Usage Examples
stream to YouTube with ffmpeg
from Paul Gullett. post
ffmpeg -f lavfi -i anullsrc \
-f v4l2 -s 3480x1920 -r 10 -i /dev/video0 \
-vcodec libx264 -pix_fmt yuv420p -preset ultrafast \
-strict experimental -r 25 -g 20 -b:v 2500k \
-codec:a libmp3lame -ar 44100 -b:a 11025 -bufsize 512k \
-f flv rtmp://a.rtmp.youtube.com/live2/secret-key
ffmpeg -f lavfi -i anullsrc -f v4l2 -s 1920x960 -r 10 -i /dev/video2 \
-vcodec libx264 -pix_fmt yuv420p \
-b:v 2500k \
-codec:a libmp3lame -ar 44100 -b:a 11025 -bufsize 512k \
-f flv rtmp://a.rtmp.youtube.com/live2/$SECRET_KEY
stream to another computer with gstreamer
in gst_viewer.c
with gst-rtsp-server
./test-launch "( udpsrc port=5000 ! application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264 ! rtph264depay ! h264parse ! rtph264pay name=pay0 pt=96 )"
Receive on ROS.
GSCAM_CONFIG="rtspsrc location=rtspt://10.0.16.1:8554/test latency=400 drop-on-latency=true ! application/x-rtp, encoding-name=H264 ! rtph264depay ! decodebin ! queue ! videoconvert" roslaunch gscam_nodelet.launch
Simplified computer to computer streaming with rtsp and gstreamer
This was tested going from an x86 machine to a Jetson Nano. The THETA Z1 is connected to the x86 Linux machine. It is not working with the Jetson as the sender.
On x86 computer sending THETA video.
Modify the pipeline in gst_viewer.c
This example has the IP address hardcoded in. Switch to a variable in your code.
pipe_proc = " decodebin ! jpegenc ! rtpjpegpay ! udpsink host=192.168.2.100 port=5000 qos=false sync=false";
If you are looking for the IP address of the receiver, you can use arp-scan on the command line.
Example:
On the receiving device, if the receiver is a NVIDIA Jetson Nano.
$ cat receive_udp.sh
gst-launch-1.0 udpsrc port=5000 ! application/x-rtp,encoding-name=JPEG,payload=26 ! rtpjpegdepay ! jpegdec ! videoscale ! video/x-raw,width=640,height=320 ! nveglglessink
Save to File
Using the v4l2loopback capability and thetaV loopback example, here are 2 example gstreamer pipelines to grab the video:
As a lossless huffman encoded raw file:
gst-launch-1.0 v4l2src device=/dev/video99 ! video/x-raw,framerate=30/1 \
! videoconvert \
! videoscale \
! avenc_huffyuv \
! avimux \
! filesink location=raw.hfyu
And with default h.264 encoding on a Jetson:
gst-launch-1.0 v4l2src device=/dev/video99 ! video/x-raw,framerate=30/1 \
! nvvidconv \
! omxh264enc \
! h264parse ! matroskamux \
! filesink location=vid99.mkv
Pro tip, when you install v4l2loopback, use the video_nr option to create the video device somewhere high so it does not get displaced by PnP of other cameras.
The Huffyuv format is a large file format. VLC can play it.
Here's a shot of me playing a file that I generated with Les's pipeline.
On x86, this is the pipeline I used to save to a H.264 file.
$ gst-launch-1.0 v4l2src device=/dev/video2 ! video/x-raw,framerate=30/1 ! autovideoconvert ! nvh264enc ! h264parse ! matroskamux ! filesink location=vid_test.mkv
Example of playing file with gst-launch.
Community member Nakamura_Lab indicated that the he experienced significant frame loss when using lossless Huffman to save to file with the Xavier NX. He could save to file with H.264. However for his use case with multiple face detection, he needed higher resolution than provided by H.264.
He ended up using H.265 encoding to save to file, which provided both high quality and no frame loss.
gst-launch-1.0 v4l2src num-buffers=600 \
device=/dev/video0 \
! video/x-raw \
! nvvidconv \
! nvv4l2h265enc \
! h265parse \
! qtmux \
! filesink location=test.mp4 -e
Stream From Raspberry Pi 4 to a Windows PC
Thanks to Shun Yamashita of fulldepth for this solution to stream the Z1 video to a Raspberry Pi 4 with USB then restream it to a Windows PC.
This is the process:
- Use GStreamer to stream UDP(RTP) to the Windows PC
- Do not use H264 decoding on the Raspberry Pi as the Windows machine is handling it and it's likely that the RPi4 can't use hardware decoding for 4K H.264.
- Tested with Raspberry Pi4 modelB with 4GB of RAM running Raspberry Pi OS
On the Raspberry Pi, the following was changed in the GStreamer pipeline in gst/gst_viewer.c.
src.pipeline = gst_parse_launch(
" appsrc name=ap ! queue ! h264parse ! queue"
" ! rtph264pay ! udpsink host=192.168.0.15 port=9000",
NULL);
RViz in ROS2 Dual-Camera Setup with OpenCV
Robot displays live images from two THETA V cameras on RViz in ROS2 using the following pipeline and OpenCV.