[MPlayer-users] Video Artifacts Transcoding MythTV .nuv files to DVD

[Mike Smith]

Hi,

Sorry for the wide distribution.  I'm getting strange
video artifacts in some ( not all ) of the DVDs that
I've burned.  I'm hoping someone has seen something
similiar and can give my some insight into the 
possible problem.

I'm capturing video from my Satellite dish using 
MythTV.  Using the MPEG4 .nuv file format captured
at 640x480.  I process the files using mythtranscode,
ffmpeg, yuvdenoise, yuvscaler, mpeg2enc, and tcmplex.
I'm upscaling to 720x480 video and 48Khz audio.  
Resulting file is put through dvdauthor, mkisofs, and
growisofs to actually burn to a DVD+R.

Playing my burned DVD in my standalone DVD player,  it
will start out fine for around 30 minutes before
having
problems ( 27,30, 34, and 40 minutes in the 4
effected)
Problems are mostly a horizontal line across the 
screen that is maybe 5 percent of the total screen
height.  How far above the bottom of the screen
varies.
This garbled line will exist maybe a second or two,
then disappear for 6 - 10 seconds, then reapear
somewhere else.

On two of the recordings I also get rectangles that
go black for a second or two, then go back to the
having a picture in them.  On a 27 inch screen the
rectangles are about 1/2 inch wide by 1/4 inch high.

Facts:

1) All recordings captured at same resolution,
   bitrates, etc.

2) All transcoding done with exact same options and
   settings.  I have played with increasing max
   bit rate, but it has no effect.

3) Effecting a few, but not all of my recordings.

4) Doing transcoding on three different computers.
   A 2.4 Ghz Pentium 4 system which is also my
   NFS file server for the others two.  A 1Ghz Pentium
   4 system, and a 2Ghz Pentium 4 Laptop.  I'm trying
   to see if transcoding the same movie on all three
   systems gives me the same problem.

5) The first time I saw this problem,  I re-transcoded
   at a higher bitrate.  Problem was still evident,
   but started about 3 minutes longer into the
program.

6) I've burned a LOT of 30 minute programs ( 20
minutes
   with commercials removed ) without seeing this
   problem.  It has only occured in longer programs.

7) Playing the transcoded file ( before burning ) with
   Mplayer I don't see the artifacts.  Its like they
   aren't in the MPEG 2 source files.

8) Three out of the four movies experience problems
   with GMplayer's skip controls.  I play the movie
   file ( not on DVD, yet ) and try to skip ahead
   one minute.  It won't do it.

9) MPlayer uses the libmpeg2 codec to play the MPEG2
   output file from the transcoding process.

10) I can play the first ~30 minutes on my DVD Player
    just fine.  I can fast forward.  But,  when the
    artifacts start,  fast forward stops working. It
   just freezes.

11) I'm using a Sony DVD+/-RW DRU-530A burner.  Its 
    "rated" at 8X.  I'm using Memorex 2.4X DVD+R
    media.

12) When I burn,  I stop everything else on the 
    computer.

13) I am using Redhat 9.

14) I can provide version numbers of all the sofware
    I'm using and all the options for each command
    if that will help.

Has anyone seen anything similiar to this?  Is it
possible that my computer is overheating and screws up
the calculations?  Could one of my computers have
a hardware problem that is manifesting itself this
way?  Is it my DVD burner?

Any help much appreciated.

Mike






__________________________________
Do you Yahoo!?
Yahoo! Mail SpamGuard - Read only the mail you want.
http://antispam.yahoo.com/tools