[mythtv] New Mythtv user with Matrox Marvel G200TV

Ray mythtv-dev@snowman.net
Sat, 26 Oct 2002 17:31:53 -0700

First and formost I want to say thanks to Isaac and everyone else who has
contributed to this project.  I'm really impressed with Mythtv.  My system  
is as follows:

Dual Celerons @ 500
256MB Ram          
2 - 60GB 7200RPM Hard drives, 1 on a ATA33 controller and 1 on ATA66
Matrox Marvel G200TV for video capture and display                  
Trident 4d Wave PCI sound card using Alsa.        
DirecTV Satellite as my primary input/tuner

Some issues I've run into so far:

1.  The Marvel captures best used with it's hardware mjpeg compression which
isn't supported in Mythtv (but IS well supported under Linux via the mjpeg
tools).  Using raw uncompressed capture the card is limited to around
352x240 with the current Linux drivers.  

2.  TV Out.  this card has 2 methods of outputting video to a TV.  The first
method is used by the mjpeg tools and Xawtv.  This method is easy to setup
and produces excellent output.  The second method requires using the
matrox framebuffer driver and basically involves mirroring your
desktop/console to the TV.  It works but it's a pain to get set up just
right and never really looks as good as the first method.  Unfortunately
this is the only one supported by Mythtv.

3.  For some reason when I watch TV with the record method set to mpeg4 I
see random odd artifacts on the screen.  Normally they are a few small
blocks of color.  I'm not sure these are real compression artifacts though
since they don't appear if I just record and playback later.  Also changing
resolution and quality settings seem to have no affect.  I saw some mention
of this in the archives but it was apparently fixed by a newer avifile that
was included in cvs last month and I'm using the current release version.

4.  Timed recording isn't real useable since Mythtv doesn't support external
tuners.  I know this is in the FAQ but I really didn't understand the
reasoning in the answer.  I have a script to change channels on my dss
receiver via serial port so I really just need to get the desired channel #
out to said script.  I'll probably ask about this in more detail after I've
looked more carefully at the code.  I'm not a real programmer so it may take
a while.

Basically, it looks great and sort of works with my particular hardware but
it would work far better if it could make use of external tools for bits
that actually interface with the hardware.   With all of the cheap mjpeg
cards out there and the growing popularity of DV capture and digital cable I
can only see this becoming an issue for more people in the future.