pje / WavTap

globally capture whatever your mac is playing—as simply as a screenshot
MIT License
752 stars 84 forks source link

Recording drops #30

Closed decklin closed 11 years ago

decklin commented 11 years ago

I'm using WavTap to record output from Ableton (I have tried experimenting with buffer/latency settings there to no effect.) I typically record about an hour of audio at a time. Randomly (I'd say every 5 minutes or so on average?), WavTap's recording drops up to about half a second of audio from the output file (not silence; it just skips ahead, as if you had just hit "cut" on that fraction of a second in an audio editor).

Have you experienced this in any other situations? Can I help track it down?

I've tried both the installer version and building from source. (I had to upgrade Xcode to 4.5 to build -- might be good to note this in the README somewhere.)

pje commented 11 years ago

Thanks for reporting! That sucks and is weird.

Sorry to say I don't have any meaningful advice right now. I would ask, though: what sample rate / sample sizes were you using? Were settings different across devices? WavTap's still not super-stable in those areas.

decklin commented 11 years ago

I have my output sample rate at 44100 to match how the built-in output is set in Audio MIDI Setup.app. Ableton doesn't have an output depth option - I'm guessing it gets that from the device. The built-in output has 16/20/24-bit integer options and 32 bit float. WavTap shows only 32-bit integer. Wild-ass guessing: maybe having WavTap show up as 16-bit when the default output is 16-bit would help?

I'll try another device (USB) and a new machine over the next week and report back on those.

decklin commented 11 years ago

OK, stupid question: how do I route WavTap's output to my USB device? I see some references in the git history to menu items for selecting routing, but everything related seems to have been removed. I've tried setting the USB device as the default output before loading the kext and starting WavTap.app, but wasn't able to get any output at all. Is this a separate feature that needs to be reimplemented?

(I still have the other, newer machine to test on but need to move my Ableton library over. Will report back on that later.)

pje commented 11 years ago

@decklin: Yeah, WavTap just routes its output to the device you'd been using when you launched WavTap. That's intentionally not configurable—it's not supposed to be a routing app.

I've tried setting the USB device as the default output before [...] starting WavTap.app

That should do it.

It's possible this is a new bug: if it's still happening, can you list reproduction steps?

decklin commented 11 years ago

I think my USB problem is a separate issue particular to my device; I'll open a separate issue for that.

decklin commented 11 years ago

So far, I am unable to reproduce this on the newer machine. I'll update again next week; I have to return the older machine anyway so if everything is still OK I'll just close this.

decklin commented 11 years ago

Still not reproducible on new hardware; closing.