[gst-devel] Pipeline performance assessment

[Baldur Gislason]

I have been doing some experiments with transcoding using gstreamer
and I've had some pretty terrible performance.
VLC has no problem performing the same task with as far as I can tell,
identical encoder profiles, leaving plenty of resources behind, while
with gstreamer I am maxing out one core and going about 40-50% on the
remaining three, and not quite keeping up with real time transcoding.
Machine is a 64 bit Linux system on an Intel Xeon E5507 quad core processor.
I am decoding MPEG2 and encoding H.264.
I was wondering if there was a recommended method of wathing the CPU
time used by an element in a pipe.
My current pipeline goes like this:
udpsrc -> mpegtsdemux
demux -> decodebin2
decoder -> x264enc -> queue -> mpegtsmux
decoder -> audioconvert -> audioresample -> ffenc_aac -> queue -> mpegtsmux
mux -> filesink (for testing purposes, would be udpsink in production)
Is there any inherent problem with this configuration? I tried placing
queues between decoder and encoders but that did not make any
difference
I have a hunch that the handling of the uncompressed video is
inefficient but I'm not quite sure what the best tools are for finding
bottlenecks of streaming applications.

Baldur