audio drop due to dropped frames

zigip wrote on 7/20/2009, 10:53 AM
(Sorry if this is a repost - was not able find my original post)
I have a Canon HDV30 camera, and i capture HDV recordings off of th tape using HDVSplit.

Occassionally i get frames dropped (please no replies on how to avoid dropping frames).

On some of the files with dropped frames (even if just 1 droppe frame), Vegas shows no audio around the drop for 10s of seconds, sometimes more than a minute. The audio before the drop is good, so I know it not a codec issue. The "no audio" is see on both the audio channel (flat lined for that section) as well as in playback (silence output).

I know the audio IS there, because if I rename the .m2t (from HDVSplit) to .vob, I can play it in VLC player and hear the audio (except for the blip due to dropped frames). VLC player does not give me the 10s of seconds audio drop that I have in vegas.

I have resorted to having VLC doing a "conversion" to be abe to use the file in vegas. The conversion seems to clean up the audio so I dont get the 10s of seconds drop.

So it seems that Vegas has some difficulty in resyncing the audio after frames drop. The video looks fine.

Any suggestions?

Comments

Eugenia wrote on 7/20/2009, 2:16 PM
>I have a Canon HDV30 camera

There is no such camera. HV30 is the name.

> and i capture HDV recordings off of th tape using HDVSplit.

Bad decision. I don't know which version of Vegas you use, but at least pre-9 versions don't like HDVSplit files.

>Occassionally i get frames dropped (please no replies on how to avoid dropping frames).

I am afraid that's your problem. I have pretty much the same camera and I had NEVER had a dropped frame with Vegas. You need either:
1. Better tapes
2. A NEW firewire cable (different make too than the one you use)

>I know the audio IS there, because if I rename the .m2t (from HDVSplit) to .vob,

VLC can playback .m2t files just fine, no reason for renaming.

> I can play it in VLC player and hear the audio (except for the blip due to dropped frames).
> VLC player does not give me the 10s of seconds audio drop that I have in vegas.

VLC is a media player and not an editor. It does not use the same kind of internal processing and caching as Vegas does. Therefore, "errors" will show up with a different face in different applications. This is to be expected.

What you should be concentrating on is to never get dropped frames again. For now, you might have to discard that part of the video and don't use it. Or, load it in another app that might not have the problem of the 10 seconds, export in a lossless codec, and then load that file on Vegas instead of the .m2t file. You might get a different behavior on the problematic part of the video.
zigip wrote on 7/21/2009, 8:06 AM
Eugenia,
Thanks for you reply.

1. I have heard others use HDVsplit, so that is what I use.
2. I generally have no problem. 99% of the time i get no drops on capturing a tape.
3. The error seems to be due to the tape; if i try to recapture, then the drops occur at the same place.
4. So I doubt the firewire cable is the problem
5.Better tapes: I use only HDV tape (not DV) from SONY, Panasonic. Are there better/more reliable brands?
Eugenia wrote on 7/21/2009, 12:55 PM
>The error seems to be due to the tape;

Never use a tape more than 2-3 times with HDV.