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Capturing PCM from LD
https://forum.lddb.com/viewtopic.php?f=30&t=8560
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Author:  forper [ 10 Aug 2019, 08:11 ]
Post subject:  Capturing PCM from LD

Okay I bought a piece of crap C-media CM6206 USB sound card off ebay for 15 bucks to record WAV from LD:

Image

So I got my LD player, MDP-355GX SPDIF out to CM6206 SPDIF in using Audacity software. Audacity can register the signal but when I record I just get fuzz. I tried line in from the 355 and it records the actual sound, although poorly. The digital audio on the 355 is confirmed working.

I went through all the settings I could on Audacity and made a number of tests at different sampling rates, bit depths and all fuzz.

Can anyone recommend a simple PCM recorder software or settings for audacity? Or is my CM6206 just faulty do you reckon? Thanks.

Author:  deadlegion [ 10 Aug 2019, 14:06 ]
Post subject:  Re: Capturing PCM from LD

C-Media?
Probably rubbish.

Author:  signofzeta [ 10 Aug 2019, 16:57 ]
Post subject:  Re: Capturing PCM from LD

They don’t still have that generic media recorder thing in Windows? They must.

Author:  forper [ 11 Aug 2019, 00:37 ]
Post subject:  Re: Capturing PCM from LD

I found a generic windows sound recorder but you can't even select the recording source. Thanks anyway.

okay deadlegion. Somebody here said any old junk would do the job easily.

Author:  tasuke [ 11 Aug 2019, 13:43 ]
Post subject:  Re: Capturing PCM from LD

i have one of these i use to record the direct 2-channel analog stereo from playback of whatever Audio or A/V components i'm using.

the results sound terrific, at least to my piss-poor ears;

Image

Author:  takeshi666 [ 11 Aug 2019, 14:49 ]
Post subject:  Re: Capturing PCM from LD

I think what forper is trying to do is get bit-perfect duplicate of the digital audio track by recording it directly with a PC so there's no analog conversion taking place anywhere until playback. Unfortunately I don't think any built-in sound card comes with an optical in socket so he picked up this...whatever hunk of China junk this is.

Author:  sonicboom [ 12 Aug 2019, 16:03 ]
Post subject:  Re: Capturing PCM from LD

M-Audio Transit will work. USB2 connection. Its old and probably cheap on Ebay. There is a new Pro version that will require an adapter since the optical input is on a mini connection. The new one probably has better drivers than the old version. Here is a link to the original model for reference. No affiliation. I have the old one and confirm it works as advertised.

https://www.amazon.com/M-AUDIO-Transit- ... B0000CDHP5

Any MOTU interface with Toslink, like the Traveler, will work great also but is more expensive. I personally use a Traveler mk 1 myself and just did this the other day with come concert LDs. I've found these cheap locally on Craigslist. This will require a firewire connection but their newer products also have USB connectivity.

https://motu.com/products/motuaudio/traveler-old/

Ideally when you do the capture you should set the clock source to Optical/SPDIF or External so that the LD player is the sync master. This should help reduce jitter or noise. Setting should be 44.1KHz, 16 bit, Stereo.

Author:  forper [ 12 Aug 2019, 22:07 ]
Post subject:  Re: Capturing PCM from LD

Thanks so much, although I wish I could use what I already have at least there is a reasonable option. After I move I'll have a look for a used M Audio transit. Thanks, thought I was going to be on my own on this one.

Author:  jd213 [ 13 Aug 2019, 11:15 ]
Post subject:  Re: Capturing PCM from LD

can definitely recommend M-audio, I've been using their 2496 card for 15 years now and never had any major problems. One thing that you might be aware of already, but Audacity needs to be set to WASAPI, otherwise it won't be a bit perfect capture.

Author:  forper [ 13 Aug 2019, 12:59 ]
Post subject:  Re: Capturing PCM from LD

Thanks, I wasn't aware but had tried it in one of my tests. Yes all settings, all bitrates, I just get fuzz and it doesn't record in real time either. About 4 minutes of recording comes out to a 9 second file. Don't know what's going on there.

Author:  jd213 [ 14 Aug 2019, 07:25 ]
Post subject:  Re: Capturing PCM from LD

Hmm, was just going to mention bit rates, or rather bit depth. I haven't used Audacity much but I seem to remember it showing the bit depth wrong (or at least weirdly), since a 16-bit wav captured in Sound Forge would be shown as 24-bit, and a 24-bit wav file would be shown as 32-bit. I guess you tried different bit depths already but if not, maybe try setting it to 24-bit (since LD PCM is 16-bit).

Another software that I've seen recommended from a number of people is Cockos Reaper, it's not freeware but it has a 60 day demo, so maybe try it before getting a new capture device: https://www.reaper.fm/index.php

Author:  lons_vex [ 14 Aug 2019, 09:26 ]
Post subject:  Re: Capturing PCM from LD

Back in the good old days I used a software called "Cool Edit" the record audio from LD.
I assume it has not been updated in ages and only works on Windows XP, but it was pretty awesome back then.

Author:  signofzeta [ 14 Aug 2019, 17:35 ]
Post subject:  Re: Capturing PCM from LD

Man you people are REALLY overthinking one of the most basic utilitarian recording jobs imaginable.

1: Plug digital out from LD player into your computer (small doodad may be required but don’t be a dunce and start ordering stuff unless you’re sure you don’t already have a digital out.)

2: Open anything that can record stereo (ANYTHING) and select the correct input. I would use software that shipped with the OS if possible.

3: Hit record. It’s like 600MB an hour so don’t loose track of time/space.


That’s it. If you apply any process or do anything at all to the file it’s no longer the original so you don’t need anything like “good” software or hardware. Recording a guitar is a career but recording digital audio from an LD player is like community college broadcasting 100.

To use an example, a 2008 MacBook will do this right out of the box. Nothing at all required. New ones don’t have any ins at all but they all have QuickTime which is one of 1000 different programs that can...literally just record a file. This stuff is crazy simple.

Maybe this seems dog dumb simple to me because my generation grew up on tapes and MDs and we did this stuff sometimes ALL WEEKEND trying to bulk up each other’s dub collections. Plugging one thing into another and hitting Record. That’s it. If you don’t have a digital in on your computer then you’re way overdue for getting one if you’re into this kind of thing. They are like $10-20 on eBay now but of course you can buy a $10,000 sound card if you want to do the same thing but the recording will be IDENTICAL all things being equal.

Author:  signofzeta [ 14 Aug 2019, 17:44 ]
Post subject:  Re: Capturing PCM from LD

lons_vex wrote:
Back in the good old days I used a software called "Cool Edit" the record audio from LD.
I assume it has not been updated in ages and only works on Windows XP, but it was pretty awesome back then.


I had a beta version of the original Soundforge that I warezed in like 1999 and I used it until Windows no longer ran it. It was like the Office 97 of wave editors. It was light and fast and everything was cool.

Audacity, at a glance, should be just as satisfying but it’s all...open sourcy. It’s got way too many functions that nobody understands or uses, buttons and stuff are all clunky like they were made for a Linux guy or something. It also has gone through long periods of instability across multiple versions for sometimes a year or more. It loses stuff. The VLC of wav editors. It’s a classic and a life saver but it’s also kinda crap at the same time. If there was something worth paying for I’d for sure get it. But mostly just hear that “Audacity is the best” so if the stuff that costs money is worse I sure don’t want it.

Author:  jd213 [ 14 Aug 2019, 18:03 ]
Post subject:  Re: Capturing PCM from LD

signofzeta wrote:
Man you people are REALLY overthinking one of the most basic utilitarian recording jobs imaginable.

1: Plug digital out from LD player into your computer (small doodad may be required but don’t be a dunce and start ordering stuff unless you’re sure you don’t already have a digital out.)

2: Open anything that can record stereo (ANYTHING) and select the correct input. I would use software that shipped with the OS if possible.

3: Hit record. It’s like 600MB an hour so don’t loose track of time/space.



Unfortunately it's not that simple if one desires bit-perfect captures, since the audio could get internally converted to analog and then back to digital by the PC/input device, or otherwise altered so that it's no longer an exact digital copy.

The first posts on these threads on FanRes would probably be good starting points for making sure that you're recording the exact PCM data:
https://forum.fanres.com/thread-2742.html
https://forum.fanres.com/thread-2686.html

Author:  takeshi666 [ 14 Aug 2019, 18:25 ]
Post subject:  Re: Capturing PCM from LD

signofzeta wrote:
lons_vex wrote:
Back in the good old days I used a software called "Cool Edit" the record audio from LD.
I assume it has not been updated in ages and only works on Windows XP, but it was pretty awesome back then.


I had a beta version of the original Soundforge that I warezed in like 1999 and I used it until Windows no longer ran it. It was like the Office 97 of wave editors. It was light and fast and everything was cool.

Audacity, at a glance, should be just as satisfying but it’s all...open sourcy. It’s got way too many functions that nobody understands or uses, buttons and stuff are all clunky like they were made for a Linux guy or something. It also has gone through long periods of instability across multiple versions for sometimes a year or more. It loses stuff. The VLC of wav editors. It’s a classic and a life saver but it’s also kinda crap at the same time. If there was something worth paying for I’d for sure get it. But mostly just hear that “Audacity is the best” so if the stuff that costs money is worse I sure don’t want it.

Goldwave is my sound editor of choice. I use a pretty old version too. I think I've only ever used Audacity to record when Goldwave didn't recognize the sound source for some reason, and even then I just exported it as a wave file to edit in Goldwave anyway.

Author:  forper [ 14 Aug 2019, 22:13 ]
Post subject:  Re: Capturing PCM from LD

Thanks to Jd and Lons Vex. I tried all of those and no luck. It must be the hardware.

I even tried hooking up my MDS-JB980 MD deck and getting a driver for that to become an input device but no luck there either, I couldn't even get the old NetMD driver to work anymore on Windows 7.

signofzeta wrote:
Man you people are REALLY overthinking one of the most basic utilitarian recording jobs imaginable.

1: Plug digital out from LD player into your computer (small doodad may be required but don’t be a dunce and start ordering stuff unless you’re sure you don’t already have a digital out.)

2: Open anything that can record stereo (ANYTHING) and select the correct input. I would use software that shipped with the OS if possible.

3: Hit record. It’s like 600MB an hour so don’t loose track of time/space.



That's what I did. It didn't work if you actually read the thread.

I grew up on tapes and MDs too.

Author:  signofzeta [ 15 Aug 2019, 00:07 ]
Post subject:  Re: Capturing PCM from LD

jd213 wrote:
signofzeta wrote:
Man you people are REALLY overthinking one of the most basic utilitarian recording jobs imaginable.

1: Plug digital out from LD player into your computer (small doodad may be required but don’t be a dunce and start ordering stuff unless you’re sure you don’t already have a digital out.)

2: Open anything that can record stereo (ANYTHING) and select the correct input. I would use software that shipped with the OS if possible.

3: Hit record. It’s like 600MB an hour so don’t loose track of time/space.



Unfortunately it's not that simple if one desires bit-perfect captures, since the audio could get internally converted to analog and then back to digital by the PC/input device, or otherwise altered so that it's no longer an exact digital copy.

The first posts on these threads on FanRes would probably be good starting points for making sure that you're recording the exact PCM data:
https://forum.fanres.com/thread-2742.html
https://forum.fanres.com/thread-2686.html


So I may be doing it wrong but there’s no way for me to tell...that sounds like something an insane person would say.

Knowing the hardware I have personally I know for sure my sampling rate is correct and also that that there is no D/A/D going on (I can’t even...that makes no sense to me). However it doesn’t seem like..you seem to be saying that most people’s computers are going to default sample at 48khz and upconvert the difference. I don’t really recall ever experiencing that. Even stuff I have that does 96khz defaults to 44.1. All my devices have both 44.1 and 48khz options if not higher. I’m pretty sure but then most of my stuff is more kinda pro audio than “computer gear”. Maybe the $10 USB stuff I’m promoting doesn’t in fact accommodate. The $60 stuff should though.

Either way, it’s a good idea to check these things to be sure but after even then this is still a very simple process.

Author:  jd213 [ 15 Aug 2019, 03:44 ]
Post subject:  Re: Capturing PCM from LD

signofzeta wrote:
So I may be doing it wrong but there’s no way for me to tell...


The 2nd FanRes link literally contains a way for you to tell.

And yes, digital-analog-digital conversion in a PC is certainly possible in cases such as when WASAPI isn't used: https://manual.audacityteam.org/man/tut ... ndows.html
"WASAPI loopback has an advantage over stereo mix or similar inputs provided by the audio interface that the capture is entirely digital (rather than converting to analog for playback, then back to digital when Audacity receives it)."

Author:  sonicboom [ 17 Aug 2019, 18:19 ]
Post subject:  Re: Capturing PCM from LD

I'm an audio engineer by trade. Its my main source of income. I've been doing this for 20 years now. Never have I ever heard of the insanity of something coming in on Optical S/PDIF and getting D/A converted internally except to exit from an analog output which is not the case here. That sounds like suspect hardware/software if that is really happening. How can a piece of software in a computer (binary - digital) convert a digital signal to analog then digital again and why on Earth would that be plausible ever? All analog audio must be A/D converted to use in a computer but digital audio stays digital until you play it out of an analog output.

Actually, Audacity being free and Windows being Windows this all makes sense :)

So again, keep this simple because it really is. LD Optical output>USB Optical device Input>USB cable>Host computer USB input>Audio Software. Set the software for 44.1KHz, 16 Bit, Stereo WAV file. That is the setting and there is no need to try anything else in this scenario. If the software has a selection for input source, choose the one for the (USB) capture device. If there is a selection for (word) clock source choose external or optical or USB, whatever they call the source input (the USB box). Do a 1 minute test. Depending on the software and your hardware you may not be able to monitor the digital audio in real time. When the recording is finished be sure to reset the (word) clock source to internal or you may run into sync issues when you playback.

The main issue, I suspect, is Windows and/or Audacity coupled with the lack of experience. Don't get discouraged - you'll figure it out eventually.

jd213 wrote:

Unfortunately it's not that simple if one desires bit-perfect captures, since the audio could get internally converted to analog and then back to digital by the PC/input device, or otherwise altered so that it's no longer an exact digital copy.

The first posts on these threads on FanRes would probably be good starting points for making sure that you're recording the exact PCM data:
https://forum.fanres.com/thread-2742.html
https://forum.fanres.com/thread-2686.html


signofzeta wrote:
Knowing the hardware I have personally I know for sure my sampling rate is correct and also that that there is no D/A/D going on (I can’t even...that makes no sense to me).

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