gstreamer loading CPU to 100%

Hi all,

Thanks for all your help so far. I’m having an issue with the gstreamer plugins for the DSP. When I decode a h264 with the audio the CPU utilization in top reads around 50% for gst-launch until the movie locks up after awhile then the utilization reads almost 100% and the whole system grinds to a halt till I can kill it. At first I though I had a problem with not enough ram since I have a b6 board but now I think something is taking all the cpu cycles.

Does 50% sound right when its running, that seems a little high to me since it should be the DSP doing the decoding. This is the command I used to start the decode:

gst-launch filesrc location=/media/sda1/BigBuckBunny_640x360.m4v ! typefind ! qtdemux name=demux demux.audio_00 ! queue max-size-buffers=1800 max-size-time=0 max-size-bytes=0 ! typefind ! TIAuddec1 ! alsasink demux.video_00 ! typefind ! TIViddec2 ! xvimagesink




I see similar results on my beagleboard rev C. I will be working in next weeks on profiling the plugins to identify where the CPU consumption is going on, but I don’t promise deadlines, I already have a ton of work queued for gstreamer :wink:




Thanks for the help, I’m in no hurry. Let me know if there is anything I can do to help.


1) I tested gstreamer to decode 1280x720 mpeg video and tried to
profile it (revision B4 board).
I observe CPU% usage at about 75-80%, however I observe that state of
gstreamer process is 'sleeping' most of the time (using 'top'
application), which I believe is the state of ARM processor, as DSP
should be doing the decoding.

gst-launch filesrc location=/home/foo.mpg ! dvddemux ! mpeg2dec !

However, when I decode the same video using mplayer (-vo fbdev), I see
CPU utilization as 95% and state of mplayer process is 'running'

2) In order to profile DSP capability, I tried decoding different
quality video

I am using Robotica hd720p wmv video from
and convert them to mpeg, using ffmpeg at different quantization
levels ranging from -qscale 1 (high quality) to 31 (low quality).

I observed that dsp is able to play videos properly upto qscale of 8
(roughly about 2500kbps bitrate), however higher datarate videos
(qscale < 8, or data rate > 2500kbps) results in framedrop,

Can somebody put thoughts on how to harness DSP to its maximum
capability, and how to see DSP %usage while decoding.

Deepak Malani