[RESOLVED] Bad delay values for audio demuxed from bluray with a range set

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Re: Bad delay values for audio demuxed from bluray with a range set

Post by Guest »

Players are supposed to use PTS to determine the presentation time.
Yes, but players start at the beginning, the issue crops up when using RANGE, i.e. starting somewhere in the middle.
DGIndexNV does it right when demuxing from the start, the issues only show up when using RANGE because studios use some questionable authoring techniques.
Stock clips for studio intros, etc, with missing or mismatched audio, jumping timing stamps etc
Summary
DGIndexNV does it right, the studios are using hacky authoring techniques :salute: :salute: to DGIndexNV and its author
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Re: Bad delay values for audio demuxed from bluray with a range set

Post by admin »

I have to keep pointing out that if you do things from the start it is only "correct" if the original file is in sync. Sure that will be true of bluray M2TSs, but not necessarily of arbitrary TSs.

But thanks for the props. ;)

Testing 'forced subs only' demuxing right now, from TS or MKV.
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Re: Bad delay values for audio demuxed from bluray with a range set

Post by admin »

Forced subs only working fine!

One more small thing to do then slipstream time.
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Re: Bad delay values for audio demuxed from bluray with a range set

Post by admin »

admin wrote:
Wed Jun 20, 2018 6:19 am
ggtop wrote:
Wed Jun 20, 2018 1:41 am
Do you have a (commandline) tool which analyzes those "easy to find" timestamp mismatches? :scratch:
I used to have one but haven't used it in years. Let me see if I can find it. It's possible I had it only on my work computer at the time. I'll post again if I find it.
Sorry, ggtop, I don't have it and I remember it was MPEG2 only in any case.
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Re: Bad delay values for audio demuxed from bluray with a range set

Post by admin »

Filename DELAY mechanism has been removed in slipstream 149.
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by Guest »

Another method that might help get started
Open the mpls with MediaInfo
Use whichever view you prefer
Go to Debug > Advanced
Look for Delay relative to video for the audio track you want
Confirm with eyes and ears
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by admin »

I prefer not to recommend things I have not thoroughly tested. How do we know MediaInfo's heuristic is any good? I'm trying to get away from these dodgy heuristics! Use eyes and ears, as you said.

EDIT: If I mux the streams from your range to MKV without entering a delay, then MediaInfo just reports delay 0. What good is that? Otherwise, it just reports the delay entered into mkvtoolnix.

I don't see why you have suggested this at all.
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

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Just as a start point prior to the eyes and ears
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by admin »

I used trim ts on your stream and then checked it with MediaInfo. It gives a delay that is close to what DGIndexNV used to give, i.e., still a full second off (suggesting that they both use similar heuristics). I just don't consider that a useful starting point. But if you find it useful, I can't argue with that.
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by Guest »

If the stream is being trimmed there seems to be no good automated way to determine delay for the audio
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by admin »

It's not just trimmed streams. For example, an off-air capture will be the same way. Streams like this are why you need to find a correct delay in the first place. If you limit things to streams that are already zero delay, there's no need to try to determine it. ;)
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by ggtop »

Coming a bit late to the party...

I also agreee that checking with eyes and ears is the only reliable method.
I've seen too much mastering anomalies such as different audio formats on the same PID over m2ts in a mpls, no Audio in a m2ts etc.

I've written some checks I perform wirh Mediainfo in batch files to get some basic info of the processed source.

Afterwards I always check the muxed file for A/V sync.

ggtop
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Re: Bad delay values for audio demuxed from bluray with a range set

Post by ggtop »

admin wrote:
Thu Jun 21, 2018 3:25 pm
I know you weren't asking for anything. I was just trying to make my position clear. If you figure out the source of your unexpected delay please let me know. Thanks.
I will do some more tests in the next week and let you know.
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Re: Bad delay values for audio demuxed from bluray with a range set

Post by ggtop »

admin wrote:
Thu Jun 21, 2018 8:58 pm
Sorry, ggtop, I don't have it and I remember it was MPEG2 only in any case.
Never mind. Thank you anyway.

BTW For MPEG2 sources from DVD I normally use the A/V check feature of PGCDemux (works on IFO level)
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Re: [RESOLVED] Bad delay values for audio demuxed from bluray with a range set

Post by ggtop »

Hi,

just wanted to reply on the weird issue I reported. I finally found out that the demuxed audio stream has an issue at around position 00:01:57h.
That was reported by TSMuxer on attempting to mux a Bluray folder from the original source. I used EAC3to to insert a silent frame at that position and now evrything is fine.

BTW All the tools I know didn't report an issue at that timestamp.

ggtop
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