Few weeks ago I posted some notes about using the Logitech HD Pro Webcam C920 with Gstreamer. I have since ported the setup to the Beaglebone, effectively turning my Beaglebone into a streaming IP camera that can deliver constant bitrate H.264 video at full 1920x1080p30 resolution without breaking a sweat.
You may already know about my existing enthusiasm for Logitech webcams, which is due to the combination of relatively good image quality, high resolution and easy to use UVC interface. I was therefore very happy to learn about their newest camera, the HD Pro Webcam C920, which in addition to the standard HD webcam stuff we already know from the C910, also provides hardware encoded H.264 video stream! This is rather new and there isn’t much software that can take advantage of it; however, with a little tweaking and hacking we can get the H.264 stream into Gstreamer, where after we can do pretty much whatever we want.
Wednesday evening the Logitech Webcam Pro 9000 UVC camera and the Gumstix Overo Fire based video recorder have been integrated into the rocket. I will not have access to them before the launch day on Sunday. Shown below is the camera and video recorder integrated into the rocket.
We will be using the Logitech Webcam Pro 9000 for the flight, streaming MJPG video in 640×480 at 30 fps. Although the camera can stream even 1280×720 at 30 fps the USB interface on the Gumstix Overo Fire can not keep up with the required data rate. So here is a test video recorded as JPEG frames in an AVI container – just like it will be recorded by the Gumstix Overo Fire during the flight.
Apparently, Youtube is not very good to process MJPG video (fair enough since MJPG is a sucker anyway) so you should definitely try the source video (35 MB AVI).
It has been a busy night but I have made good progress with the Gumtix Overo Fire. Today’s report is action packed with kernel panics, painful downgrades and a working webcam.
Up until now I have been using the standard (link) YUV 4:2:2 pixel format with my Logitech Webcam Pro 9000. This format is good for most cases; however, the framerate is limited to 15/2 fps at 1280×720 resolution, while the other supported formats (MJPG, RGB3, BGR3, YU12, YV12) support this reolution with up to 30 fps! So it was time for me to figure it out. Continue reading “Webcam pixel formats and Gstreamer caps filters”
I have had this idea of using my webcam for digital video transmission for quite some time now. Capturing and processing video from UVC webcams has been a routine for a long time and I have had great success with Logitech webcams (the 9000 series) that have great UVC support. I still had a problem though with finding a good way to interface the GNU Radio transmitter and receiver to the video processing pipeline implemented in Gstreamer.
In my experiment with receiving packet radio from the ISS I used a named pipe to create a real time interface between the GNU Radio receiver and the packet decoder multimon. I decided to try this trick for sending video in to and out of GNU Radio and it works! The following experiments were implemented and executed on the 27th and 28th of July with some minimal preparation on the 26th.
Few days ago I found out the Ustream now has its own desktop application for broadcasting – Ustream Producer. I decided to give it a try, in particular since I am looking for a portable setup and I do not have a Mac laptop.
Here is my latest attempt in my Moon with a Webcam series, though this time I used a very cheap camcorder instead of a webcam. Still plenty of room for improvement.
I used a Meade ETX-90 telescope f=1250mm with 26mm eyepiece → 48X magnification. This time I was holding the camera by hand but I have a plan for improving that part.
I am working on a setup where I want to mount a cheap webcam onto my Meade ETX-90 telescope for terrestrial observations. While I was working on the setup the other night I looked out the window and saw the Moon behind a tree. Without thinking too much I pointed the telescope towards the Moon and recorded this video.
As for the bad quality keep in mind that:
- it was recorded through a double-glas window (which was dirty)
- the Moon was behind a tree
- it was recorded with a webcam