[PD] WAS: -rt freeze on a mac linux-2.6.3 and the patch

navz at dreaming.org navz at dreaming.org
Wed Feb 25 06:08:53 CET 2004

you know, i've actually discovered something:

I had been using a really fat video file (codec/frame rate/frame size) and 
that was eating all of the computer's resources. Its not the kernel.. the patch
helps this keyboard lock problem and the rest is just fine thus far.  I
realized this when using pdp on a different machine with linux 2.4 and the same
video clip.

So, I decided to to a quick survey in codecs/settings for 
pdp/pidip so future newbies might read this and save themselves the 

Here is a bit of research I did into video codecs that work with the 
pdp/pidip library.


To determine what codecs work well with pdp/pidip libraries in 
pd.  The term *works well* can be understood as a codec/setting that:

- is readable by pdp_qt and/or pdp_yqt; 
- plays back without using too much ram or cputime
- doesnt hang the kernel or x environment; 
- results in files that are of a manageable size  

Essentially, the point was to determine the best method to transcode 
Apple Quicktime DV NTSC native uncompressed 29.97 fps files for future use in
pdp/pidip for a mixing and live stream environment.


- transcode a short clip into each of the codecs available for export in 
the default Quicktime Pro 6.4 release for OS X.  Test the codecs in 
pd/pdp/pidip for linux using the pdp_qt.pd and help-pdp_yqt.pd help 
patches.   Try processing video with effects.  Try resizing and using fullscreen
output.  Guage responsiveness of screen redraws and ancillary 

pd/pdp/pidip machine setup:

850mhz celeron processor
Debian GNU/Linux sarge (testing/unstable)
Linux kernel 2.4.22


running length: 00:00:16.11
codec: Apple DV-NTSC 
frame size:720 x 480 pixels
other: Millions of Colours, Integer (big endian)
audio:  Stereo, 48000 Hz, 16 bits
frame rate: 29.97 fps
data rate: 3.6 MB/S
Data Size: 59.1 MB


frame size: 360 x 240 pixels
frame rate: 15 fps
audio settings remained unchanged
unchecked prepare for internet streaming option


Apple H.263
Apple Pixlet Video
Apple VC H.263
Component Video
JPEG 2000
Motion JPEG A
Motion JPEG B
MPEG-4 Video
Photo - JPEG
Planar RGB
Sorenson Video
Sorenson Video 3


I rated them out of 5 based on how well I felt they performed.  The 
lighter the effect on the operating system the better.  I'm looking for a 
lean codec, something that can be used for multiple video instances for 
mixing and streaming.

The following codecs worked somewhat:

Photo - JPEG:  Horrible pig.  Works in both pdp_qt and pdp_yqt but who 
cares.. (1/5)

Animation:  works in pdp_qt but locked X once and was redrawing slowly 
the second time.  pdp_yqt gives a green screen. (2/5)

PNG:  works in both qt_pdp and yqt_pdp but still too fat.  (2/5)

Sorenson (not Sorenson3):  works in pdp_qt and pdp_yqt pretty well. Still 
a little heavy, causing slow screen redraws. (3/5)

Cinepak:  works well in pdp_qt, green screen in pdp_yqt (4.5/5)

Video:  works well in pdp_qt, green screen in pdp_yqt (5/5)

Component Video:  very good, works in both pdp_qt and pdp_yqt and very 
light (5/5)

None:  very good, works in both pdp_qt and pdp_yqt and very light (5/5)

DV-NTSC:  both pdp_qt and pdp_yqt accepted the codec, but as soon as i 
tried to send them a play message... seg fault.. socket reset by peer (honorable

FILE SIZES of transcoded files:

64M 	BMP.mov
7.5M 	H261.mov
46M 	PNG.mov
64M 	TGA.mov
64M 	TIFF.mov
7.7M 	VCH263.mov
63M 	animation.mov
8.2M 	cinepak.mov
44M 	componentvideo.mov
60M 	dvcpro50ntsc.mov
71M 	dvcpro50pal.mov
37M 	dvcpropal.mov
31M 	dvntsc.mov
37M 	dvpal.mov
17M 	graphics.mov
53M 	jpeg2000.mov
9.8M 	motionjpega.mov
9.7M 	motionjpegb.mov
7.2M 	mpeg4.mov
64M 	none.mov
5.0M 	applepixlet.mov
8.7M 	photo-jpeg.mov
64M 	planarrgb.mov
13M 	sorenson.mov
20M 	sorenson3.mov
13M 	video.mov


Video Component and None are the best settings to use, based on their 
portability between pdp and pidip and the fact that they are light and do 
not cause any seriously ill effects to the operation of the system or 
other running processes.  Since Component Video encoding results in a 
smaller file size (44MB) than None (64MB) it is best to go with Component 
Video encoding when transcoding media from Quicktime Pro for use in 
pdp/pidip.  Perhaps, in the future, or with additional codec libraries, there
might be a way to read files that work just as well but with better compression
so the files are more portable and take up less drive space.


- I did not test every setting in each codec, rather went with the 
default options.

- The pd machine has only the default libavcodec package from ffmpeg CVS

- I did not use quantific methods to evaluate the degrees of resource 
taxation.  Rather, it was a subjective analysis, that started as a 
quick test and ended up being ...  If it were useful for development I 
could do a further survey that incorporates some sort of output from cpu 
or memory usage.



> --__--__--
> Message: 12
> Date: Mon, 23 Feb 2004 22:08:42 -0500
> From: navz at dreaming.org
> To: pd-list at iem.at
> Subject: [PD] -rt freeze on a mac linux-2.6.3 and the patch
> hi,
> i am using linux 2.6.3-rc3-ben1 (for ppc) on an ibook g4, with
> pd-0.37-1test6.  When i tried using the -rt option on pd start, the
> kernel hangs the keyboard and if I try and kill X (Xfree
> (4.4.0 RC 2)) then I am left with a green screen.
> also, i have used this patch, on s_inter.c line 515
> //  p3 =3D (higher ? p2 - 1 : p2 - 3);
>     p3 =3D (higher ? p1 + 3 : p1 + 1);
> and now, after doing a make with this patch, the pd process will almost d=
> rown
> out my other processes completely.  for example, i launched pdp_zoom and
> loaded
> a quicktime and it suddenly slowed everything (including the movie) down
> to a crawl... my only hope was to escape to a terminal and kill -9 the
> pd process.  although this was a very difficult thing to do since
> everything (including keyboard interrupts and mouse/trackpad response)
> was saturated by the rampant pd process.
> hope this helps.
> cheers,
> naveen
> ----------------------------------------------------------------
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