[mythtv-users] My Perennial Problems with XvMC

[Dylan Semler]

On 9/19/06, Brad Fuller <bradallenfuller at yahoo.com> wrote:
> So, the thing to do is to turn off the  screen saver (for good) and see
> if that _really_ changes the problem.

The problems is not that the screen saver is causing distortions in
liveTV.  The problem occurs when anything significant is drawn to the
screen while the HD-3000 is recording.  This will cause
deteriorations/distortions in the file that is being written.  This
problem is particularly evident while watching LiveTV on said BE, as
the there is always significant changes to the screen (i.e. the liveTV
that is being watched).

> Because, I think it strange that problems are written into the file
> because of a screen saver. There's not a lot of processing when
> recording HD, right? Just copying the frames - no mpeg encoding going on.

Yup, I've tried with using myth to "record" the HD and I tried with
azap (while scrolling a webpage on the screen).  As long as something
on the screen is changing, errors are written to the video file.
However, see below.

> (BTW, what does 4200/6200 issues have to do with the HD3000?)

Since the problem occurs when drawing something to the screen, one
might wonder if it's a graphics card causing some sort of inteference
with the tuner card.  The fact that it was observed with two different
graphics cards significantly reduces the likelihood that it's a
graphics card problem.


Your reply has prompted me to test with azap alone.  With a properly
configure channels.conf in place, and with try26 corresponding to the
local fox channel, I issue the following command:

[Dylan at boron szap]$ ./azap -r try26
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 669000000 Hz
video pid 0x03ee, audio pid 0x03ef
status 00 | signal ffff | snr fcad | ber 00000000 | unc 00000000 |
status 1f | signal ffff | snr fc89 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fc97 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcbf | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fc97 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcbd | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcd3 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcb3 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcb5 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcd5 | ber 00000000 | unc 00000000 | FE_HAS_LOCK

----------------   now i begin scrolling up and down on a web page
---------------------

status 1f | signal ffff | snr fca5 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 00 | signal ec8a | snr fcb3 | ber 00000000 | unc 00000000 |
status 00 | signal ffff | snr fccf | ber 00000000 | unc 00000000 |
status 1f | signal ffff | snr fc9f | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fb8b | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ef9c | snr fc05 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 00 | signal ffff | snr fbff | ber 00000000 | unc 00000000 |
status 00 | signal f603 | snr fcbd | ber 00000000 | unc 00000000 |
status 00 | signal ffff | snr fc7f | ber 00000000 | unc 00000000 |
status 1f | signal ffff | snr fcb9 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fca5 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcd9 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcc1 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcb9 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcdb | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 00 | signal ffff | snr fcc3 | ber 00000000 | unc 00000000 |
status 1f | signal ffff | snr fcb3 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fccd | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fc93 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal fd2e | snr fc45 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal fd2e | snr fc25 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal f603 | snr fcd5 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcc1 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal f998 | snr fca1 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 00 | signal f2af | snr fca9 | ber 00000000 | unc 00000000 |
status 1f | signal ffff | snr fc19 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal f2af | snr fcd9 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal f603 | snr fca1 | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 00 | signal ef9c | snr fbc3 | ber 00000000 | unc 00000000 |
status 00 | signal f603 | snr fcd1 | ber 00000000 | unc 00000000 |
status 00 | signal ffff | snr fbf7 | ber 00000000 | unc 00000000 |
status 1f | signal ffff | snr fb8f | ber 00000000 | unc 00000000 | FE_HAS_LOCK
status 1f | signal ffff | snr fcdb | ber 00000000 | unc 00000000 | FE_HAS_LOCK



So somehow when the screen image changes significantly, the HD-3000
looses lock.  This I believe, looks like the root of the distortions
and deteriorations I've been seeing.  Now, anybody know how to fix
this?

Cheers,
-- 
Dylan

Type faster.  Use Dvorak:
http://dvzine.org