VirtualDub: disable frame inserts vs. not?
 

I was about to bump the old thread with Sanlyn's VD settings: https://www.digitalfaq.com/forum/vid...-settings.html but was given that warning about bumping an old thread so decided to make a new one, hope that was right...

When LS states that we should not uncheck the drop/insert frames for the timing settings and goes on to say that dropped frames can occur regardless and that would only stop the reporting of that, I guess I can understand that. But for the inserts, he does state that "All that accomplishes is essentially disabling drop reporting, and prevent inserts to fight off audio skew." which implies that disabling inserts really does disable inserts and not just mask an issue.

On my captures, I always have some degree of inserts but never dropped frames, I'm using a TBC and a recommended workflow. In the past I've been earmarking captures with >20 inserts over a 1.5-2h tape, for re-capture. But things don't usually improve much. and when the inserts happen there is a notable stutter in the playback, although it does occur over less than a second, and presumably worse when the inserts are all clumped together.

My question I guess basically is if I uncheck this, but leave the Audio re-sampling part checked, my understanding is that the audio stream is then just re-sampled or sped/slowed up/down to avoid the audio skew. so same result (no audio drift) but different means of doing so? over the course of a tape I believe the math of this resampling should be imperceptible and therefore favorable to having micro stutters in the video.

am I understanding this correctly or maybe not? or perhaps do people just usually prefer an unaltered audio stream at the expense of just a few random micro second stutters in the video playback?

sorry if this was asked/answered already, closest I've seen was that third to last question posed in that above settings guide, but it wasn't really answered. thanks

I'll bump this only just once. Thanks!

so basically thoughts on having frame inserts set to 'OFF' in VirtualDub and just having it re-sample the audio? should it not just keep the audio/video in sync still with slight almost imperceptible change in the audio? or am I missing something completely.

Acros_13, on a big scale it doesn't really matter much, because this setting is a damage control - not the cure, and your video is screwed one way or another.
Usually there are 2 major components responsible for frame skipping - capture card and video compression ratio.
There is a Average Rate on a side panel in VirtualDub in capture mode. The number should stay static throughout the capture process.
If it goes down from 29.97 (NTSC)/25(PAL) then your capture sheds the frames.
For example, in my settings I disabled all the interventions from VirtualDub, i.e. no adding frames, no dropping them, no audio resampling.

when it comes to frame inserts, if instead of connecting audio into my Santa Cruz sound card, I connect it to the capture card itself (ati usb600 or hauppaugge clone or X1900 AIW) would this prevent them? I know most of the time people are saying to use the sound card instead. I haven't captured any using the USB600 or Hauppauge clone's audio, but I had with the X1900 and there was one tape where the audio seemed to clip at times whereas the Santa Cruz did not, so I quit that experiment pretty quick. Not sure what my inserts were on that capture, but wish i remembered....

I don't think that rerouting audio through a capture card, gpu, or any other hardware such as delay box (aiw x1900 or ati usb600) would prevent frame inserts or drops. All it would do is either A. nothing or B. add noise to the sound. What could maybe prevent drops is lower sampling quality ie. from 24 to 16 bits as it could save on the cpu which may prevent framedrops. Also what you could maybe do is record sound on another unit such as a computer. But that would likely mean resyncing sound manually later on the dropped frame parts if there are drops.

Iam not an expert so take my info for what it is.