Bit-perfect LD-capture - What's necessary?

[deleted user]

I googled that Pioneer model Dr. Cooper mentioned and from looking at the backplate (assuming the picture is of the right model) it appears it has both optical and coaxial outputs, so that would probably not be a problem.

[zoidberg]

Yeah the DVD/LD combi players were pretty well featured. You still need a demodulator for LD AC-3 though

[bronan]

Just a warning with cheap CD-Rs, you may not be getting a bit perfect copy. When I was making the DTS Test cd I found one of copies burnt on a Sony CD-R and ripped back wasn't bit perfect. The Taiyo Yudens I tried all worked fine.

[SilverWook]

Are you sure there wasn't some other factor involved? I've been using Phillips and Verbatim discs as of late. How do I check for errors?

[deleted user]

bronan, when you say it wasn't bit perfect, did you try doing a subtraction of both signals and seeing the differences? Just curious what effective difference would have resulted from that.

[bronan]

Sorry, I wasn't very clear. What I did was burn a master CD, then rip it back to PC. This created the bin/cues for distribution. I then burned test CDs from the master to make sure it was OK. The master I made onto the Sony CD produced junk CD-Rs no matter what brand I burned from it after doing the bit perfect DTS test, even though it shows in my PC as a valid disk. It's possible there was other factors involved in this instance, but regardless cheap CD-Rs can have a much higher error rate than you would think.

[Wisp of Smoke]

I had done the same thing and likewise used DTS-CDs for testing my duplication and authoring of wav files. It's a great test actually.

In years past before DTS was established on DVD, DTS could piggyback it's consumer 6 channel compressed audio stream inside a PCM packet / container that could be put onto a CD-audio disc. Only it wasn't a PCM stream. Analog audio outputs were no good- had to be a true digital out. If anything in the playback chain messed with the stream in the slightest before reaching the DTS decoder and you would only hear digital noise. ( hence the warnings that often came with these specialty discs.)

Anyhow - Likewise with disc authoring or file copying. If something in the chain tried to alter audio levels, EQ, sampling rate, ...whatever... the DTS bitstream was destroyed. That digital file has to remain pure. I found my best CD authoring and CD audio exaction tools this way.

[digitalfreaknyc]

Are there directions using Reaper outlined?

[bronan]

Not yet as far as I know. I've been planning on doing a guide, but it's just finding the time. I think I should have some time next week to knock it out. There's really not much to it, the crucial thing is getting your sound card setup correctly.

[pipefan413]

Re. bit perfect capture, I'm wondering one specific thing: is ASIO definitely required for bit perfect capture?

I ask because I bought a ZxR with DBPro daughter card for bit perfect capturing (amongst other things) on the basis that it claims to be able to record 44.1 kHz... but if I use its built in ASIO driver, Adobe Premiere won't let me record in anything other than 48 kHz. I can if I use a different mode e.g. MME/DirectSound/WASAPI but it's a question of whether that could still achieve a bit perfect cap. I was under the impression that ASIO was all about low latency and there was nothing inherent to WASAPI or DirectSound that would prevent them being bit perfect but you stress that ASIO is needed so I'm wondering if you tested other driver types and concluded from that testing that they didn't work. I'm assuming you would have to put the driver into exclusive mode (not shared) for bit perfect, at least.