[mythtv] mythtranscode -> avi

Chris Petersen lists at forevermore.net
Thu Aug 19 20:16:22 EDT 2004

> Sorry it's taken me so long to reply.  Moving across the country will do that.

I'm patient.  :)  Hope the move went well.

> I assume you want to translate from mpeg4-nuv->divx (or some other
> mpeg4 container) right?

Correct.  Though the more I think about it, I wonder if simply 
demultiplexing would work (if there's a way to keep the timecodes in 
place) -- though I'll admit that I have no idea if it would then be 
easier for something else to remultiplex the files, or just have 
mythtranscode give me an avi.

> This is something different (converting mpeg4->mpeg2).  I don't think
> we really want to go there.

Basically, if I can get an avi (or ogg or whatever) type container that 
transcode (or ffmpeg or mencoder) can read, I can handle the mpeg2 stuff 
(or take nuvexport contributions from users who can).  I'm definitely 
not asking for mythtranscode to do the job of nuvexport.

My intent, other than to have an easy way to export nuv files to 
something a little more common, is to have a basic starting point for 
export encodings.  Once the file is in a format that other programs can 
understand, it won't be that much work to move, reencode, etc.

>>And please correct me if I'm wrong, but having mythtranscode do the avi
>>conversion instead of mencoder (if it is ever made to work) would also
>>allow myth's meta data to stay in the file (title/subtitle/description
>>at the very least)
> In theory, though there should be an easy way of doing that today as well.

except that mencoder (or avidemux2) doesn't play nice with nuv files. 
But yes, all of that could be added in later via nuvexport or another 
assistant script.

> That last bit is what makes doing container modifications difficult. 
> Basically, we can't get frame-level accuracy around cut-points in any
> other container except NUV.  I've looked at lots of options, and they
> are all pretty messy (the one I finally settled on was the easiest at
> the time, though perhaps not, in the end, the best choice)

Ok.  This probably explains why I've had so much trouble with other 
programs that claim to be able to handle nuv files (although not why 
there are problems with files that haven't had their commercials removed).

> So, I guess I'm saying that it isn't someting I'll have time for, or
> see much need for.  But I guess you knew that already.

Well, I hope that someone else will step forward (if it's even feasible 
to do so).  It would make archiving shows a lot more feasible for those 
of us without the fancy mpeg2 encoder cards (granted, I'm probably 
getting one of them soon, too, now that Gavin has figured out how to 
cleanly remove the commercials).

Thanks for the info, though.  I've been running under the assumption 
that it would be a quick patch to save things into an avi instead of an 
nuv, and it's obviously more complicated.


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