What a pity

[Jeff Shanab]

This is the first I am seeing of this and I am in no way a GStreamer
expert. I have some familiarity as I have been looking into it as a
replacement for the manual system I have that is using modified live555.

I assume since this is all open source, you have built it your self and
done a CPU sampling kind of profiling.

Am I seeing the encoding of H264 and AAC. Do we know if the GPU is being
used?
You may find encoding H264 with fast CPU better than waiting to move raw
frames across the bus to the GPU and then the compressed data back to main
memory.
( Encoding is of course a LOT more bus traffic than Decoding which only has
to move compressed data to the card which decodes and displays.  can be a
25 to 1 difference!)

I also do not see any buffers. Moving that keyframe is going to cause a
pause.
There is probably some default, and someone else can chime in, but I think
you must consider that video must come in at one rate and audio another,
You must operate with some latency by using buffers because you cannot
predict the future for packets you have not gotten.
A tiny amount of buffers lets you operate just behind enough to
imperceivable have what you need at the correct time.

Now the hls stuf is going to have a built in latency of it's own of course.

Profile, Profile, Profile :-)




On Sun, Jan 2, 2022 at 6:16 PM James via gstreamer-devel <
gstreamer-devel at lists.freedesktop.org> wrote:

> gstreamer seems very nice in concept. The fact that I've been trying for 3
> months and can get no help is a big deterent.
>
> I've got a 4 core i7 NUC clocked to 4.8G and I get a stream of QoS
> messages telling me the computer is too slow.
> (GST_DEBUG=2,pulsesrc:6)
>
> The machine is idle running a single pipeline.
> The stream stutters. ffmpeg shows dup and often a 100 dropped frames on
> each segment.
>
> Using audiotestsrc renders perfectly.
>
> #! /bin/bash
>
> IP=`hostname -I`
>
> gst-launch-1.0 -e -v v4l2src device=/dev/video2 ! \
>         video/x-h264,width=1920,height=1080,framerate=30/1 ! \
>         h264parse ! \
>         tee name=vt \
>         vt. ! queue ! hlssink2 max-files=5 name=hl \
>         playlist-root=http://$IP playlist-location=/dev/shm/channel1.m3u8
> location=/dev/shm/segment_%05d.ts \
>         pulsesrc device=0 ! audioconvert ! avenc_aac ! \
>         tee name=at \
>         at. ! queue ! aacparse ! hl.audio
>
> The redundant tee's are for use later.
> unless I see a euroka moment I'll have to try somethink else
> James
>
>
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