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Capturing LD audio

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Hello all,

I have the GOUT Star Wars DVD's and have made anamaphoric versions of them using the DVD-Rebuilder software. However, I also have the Definitive Collection laserdiscs, and the compressed sound on the DVD's is driving me nuts. I would like to capture the PCM tracks from the laserdiscs and replace the compressed dolby 2.0 tracks on the dvd's.

I have a sound card with a digital input, so I can connect my laserdisc players digital out directly to it. I was wondering if someone had some info on what software to use to catpure the audio, how to sync it up with the GOUT dvd's, and so on. I appreciate any feedback anyone can provide. Thanks!

Greg
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You're in luck as Belbucus recently captured and synced a bunch of different audio tracks to the GOUT. You need to add a 1.017 second delay or something like that but yeah, there are multiple audio tracks available in FLAC format to mux with the GOUT. Have a look around in this forum and the Star Wars Preservation one to find the thread (sorry, I'm too tired from work to track it down for you).

To contact me outside the forum, for trades and such my email address is my OT.com username @gmail.com

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Assuming this is a follow-up to this thread, could you not get hold of Belbucus' files, or did you just want to have a go at doing it yourself?

Most audio software is able to record; e.g. SoundForge, Audition, Audacity. Just set the input to SPDIF in your sound card drivers or Windows recording control.

The PCM on the laserdiscs is 44.1kHz, you will probably need to upsample to 48kHz to be compatible with your DVD player.

There are small gaps in the audio at each side change that need to be patched; ideally you should also record the PCM off the "Faces" laserdiscs to patch the gaps.

The laserdisc audio drops synch with the DVD at two points, as Belbucus reports:
1) The cut from Mos Eisly exterior to beginning of Han’s confrontation with Greedo.

2) Oddly enough, at what would have been the last reel changeover when projected theatrically (probably just a coincidence).
You will need to adjust the PCM at these points; it's useful to have the AC-3 track extracted from the DVD for this purpose.

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And is there any way how to get these files for people without usenet access and without demonoid access ?
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Thanks to all. I searched demonoid for the ready made pcm tracks, but could not find them. I think they went up and were taken off again really quickly. Or at least I couldn't find them. I would prefer to just try the ready made tracks, but will capture my own if I can't find them. I like the gout dvd's video better than the lasers, but the audio is so much weaker it drives me nuts. Thanks for all comments.

Greg
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I've captured LD audio with a digital soundcard (M-Audio 24/96) for the purpose of re-authoring a DVD, and it can be a real pain, especially if the LD uses a different master as you might need to check and make sure the audio syncs up at every reel change point. Also, NTSC LDs seem to use 44,056Hz instead of 44,100Hz, but I don't know of any way to capture them other than at 44,100Hz.

When your computer thinks a 44,056Hz wav is 44,100Hz, it'll play it slightly faster speed. So when I first tried it, the sound got slightly out of sync partway through the movie. It still seemed to get out of sync when I manually set the sample rate (without re-sampling) to 44,056 in Sound Forge, so I just made a wav of the AC3 audio from the DVD and made sure it synched up at various points in the movie.

To do this, I split up the audio into two wav files, one for each side of the LD. I then made sure the start point was at the same frame as the DVD audio, then I found a point (like a loud, sharp noise) towards the end of each LD audio file and calculated how far off it was from the DVD audio. I then re-set the sampling rate (again, without re-sampling) to match the speed of the DVD audio. When everything was in sync, I finally re-sampled the audio (without using an anti-aliasing filter since I don't believe it's needed when you're going to a higher sampling rate) to 48kHz for DVD audio, and re-muxed it with the video. It still gets slightly out of sync at one point and then gets back in sync. Probably a reel change that I didn't account for. Oh well, it's not too bad.

Anyways, rather than going through all this trouble for the OUT, I just used the LPCM audio taken from the LDs that was on the fan-made OUT DVDs I got years ago from someone on this site, I think. I forget who did them, but it didn't require much work, I just had to take out the bits of silence that were at the LD side change points and make sure the audio started at the same point as the DVD audio.

Started with ESB and finished it last night, and it sounds beautiful.