appsrc performance issue

[Nicolas Dufresne]

Le mardi 07 janvier 2020 à 14:00 -0500, Nicolas Dufresne a écrit :
> Le mardi 07 janvier 2020 à 00:16 -0600, mksafavi a écrit :
> > Hi.
> > 
> > when I push my buffer to appsrc it takes too much time. (about 20ms
> > for each
> > buffer).
> > I want this process to be zero-copy.
> > 
> > my data after processing is stored in a physically contiguous array
> > pointer
> > (data->dest_vptr).
> > then I wrapped this array on a gst_memory and append it to the
> > out_buffer
> > which I push to appsrc.
> > 
> > out_buffer = gst_buffer_new();
> > gst_buffer_append_memory (out_buffer,gst_memory_new_wrapped
> > (GST_MEMORY_FLAG_READONLY,data->dest_vptr, DEST_BUF_SIZE, 0,
> > DEST_BUF_SIZE,
> > NULL, NULL));
> > source = gst_bin_get_by_name(GST_BIN(data->sink), "testsource");
> > ret = gst_app_src_push_buffer(GST_APP_SRC(source), out_buffer);
> > return ret;
> > 
> > in my pipeline, I have an accelerator that takes 19ms to finish its
> > job.
> > filesrc -> decoder -> encoder -> filesink : 10ms per frame
> > filesrc -> decoder -> appsink -> [accelerator] -> appsrc -> encoder
> > ->
> > filesink : 50ms per frame ( expecting approximately 30ms)
> > 
> > apprsc parameters:
> > testsource = gst_bin_get_by_name(GST_BIN(data->sink),
> > "testsource");
> >     g_object_set(testsource, "format", GST_FORMAT_TIME, "block",
> > FALSE,
> > NULL);
> >     gst_object_unref(testsource);
> > 
> > Am I doing an unnecessary copy somewhere? or having bad appsrc
> > parameter
> > settings?
> > I also checked with fake sink directly after appsrc and made sure
> > the appsrc
> > is bottlenecking.
> 
> Did you located a copy? do you notice higher CPU if you do appsink ->
> appsrc (skipping the accel) ? (GST_DEBUG="*PERF*:5") A copy can
> happen
> in such case if the decoder requires GstVideoMeta. Here's an example
> code using appsink that enables GstVideoMeta (to allow zero-copy):
> 
> https://gitlab.freedesktop.org/mesa/kmscube/blob/master/gst-decoder.c#L242
> 
> This is all dependent on the decoder being used, which you have
> abstracted here.

I forgot, you might also want to proxy the allocation query, as it is
possible that the decoder was writing directly into the encoder
allocated buffers, which may save a copy too.

> 
> > thanks
> > 
> > 
> > 
> > --
> > Sent from: http://gstreamer-devel.966125.n4.nabble.com/
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