really oddball problem with TMPGEnc

[maca]

I've been doing this stuff for a while, even to the point where I'm often able to answer other people's questions on the forum. But lately I've been encountering a weird problem with both TMPGEnc Plus and Express versions that has me stumped.

Sometimes, if I'm attempting to do a 2-pass vbr encode, it'll go through the entire "analyzing" bit, then say the avi is not a valid format, and quit with 50% of the job done. Fair enough, there seems to be something wrong with the avi. But if I then try the encode as a 1-pass cbr, it goes through flawlessly.

If there's something wrong with the avi, there's something wrong with the avi, right? Why should it be rejected when I'm trying a 2-pass, but work on a 1-pass? Any clues from anyone? Again, I'm only having this problem when using TMPEnc products, which is my favorite encoder to use.

[Tolyngee]

I'll take a stab at it: I wonder if it doesn't like the very tail end of your AVIs. Weird things can occur right at the very tail end of AVIs that otherwise don't affect anything.

This would explain why a one-pass would work. It gets to the end, finds a problem, but goes "eh, I'm done, who cares?" But, although the multi-pass possibly could also not care in the very end, perhaps because it even found ANYTHING that it doesn't like, it decided to not continue.

It might be completely wrong with this, of course.

But try doing a clean cut of one of these AVIs with VirtualDub and see if it has any affect.

If I am completely wrong, then, eh never mind, what do I know? (but, yeah, I had an issue like this occur years ago...)

[maca]

That's an interesting theory which sounds as good as anything else. Maybe I'll try chopping off a few frames at the end in virtual dub and see what happens.

Every time this has happened, it's at the very end of the first pass, so that's worth a shot, thanks.

[whitejremiah]

or, one better, take the video and load it up into virtualdub, direct copy the video and audio strems into a new file....wont lose anything, and it may fix the problem, particularly if it's in the header or an indexing problem (which it sounds like it may be)

[Tolyngee]

I believe the VirtualDub docs mention that a clean cut it defined as a cut at the frame preceding a key frame. (read the docs to be certain what it suggests)

The problem I once had (I should have been clearer on this) was that an encoder was finding that the A/V at the very tail end wasn't equal in length. (.5 secs worth of video frames vs. .6 secs worth of audio after the final keyframe, for example).

While this doesn't affect playback, it can have an affect on sync if not corrected at some point, and you want to join multiple clips that have this problem at the end.

If the encoder isn't willing to ignore/correct this, it'll report it as a problem.

And, again, the one-pass encoding perhaps was written to not care whatsoever about this...

But, if I am right on all of this, I would be interested to know if the one-pass passes on this discrepancy, or if the new encode results in a clean cut.

White: that sometimes worked for me, but sometimes a cut is needed to correct the discrepancy... Like I said, I believe even Vd's docs touch on this potential issue with AVIs...

[maca]

or, one better, take the video and load it up into virtualdub, direct copy the video and audio strems into a new file....wont lose anything, and it may fix the problem, particularly if it's in the header or an indexing problem (which it sounds like it may be)

I always do this as the first step anyway, so this isn't the problem. The file I'm putting into TMPEnc is always the stripped video stream of the avi, which I've peeled off with virtualdub.

But I think you guys basically have the answer, and I'll try it when I have time to run that pesky file through again. Thanks. And I'll read the virtualdub guides to find out where to cut, etc.