Does eac3to automatically remove audio delay ?

[madhatter300871]

Hi all.

I think the answer to this is "yes" but would like someone (or even better a few people) to confirm this.

If I strip a video stream, an audio stream(s), subtitle stream(s), chapters list etc. from a blu-ray disc using eac3to does eac3to automatically cater for any audio delays ?

My command would be something like :-

eac3to input.m2ts 1) 3: d:\video.vc1 5: d:\dts_audio_track.dts

or even :-

eac3to input.m2ts 1) 3: d:\video.mkv 5: d:\dts_audio_track.dts

Has eac3to removed any audio delay ?

From what I have read online the answer seems to be "yes" but I cannot see anything anywhere in the eac3to output indicating that an audio delay has been found and the demuxed stream adjusted accordingly (or not).

When I then encode the video track to divx/xvid/x264 or whatever and multiplex into a container the audio is in synch but I have only done 2 or 3 movies so far (I don't have a big blu-ray collection yet !!). Is this just luck or does eac3to get delay information from the source stream and adjust demuxed audio streams accordingly.

Hopefully I'll get a few replies.

Many thanks.

[TinTime]

Yes, it will fix delays during demuxing. If it does then it will report it in the log. If there's no delay to fix then it will say nothing (as you've found).

The only exception is for TrueHD. I think this will have the delay value added to the filename if you demux it. I've never tried this - I always convert TrueHD to FLAC rather than demux, in which case the delay is applied.

[madhatter300871]

Thanks TinTime for your reply.

So worrying about the audio delay is a thing of the past when using eac3to with blu-ray content, the demuxed audio is all set ready to go with any delays removed.

I'll keep my eyes on the logs and see if I ever get a blu-ray with a delay applied to the audio stream just out of interest.

Another reason for asking this question is that I did not have good results using eac3to on a standard MPEG2 VOB. It reported audio delay as -8ms while mediainfo reported it as -128ms and dgindex demuxed it and included -128ms in the file name, this shook my confidence in blu-ray audio delay handling.

I have not managed to get mediainfo to report an audio delay for my blu-ray content, but this could just be because on the few disks that I have there is no audio delay !

[TinTime]

Originally Posted by madhatter300871

Another reason for asking this question is that I did not have good results using eac3to on a standard MPEG2 VOB. It reported audio delay as -8ms while mediainfo reported it as -128ms and dgindex demuxed it and included -128ms in the file name, this shook my confidence in blu-ray audio delay handling.

I think that I once read a post from neuron2 about discrepancies between audio delays reported by different tools. There was a reason for this but I can't remember what it was and I didn't fancy looking through all of his posts trying to find it for you! Sorry to be vague about this.

I've had problems in the past demuxing DVDs with eac3to (not with the initial audio delay but it occasionally finds and corrects audio gaps where it shouldn't) so I always use DGIndex for that instead.

[Audionut]

Originally Posted by TinTime

I think that I once read a post from neuron2

Here is a good start.

http://forum.doom9.org/search.php?searchid=5086840

[madhatter300871]

Thanks audio nut

But that link doesn't seem to exist !

I know i am very (VERY) late in replying to this, i have not been too well. Hope its ok to bring posts back to life after nearly one year !