[mythtv-users] Optimum encoding for remote mythtv

[Joseph A. Caputo]

On Monday 10 May 2004 13:07, Johnny Lee wrote:
> > On Mon, 2004-05-10 at 10:57, Boyd II, Willy wrote:
> >> Not sure if this has been addressed yet, as I just caught this
> >> reply and I'm not using threaded messaging.... but:
> >>
> >> You won't help your download times be leaving the bitrate the
> >> same.  Th The only thing that will change by reducing the
> >> resolution, is slightly better quality on a TV, because you're
> >> encoding less pixels, but more information about them.  Make
> >> sense?  I can't think of a better laymen's way to explain but
> >> someone else probably can.
> >>
> >> So I would suggest doing both:  reduce resolution to, say,
> >> 352x480, and drop the resolution a bit until you find it just
> >> acceptable to watch. i.e. 2000kbps might look really bad at
> >> 720x480, but not quite so bad at 352x480.
> >
> > While this is most definately true, I might suggest what someone
> > else mentioned.
> >
> > Record the programs at 720x480 at 8/12/16000 per second. Make sure
> > you get a good record of the program. The idea here is not to
> > transfer the file but get as a high of quality digital stream that
> > you can handle to start with.
> >
> > Next, use mencoder, or the transcode options of mythtv. transcode
> > it over to mpeg4 maybe with ogg sound or somesuch. as far as the
> > video, you can then reduce it to something smaller and limit the
> > bitrate down to 1k or 1.5k. An mpeg4 stream will have the same
> > quality as a meg 4 stream at the same resolution and a much lower
> > bit rate. The downside is that the transcode will take some time to
> > complete if you dont ahve a beefy cpu. The upside is your file
> > transfers wil lbe MUCH faster for the same quality of video.
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>
> I have a similar setup.
>
> P4 2.53ghz
> 512MB 1066mhz Rambus
> 120GB 7200 8MB Hard drive
> Nvidia Geforce MX 440 64MB w/ TV out (primary)
> Winfast Deluxe w/ dbx stereo (NTSC Analog cable)
> Fedora Core 1
> xv decoding on
> kernel deinterlace on
>
> My configuration is using:
>
> Default recording rate(i primarily use this 99% of the time)
> Video - MPEG4 5000bps 640x480 (proper 4x3 ratio)
> Audio - 41k
>
> Live TV rate
> Video - MPEG4 6000bps 640x480 (proper 4x3 ratio)
> Audio - 41k
>
>
> With this setup I can do pretty much anything and don't really have
> any issues with frame loss. I can record a show and be watching a
> prerecorded show at the same time. Sometimes I even transcode a show
> while one is recording and haven't noticed any issues.
>
> On a side note. Does anyone know how I can convert this to mpeg2 for
> SVCD? I use avidemux2 and it works properly for DVD but when I try to
> do SVCD for some reason the audio doesn't work on the exported mpeg
> file...

What are you using to convert to MPEG-2?  If you use nuvexport it should 
work.  If you use avidemux2, be careful -- the audio must be 41 kHz mp2 
audio, and the *total* bitrate must not exceed 2778 kbps (2600 max 
video + 384 kbps audio would exceed the max total, so be careful.)

The DVD standard supports other types of audio (like AC3) that SVCD 
doesn't support, which is why you have to pay attention.

-JAC