Editing using VirtualDub - Navigation slow, MPEG2Schnitt doesn't always join right

[WannaB]

Hi,

I've read the guides on this site and read through the forums for as much information as I can. I want to make SVCDs and eventually DVDs from HDTV sources. The methods I use work for me, but they're kind of slow for editing files. I wonder if anyone can give me some tips to speed up navigation when editing out commercials.

Okay, here's what I do. I capture transport streams with a MyHD card. I then demux that with ProjectX. I convert the *.ac3 file to wave using HeadAC3he. I run the *.mpv file through DVD2AVIdg 1.3.0 (using the 32-bit SSE2 MMX iDCT algorithm which helps a lot). Then I use the *.d2v and *.wav files as sources in an AVISynth script, open it up in VirtualDub and edit out the commercials (plus crop, resize, etc.), frame serve it into TMPGEnc and I'm done. Works great, except navigating the file to edit the commercials in VirtualDub is still pretty slow. Also, I can't check the audio at the edit points because the file doesn't play back normally in VDub. Is there any way to speed up navigation so that it works more like editing an AVI (realtime a/v sync, very fast scanning through the file, etc.)?

The other things I've tried are using HDTVtoMPEG2 to edit the commercials (it doesn't do a very clean job) and MPEG2Schnitt to edit them out. I like MPEG2Schnitt a lot, but sometimes it won't cut right. It will cut and join the first two or three parts correctly and then scan really quickly through the remaining parts without joining or doing anything to them. It doesn't return an error or anything and it proclaims success when it's done, but it really only processes part of the file.

I've also tried opening the *.mpv file directly in VirtualDubMod but I only end up with a black screen. It seems to be reading the file just fine because I can see the frame types down at the bottom, but I can't edit out the commercials if I can't see where they are.

Any tips would be appreciated.

Thanks guys

[minolta]

The new version of DVD2AVIdg by neuron2 can directly open transport streams and has a graphical pid changer:

http://forum.doom9.org/showthread.php?s=&threadid=76083&highlight=dvd2avidg

As always, it can demux ac3 audio (with explicit time offset) and decode to wav, so that might speed up your audio process. I'm still not sure how I'd handle 5.1 audio through. Is there an advantage to using ProjectX that I'm unaware of...

Other than that, cutting out commercials is painfully slow for myself as well. I've once used media player classic (which can now read transport streams) to quickly find frames. It was very fast (scan with slider, step forward frame with 'right' (no backwards), find frame # with play->goto), but stoped using it for some reason :confused:. You would then decomb (if necessary, but don't decimate yet), verify in virtualdub (use edit->goto), trim in script, and apply decimate (if necessary). Guess I'll take my own advice and start using it again.
-Minolta

[WannaB]

From reading through the guides I think ProjectX will do some error correction and audio re-syncing if there are any problems in the stream. I've been tempted to just use DVD2AVIdg and skip ProjectX as you suggest but I wasn't sure if it would fix stream errors, too.

What I've done for the couple of times that MPEG2Schnitt has failed on me was just to note the times of the cuts and then use VDub, Edit, GoTo and jump to the approximate spot of the edit to find the right frame. It's similar to what you've done in WMP. It's kind of clunky and seems like double the work, but it's still faster than trying to navigate the file from scratch in VDub. But there's got to be a better way. ;)

[hms]

I encountered the same problem in Schnitt.
But it is easy to fix:
As Schnitt is cutting just count the cuts and note where and when it skipps.
Then just open that cut section and edit and move the cut-in frame to the next frame.
For some reason some mark-in frames cause trouble and then Schnitt simply skips the rest of the project and finishes with cutting the audio.

[WannaB]

Thanks for that tip. I'll try it the next time it happens.

[jrmann1999]

The math involved in simply decoding 1080i and 720p is your limiting factor in speed. Add to that fact you're(hopefully)using vdubmod to edit your video you are probably filtering, deinterlacing, and/or cropping . On my XP 2400+ w/ 266mhz ram I can accurately cut commercials in about 5-10 minutes. When I get to encoding I get about 14fps(.500-.700 in CCE). I know that SSE2 helps, but only by about 3-4 fps.

BTW, using the same card I've noticed that ProjectX tends to really butcher the audio delay. Streams coming out of it are never right in my experience leading to manual sync which is a pain in the rear. I've switched 99% to DGIndex + ac3delaycorrector. The rare case of using PX is on a really bad stream that usually goes the way of the dodo anyways becuase it's just a pain to manually sync audio.

If you're doing to do transcoding of audio to mp2(for svcd) why waste the time converting to wav? It's absolutely useless when there are so many ac3->??? conversion utilities out there.