[mythtv-users] Live TV Pauses

Thu Jul 1 07:51:53 EDT 2004

On Thu, Jul 01, 2004 at 12:34:12PM +0100, Ivan A. Beveridge wrote:
> WRT alsa, I have added the entries to modprobe.conf that enable OSS
> compatability mode. I am still getting the jitters (so to speak ;)
> though.

I think I was probably using alsa's emulation of oss before (the output
was /dev/dsp) :^)

> Taking the "least complicated" option (viewing a previously recorded tv
> programme) ...
> 
> The symptoms (aside from the obvious) are (user) CPU loading shoots up 
> when viewing the recording. The problem is that, when user CPU loading
> is high (80-97p/c) nothing owns up to using that much CPU when viewing
> in "top" ... which is annoying (and confusing). These are some outputs
> of "vmstat 1" .... the context switches seem to be the most noticeable
> change:

> Mplayer in myth is using the default settings (I didn't change anything
> for movie viewing), so it's using XV under X.
> 
> This may be of use ... I can't see how an cpu-intensive thing like
> mplayer viewing MPEG4 can cause a system to jump ~25-30p/c CPU, where
> something less cpu-intensive (viewing MPEG2) causes the system to jump
> ~90p/c CPU.

I should add that the MPEG2 quality is high ... 720x576 (PAL), so that 
may well have some bearing (oops).

> [3] For completeness, file shows the movie as: "AVI, 640 x 272, 23.98 fps, 
>      video: DivX 3 Low-Motion, audio: MPEG-1 Layer 3 (stereo, 44100 Hz)"

Perhaps I was comparing apples with pears :(

This is the output from "mythfrontend -v playback", when viewing a
recorded tv programme:

=============================================
2004-07-01 12:42:11 mythfrontend version: 0.15.20040525-1 www.mythtv.org
2004-07-01 12:42:11 Enabled verbose msgs : important general playback
mythtv: could not connect to socket
mythtv: No such file or directory
lirc_init failed for mythtv, see preceding messages
2004-07-01 12:42:12 Registering Internal as a media playback plugin.
2004-07-01 12:42:12 Registering MythDVD DVD Media Handler as a media
handler
2004-07-01 12:42:12 Registering MythDVD VCD Media Handler as a media
handler
2004-07-01 12:42:22 All Programs
2004-07-01 12:42:24 Connecting to backend server: 127.0.0.1:6543 (try 1
of 5)
2004-07-01 12:42:24 Using protocol version 8
2004-07-01 12:42:25 Using protocol version 8
2004-07-01 12:42:31 Output filters for this recording are: ''
2004-07-01 12:42:31 Interlaced: -1  video_height: 576  fps: 25
2004-07-01 12:42:31 Estimated bitrate = 256000
2004-07-01 12:42:31 Interlaced: -1  video_height: 576  fps: -1
Input #0, mpeg, from
'/media/mythtv/1017_20040630232500_20040701012000.nuv':
  Stream #0.0: Video: mpeg2video, 720x576, 25.00 fps
  Stream #0.1: Audio: mp2, 48000 Hz, stereo, 256 kb/s
2004-07-01 12:42:31 Position map found
2004-07-01 12:42:31 Opening OSS audio device '/dev/dsp'.
2004-07-01 12:42:31 Audio fragment size: 4096
2004-07-01 12:42:31 Over/underscan. V: 0, H: 0, XOff: 0, YOff: 0
2004-07-01 12:42:31 Using XV port 56
2004-07-01 12:42:31 Image size. dispxoff 0, dispyoff: 85, dispwoff: 720,
disphof
f: 406
2004-07-01 12:42:31 Image size. imgx 0, imgy: 0, imgw: 720, imgh: 576
2004-07-01 12:42:32 Changing from None to WatchingPreRecorded
2004-07-01 12:42:32 waiting for prebuffer...
2004-07-01 12:42:32 prebuffer wait timed out..
2004-07-01 12:42:32 waiting for prebuffer...
2004-07-01 12:42:32 prebuffer wait timed out..
2004-07-01 12:42:32 waiting for prebuffer...
2004-07-01 12:42:32 prebuffer wait timed out..
2004-07-01 12:42:32 waiting for prebuffer...
2004-07-01 12:42:33 Delaying to next trigger: 269996
2004-07-01 12:42:33 Delaying to next trigger: 213996
3
69
79
84
55
59
84
100
8
1
0
0
79
30
2
1
-1
0
0
32
1
0
15
58
68
'video_output' mean = '46666.27', std. dev. = '28305.53', fps = '21.43'
'video_output' mean = '47544.42', std. dev. = '12836.89', fps = '21.03'
'video_output' mean = '50856.93', std. dev. = '14960.85', fps = '19.66'
'video_output' mean = '49708.06', std. dev. = '14104.37', fps = '20.12'
'video_output' mean = '46793.08', std. dev. = '11302.83', fps = '21.37'
'video_output' mean = '42578.02', std. dev. = '3701.86', fps = '23.49'
'video_output' mean = '45340.71', std. dev. = '9812.54', fps = '22.06'
'video_output' mean = '43278.46', std. dev. = '4748.08', fps = '23.11'
'video_output' mean = '42161.67', std. dev. = '4868.87', fps = '23.72'
'video_output' mean = '40057.81', std. dev. = '3637.93', fps = '24.96'
'video_output' mean = '40020.49', std. dev. = '2160.14', fps = '24.99'
'video_output' mean = '39992.55', std. dev. = '506.12', fps = '25.00'
'video_output' mean = '41601.40', std. dev. = '5446.46', fps = '24.04'
'video_output' mean = '42388.64', std. dev. = '3710.20', fps = '23.59'
'video_output' mean = '40286.25', std. dev. = '835.71', fps = '24.82'
'video_output' mean = '40008.34', std. dev. = '807.51', fps = '24.99'
'video_output' mean = '40001.30', std. dev. = '835.21', fps = '25.00'
'video_output' mean = '39999.95', std. dev. = '752.53', fps = '25.00'
'video_output' mean = '40000.76', std. dev. = '672.06', fps = '25.00'
'video_output' mean = '41170.22', std. dev. = '937.70', fps = '24.29'
'video_output' mean = '40298.49', std. dev. = '641.44', fps = '24.81'
'video_output' mean = '40001.51', std. dev. = '714.59', fps = '25.00'
'video_output' mean = '40001.24', std. dev. = '1622.69', fps = '25.00'
'video_output' mean = '42955.49', std. dev. = '6102.56', fps = '23.28'
'video_output' mean = '41467.32', std. dev. = '852.93', fps = '24.12'
2004-07-01 12:44:20 Changing from WatchingPreRecorded to None
2004-07-01 12:44:20 Changing from None to None
=============================================

Cheers

Ivan
-- 
Ivan Beveridge	<ivan at dreamtime.org>