AVI audio delay

[Andrey]

Hi !
Is there any way to find audio delay defined for 2nd audio stream in avi ?
Thanks in advance !

[Abond]

did you try GSpot?

[Andrey]

Yep.
May be I'm too tired now :( (some this week problems allow me to sleep no more than 5h a day) but I do not see any delay info in audio prperties GSpot shows me...

[Abond]

At the field Streams and Interleaving there is a window marked as I/L where is written some info and also something like "p=480" or "N=420". This is the delay in ms p=positive, n=negative. For the second audio obviously you should click on the audio field at 2/ (or something like that) and to look for interleaving info in I/L window. I think this is how to, but I haven't ATM avi with two streams to check.

[Andrey]

Oh.
I've checked another avi, this data is presented.
But when I check my avi, the next info appears:
Type: OpenDML AVI, "rec list" style
I/L: Not supported.

So, I'm not blind :)

Hm. I see two possible reasons for that:
1st. I've created this file with AViMuxGUI (last version).
2nd. Two audio streams are of aac type.

Ok. Seems that I should find actual delay by myself again.
FYI: :) The reason for all this:
I've TV show compressed. With two streams: English and translation in my native. Now I've found a better quality source of translation. I've compared them - source is the same. So I manage to replace it with new and better one. :)
But now I need to find an actual delay again... Shit.

[Abond]

Ah, I see. May be the problem is that avi doesn't support more than one audio natively (AFAIK). Well, may be VDubMod will give you some information (File-File information). If not, try to remux the file disabling the audio you are not interested in and try again with GSpot or VDubMod.

[Andrey]

I knew that VDubMod cannot remux file with aac audio.
But you give me idea...
I've tried NanDub.
It can do it, but then audio info is either lost or wrong.
At least, no player plays the audio :) ,GSpot and dubs show some info, but not a delay.
AVIMuxGUI when remuxing does not maintain delay info.

[alexnoe]

Most programs, including avi-mux gui and vdub(mod) don't allow any delay to be stored in avi files. They rather pad with silence or remove the beginning of the audio stream. Therefore, there is nothing to keep.
May be the problem is that avi doesn't support more than one audio natively (AFAIK)A lie of a few people trying to propagate OGM. AVI natively supports 99 audio streams.

[Matthew]

No doubt this won't help, but for AC3 you can calculate the delay by running the AC3 through besplit/besliced and recording "sync found after XYZ bytes". Divide XYZ by the 4*bitrate and multiply by 32 ms. All this is doing is calculating the length in ms of the partial frame at the beginning.

@alexnoe, with MP3 that silence is lost when demuxing though, right? I must say I'm really surprised that there is no method available to calculate the delay. Fairly recently I had a ~1000 ms delay on an avi and manually syncing after re-encoding was really annoying.

[alexnoe]

If you muxed it with VDub(Mod) or NanDub, and demux with AVI-Mux GUI, then the delay will be lost.
Reason: VD(M)/ND insert some crap, instead of valid MP3, which AVI-Mux GUI removes if you process such a file.

If you mux with AVI-Mux GUI, valid MP3 data will be used to insert the delay, meaning that it will be preserved when demuxing.

[Matthew]

That's pretty nifty on your part :)

But nandub is still very commonly used by others, so would be nice to be able to detect the delay (i.e. determine ms via length of junk). Humbug.