HDMI capture card audio problem

[WildW]

I'm having issues with my cheap no-brand chinese HDMI PCI-e capture card. . . serves me right I suppose. I'm capturing 1920x1080 using Virtualdub, Huffy video codec. The picture is always great, but my sound will spontaneously change speed and go out of sync, usually half an hour into a capture. It's quite difficult to explain so I've uploaded a short clip (17MB, x264/AAC) - it's also creepy as hell :P

The PC ought to be capable - overclocked i5 4670k, 8GB ram, capturing to 4TB WD Black hard disk. I've tried a bunch of stuff without much luck to try to prevent it happening. Network disconnected, preview window shrunk/disabled completely, but it still happens. Virtualdub reports zero frames dropped at the end of the capture.

CPU usage during capture is 40 to 60% according to VirtualDub - I assume this is of a single CPU core as VirtualDub only ever seems to use a single thread, so this could just be a case of antiquated software. CPU use could well be occasionally spiking and failing to keep up.

I'm very open to suggestions for better capture software, either free or not crazy-expensive. The capture card came with a Honestech DVR package that doesn't seem to suffer this issue, but will only capture to MPEG2 with all the interlacing intact, and that gives lousy results.

[usually_quiet]

AmaRecTV is alternative software that you could try. Regardless of the capture software, I would choose to capture an interlaced source as interlaced. If de-interlacing was necessary I would de-interlace afterwards and not in real time during capture, assuming the option to do it later was available to me.

[sum_guy]

Can you try capturing at a lower resolution or bitrate to see if the problem is repeatable?

[WildW]

Thanks - I'm giving AmaRecTV a try right now. It's the first other bit of software I've seen that both detects my capture card and lets me select codecs/etc instead of just forcing me to use mpeg2.

[Brad]

Capture -> Timing -> Do not resync between audio and video streams. I assume the current selection is "Sync audio to video by resampling the audio to a faster or slower rate".

Also, always capture uncompressed audio and uncheck "Enable audio playback".

The video seems to exhibit black crush, aliasing, and is deinterlaced to half-rate. But if you're happy with it I won't argue with you.

[WildW]

Been impressed with AmaRecTV so I may go on using that.

vaporeon - Thanks for the note on timing options, that's not a menu I've explored before. You're right, it was set as you described by default.

I must admit I had to Google black crush, but that sounds like something I wouldn't have control over as my source path is all digital. I just threw the video into handbrake to illustrate the point so I'm not too worried about the deinterlace this time :P