4-channel capture, weird clicks

[Edward Troxel]

I use a SIIG OHCI firewire card connected to a Panasonic AG-DV2000 deck.

[AlexOsadzinski]

An update: I sent Don an audio clip on which I can hear clicks, and he can't. Interesting. It's possible that there's something in the waveform that causes the sound cards in my PC and laptop to generate clicks, or that something in the Windows XP sound system is freaking out. If so, it's strange that it does so only on channel 3/4 capture, and not channel 1/2 capture.

So, tonight, I'll do a capture from channels 3/4 of my XL-1S, send Don a clip, and then record back out to (fresh) tape. If there's no clicks on the re-recorded tape then, clearly, there's just something wrong with audio playback on my PC and laptop. This will encourage me to buy a better sound card. I'll report back.....

[Don Palomaki]

To add to the comment, FWIW, when I've seen clicks in captured digital audio files, they generally have been breaks or gaps in the wave form. sudden, total digital silence for a number of samples. Did not see any of those things or hear any either.

[AlexOsadzinski]

More info: I carefully recorded onto Stereo 2 left (i.e. channel 3 or 4, don't know how they're numbered), with the gain turned to zero on the other three channels. I used my Azden SGM-2X through the MA-200. Peak level was -12dB, so it shouldn't be too hot.

Analog playback is fine. During capture, and subsequent playback on my PC, the clicks are loud and obvious (much more so than from my TRV-10). I've sent Don a sample, just to confirm that he can see/hear them. I can see spikes (downward spikes, FWIW) in Sound Forge 6.0. Copying the captured file to Premiere's timeline and writing back out to tape over firewire, I can now hear the clicks through the XL-1S's analog audio outputs. So, the clicks seem to have been introduced via firewire capture and, of course, then persist when you write back out to tape.

At this point, my best guess is a Scenalyzer Live bug, possibly when it's upconverting 12 bit to 16 bit during capture. I'll contact the author again to see what he's found, and will report back.

[Brad_DeWees]

Mine's fixed (knock on wood).
I forgot to ask myself the ever important question: "What did you do to it?"

Once I did, I disconnected the new external firewire drive enclosure and powered it off. Now my capture seems to work fine for both Stereo 1 and 2. My guess is that I was getting excessive PCI interrupts from the drive enclosure which was causing the capture to skip.

Note: I say skip because on mine, I eventually noticed that there seemed to be a frame missing everytime I heard a click. Scenalyzer did not report dropped frames however.

[AlexOsadzinski]

I heard from Andreas, the author of Scenalyzer. He's able to reproduce the problem on his computer, and is working on a fix. Note: this doesn't necessarily mean that it's a Scenalyzer problem....he didn't specify. It could just as easily be some weird PC architecture bug that he's developing a workaround for. As soon as I hear from him with the final results, I'll let y'all know.

[AlexOsadzinski]

Andreas sent me a test version of Scenalyzer, and the problem is fixed! How's that for great service? I've asked him if/when this will appear in future releases (I'm sure that it will).

Interestingly, I at first thought that he hadn't completely fixed the problem, because I could hear two tiny glitches. But, they're on the original recording when played in analog mode. I think that I've been wearing out the same piece of tape with too many experiments :-(

Thanks also to Don for listening to and looking at my audio samples.

[Edward Troxel]

What was the version number/date of Scenalyzer that he sent you?

[AlexOsadzinski]

Version 1.4, Jul 19 2002 02:40:04. Andreas sent me an email a few minutes ago describing the changes that he'd made. I quote:

"I have fixed one problem in the Dv-Audio-Resync-Module of sclive (this makes sure that the audio is perfectly synchronous to the video - this is a topic with some capture-cards) and one problem in the Audio-Channel-Swapper (swaps the two channel if you capture the second channel) of sclive."

He also said that, if all goes well with testing, he'll release a new version with these changes next week. Note: I haven't tested this build extensively. I'm in a rush to get my work done (I'm a venture capitalist in real life) before leaving for a joyful week of wildlife videography, so only quickly tested stereo 2 capture, which seemed to work. Doubtless, Andreas is doing full regression testing on this new release.

Holy god! thank goodness if you got this to work. I have a 45min mini-feature that needs to be recaptured and edited all because of those stupid annoying clicks.

If you can, e-mail me that version or tell me what version it is so i can get back to work and do some major re-editing.

I'd be oh so greatful!

Thanks,
Adam
adamjamalcraig@softhome.net

[AlexOsadzinski]

I don't want to violate Andreas' trust (he sent me the patched version as a "non-public" release), so would you mind emailing him at info@scenalyzer.com? He's been very responsive and I'm sure will send you that version. If he's not around, please email me at alex@trinityventuresnospam.com (removing nospam...I hate email address harvesting programs) and I'll try to help directly.

The version that Andreas sent me is 1.4, Jul 19 2002

Ok, i just e- mailed him. Thanks for the help of getting to the root of this problem.

Adam

[Adam Wakely]

I'm really trying to get a 4 channel capture to work with my DV Raptor card via the firewire. Scenalyzer loads up but doesn't seem to connect with it, then it crashes. I see that it's not compatible yet. I used to use raptor edit and capture the 2nd audio tracks via my sound card but their trial version (which used to work) doesn't work with Windows XP. It's becoming a long, tired job setting up wave files for perfect sync!
Any suggestions to get 4 audio tracks from my DV Raptor card?

Thanks...