VCDs "stick" in Philips DVD plyer

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I have been making my own VCDs using VirtualDub to capture, Panasonic to encode, and Adaptec 4 to burn the CD. I use iFilm edit to cut up large MPEG files.

A frequent problem is that the movie "sticks" for a few seconds, then restarts.

I have burned the MPEG onto different CDs and the movie sticks at the same point. Therefore I conclude a problem with the MPEG stream. The VCDs play OK on a computer.

Can anyone point me to a possible solution to this?

Could it be iFilm edit that is doing something to the file? WebFlixPro seems to produce non white book compliant MPEG files if used to cut up large MPEG files. Are there any other programs that can cut up MPEG files?

-- John Vickers (johnvick@ihug.co.nz), December 07, 1999

Answers

An .mpg stream is reliant on the consistency of the GOP for proper playback. If such a stream should be cut it should be such that the resulting segments ALWAYS start on an I-frame (.mpg keyframes) and whenever possible end on a B or P-frame just prior to the next I- frame of the next segment. If it doesn't start on an I-frame or the I- frame gets corrupted somewhere in the middle of playing such a stream, the picture simply freezes on the last good reconstructed frame while waiting/searching for the next good I-frame with which to start the next GOP. The file may be White Book compliant and all that but with the aformentioned problem will freeze at such a point anyway. Cutting up .mpg streams is therefore not approachable in the same way with conventionally-coded .avi (where every frame can be an I-frame)and is primarily what .mpg editors are for; the one that I use does the job elegantly: VCDCutter by Jiao Shenwu, which can be had for $20 from his China website. A more sophisticated one is M- editor by Darim, which is about $99, and has the added bonus of joining together .mpg files into a longer (bigger) file while duly altering markers, headers, etc. to reflect such a change to the s/w or set-top player. Panasonic has provisions for forcing how the GOP is implemented. I do not use the default 15,3,3; the 12,3,3 contains slightly more I-frames without a very big increase in resulting filesize. With more I chances of freezing probably go down.

-- EMartinez (epmartinez@hotmail.com), December 09, 1999.

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