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Original commit message from CVS: * docs/random/ensonic/profiling.txt: Ideas about qos profiling.
59 lines
2 KiB
Text
59 lines
2 KiB
Text
$Id$
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= core profiling =
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* scheduler keeps a list of usecs the process function of each element was
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running
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* process functions are: loop, chain, get
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* scheduler keeps a sum of all times
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* each gst-element has a profile_percentage field
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* when going to play
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* scheduler sets sum and all usecs in the list to 0
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* when handling an element
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* remember old usecs t_old
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* take time t1
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* call elements processing function
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* take time t2
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* t_new=t2-t1
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* sum+=(t_new-t_old)
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* profile_percentage=t_new/sum;
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* should the percentage be averaged?
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* profile_percentage=(profile_percentage+(t_new/sum))/2.0;
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* the profile_percentage shows how much CPU time the element uses in relation
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to the whole pipeline
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= qos profiling =
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* what data is needed ?
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* streamtime,propotion pairs from sinks
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draw a graph with gnuplot or similar
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* number of frames in total
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* number of frames dropped from each element that support QOS
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elements that don't support QOS wont have this information anyway
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* idea1: parse data from debug log
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GST_QOS gstbasesink.c:1188:gst_base_sink_send_qos:<xvimagesink0> qos: proportion: 0.895615, diff -16437500, timestamp 0:00:09.208333333
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basesink gstbasesink.c:1542:gst_base_sink_render_object:<xvimagesink0> buffer late, dropping
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basesink gstbasesink.c:2534:gst_base_sink_change_state:<alsasink0> rendered: 1028, dropped: 0
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basesink gstbasesink.c:2534:gst_base_sink_change_state:<xvimagesink0> rendered: 598, dropped: 10
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+ easy to do
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- debug log changes timing
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* idea2: query data (via gst-launch)
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* add -r, --report option to gst-launch
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* send duration to get total number of frames (GST_FORMAT_DEFAULT for video is frames)
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* during playing we need to somehow listen to/capture/intercept QOS-events to record
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'streamtime,proportion' pairs
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* after EOS, send qos-queries to each element in the pipeline
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* qos-query will return:
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number of frames rendered
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number of frames dropped
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* print a nice table with the results
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+ robust
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+ also available to application
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- changes in core
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