Here is a video recording of my presentation of the onboard cameras and the video transmitter, given at the Copenhagen Suborbitals Nexø II debriefing event.
DVB
Nexø II rocket camera performance
In my previous post, I posted the raw footage recorded from the Nexø II onboard cameras. These videos give an excellent qualitative indication of how well the video downlink worked. I have now also processed the received telemetry data and have a more quantitative idea of the performance.
Raw footage from the Nexø II rocket cameras
In my previous post, you could watch an edited video from the Nexø II onboard cameras. I have now also made the raw footage available on my YouTube channel.
Video received from the Nexø II rocket cameras
During the last year or two, you may have heard me talk about rocketcam or rocket-cameras, teasing with pictures but without providing too many technical details. Actually, it all started with a cryptic tweet I posted on October 23, 2016:
I have a plan. pic.twitter.com/pboLyN4oK6
— Alexandru Csete (@csete) October 23, 2016
x264enc problem in GStreamer video switcher solved
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.
An experiment with Theora and Ogg for DVB
Yesterday I have been testing the DVB setup using Theora encoded video in Ogg container instead of the H.264/MPEG-TS I have been using so far. Initial tests looked promising, but at the end the link was rather choppy and broken. On this first screen shot I am running the simulator (i.e. no USRP) with a … Read more
GstInputSelector to switch between different cameras
An email on the gst-devel mailing list last week pointed me to a rather interesting example in the gst-python repository: switch.py – shows how to use the GstInputSelector element in a Python script to select between different input streams. When I looked at the example I thought right away that it would be cool to use it to switch between different cameras in my simple DVB setup that uses Gstreamer and GNU Radio.
Simple DVB with Gstreamer and GNU Radio
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.