[mythtv] Myth .nuv MPEG4 format portability [Possible Breakthrough]

[Rob Snow]

I just ran into something that seems pretty substantial.  I was still working with 
getting mencoder to make something that works on my Windows machine for 
portability.  As you might remember quite a few of us are unable to get something that 
is portable with a -oac copy -ovc copy.  This is still the case, however, in running 
some tests I have found something that might be interesting to others. 
 
I can make a usable .avi file with mencoder IF I do not -oac copy the audio stream.  If I 
use a -oac mp3lame I get a usable .avi file that plays under Windows with -ovc lavc.  I 
have not had much time to test this and won't be able to until PM today (that work 
thing). 
 
I was actually trying to create a small .avi file for distribution to others who follow the 
lists to get a survey of who could/couldn't play the file to see if I could find any 
commonality.  Since it was just a go/no-go test, I was trying to make it really small.  
(video bitrate of 100 passed to lavc) and noticed that the audio was as large or larger 
than the video track...simple fix, I downsampled it by removing the -oac copy option 
and replacing it with a -oac mp3lame.  When I encoded this it triggered a different set of 
"Skipping frame" messages that I had seen before.  This turned on some type of light 
in my head so I tried to play it under Windows...shazzam, it worked...something is 
definately different. 
 
I've tried it all the way up to my previously non-working bitrates/attempts and it seems 
to work like a charm with -oac mp3lame -lameopts <whatever>. 
 
I'm not sure what this tells us about our .nuv files or mencoder, but thought it might 
be an interesting data point for those interested. 
 
-Rob 
 
P.S. 
A quick test showed that -oac mp3lame -ovc copy still did not work (with gspot or 
WMP) and neither did -ovc xvid, however, I would not consider those completely 
conclusive as I might need to clean my video codecs under windows to verify after a lot 
of messing with them last night.