Display of 4 cameras with gstreamer

gstreamer-webcam-array.sh

#! /usr/bin/bash

# This script to plot an array of 4 cameras with gstreamer
#
# To have them in sequence, define d0-d3 in increasing order, then circle your
# hand through all cameras. Change d0-d3 to the order your hand appears in.
# Then, you'll get a spatially coherent display of cameras next to each other.

# Ids from /dev/videoXX, get with `$ gst-device-monitor-1.0 | grep v4l2src`
d0=7
d1=11
d2=9
d3=3

# Image width/height. The pipeline will rotate the cameras so they're swapped
IM_W=240
IM_H=320

# The pipeline itself
gst-launch-1.0                                        \
    videomixer name=mix                               \
            sink_0::xpos=0     sink_0::ypos=0         \
            sink_1::xpos=240   sink_1::ypos=0         \
            sink_2::xpos=480   sink_2::ypos=0         \
            sink_3::xpos=720   sink_3::ypos=0         \
        ! videoscale                                  \
        ! "video/x-raw,width=$(("$IM_W" * 4 * 5/3))"  \
        ! ximagesink sync=0                           \
    v4l2src device="/dev/video$d0" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d0" font-desc="Sans, 72" ! queue ! mix. \
    v4l2src device="/dev/video$d1" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d1" font-desc="Sans, 72" ! queue ! mix. \
    v4l2src device="/dev/video$d2" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d2" font-desc="Sans, 72" ! queue ! mix. \
    v4l2src device="/dev/video$d3" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d3" font-desc="Sans, 72" ! queue ! mix. ;



## This other pipeline using compositor rather than videomixer
## Cant be resized easily after stream
# gst-launch-1.0 \
#     v4l2src device="/dev/video$d1" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d1" font-desc="Sans, 72" ! queue ! comp. \
#     v4l2src device="/dev/video$d0" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d0" font-desc="Sans, 72" ! queue ! comp. \
#     v4l2src device="/dev/video$d2" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d2" font-desc="Sans, 72" ! queue ! comp. \
#     v4l2src device="/dev/video$d3" ! "video/x-raw,width=$IM_H,height=$IM_W" ! videoflip method=clockwise ! textoverlay text="$d3" font-desc="Sans, 72" ! queue ! comp. \
#     compositor name=comp                    \
#         sink_0::xpos=0                      \
#         sink_1::xpos=$(("$IM_W"))           \
#         sink_2::xpos=$(("$IM_W"*2))         \
#         sink_3::xpos=$(("$IM_W"*3))         \
#     ! videoscale                            \
#     ! "video/x-raw,width=800,height=600"    \
#     ! ximagesink                            ;