[mythtv-users] Re: Re: Transcode to DVD-compatible MPEG-2 without quality loss?

[Steve Adeff]

On Monday 24 October 2005 16:04, Mike Frisch wrote:
> On Mon, Oct 24, 2005 at 12:44:21PM -0400, Steve Adeff wrote:
> > Have you tried processing your mpeg with ProjectX before encoding? I've
> > had great luck using ProjectX, mencoder, and avidemux2 on my ATSC mpeg2
> > files.
>
> I've had no luck with ProjectX in the past when working with .ts files
> from my Twinhan DVB-S card, but I am willing to give it another shot
> with MythTV recordings.
>
> > as for quality loss, YOU WILL ALWAYS GET QUALITY LOSS WHEN TRANSCODING.
> > this
>
> Understood and accepted :)
>
> > quality. Now, if your mpeg2 files meet the DVD standards, ProjectX can
> > convert to an mpeg2-ps from an mpeg2-ts that should work for DVD's. it
> > just remuxes the files without any transcoding.
>
> I am hoping it can do so without error and without losing A/V sync.  The
> latter is what seems to be a all too COMMON problem :(


I've used the latest version of ProjectX on my QAM recordings through my 
HD3000. When I play them back through mplayer the sync is fine. ProjectX will 
also let you do basic commercial cutting (it only cuts along GOP groups, so 
its not perfect). I use avidemux2 to do my commercial cutting, and then I 
encode to XviD for backup, but it can do DVD format as well. Avidemux2 does 
require re-syncing the audio, but its a trivial matter. The only problem 
avidemux2 has so far is with mixed progressive-telecine shows, the only of 
which I've encoutnered so ar is Supernatural, but I'm sure theres more out 
there. For this I use mencoder with the pullup filter to fix the telecine and 
do my cropping and resizing, encode to huffyuv or xvid at is highest quality 
settings. Then I open it in avidemux to do my commercial cutting and final 
encode to XviD.  So far this process has worked 100% for me.

Also, Considering your dropping in resolution eitherway the quality loss is 
not a real issue, either way the encode will look as good as possible for the 
format you choose. I've found my XviD encodes are about 95% as good as the 
original stream when played back on my 21" monitor, which, considering I can 
fit a 45min show on a 80min CD with the original AC3 audio, I figure thats 
pretty darn good ;-)

I would like to know if you get this working with your PVR card though, I plan 
on writing a how-to for the avidemux2 documentation and if I know the PVR 
output works with the process I can put that info in.

Hope this helps!
Steve