Gst-launch-1.0 vs mainPipe = gst_parse_launch

Application Development
1

Please can someone guide me.

I have a pipeline that runs

#!/bin/sh
gst-launch-1.0 -ve v4l2src device=/dev/video0 ! capsfilter caps=image/jpeg,width=1920,height=1080,framerate=30/1 ! jpegdec ! videoconvert ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=1000000000 ! clockoverlay name=DT halignment=left valignment=top font-desc=“Sans, 12” time-format=“%d %b %Y %H:%M:%S” ! textoverlay name=O1 text=“look at me” halignment=left valignment=top ! tee name=t !
queue ! xvimagesink name=sink sync=false
t. ! queue ! x264enc speed-preset=ultrafast tune=zerolatency byte-stream=true bitrate=4000 key-int-max=25 ! rtph264pay ! udpsink host=224.1.1.1 auto-multicast=true port=5001
t. ! queue !
x264enc speed-preset=ultrafast tune=zerolatency byte-stream=true bitrate=4000 !
mux. pulsesrc device=alsa_input.usb-0d8c_USB_Sound_Device-00.analog-stereo !
queue !
audioconvert !
audioresample ! audio/x-raw, rate=48000 !
queue !
avenc_aac !
queue !
mpegtsmux name=mux !
filesink location=withtee.mp4

feeding the pipeline bit ie from v4l2src to

// Create pipeline from string
mainPipe = gst_parse_launch (argv[2], NULL);

results in

(dvrPR:177971): GStreamer-WARNING **: 14:51:40.632: Trying to link elements t and queue2 that don’t share a common ancestor: queue2 hasn’t been added to a bin or pipeline, and t is in pipeline0

I dont understand, I can’t figure how to make the error go away. Please
James

2

This cannot work because you are reading in exactly one command line parameter. And you have a lot of them.
Enter the following

printf("ParamCount: %i\n", argc);
3

Thankyou for the help.
I’m a bit confused: There is only 1 argv which is the pipeline ie argv[2] is the complete pipeline argc for the program is 2, argv[1] being the card no and argv[2] being ‘v4l2src … filesink location=xx’

I think my error was trying to use line continution “\” in my single arg. Using a horrible single line does work.
so the argv accepted by gst-launch-1.0 is not the same as argv accepted by gst_parse_launch.

My pipeline willl change slightly with some cards ie some do jpeg output, some do h264, which is why I parse a command line, not build statically