Using v4l2loopback and GStreamer with MJPEG cameras - gstreamer

I have one 4k camera which has MJPEG and YUY2 formats. Currently, I can run
$ gst-launch-1.0 v4l2src device=/dev/video1 ! "video/x-raw,format=YUY2,width=640,height=480,framerate=30/1" ! tee name=t ! queue ! v4l2sink device=/dev/video20 t. ! queue ! v4l2sink device=/dev/video21
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
And stream video1 image to two different devices.
Q: How to pass MJPEG image from video1 to both video20 and video21, which are in YUY2 format.

In the MJPEG case you need to add image/jpeg caps to v4l2src. After v4l2src you need to convert it to raw video.
Gstreamer has jpegdec and avdec_mjpeg plugins. In my current version jpegdec does not support YUY2 output, so I would use avdec_mjpeg. Alernatively you can use jpegdec with videoconvert (i.e.... ! jpegdec ! videoconvert ! ...).
The following line should do it:
gst-launch-1.0 v4l2src device=/dev/video1 ! "image/jpeg,width=3840,height=2160,framerate=30/1" ! avdec_mjpeg ! "video/x-raw,format=YUY2,width=3840,height=2160,framerate=30/1" ! tee name=t ! queue ! v4l2sink device=/dev/video20 t. ! queue ! v4l2sink device=/dev/video21

Related

gstreamer pipeline saves my camera stream to a file, but I need a pipeline to stream it live to my monitor

ok, this works
This gstreamer pipeline works well to save my camera video stream to a file on my raspberry pi.
gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,framerate=30/1,format=UYVY' ! v4l2h264enc ! 'video/x-h264,level=(string)4' ! filesink location = test_video6.h264
but what is the correct pipeline to display a live video stream from my camera in order to watch it in real time on my monitor, instead of just saving it to a file to view it later with VLC.
For example, I have tried adding
! videoconvert ! autovideosink
to the above pipeline, but it does not work.
Try this:
gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,framerate=30/1,format=UYVY' ! v4l2h264enc ! 'video/x-h264,level=(string)4' ! decodebin ! videoconvert ! autovideosink
If this doesn't work you can use the general example of a video pipeline from here and use:
gst-launch-1.0 v4l2src ! decodebin ! videoconvert ! autovideosink
from there you can add the settings you want.
EDIT: Another implementation is creating a tee of your file and send it to play through a queue in this case you do:
gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw,framerate=30/1,format=UYVY' ! v4l2h264enc ! 'video/x-h264,level=(string)4'! tee name="source"! queue ! filesink location = test_video6.h264 source. ! queue ! decodebin ! videoconvert ! autovideosink

How to form a gstreamer pipeline to encode mp4 video from tiff files?

I'm new to gstreamer and am stuck trying to form a gstreamer pipeline to encode mp4 video from tiff files on nvidia Jetson platform. Here is the pipeline I've come up with :
gst-launch-1.0 multifilesrc location=%03d.tiff index=0 start-index=0 stop-index=899 blocksize=720000 num-buffers=900 do-timestamp=true typefind=true ! 'video/x-raw,format=(string)RGB,width=(int)1280,height=(int)720,framerate=(fraction)30/1' ! videoconvert ! 'video/x-raw,format=(string)I420,framerate=(fraction)30/1' ! omxh264enc ! 'video/x-h264,stream-format=(string)byte-stream,framerate=(fraction)30/1' ! h264parse ! filesink sync=true location=test.mp4 -e
With this, the mp4 file gets created successfully and plays but the actual video content is all garbled. Any idea what am I doing wrong ? Thank You
You are not doing any demux/decode of your TIFF data, so you throw random bytes at the encoder.
Also you are doing a lot of things with caps without having proper elements between that could alter the formats correctly.
You should use decodebin to let GStreamer handle most of the things automatically. E.g. something like that:
multifilesrc ! decodebin ! videoconvert ! omxh264enc ! h264parse ! filesink
Depending on your encoder you want to force the color format to be a 4:2:0 so that it does not accidentally encode in 4:4:4 (which is not very common and not supported by many encoders):
multifilesrc ! decodebin ! videoconvert ! video/x-raw, format=I420 ! omxh264enc ! h264parse ! filesink

combine two gstreamer pipelines

I have 2 gstreamer pipelines. One displays a scaled live video captured from camera on the screen and the other takes the video in its original format and saves it to a file on the disk after encoding it with the H264 format. The two pipelines are as follows;
# Capture and display scaled camera feed
gst-launch-1.0 -v autovideosrc ! videoscale ! video/x-raw,
width=480,height=270 ! xvimagesink -e --gst-debug-level=3 sync=false
# Save the camera feed in its original format to disk
gst-launch-1.0 -v autovideosrc ! omxh264enc ! 'video/x-h264,
stream-format=(string)byte-stream' ! h264parse ! qtmux ! filesink
location=test.mp4 -e
These two pipelines work by themselves and I was wondering how i could combine them into one i.e. show the scaled video on the screen AND record the video in its original format to a file?
Looks like I needed the tee element. not sure if I am doing this right but it seems to work:
gst-launch-1.0 -v autovideosrc ! tee name = t ! queue ! omxh264enc !
'video/x-h264, stream-format=(string)byte-stream' ! h264parse ! qtmux !
filesink location=test.mp4 t. ! queue ! videoscale ! video/x-raw,
width=480,height=270 ! xvimagesink -e sync=false

RTMPSrc to v4l2sink

I would like to receive a rtmp-stream and create a pipe with v4l2sink as output
gst-launch rtmpsrc location="rtmp://localhost/live/test" ! "video/x-raw-yuv,width=640,height=480,framerate=30/1,format=(fourcc)YUY2" ! videorate ! v4l2sink device=/dev/video1
But I get only a green screen: https://www.dropbox.com/s/yq9oqi9m62c5afo/screencast1422465570.webm?dl=0
Your pipeline is telling GStreamer to treat encoded, muxed RTMP data as YUV video buffers.
Instead you need to parse, demux, and decode the video part of the RTMP data. I don't have a sample stream to test on, but you may be able to just use decodebin (which in GStreamer 0.10 was called decodebin2 for whatever reason). You'll also want to reorder the videorate to be before the framerate caps, so it knows what to convert to.
Wild stab in the dark:
gst-launch rtmpsrc location="rtmp://localhost/live/test" ! decodebin2 ! videoscale ! ffmpegcolorspace ! videorate ! "video/x-raw-yuv,width=640,height=480,framerate=30/1,format=(fourcc)YUY2" ! v4l2sink device=/dev/video1
Now It works:
gst-launch rtmpsrc location="rtmp://localhost/live/test" ! decodebin2 ! videoscale ! ffmpegcolorspace ! videorate ! "video/x-raw-yuv,width=1920,height=1080,framerate=30/1,format=(fourcc)YUY2" ! v4l2sink device=/dev/video1

Use gstreamer to stream video and audio of Logitech C920

I'm quite a newbie on using gstreamer. I want to stream video and audio from my C920 webcam to another PC but I keep getting wrong in combining things..
I can now stream h264 video from my C920 to another PC using:
gst-launch-1.0 v4l2src device=/dev/video1 ! video/x-h264,width=1280,height=720,framerate=30/1 ! h264parse ! rtph264pay pt=127 config-interval=4 ! udpsink host=172.19.3.103
And view it with:
gst-launch-1.0 udpsrc port=1234 ! application/x-rtp, payload=127 ! rtph264depay ! avdec_h264 ! xvimagesink sync=false
I can also get the audio from the C920 and record it to a file together with a test-image:
gst-launch videotestsrc ! videorate ! video/x-raw-yuv,framerate=5/1 ! queue ! theoraenc ! queue ! mux. pulsesrc device="alsa_input.usb-046d_HD_Pro_Webcam_C920_F1894590-02-C920.analog-stereo" ! audio/x-raw-int,rate=48000,channels=2,depth=16 ! queue ! audioconvert ! queue ! vorbisenc ! queue ! mux. oggmux name=mux ! filesink location=stream.ogv
But I' trying to get something like this (below) to work.. This one is not working, presumably it's even a very bad combi I made!
gst-launch v4l2src device=/dev/video1 ! video/x-h264,width=1280,height=720,framerate=30/1 ! queue ! mux. pulsesrc device="alsa_input.usb-046d_HD_Pro_Webcam_C920_F1894590-02-C920.analog-stereo" ! audio/x-raw-int,rate=48000,channels=2,depth=16 ! queue ! audioconvert ! queue ! x264enc ! queue ! udpsink host=127.0.0.1 port=1234
You should encode your video before linking it against the mux. Also, I do not see you declaring the type of muxer you are using and you do not put the audio in the mux.
I am not sure it is even possible to send audio AND video over the same rtp stream in this manner in gstreamer. I know that the rtsp server implementation in gstreamer allows audio and video together but even in it I am not sure if it is still two streams just being abstracted away from implementation.
You may want to just use to separate streams and pass them through to a gstrtpbin element.