Thread 5 "rx-thread" received signal SIGSEGV, Segmentation fault. Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Starting program: /usr/bin/qsstv /usr/bin/qsstv You can't do that when your target is `None' Type "apropos word" to search for commands related to "word". Type "show configuration" for configuration details.įor bug reporting instructions, please see:įind the GDB manual and other documentation resources online at: This GDB was configured as "x86_64-linux-gnu". There is NO WARRANTY, to the extent permitted by law. This is free software: you are free to change and redistribute it. License GPLv3+: GNU GPL version 3 or later ![]() To debug the behavior and figure out what was happening, I ran qsstv through gdb:Ĭopyright (C) 2016 Free Software Foundation, Inc. this was happening with SSTV signals from a variety of sources. I was having some issues with qsstv crashing midway through drawing images. ![]() Here is a sample that I created by running an image of Jupiter from NASA through the SSTV transmit tab: debugging: Have just been using the sstv sample found in wikimedia commons. Qsstv is crashing whenever it tries to autosave an image. The image will appear one line at a time in the middle of the window. The waveform of the audio signal should show up on the right side, and the instantaneous spectral plot should be dancing in the upper right corner. Now you can switch over to the "Video" program, or whatever audio player you're using, to play the SSTV signal. Now that qsstv is working and the audio channels are properly configured, you can click the "Play" button in qsstv (the blue button with a right-facing triangle). The "Monitor of built-in audio analog stereo" device should have a volume indicator that should be jumping around. Now open pavucontrol, and go to the Input Devices tab. Start playing a sound (using the program "Video", for example) to audio out This links the audio input that qsstv is receiving to the audio output monitor that you've created (the thing that captures all the audio out). Pick Monitor of built-in audio analog stereo Should see "Monitor of built-in audio analog stereo" Once the qsstv program is open, you can configure the audio in/out settings with pavucontrol.Ĭonfigure pavucontrol make output monitor:Ĭlick "Monitors" from drop down menu on bottom Start qsstv by running that command from the command line. If you need a way to pipe audio out to audio in, use pavucontrol apt-get install pavucontrol Later in the page we'll look at some other, alternative configurations using SDR.īefore you begin, you'll want to set up a tool to control your audio streams: pavucontrol. This install assumes a basic "offline" setup: piping a pre-recorded SSTV signal from audio out to audio in, and demodulating it with qsstv. utilize an RTL-SDR and software to tune the SDR receiver, and use that to tune into the sstv signal.download an MP3 of a pre-recorded sstv signal.set up a microphone next to your radio transceiver and tune it in to an sstv signal.This means you can use qsstv several ways: It simply takes audio input from the microphone or line in. The program does not implement any kind of radio receiver - that's the job of a handheld radio transceiver or an SDR system. ![]() The utility qsstv is an open-source slow scan television program. Slow scan television was allowed for use by radio amateurs in 1968, and was utilized as a part of the Apollo lunar missions.Ī sample SSTV signal is provided on Wikipedia: This is a method for transmitting images, pioneered by ham radio operators, for transmitting images using narrow bandwidth (3 kHz), an order of magnitude smaller than the bandwidth required to send moving television images (6 MHz). My first experience using qsstv was part of the Defcon Darknet CTF game, where one of the challenges involved slow scan TV images and several related challenges.įirst, let's talk about slow scan TV. Qsstv is a utility for dealing with slow scan television signals. 2.1.3.2 hook up output monitor to qsstv input:.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |