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View Full Version : Re-authoring a Standalone DVD Recording - Tell Me How


forkstriker4
2007-05-28, 06:06 PM
I am attempting to re-author a standalone DVD recording of a concert. I want to remove the commercials from the recording. The video is divided into multiple VOB files on the DVD. If possible, I would like to not re-encode the video at all and remove commercials. Can I do this? Would it not work with the I, P, and B frame structure of the video? I think I should I be joining all the VOB files into one as that would make work more simple on the DVD. What do you all say?

Also the audio on the DVD is messed up beyond repair. I can only improve it. I will be decompressing the AC-3 audio stream and editing it for improvements. I will have a few different versions of this original audio for the listener's preference and would like to include (at a max) three different ones. How can I successfully multiplex all of these audio streams into the video? Any suggestions with dealing with AC-3 streams in general?

How can I make the re-authored DVD highly compliant?

I can de-multiplex the video and audio, decompress and re-compress the AC-3 audio stream, but other than that, my methods are unstable.

There are plenty of resources around to answer my questions, yes, but there are too many. I would like some direction from others with experience.

Thanks!

spiritinaphoto
2007-05-28, 08:42 PM
Yeah, joining the files together would be wise, since I'm certain when it comes to the authoring step it'll have to change how the VOBs are split up.

As for the audio track, I do not recommend recompressing the AC3 track back to AC3 when you finish editing the sound. AC3 is lossy, and if you recompress the file, you'll lose even more information from the sound file and it'll sound worse (it'd be more noticeable if it's one lossy format converted to another, but the degradation will still be there even if you stick with the same codec). If you must tamper with the audio, please use LPCM when you multiplex it back with the video.


As for what programs to use, that depends on what operating system you're using. I'll leave that part of the question to someone else to answer (unless you just happen to be a Linux user, in which case I'd come in handy).

DanielG
2007-05-28, 08:55 PM
If possible, I would like to not re-encode the video at all and remove commercials. Can I do this? Would it not work with the I, P, and B frame structure of the video?

I'd recommend checking out VideoReDo. www.videoredo.com It doesn't re-encode the whole video when you remove commercials (though it may need to re-encode a few frames around the cut you don't cut on a GOP boundary)

Otherwise, check out Mpeg2Schnitt www.videohelp.com/tools/Mpeg2Schnitt

forkstriker4
2007-05-28, 09:36 PM
As for the audio track, I do not recommend recompressing the AC3 track back to AC3 when you finish editing the sound. AC3 is lossy, and if you recompress the file, you'll lose even more information from the sound file and it'll sound worse (it'd be more noticeable if it's one lossy format converted to another, but the degradation will still be there even if you stick with the same codec). If you must tamper with the audio, please use LPCM when you multiplex it back with the video.What if I compress the audio track back into AC-3 at the same bit-rate it was originally? The compression which was applied would already have degraded the audio and the only processing I did was increase the volume.

forkstriker4
2007-05-28, 10:51 PM
I'd recommend checking out VideoReDo. www.videoredo.com It doesn't re-encode the whole video when you remove commercials (though it may need to re-encode a few frames around the cut you don't cut on a GOP boundary)

Otherwise, check out Mpeg2Schnitt www.videohelp.com/tools/Mpeg2SchnittI guess I will have to try these programs out. I just tried to split up the video using MPEG2 Splitter (I think) and it created some completely fine, but non-compliant MPEG 2 files.

spiritinaphoto
2007-05-29, 12:09 AM
What if I compress the audio track back into AC-3 at the same bit-rate it was originally? The compression which was applied would already have degraded the audio and the only processing I did was increase the volume.
Since you did change the audio (i.e. volume), the signal is different and it probably will find something else to take out. If you have to modify AC3 (or mp2) audio, leave it as LPCM from then forward, but remember to mention what the original audio source was in your lineage info. I'm pretty certain you cannot seed it here if you do AC3 > WAV > some editing > AC3.

musik_maniak
2007-05-29, 12:44 AM
I know TMPGEnc DVD Author will allow you to cut out the commercials.