[mythtv] mplayer + nuv/(mpeg4|rtjpeg) patch

Geoffrey Hausheer ou401cru02 at sneakemail.com
Fri Apr 4 09:43:12 EST 2003


On Thu, 3 Apr 2003 20:17:40 -0500, "Matt Zimmerman mdz-at-debian.org
|mythtv/1.0-Allow|" <n4n4hbjjnh0t at sneakemail.com> said:
> On Thu, Apr 03, 2003 at 07:55:26PM -0500, Andy Davidoff wrote:
> 
> > This is at least the second request I've replied to with Andrew's
> > original message.  Could this patch could be added to the web-page
> > or otherwise archived somewhere?  I can host it if necessary...
> 
> The last version of this patch that I saw broke MPEG-4 in the process of
> making nuppelvideo work.  Given a version which worked for both codecs, I
> would gladly merge it into the existing patch that I distribute.
> 

On a similar topic, any idea how difficult it would be to make mencoder
WRITE nuv files (likely only MPEG4 would be needed)?
I've been working on coding a transcoder into myth so i can record
initially in RTJPEG, and transcode to MPEG4, to get a high-quality
encoding at high resolution with multiple imputs without swamping my poor
CPU.

Unfortunately, the encoders/decoders in myth are not really designed for
this.  I can extract the audio/video and write it to a file in
uncompressed format (by adding some hacks to libmythtv) (I think...i have
no idea how to actually display the raw data), but I haven't figured out
how the encoder works well enough to maintain sync, and write a valid nuv
file.  The encoder in myth is also heavily threaded, which is really not
necessary for transcoding, since runtime is irrelevant.  I looked at how
ffmpeg does it, and it is pretty straight forward (decode a frame,
process frame, encode frame...there is some code to sync video to audio,
but it is not bad).

Anyhow, my second choice is to get mencoder to read/write nuv files, and
do a system call for the transcoding.  This is not an ideal solution,
since it means that the user would need a hacked mplayer to get this
funcationality (rather than it just natively being part of libmythtv) ,
but mplayer also has a lot of processing options, which, if we want in
myth, would need to be coded in and that may be a lot of work.

So my preference at the moment is to get this working first by whatever
method is easiest, but I know nearly nothing baout MPEG4, NuppelVideo,
synchronization or anything else, so I'm not making much headway.

Thanks,
.Geoff
-- 
  Geoffrey Hausheer
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