[mythtv-users] XvMC at 1080i output

[Mr Joe Barnhart]

I'm going nuts trying to get smooth playback of HDTV
files captured at 1080i and 720P.  My setup is a
KnoppMyth box (R4V5) with Abit NF7-M m/b with onboard
GeForce 4MX graphics, Athlon 2800+, 1G RAM,
200G+250G+250G disk (XFS+LVM).  I'm using a Pioneer
rear-projection TV with a VGA input locked to 1080i.

The video output from this combination is unwatchable.
 With 720p source material, the image flashes back and
forth in time rapidly, "stuttering" in video.  At
times the flashing back and forward stops, but the
video slows down and the audio has gaps.  This is with
straight XvMC with no added filtering.

With 1080i source material, the A/V streams are
smooth, but the video resolution is reduced.  It
appears to be something like 500 lines instead of
1080.  The jaggies are so bad that it makes it
difficult to watch a football game, because of the
artifacts on the lines on the field.  If I use the
skip back or forward buttons, the image hangs, forcing
me to restart gdm.

I tried using Xv, but unfortunately my system just
isn't up to decoding and playing 1080i streams in
software.  I can't get smooth playback, or continuous
audio.  The 720p stream plays better but it also
suffers from reduced resolution and isn't up to HD
quality.

I am using all stock software from the 0.16 release. 
I'm a little surprised to find that XvMC does not work
as expected.  Am I doing something obviously wrong?  I
have attached a log from the frontend during playback.
 I'm searching for suggestions here.  I'm so close,
but this just isn't watchable.  I'll consider ANY
modification to the system (i.e. dump the video,
faster processor, etc.)  My only unchangable item is
the TV set.

Snipped log:
-----------------
...first play 720p...

2004-10-03 22:24:24 mythfrontend version:
0.16.20040906-1 www.mythtv.org
2004-10-03 22:24:24 Enabled verbose msgs : important
general playback
2004-10-03 22:24:25 Registering Internal as a media
playback plugin.
2004-10-03 22:24:25 Registering MythDVD DVD Media
Handler as a media handler
2004-10-03 22:24:25 Registering MythDVD VCD Media
Handler as a media handler
2004-10-03 22:24:26 Registering MythMusic Media
Handler as a media handler
2004-10-03 22:24:37 All Programs
2004-10-03 22:24:41 Connecting to backend server:
127.0.0.1:6543 (try 1 of 5)
2004-10-03 22:24:41 Using protocol version 13
2004-10-03 22:24:41 Using protocol version 13
2004-10-03 22:24:49 detectInterlace(Detect Scan,
Detect Scan, 59.9401, 720) ->Progressive Scan
2004-10-03 22:24:49 Interlaced: Progressive Scan 
video_height: 720  fps: 59.9401
2004-10-03 22:24:49 Estimated bitrate = 448000
2004-10-03 22:24:49 Position map filled from DB to:
754956
2004-10-03 22:24:49 SyncPositionMap prerecorded, from
DB: 48408 entries
2004-10-03 22:24:49 detectInterlace(Ignore Scan,
Progressive Scan, 59.9401, 720) ->Progressive Scan
2004-10-03 22:24:49 Interlaced: Progressive Scan 
video_height: 720  fps: -1
2004-10-03 22:24:49 Position map found
2004-10-03 22:24:49 Opening OSS audio device
'/dev/adsp'.
2004-10-03 22:24:49 Audio fragment size: 4096
2004-10-03 22:24:49 Over/underscan. V: 0, H: 0, XOff:
0, YOff: 0
Using XvMC version: 1.0
2004-10-03 22:24:49 XvMCSurfaceTypes::find(w 1280, h
1, c 1, i 2, m 0,sw 0, sh 105, disp, p<= 105, 7200
<=p, port, surfNum)
2004-10-03 22:24:49 Trying XvMC port 105
2004-10-03 22:24:49 XvMCSurfaceTypes::find(w 1280, h
1, c 0, i 2, m 0,sw 0, sh 105, disp, p<= 105, 7200
<=p, port, surfNum)
2004-10-03 22:24:49 Trying XvMC port 105
2004-10-03 22:24:49 XvMCSurfaceTypes::find(w 1280, h
1, c 1, i 2, m 0,sw 0, sh 106, disp, p<= 106, 7200
<=p, port, surfNum)
2004-10-03 22:24:49 Trying XvMC port 106
2004-10-03 22:24:49 Found a suitable XvMC surface 0
2004-10-03 22:24:49 Using XV port 106
2004-10-03 22:24:49 Image size. dispxoff 0, dispyoff:
0, dispwoff: 1920, disphoff: 1079
2004-10-03 22:24:49 Image size. imgx 0, imgy: 0, imgw:
1280, imgh: 720
2004-10-03 22:24:51 Changing from None to
WatchingPreRecorded
2004-10-03 22:24:51 nVidiaVideoSync: VBlank ioctl did
not work, unimplemented in this driver?
2004-10-03 22:24:51 DRMVideoSync: Could not open
device /dev/dri/card0, No such file or directory
2004-10-03 22:24:51 Using audio as timebase
2004-10-03 22:24:51 Video timing method: RTC
2004-10-03 22:24:51 Refresh rate: 33366, frame
interval: 16683
2004-10-03 22:24:51 A/V diverged by 16.9184 frames,
extending frame to keep audio in sync
2004-10-03 22:24:51 A/V diverged by 29.3974 frames,
extending frame to keep audio in sync
2004-10-03 22:24:51 A/V diverged by 30 frames,
extending frame to keep audio in sync
2004-10-03 22:24:51 A/V diverged by 30 frames,
extending frame to keep audio in sync
2004-10-03 22:24:51 A/V diverged by 30 frames,
extending frame to keep audio in sync
2004-10-03 22:24:51 A/V diverged by 30 frames,
extending frame to keep audio in sync
2004-10-03 22:24:51 Running as SUID root would allow
some threads to run with realtime priority, improving
video smoothness.
2004-10-03 22:24:51 A/V diverged by 30 frames,
extending frame to keep audio in sync

...snip...now let's play 1080i...

2004-10-03 22:25:23 detectInterlace(Detect Scan,
Detect Scan, 29.97, 1088) ->Interlaced Scan
2004-10-03 22:25:23 Interlaced: Interlaced Scan 
video_height: 1088  fps: 29.97
2004-10-03 22:25:23 Estimated bitrate = 384000
2004-10-03 22:25:23 Position map filled from DB to:
107767
2004-10-03 22:25:23 SyncPositionMap prerecorded, from
DB: 7186 entries
2004-10-03 22:25:23 detectInterlace(Ignore Scan,
Interlaced Scan, 29.97, 1088) ->Interlaced Scan
2004-10-03 22:25:23 Interlaced: Interlaced Scan 
video_height: 1088  fps: -1
2004-10-03 22:25:23 Position map found
2004-10-03 22:25:23 Opening OSS audio device
'/dev/adsp'.
2004-10-03 22:25:23 Audio fragment size: 4096
2004-10-03 22:25:23 Over/underscan. V: 0, H: 0, XOff:
0, YOff: 0
Using XvMC version: 1.0
2004-10-03 22:25:23 XvMCSurfaceTypes::find(w 1920, h
1, c 1, i 2, m 0,sw 0, sh 105, disp, p<= 105, 10880
<=p, port, surfNum)
2004-10-03 22:25:23 Trying XvMC port 105
2004-10-03 22:25:23 XvMCSurfaceTypes::find(w 1920, h
1, c 0, i 2, m 0,sw 0, sh 105, disp, p<= 105, 10880
<=p, port, surfNum)
2004-10-03 22:25:23 Trying XvMC port 105
2004-10-03 22:25:23 XvMCSurfaceTypes::find(w 1920, h
1, c 1, i 2, m 0,sw 0, sh 106, disp, p<= 106, 10880
<=p, port, surfNum)
2004-10-03 22:25:23 Trying XvMC port 106
2004-10-03 22:25:23 Found a suitable XvMC surface 0
2004-10-03 22:25:23 Using XV port 106
2004-10-03 22:25:23 Image size. dispxoff 0, dispyoff:
0, dispwoff: 1920, disphoff: 1079
2004-10-03 22:25:23 Image size. imgx 0, imgy: 0, imgw:
1920, imgh: 1080
2004-10-03 22:25:26 Changing from None to
WatchingPreRecorded
2004-10-03 22:25:26 nVidiaVideoSync: VBlank ioctl did
not work, unimplemented in this driver?
2004-10-03 22:25:26 DRMVideoSync: Could not open
device /dev/dri/card0, No such file or directory
2004-10-03 22:25:26 Using audio as timebase
2004-10-03 22:25:26 Video timing method: RTC
2004-10-03 22:25:26 Refresh rate: 33366, frame
interval: 33366
2004-10-03 22:25:26 waiting for prebuffer...
2004-10-03 22:25:26 prebuffer wait timed out..
2004-10-03 22:25:26 waiting for prebuffer...
2004-10-03 22:25:26 A/V diverged by 6.54858 frames,
extending frame to keep audio in sync
2004-10-03 22:25:26 A/V diverged by 11.2502 frames,
extending frame to keep audio in sync




		
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