[mythtv-users] nuvexport without transcoding?

[Gregorio Gervasio, Jr.]

>>>>> Chris Petersen writes:

>> If so, has anyone looked into doing a .nuv->.avi conversion without 
>> re-encoding the data?  For example, if I'm recording .nuv files in mpeg4 
>> at 640x480, I don't really want to decode the data and then re-encode it 
>> to convert/export it as an .avi.  Shouldn't it be possible to just 
>> extract the mpeg4 data and reformat it as an .avi file (or whatever) 
>> without any additional encoding?

c> You could, but that would require mencoder being able to understand
c> myth's nuv format, which it hasn't in awhile.  Other than that, it
c> should be pretty easy to just use the stream copying functions of
c> mencoder.

        I've been meaning to ask this for some time now -- what
exactly do you mean when you say mencoder can't understand the
MythTV's nuv format?  Does it not work on any file at all for you?
Does it work only on certain types of recordings?

        I never convert my files these days but as far as I can tell,
the patched mencoder-0.90rc5 has always worked on most of my mpeg4 nuv
files.  It segfaults in the codec when playing a few (~1 in 10) files,
but it has always behaved this way since I started using the patched
mencoder last year; it's not something that changed in the last few
months.

        I just tried what the original poster asked on a file recorded
using MythTV CVS from Sunday night, and it still works:

mencoder -oac copy -ovc copy file.nuv -o tmp.avi
mencoder -forceidx -oac copy -ovc copy tmp.avi -o file.avi

This takes less than 1.5 minutes for a 30-minute recording and only
because it's disk limited (12% CPU for Athlon XP 2200+).  The two
passes are needed apparently because the index can't be rebuilt
properly when the source is a .nuv file.  Otherwise, seeking won't
work.
-- 
Gregorio Gervasio, Jr.