mpegts latency

[Nicolas Dufresne]

Le mer. 31 juill. 2019 08 h 25, TheGiamig <thegiamig at gmail.com> a écrit :

> Hi all,
> I'm facing a latency problem using mpegtsmux and tsdemux elements
> (windows7,
> gstreamer 1.15.1).
>

Unrelated, but quick reminder that 1.15 is a development branch and should
be considered unstable. You should use 1.16 stable releases.


> I have to stream some h264 video content but my problem occurs also without
> actually stream through UDP.
>
> If I launch the following pipeline I can see the captured video without
> latency problems (few ms):
>
> gst-launch-1.0.exe dx9screencapsrc x=0 y=0 width=100 height=100 !
> videoconvert ! queue ! x264enc tune=zerolatency speed-preset=ultrafast
> byte-stream=true ! queue ! h264parse ! avdec_h264 ! videoconvert !
> autovideosink
>
> But if I add mpegtsmux and tsdemux elements the video latency will be
> around
> 1sec:
>
> gst-launch-1.0.exe dx9screencapsrc x=0 y=0 width=100 height=100 !
> videoconvert ! queue ! x264enc tune=zerolatency speed-preset=ultrafast
> byte-stream=true ! mpegtsmux ! queue ! tsdemux ! h264parse ! avdec_h264 !
> videoconvert ! autovideosink
>
> Any idea about this latency increment?
>

tsdemux has 700ms latency, as required by the MPEG TS specification. I am
considering adding a property to lower that, for those who know what they
are doing. Lowering it too much would lead to erroneous timestamp to be
produced.

On top of that, h264parse adds 1 frame latency, your display element likely
add another one, and the capture element very often have up to one frame
latency, there is finally a 20ms processing delay allowed iirc. So that's
pretty close by 1s.


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