Open GOPs - ComSkip

[bman2005]

Hello! Post 1....

Hey gang. First post on the forum - hurrah. I am a newb so cut me some slack if this post is in the incorrect forum. Here is the quick run down on what I have done and the problems I have run into.

1) Record shows via Tivo.
2) Transfer recorded shows to PC (via Tivo2Go)
3) Converted shows to .mpg (via TvHarmony)
4) Cropped commercials (via ComSkip)
5) Import .mpegs into Sonic DVDit 6

Here comes the problems.

1)Once imported, the software (Sonic) shows that the video length is longer then the associated audio clip. After some research and troubleshooting, I have determined that the ComSkip software is messing up the GOP timeline (leaving them open) - or the headers (im not sure what they do anyway). The DVD autoring/ editing software doesn't recognize that the video is actually the same length of the audio.

What I have done to get around the issue.

1) Rewrite the GOP timeline (via DVDLab)
2) Demux (via DVDlab) into separate .mpv/.mpa files.
3) Import elements into SonicDVDit.

This appears to work - I am writing a DVD now to see if the audio syncs with the video.

Anyrate, is there a better way to crop the commercials out. I liked the automation of ComSkip but it appears that this software will only work if you plan on watching the final cut .mpg on the computer with a player that will close all open GOPs on the fly while viewing. I have no problem watching the .mpegs on the computer but once I put them on a DVD using Sonic (which requires closed DVDs...which I also think is a requirement for DVD compliance) the audio stops and video keeps running.

Any way, there appears to be a TON of information and apps on this site. There is a lot to decipher. If there are better applications that will lead to a better final product for the type of editing that I am doing, please let me know.

Thanks in advnace for your help and direction

Bman

[Shadowmistress]

Since nobody's bothered to answer this one, I'll throw my 2 cents in here.

I believe what you're facing here is a mux rate issue and not a GOP thing. (You were close, but they're not quite the same.) From what I understand, some software muxes audio and video at a slightly different rate than other software (God only knows why) wherein they differ in rate only by milliseconds. This could cause a difference of a few minutes on a 2 hour movie depending on what software you used to just mux. Because the difference is only in milliseconds, other software can't detect this difference and correct it, but it can remux at it's own built in rate thereby keeping it in sync to the rate dvd players expect. This is what dvdlab is doing - throwing away the old mux rate and creating a new one from it's built in specs. (I know I'm doing a shit job of explaining it but I myself don't even understand it that well.)

What I know is that tmpgenc and dvdlab mux at the same rates and are compatible with eachother and dvd players. I've never heard of TvHarmony or ComSkip so it could be either of those programs with the different mux rate to normal. I'd suggest using tmpgenc to convert to mpg instead of TvHarmony and see if Comskip keeps it in sync after that. If that fails and Comskip is the remux rebel, I'd suggest using tmpgenc's built in editing filter to crop the commercials. It probably won't be as automated as what you're used to, but it will stay in sync.

[reboot]

Comskip doesn't do anything to your video.
How you use comskip's output to cut the commercials, is what's causing the issue.
If you're using comclean2 with cuttermaran, you should have no problem.
If you're using womble, you should have no problem.
If you're using videoredo, you should have no problem.
If you're using the original comclean with mpeg2cut or mencoder, then you can have timestamp problems.
Outline your exact procedure, and what software you use.
There are workarounds (retime.exe and/or PVAStrumento) in the gbpvr forums.