strange join problem with virtualdub

[kropotkin]

I have a very strange problem with 2 videos. The videos have the same proprieties: MJPEG 704x480 25fps 44100 stereo 16 bit sound.
However if i try to join them with virtualdub i get the "cannot append segments:The videos have different data formats." More to add, the vidoes were actually segments, recorded with avio_io. So they SHOULD be joined.

Any ideas?

[MoonDoggie]

I have the same problem, still haven't figured it out..

If you do let me know please. I'm tired of having to encode
5 or six different mpg's then joining them..

MoonDoggie

[Peter B]

I think you will find there has been some dropped frames and Virtual Dub sees them as different frame rates (probably something like 24.9567 fps or similar) so will not append them. I haven't got an easy answer, sorry!

[MoonDoggie]

Ahh.. that's what i was afraid of. I did get about 6 dropped
frames in each of the segments I recorded.. Bummer.

Guess I'll have to use avisynth to put em back together and
re-encode.. What fun..

MoonDoggie

[cuddles]

In AV_IO have you checked "insert drops as full frames"?? in capture settings.
Cheers

[MoonDoggie]

Hmm, lucky for me I saved the setting from the capture I did
(FireFly episode) and it seems that I didn't check that one.

I take it that I should have?
If so, bugger it all to hell..lol. No way of re-recording it cuase I
was capp'ing direct from cable..

MoonDoggie

P.S. Must remember to try that on next weeks episode.

[MoonDoggie]

Almost forgot. Looks like I was getting about 10dropped frames
for every 4,000 or so. I'm thinking thats not good.

Wonder if I'm running into a VIA issue.

MoonDoggie

[Peter B]

10 dropped frames per 4000 is fine, no VIA issue at that low rate, if they are occasional it should be fine, if not, and they occure in a bunch, have you defragmneted you harddrive before capture?

You can still use your captured files, if you want (S)VCD then just encode them seperately and join with TMPEGenc's merge & cut tools, if you want MPEG4, join in Virtual Dub after encoding (or Nandub if using VBR Mp3 audio) and check insert frames for you next project. Set frame rate to 25 fps when encoding in Virtual dub though...

[MoonDoggie]

10 dropped frames per 4000 is fine, no VIA issue at that low rate, if they are occasional it should be fine, if not, and they occure in a bunch, have you defragmneted you harddrive before capture?

Actually, I captured to a 30gig empty udma66 drive, so nothing to defrag. I ended up doing some new test captures and during a 10min capture I got about the same amount of drops. So I did some snooping into my device manager and discovered UDMA 66 wasn't enabled for the capture drive.(Go figure) So i enabled it and tried agian.. 2 drops out of 18,000 frames. Moocho better.

You can still use your captured files, if you want (S)VCD then just encode them seperately and join with TMPEGenc's merge & cut tools,

Thats what I ended up doing, worked out fine.. Just took a bit of extra time.

Set frame rate to 25 fps when encoding in Virtual dub though...

Not sure I understand why 25fps? I normaly capture at 29.970fps Any special reason not to?

MoonDoggie

[Peter B]

Sorry, 29.97 is OK if your using NTSC, I am from PAL land and just think in PAL rates

[MoonDoggie]

Ahh. Ok. I should have realized that.
I do that all the time myself.

I was wondering about something though, I have noticed alot of video's that are 23.970fps and when I run them through DVD2SVCD, it runs a program called pulldown.exe and when I check them out in the player, they say that their 29.970fps.. So, I wonder if it would be in my interest to cap from cable tv at 23.970fps then do the pulldown trick..
Is this a valid idea? Or am I on the wrong track here?

Thanks for all the info guys..

MoonDoggie

[Eddy]

You could try capturing at 29.97 fps then try to reconstruct the original full frames at 23.976 fps and reencoding with 3:2 pulldown to get 29.97 fps again. That way the quality should be much higher, because no fields will be encoded twice and encoding full frames is more efficient (I think).

Ofcourse this only works if the original material is progressive (film for example) and they didn't do any processing that alters individual fields differently after it was converted to interlaced video (fades for example). Also I've seen that some series are shot on film with titles and trailers shot on video. The video material probably won't look very pretty.

AviSynth has a Pulldown filter, which might do the trick, but I have never tried it as I am in the PAL world, where there is no 3:2 pulldown. So there might be better solutions.

Eddy.