What kind of stream GStreamer produce?

Question

I use following 2 commands to stream video from Raspberry Pi

RaPi

raspivid -t 999999 -h 720 -w 1080 -fps 25 -hf -b 2000000 -o - | gst-launch-1.0 -v fdsrc ! h264parse !  rtph264pay config-interval=1 pt=96 ! gdppay ! tcpserversink host=$RA-IP-ADDR port=5000 

Linux Box

gst-launch-1.0 -v tcpclientsrc host=$RA-IP-ADDR port=5000  ! gdpdepay !  rtph264depay ! avdec_h264 ! videoconvert ! autovideosink sync=false 

But what kind of stream is it? Can I read it with OpenCV? or convert with avconv|ffmpeg nc $RA-IP-ADDR 5000 | avconv? or watch with VLC ?

Answer 1

The stream appears to be an RTP stream encapsulated in a GDP stream, the latter of which which appears to be proprietary to GStreamer. You might be able to remove the gdppay and gdpdepay elements from your pipeline and use other RTP tools (there are plenty out there; I believe VLC supports RTP directly), but you could also use a GStreamer pipeline to pipe the depayloaded GDP stream (in this case, the H.264 stream it contains) from the RPi to a file on the Linux Box side, like so:

gst-launch-1.0 tcpclientsrc host=$RA-IP-ADDR port=5000 ! gdpdepay ! rtph264depay ! filesink location=$FILENAME

or, to pipe it to stdout:

gst-launch-1.0 tcpclientsrc host=$RA-IP-ADDR port=5000 ! gdpdepay ! rtph264depay ! fdsink

One or the other of these should let you operate on the H.264 video at a stream level.

GStreamer 1.0 can also interact with libav more or less directly if you have the right plugin. Use gst-inspect-1.0 libav to see the elements supported. The avdec_h264 element already in your pipeline is one of these libav elements.