[mythtv-users] Suggested Encoding Rates

[Nate Thompson]

On 4/28/05, Jason McLeod <anakin at sdf1.net> wrote:
> I found some video guys here at work, who know a few things about
> video encoding.
> 
> They where telling me that the NTSC standard is 720x480, although
> cable broadcasts don't use that high, it's much closer to 480x320.  I
> originally had my resolution for capturing set to the max, but I'll
> try scaling it down to the true broadcast size, that should save some
> space.
> 
> Since I'm using a very weak box to run the Myth backend on, I'd
> rather have the size determined while the card is encoding with the
> hardware MPEG2 encoder.
> 
> -Jason
> 

Actually, if I'm not mistaken, changing just the resolution will have
little-to-no effect on the size of the files. You must lower the
bitrate.

Nate

> Blog: http://jason.sdf1.net
> GPG Fingerprint:
> anakin at sdf1.net - A6CC 40B4 99A4 1C08 55A7  BCFC ECDF ED68 115E 5993
> 
> On 28-Apr-05, at 1:35 PM, Timothy Daniel Hamer wrote:
> 
> > On Thu, 28 Apr 2005, Scott Alfter wrote:
> >
> >
> >> Neil Bird wrote:
> >>
> >>>   I was just about to post this and a related question.  I'm
> >>> running my
> >>> PVR-350 with fairly high (normally) res. PAL settings, and a
> >>> bitrate of
> >>> ~6200 somethings.  I get images of ~2.0-2.2 Gb per hour.
> >>>
> >>>   Now, I just downloaded [bittorrent] an episode of something I
> >>> missed.
> >>>  The AVI's ~364 Mb for the, I guess, ~43 mins., but is, whem played
> >>> through MythVideo, of comparable quality to the stuff I record at
> >>> 6x the
> >>> size!
> >>>
> >>
> >> Those AVIs you downloaded probably aren't using MPEG-2, but
> >> instead use some
> >> variant or another of MPEG-4.  That's why they can deliver the
> >> same quality in
> >> less space.  Comparing MPEG-4 to MPEG-2 is like comparing Ogg
> >> Vorbis to MP3.
> >>
> >> You could transcode from MPEG-2 to MPEG-4 (MythTV will even do
> >> this for you),
> >> but the transcoded recordings won't be playable through your
> >> PVR-350.  (That
> >> assumes you're using its MPEG-2 decoder; I stopped using mine when
> >> I upgraded
> >> to an LCD TV and switched from S-video to DVI.)
> >>
> >>  _/_
> >> / v \ Scott Alfter (remove the obvious to send mail)
> >> (IIGS( http://alfter.us/            Top-posting!
> >> \_^_/ rm -rf /bin/laden            >What's the most annoying thing
> >> on Usenet?
> >>
> >>
> >
> > I noticed the same thing with downloaded files vs. files captured
> > from my pvr 150, but even when i use mythtranscode to convert them
> > to mpeg-4, i can get downloaded AVI files that look much better and
> > are smaller. Should i use one of the external transcoding programs
> > instead of mythtranscode?
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
> 
> 
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> 
> 
>