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How do you find out if a surround track actually contains surround information?

Posted: Thu Jan 05, 2017 11:13 pm
by Gnd0
Hi,
from time to time I'd like to check if a stereo AC3 sound track which is tagged "Dolby Surround" in Handbrake actually contains surround information. My problem is that I do not own any surround equipment yet so I can't just listen to find out. In general, I don't entirely trust the guys who mastered a DVD because I've seen a lot DVDs containing stereo tracks which are actually twin-mono tracks so I assume that this happens with surround tracks as well.

My idea is to demux a surround track on my computer and save each channel as a mono track. This way I could find out whether it is a real surround track or just stereo. If the source is a mislabeled stereo track, there should not be any relevant sound information on the surround channel. Besides of that, I could check what happens when Handbrake downmixes from 5.1 to dpl1.

Anyway: I know that this is quite a nerdy question, so could you please tell me:

Is this a stupid idea? If yes, why?
If no: Is there is a program available capable of decoding surround channels to mono files? I had a look at ffmpeg but it seems that it only splits Dolby Digital but not the old-fashioned analog tracks.

Any input is highly appreciated!

Re: How do you find out if a surround track actually contains surround information?

Posted: Mon Mar 20, 2017 10:41 am
by cehoyos
Gnd0 wrote: Thu Jan 05, 2017 11:13 pm Is there is a program available capable of decoding surround channels to mono files?
MythTV contains such a filter, see FFmpeg ticket #4085.

Re: How do you find out if a surround track actually contains surround information?

Posted: Thu Jul 20, 2017 9:06 am
by --=BJ=--
I would recommend MediaInfo for easy usage