[mythtv-users] Re: Anyone tried MPEG2 to MPEG2 transcoding?

Chris Petersen lists at forevermore.net
Thu Jul 21 11:46:33 EDT 2005


> Ooops - major stuff up here, folks :(( Many, many apologies. It turns
> out that I'm not transcoding to MPEG2 at all. I must have set it back
> to MPEG4, although I really don't remember doing that. Anyway, that's
> why it appears to be working. I'm really sorry about that.

Someone tried a couple of years ago to get mpeg2 transcoding to work, 
and could never get it to work properly.  That's why Gavin (Beirdo) 
wrote the mpeg2cut module for me to include in nuvexport.  So far, 
avidemux is the *only* program capable of true lossless mpeg2 cutting 
(without resorting to cutting at a GOP, which is not good enough). 
Then, in his tests, he discovered that lvemux was the only program 
capable of stitching the audio and video back together without sync 
problems.

Unfortunately, afaik, lve does NOT work with fedora core 3 or later 
(along with some other modern distros -- I forget the exact library 
conflict), preventing mpeg2cut from doing its job.

Now, he's been working on extracting the relevant portions from each of 
those programs into a single app (esp. so that it wouldn't require X or 
anything like that), but it will likely take him awhile to finish.

For now, if all you want to do is save space, just transcode to mpeg4 
with mythtv (keep in mind, it's optimized for encoding speed, not 
quality), or if you have the time, run nuvexport's xvid exporter (I 
prefer transcode, but it defaults to ffmpeg).  Nuvexport's default xvid 
settings should give you about 350M/hour (minus commercials) at 624x464 
(weird res, but that's how the calculations best come out after you crop 
2% of the edges to get rid of broadcast noise).

-Chris


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