto select decoder and setting the renderer to default wave device the problem disappears.
Neil

 

[Owlsroost]

By changing to auto select decoder and setting the renderer to default wave device the problem disappears.
Neil

...which rather confirms what MM has been trying to say - it's a decoder and renderer problem (most probably a combination of them).

Which decoder(s) and renderer is it actually using now ? (look in the logs, or the 'shift+1' render stats display lists them out)

 

[beatnut88]

Regret ever opening this can of worms. After making the changes outlined above the audio is now in sync. but the vision stops every 20secs for a couple of secs (to keep up?). What a waste of yours and my time. Should have gone with my first instinct and re-Handbraked the file - and any others I come across. Problem solved. Sorry for the inconvenience. Have learnt to keep my own counsel in future.
Neil