[mythtv] Recording quality

Matt Zimmerman mythtv-dev@snowman.net
Sun, 20 Oct 2002 23:43:53 -0400

My next issue is with playback quality.  My recordings in mythtv are
watchable, but the quality is relatively poor.  Recording from the command
line using ffmpegrec from NVrec:

ffmpegrec  -v /dev/video0 -w 640 -h 480 -vb 2200 -vc mpeg4 -o test.avi 

which results in a quality factor of about 10, looks excellent when played
back using mplayer.  However, mythtv using these settings:

int TargetBitrate=2200
int ScaleBitrate=0
int MaxQuality=2
int MinQuality=15
int QualDiff=3

looks bad in comparison; there is a lot of pixellation and the colour looks
washed-out.  Since both are using libavcodec, I would expect their output to
be much more similar.

As you can see, there are a lot of variables here, including the fact that
different engines are used for playback.  It would be much easier to compare
if I could playback mythtv recordings using mplayer.  It already understands
NuppelVideo format, but not in conjunction with mpeg4...vektor in #mythtv
said that this would probably not be difficult to implement; can anyone give
me some pointers as to what would be required?

 - mdz