Eraserhead LD PCM mono track

[Onti]

The movie was originally released with a mono mix, but blu-rays only features stereo tracks (and Criterion has missing shots). 

https://www.lddb.com/laserdisc/27679/NDH-101/Eraserhead

Anyone have the Eraserhead laserdisc and can capture the audio to obtain the PCM mono track?

I'd like to sync the original LD audio to the Capelight blu-ray. If you can capture the video as well, this would help syncing a lot.

[pipefan413]

This is on my list so if I get it I'll let you know.

[ReconWorld]

Criterion corrected the missing shot later on.

[Onti]

This is on my list so if I get it I'll let you know.

Thanks a lot!

Criterion corrected the missing shots later on.

I didn't know that. But I'll use the Capelight release .

[ac3]

Looks like theres only an analog Mono track available on LD. The rest are stereo pcm. An older DVD might have the Mono mix.

[zoidberg]

I had this on VHS years ago and it was remixed by Lynch even then, would be surprised if the mono made it to DVD

[ac3]

The french dvd / bluray says its mono

[spaceboy710]

I have Eraserhead (1977) [30176], the Columbia analog laserdisc. I THINK it is stereo but I could be wrong. I intend to capture it sometime in the near future.

[Onti]

I had this on VHS years ago and it was remixed by Lynch even then, would be surprised if the mono made it to DVD

Maybe you’re right.

The french dvd / bluray says its mono

It seems so… Audio : Anglais DTSHD-MA 2.0mono

https://store.potemkine.fr/dvd/354502004...raserhead/

But maybe a downmix and not the original mono track?

In any case, how can we know for sure if it is 2.0 mono or 2.0 stereo? is there any cheking software?

I have Eraserhead (1977) [30176], the Columbia analog laserdisc. I THINK it is stereo but I could be wrong. I intend to capture it sometime in the near future.

Thanks.

[pipefan413]

Audio : Anglais DTSHD-MA 2.0mono

https://store.potemkine.fr/dvd/354502004...raserhead/

But maybe a downmix and not the original mono track?

I would be *very* interested to find out. I understand the "stereo" remix of this to be very conservative (it's still basically mono for the most part with the odd bit of stereo separation here and there, apparently) but nonetheless it is not original and therefore of lesser importance from my perspective.

In any case, how can we know for sure if it is 2.0 mono or 2.0 stereo? is there any cheking software?

You can do this with ffmpeg. The basic idea is that if you flip the polarity of one of the channels and then merge them into a single channel, the bits of exactly equal and opposite polarity will cancel out to nothing. So whatever's left tells you if the original analogue input was the same or not. If there's nothing whatsoever left, then the two channels are precisely identical, so mono (in this case, you'd pretty much definitively know that only one track was digitised and then it was duplicated in the digital realm). If there's *essentially* nothing left (i.e. the waveform looks like a straight flat line until you zoom way in and then there's a tiny bit of a wiggle), then the two channels were identical for all intents and purposes but due to the nature of analogue to digital conversion are no longer exactly the same, but that's still mono (in this case, by contrast to the previous scenario, the originally mono track must have been duplicated at some point in the analogue realm, and then those duplicate tracks each digitised individually). If there is audible noise left, and you can see a fairly obvious waveform, then it must be stereo rather than mono because the two channels are noticeably different.

Here's @bronan making reference to it, without the explanation:

I use this to check

ffmpeg -i "is_this_stereo.wav" -filter_complex "stereotools=phasel=1" -ac 1 "X:\output.wav"