cutting/joining MPEGs

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I have noticed that when I cut and join MPEG's in the MPEG tools menu of TMPGEnc, there is a quality loss from 'original' MPeg files to the singular, joined file. Since the feature is essentially making a copy of the shorter MPEG and joing them into one MPEG, this is not really surprising. Does anyone know of a lossless way around this? I have been making VCD's, but because I have to encode the AVI's in segments (2 Gig limit), I end up with several MPEG files to join before burning. Any suggestions greatly appreciated

-- derek (dereksider@home.com), January 18, 2001

Answers

I am assuming you do capture, hence the 2Gig segments. What program do you use to capture with? If you are using virtual dub, then that program does automatic joining of segmented AVI for you. You can frame serve it over to TMPGEnc frame by frame to be encoded to MPEG. Just extract the audio to wav first, and fed that to TMPGEnc along with your frame serve AVI.

-- lnguyen (wingstarzz@hotmail.com), January 19, 2001.

There is quality loss when joining/cutting? Why would "essesntially making a copy of the shorter MPEG and joing them into one MPEG" degrades the quality, and doesn't surprise you?

It surely surprises me a lot.

I admit that TMPEG cut/join is not as frame accurate as it claims, but there is no loss in quality.

Anyone can comment on that?

-- Rusman E. Priyana (priyana@eudoramail.com), January 21, 2001.


What "quality" are we talking about here?? TMPGenc doesn't mess with quality visually since it's merely joining the files. What I did notice about these joined files is that TMPGenc introduced a barely audible "peep" sound at the join. It's generally not noticeable, except if at the join audio volume is way, way down. The other utility for joining MPEGs is Jiao's VCDCutter, which doesn't introduce any artifacts of its own but the one thing I find unacceptable is it chops off a few frames in around the join. I was told the chopped-off frames are the extra that are outside complete GOPs. The best method is indeed to frame-serve; one is with VirtualDub, which I haven't tried :D, and another (which I do all the time) is to use Adobe Premiere with Panasonic plug-in. You simply string your AVIs on the timeline and export these to Panasonic MPEG. Premiere has a limitation on top of other limitations: NONE of the AVI clips you use should be bigger than 1Gb. Talk about 2Gb. Despite these, the Premiere/Panasonic method provides the smoothest segeuing at the joins and best quality overall. I've also used ULead MediaStudio VE (which somes bundled with ADS PyroDV card, the bunch is about $100) which allows you to use AVIs up to 4Gb (!) to be stringed on the timeline, and export these as White Book MPEG-1. Unfortunately the encoder that comes with MediaStudio is the one from Ligos which offers no control over encoding parameters and therefore produces MPEGs with quality way inferior (blockiness, etc.) to that done with the Premiere/Panasonic tandem. If Ulead can be persuaded to accept Panasonic or TMPGenc encoders as plug-ins everybody will be happy :D :D

-- Mehmet Tekdemir (turk690@yahoo.com), January 22, 2001.

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