I'm working with AI-Thermometer project using Nvidia Jeton Nano.
The project is using Pi camera v2 for video capturing.
Here's the command of showing video streams using Pi camera v2.
gst-launch-1.0 nvarguscamerasrc sensor_mode=0 ! 'video/x-raw(memory:NVMM),width=3264, height=2464, framerate=21/1, format=NV12' ! nvvidconv flip-method=2 ! 'video/x-raw,width=960, height=720' ! nvvidconv ! nvegltransform ! nveglglessink -e
I want to use the normal USB webcam (such as Logitech c930) instead of Pi camera v2.
To do so, I need to stream the USB webcam data using GStreamer in the same way as above pipeline commands.
I installed v4l-utils on Ubuntu of Jetson Nano. And tried like this,
gst-launch-1.0 v4l2src device="/dev/video0" ! 'video/x-raw(memory:NVMM),width= ...
, but it gave a warning and didn't work.
How can I show video streams from webcam?
There should not quotes around the device parameter i.e. device=/dev/video0. If the error persists, then its probably something else.
gst-launch-1.0 v4l2src device="/dev/video0" ! \
"video/x-raw, width=640, height=480, format=(string)YUY2" ! \
xvimagesink -e
Related
I am creating a video stream from my headless raspberry pi using usb camera and opencv.
Ubuntu 18.04 LTS
Raspi OS: Bullseye
USB Camera
gst syntax test on terminal:
gst-launch-1.0 v4l2src device=/dev/video0 ! videoconvert! videoscale ! video/x-raw, width=640, height=480 ! autovideosink -v
In OpenCV C++:
string pipeline;
pipeline = "v4l2src device=/dev/video0 ! videoconvert! videoscale ! video/x-raw, width=640, height=480 ! autovideosink -v";
cv::VideoCapture cap(pipeline, cv::CAP_GSTREAMER);
When I launch the pipeline from terminal it creates a window with by usb webcam feed. However when I try to use the same pipeline from c++ it throws this error:
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (734) open OpenCV | GStreamer warning: Error opening bin: syntax error
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (501) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created
terminate called after throwing an instance of 'std::invalid_argument'
what(): cannot predict with an empty OpenCV image
Aborted
What am i missing in the syntax in the code?
Edit:
After some trials I could get the pipeline generated, with this:
pipeline = "v4l2src device=/dev/video0 ! videoconvert! video/x-raw, width=640, height=480 ! appsink";
and warning:
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (961) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1
.
.
.
some stuff for that frame
.
.
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (509) isPipelinePlaying OpenCV | GStreamer warning: unable to query pipeline state
[ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (1824) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module v4l2src0 reported: Could not read from resource.
When searched for it, I found this post. Which led to a bug report here and here.
I am using OpenCV 4.5, and I assume that bug would have been fixed by later version as it was reported for OpenCV 3.4.
i am trying to play sequence of image(.jpeg) from my local folder to play as h264 video in VLC player through local host connection.
I am using Gstreamer lib to stream support and i am using from test-launch.c from github samples
OS : Linux 18.04
Gstremer ver: 1.14.2 Building from source using Cerbero
Following command is used to set the parser
multifilesrc location=/home/user/Downloads/gen/img.%4d.jpeg loop=true caps=image/jpeg,framerate=10/1 ! jpegdec ! x264enc ! h264parse ! rtph264pay name=pay0 pt=96
but no streaming happening insted i can see a error like below
(Gstremer_img2vid2:21273): GStreamer-CRITICAL **: 15:57:21.547: gst_bin_get_by_name: assertion 'GST_IS_BIN (bin)' failed
0:01:26.143446201 21273 0x55555592b850 ERROR rtspclient rtsp-client.c:3105:handle_setup_request: client 0x5555559d5260: no control in path '/test'
Any help will be appreciated thanks
You may have to provide size of the frames for jpeg decoding (here using 640x480):
test-launch "multifilesrc location=/home/user/Downloads/gen/img.%4d.jpeg loop=true ! image/jpeg,width=640,height=480,framerate=10/1 ! jpegdec ! x264enc insert-vui=1 ! h264parse config-interval=1 ! rtph264pay name=pay0"
Should be ok for receiving on localhost using vlc:
cvlc rtsp://127.0.0.1:8554/test
Hy i tried to play a doorbird live audio stream via gstreamer gst-launch.
I found a code snipped in an fhem server script.
It should be possible with the command gst-launch-1.0 filesrc location=<http://12.0.0.231/bha-api/audio-receive.cgi user=xxxx passwd=xxxx> ! wavparse ! audioconvert ! lame ! filesink location=a.mp3
But i get following error: lame not found. if i change lame to lame lamemp3enc i get the error file not found http://12.0.0.231/bha-api/audio-receive.cgi
What do i wrong?
Gstreamer playbin cannot play my IPCamera mjpeg rtsp with 2048x1534 resolution:
gst-launch-1.0 -v playbin uri=rtsp://admin:admin#192.168.1.100:554/1/1
It shows the following WARNING message:
WARNING: from element /GstPlayBin:playbin0/GstURIDecodeBin:uridecodebin0/GstDecodeBin:decodebin0/GstRtpJPEGDepay:rtpjpegdepay0: Invalid Dimension 0x1536.
I have also test the following pipeline to force video size:
gst-launch-1.0 -v rtspsrc location=rtsp://admin:admin#192.168.1.100:554/1/1 ! application/x-rtp,media="video",width=2048,height=1536 ! rtpjpegdepay ! jpegdec ! autovideosink
but it complains similar WARNING message.
It should be note that when I change my video encoding to H.264 from camera panel everything is OK with playbin!
I'm trying to open UDP stream video in Raspberry Pi using this pipeline:
VideoCapture video("udpsrc port=5600 ! application/x-rtp,payload=96,encoding-name=H264 !"
"rtpjitterbuffer mode=1 ! rtph264depay ! h264parse ! decodebin ! videoconvert ! appsink emit-signals=true sync=false max-buffers=2 drop=true", cv::CAP_GSTREAMER);
// Exit if video is not opened
if(!video.isOpened())
{
cout << "Could not read video file" << endl;
return 1;
}
However, video.isOpened() return false and I couldn't be able to open with this code. This works on loopback test and another Ubuntu 18.04 PC but RPi 4 (Buster OS) couldn't run it. Also following lines can run upcoming gstream video:
gst-launch-1.0 udpsrc port=5600 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtph264depay ! h264parse ! avdec_h264 ! autovideosink fps-update-interval=1000 sync=false
Furthermore specific code stack (e.g. [video_udp.cpp][1]) can easily handle video but also it's hard to use with opencv.
NOTE: OpenCV version is 4.2.0-pre
The problem is about using GStreamer library as a plugin of OpenCV. OpenCV doesn't throw exception even you build source code without GStreamer support. (In default, GStreamer library was directly found by Ubuntu, conversely Raspberry Pi 4 couldn't find it.)
Firstly I check build information of OpenCV with std::cout<<cv::getBuildInformation(); in Ubuntu 18.04 machine and found that:
GStreamer: YES (1.14.5)
Also I just check this on Raspberry Pi 4 side and build information was:
GStreamer:NO
Before the build OpenCV I just compare GStreamer plugins with gst-inspect-1.0 command for both of them and I just install some missing plugins like gstreamer1.0-tools . Also I wasn't know the problem, before the checking build information, so I installed some other GStreamer plugins that currently I don't remember.
Lastly, I build system by adding -D WITH_GSTREAMER=ON flag. And now it works well.
I'll edit answer if the problem related to missing plugins those are installed later. For this, I'll check this issue with clean Buster OS image.