[mythtv-users] HDTV playback woes

Tue Oct 12 01:07:44 UTC 2004

I am having a problem I can't seem to figure out. For the last month or 
so I have not been able to watch most of my hd recordings. I have been 
running the latest cvs versions as they come out. I don't know if it is 
a recording issue with patches or a playback issue. I have not been able 
to finish the last three Joan of Arcadias, Navy NCIS, Lost or Extreme 
makeover. The first problem is fast forwarding and commercial skipping 
stop working after any noise in the mpeg stream, I can ff 10 seconds at 
a time until some noise then it increases the timeline by 10 seconds but 
only increases the video by a split second. The really anoying problem 
is about half way through watching and getting interested in the show, 
playback jumps back to the beginning and we can never finish the show. I 
captured some debug from playback. It looks like I am getting some 
negative A/V diverge messages that cause the frame to jump backwards. 
Here are some messages:

2004-10-11 17:56:48 waiting for prebuffer...
'video_output' mean = '66983.34', std. dev. = '119704.30', fps = '14.93'
avsync_delay: 172, avsync_avg: 217, warpfactor: 1.11715, warpfactor_avg: 
1.00494
2004-10-11 17:56:48 A/V diverged by 13.0347 frames, extending frame to 
keep audio in sync
2004-10-11 17:56:48 A/V diverged by 5.42468 frames, extending frame to 
keep audio in sync
2004-10-11 17:56:52 A/V diverged by -3.03608 frames, dropping frame to 
keep audio in sync
2004-10-11 17:56:53 A/V diverged by -3.04867 frames, dropping frame to 
keep audio in sync
'video_output' mean = '46596.99', std. dev. = '94146.70', fps = '21.46'
avsync_delay: -44, avsync_avg: -44, warpfactor: 1.09389, warpfactor_avg: 
1.00524
2004-10-11 17:56:53 A/V diverged by -3.01403 frames, dropping frame to 
keep audio in sync
2004-10-11 17:56:53 A/V diverged by -3.15663 frames, dropping frame to 
keep audio in sync
2004-10-11 17:56:53 A/V diverged by -3.07175 frames, dropping frame to 
keep audio in sync
2004-10-11 17:56:54 A/V diverged by -3.10064 frames, dropping frame to 
keep audio in sync
'video_output' mean = '15505.66', std. dev. = '7012.44', fps = '64.49'
avsync_delay: -41, avsync_avg: -49, warpfactor: 1.04053, warpfactor_avg: 
1.00541
2004-10-11 17:56:55 A/V diverged by -3.00971 frames, dropping frame to 
keep audio in sync
2004-10-11 17:56:55 A/V diverged by -3.03267 frames, dropping frame to 
keep audio in sync
2004-10-11 17:56:55 A/V diverged by -3.05149 frames, dropping frame to 
keep audio in sync
'video_output' mean = '16405.31', std. dev. = '5446.92', fps = '60.96'

If I exit the playback and save the position after it loops back to the 
beginning then go back and try to watch it where it left off, It locks 
up the frontend in a loop. It also looks like there is a GOP frame problem:

2004-10-11 17:57:05 Interlaced: Progressive Scan  video_height: 720  fps: -1
2004-10-11 17:57:05 positionMap[ 2 ] == 2309392.
2004-10-11 17:57:06 detectInterlace(Detect Scan, Detect Scan, 59.9401, 
720) ->Pr
ogressive Scan
2004-10-11 17:57:06 Interlaced: Progressive Scan  video_height: 720  
fps: 59.940
1
2004-10-11 17:57:06 Estimated bitrate = 384000
2004-10-11 17:57:06 Image size. dispxoff 0, dispyoff: 0, dispwoff: 0, 
disphoff:
0
2004-10-11 17:57:06 Image size. imgx 0, imgy: 0, imgw: 1280, imgh: 720
2004-10-11 17:57:06 positionMap[ 0 ] == 1316.
2004-10-11 17:57:06 waiting for prebuffer...
2004-10-11 17:57:06 prebuffer wait timed out..
2004-10-11 17:57:06 waiting for prebuffer...
2004-10-11 17:57:06 prebuffer wait timed out..
2004-10-11 17:57:06 waiting for prebuffer...
2004-10-11 17:57:07 positionMap[ 2 ] == 1139280.
2004-10-11 17:57:07 HandleGopStart: gopset not set, syncing positionMap
2004-10-11 17:57:07 SyncPositionMap prerecorded, from DB: 2 entries
2004-10-11 17:57:07 Stream initial keyframedist: 30.
2004-10-11 17:57:07 detectInterlace(Ignore Scan, Progressive Scan, 
59.9401, 720)
 ->Progressive Scan
2004-10-11 17:57:29 Image size. dispxoff 0, dispyoff: 0, dispwoff: 1856, 
disphof
f: 1080
2004-10-11 17:57:29 Image size. imgx 0, imgy: 0, imgw: 1280, imgh: 720
2004-10-11 17:57:30 Changing from None to WatchingPreRecorded
2004-10-11 17:57:30 Realtime priority would require SUID as root.
2004-10-11 17:57:30 Your soundcard is not reporting free space 
correctly. Fallin
g back to old method...
2004-10-11 17:57:30 DoFastForward: Not enough info in positionMap, we 
need frame
 215859 but highest we have is 215516
2004-10-11 17:57:30 DoFastForward: Still Not enough info in positionMap, 
we need
 frame 215859 but highest we have is 215516.  Will seek frame-by-frame
2004-10-11 17:57:30 nVidiaVideoSync: VBlank ioctl did not work, 
unimplemented in
 this driver?
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:30 prebuffer wait timed out..
2004-10-11 17:57:30 waiting for prebuffer...
2004-10-11 17:57:31 prebuffer wait timed out..
2004-10-11 17:57:31 waiting for prebuffer...
2004-10-11 17:57:31 prebuffer wait timed out..
2004-10-11 17:57:31 waiting for prebuffer...
2004-10-11 17:57:31 prebuffer wait timed out..
2004-10-11 17:57:31 waiting for prebuffer...
2004-10-11 17:57:31 prebuffer wait timed out..

The above prebuffer wait timed out continues until I restart the frontend.

Backend is Athlon 2000, FC2 with pchdtv patches running v.16 cvs
Frontend is P4 3G 1Meg cache HT, FC1, NVidia 5200

- James