In October last year I learned about the UT-100 series of DVB-T modulators available from a company in Taiwan. At that time I have already been working with software defined video broadcasting; however, I still found the idea of a small USB-stick modulator very appealing for use with embedded devices. In this post I have collected my notes about setting up and testing the UT-100 modulator on Linux.
A lot has happened since I posted my ugly hacks required to take advantage of the H.264 compressor in the Logitech C920 webcam. Gstreamer 1.2 now includes a uvch264src that can be used to read H.264 encoded video stream from the camera eliminating the need for an external capture application.
A few closeup photos showing the eCAM32 3.2 megapixel camera mounted on top of the Gumstix Overo Water, mounted on the Tobi expansion board.
As promised in my last post, here is a quick demo of the eCAM32 3.2 megapixel camera connected to the Gumstix Overo Water. I am presenting two videos, one showing the setup where the eCAM32 camera board is mounted on top of the Gumstix Overo Water, the other one being a screen cast demonstrating some of the most common settings of the camera. I am using the Tobi expansion board because it has Ethernet interface allowing me to stream H.264 encoded video to a host PC running linux.
As I mentioned in my previous post, I had only had limited success with the Caspa VL and Logitech UVC cameras. While both cameras work with the Gumstix, the Caspa seems to take poor images while the Logitech USB camera performance is limited by low USB bandwidth. Therefore, I have decided to try my luck with cameras from e-Con Systems.
I’m happy to report that I am now able to encode video on the Gumstix Overo Water using the DSP in the OMAP3530. It wasn’t difficult to make it work but it took several attempts at building the kernel before I got it right and, as you might know, cross compilation takes time.
A year has passed since we had a Gumstix Overo based video recorder onboard an amateur rocket and it is time to resume working on it. This time I will continue towards the original goal, namely live radio transmission of video encoded using the built-in DSP.
Back in August 2010 I ran a brief experiment using GstInputSelector to switch between various video sources. You may have noticed that it was using Theora encoder while most of my other DVB experiments used H.264 encoder in MPEG-TS container. The reason for this was that I could not make x264enc work in the pipeline used for the video switcher.
Oct 3, 2010 – Danish Space Challenge (DSC) held a Rocket Festival at Borris Sønderland, Denmark, where five rockets built by German and Danish students were launched together with one of DSC’s own rockets. For the first time, the DSC rocket was flying an Arduino Duemilanove based flight computer which was responsible for releasing the parachute. This worked well. The payload in the rocket consisted of the digital video recorder built by yours truly, based on the Gumstix Overo Fire embedded Linux computer that I have been blogging about during the last few weeks, see here. Continue reading “Successful flight and a crash landing”
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.