[mythtv] Myth .nuv MPEG4 format portability

[Matt Zimmerman]

On Wed, Feb 26, 2003 at 10:28:22PM -0700, David Madsen wrote:

> transcode the .nuv file to a .avi file using this step.
> 
> 1. mencoder -voc copy -aoc copy <filename>
> 
> This step is necessary to fix the audio syncronization issues present with
> mpeg files.
> When recording some frames are dropped, and information is saved to keep the
> audio and video in sync in spots where frames are dropped.  I initially to
> use the mencvcd to encode straight from the .nuv files, but there was audio
> sync problems because the player wasn't reproducing the extra frames from
> the encoded data. this first step fixes this.  It's a hack, but works, and
> only takes a few minutes more.  But also requires more disk space.

I assume this step is necessary because mencvcd uses mplayer to decode the
stream, and mplayer will not insert duplicate frames in the output to make
up for the drops (while mencoder, in this context at least, will).  If you
can find a way to change this behaviour, we might be able to eliminate this
step.

> 2. mencvcd <outfile> -abr 224 -asr 44100 -mpgonly -noburn -vbr 1150 -vfr
> 4 -vnorm n test.avi
> 
> that will encode the created AVI to a VCD formatted mpeg file that can be
> burned to a cd.  or you can remove the command line options to have the
> script do it for you.
> 
> This has worked fine for me.  The resulting mpeg file can be edited with
> utilities to cut commercials etc. without losing audio sync as well.

Thanks for pointing out mencvcd; I didn't realize that it existed.

Of course, I'm still left wondering why tools for such tasks still tend to
be all shell scripts and named pipes...

-- 
 - mdz