Qsstv - Revision history

Admin: /* Adjusting scheme */

2016-08-11T21:32:13Z

Adjusting scheme

← Older revision		Revision as of 21:32, 11 August 2016
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	Next, you can adjust the modulation scheme to be something other than Martin 1 (which is the most common image mode) - you have a really big list to choose from. You can also pick different bandwidths, etc.		Next, you can adjust the modulation scheme to be something other than Martin 1 (which is the most common image mode) - you have a really big list to choose from. You can also pick different bandwidths, etc.

	Here is an example of an image sent using the Robot 72 modulation scheme: [[File:VenusJupiterSSTV_Robot72.wav		Here is an example of an image sent using the Robot 72 modulation scheme: [[File:VenusJupiterSSTV_Robot72.wav]]

	Contrast with the Martin 1 modulation scheme: [[File:JupiterSSTV.wav]]		Contrast with the Martin 1 modulation scheme: [[File:JupiterSSTV.wav]]

Admin: /* Adjusting scheme */

2016-08-11T21:31:58Z

Adjusting scheme

← Older revision		Revision as of 21:31, 11 August 2016
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	Next, you can adjust the modulation scheme to be something other than Martin 1 (which is the most common image mode) - you have a really big list to choose from. You can also pick different bandwidths, etc.		Next, you can adjust the modulation scheme to be something other than Martin 1 (which is the most common image mode) - you have a really big list to choose from. You can also pick different bandwidths, etc.

			Here is an example of an image sent using the Robot 72 modulation scheme: [[File:VenusJupiterSSTV_Robot72.wav

			Contrast with the Martin 1 modulation scheme: [[File:JupiterSSTV.wav]]

	===Begin transmission===		===Begin transmission===

Admin: /* Saving output to file */

2016-08-11T21:31:00Z

Saving output to file

← Older revision		Revision as of 21:31, 11 August 2016
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	[[Image:Qsstv_configuration.png\|500px]]		[[Image:Qsstv_configuration.png\|500px]]

			===Adjusting scheme===

			Next, you can adjust the modulation scheme to be something other than Martin 1 (which is the most common image mode) - you have a really big list to choose from. You can also pick different bandwidths, etc.

			===Begin transmission===

			Once you are ready to go, click the Play button to begin transmission. If you selected a sound output that would record to a file, you will be prompted for a filename here. This is the name of the wav file that qsstv will generate as it plays the sound. Once it is finished with its transmission, the file is finished and you can go share it with your friends.

	=Flags=		=Flags=

Admin: /* Creating SSTV Signal from Image */

2016-08-11T21:28:10Z

Creating SSTV Signal from Image

← Older revision		Revision as of 21:28, 11 August 2016
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	==Creating SSTV Signal from Image==		==Creating SSTV Signal from Image==

	To create an SSTV signal from an image, open qsstv and click the "Transmit" tab on the top. To load an image to transmit~~, click~~ the icon of the folder. ~~Now the~~ image will open in the main console, and you~~'ll be ready~~ to ~~adjust the modulation scheme and then transmit the signal~~.		To create an SSTV signal from an image, open qsstv and click the "Transmit" tab on the top.

			===Load image===

			The first thing you need to do is load an image to transmit. Click the icon of the file folder, which will take you to a file picker. Once you pick your image, it will open in the main console, and you can start to prepare for transmission of your image.

	[[Image:Qsstv_image_tx_loaded.png\|500px]]		[[Image:Qsstv_image_tx_loaded.png\|500px]]

			===Saving output to file===

			If you are interested in saving the transmission output to a file (a wav file), you can set that up in the program configuration. Click "Options" in the menu bar on the top of the window, then Configuration.

			Here, you'll click the Sound tab, and under the Sound Output section, make sure you are recording the sound output to a file.

			[[Image:Qsstv_configuration.png\|500px]]

	=Flags=		=Flags=

Admin: /* Transmitting SSTV Signals */

2016-08-11T21:23:06Z

Transmitting SSTV Signals

← Older revision		Revision as of 21:23, 11 August 2016
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	Luckily, the qsstv software makes it just as easy to transmit signals as it is to receive them. It also makes recording signals to an MP3 or wav file very easy, so it's also possible to create your own SSTV signals in audio files and post them for others to decode. You can also port those files over to a computer with an SDR to transmit them over the air (within legal limits, of course.)		Luckily, the qsstv software makes it just as easy to transmit signals as it is to receive them. It also makes recording signals to an MP3 or wav file very easy, so it's also possible to create your own SSTV signals in audio files and post them for others to decode. You can also port those files over to a computer with an SDR to transmit them over the air (within legal limits, of course.)

			==Creating SSTV Signal from Image==

			To create an SSTV signal from an image, open qsstv and click the "Transmit" tab on the top. To load an image to transmit, click the icon of the folder. Now the image will open in the main console, and you'll be ready to adjust the modulation scheme and then transmit the signal.

			[[Image:Qsstv_image_tx_loaded.png\|500px]]

	=Flags=		=Flags=

Admin: /* Receiving SSTV Signals */

2016-08-11T21:20:36Z

Receiving SSTV Signals

← Older revision		Revision as of 21:20, 11 August 2016
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	Now when you play a wav or mp3 file with an SSTV signal in it, you'll hear it coming out of the speakers, but that will also be sent to the qsstv audio inputs, where it will be fed to the SSTV demodulator, and translated from audio back into an image.		Now when you play a wav or mp3 file with an SSTV signal in it, you'll hear it coming out of the speakers, but that will also be sent to the qsstv audio inputs, where it will be fed to the SSTV demodulator, and translated from audio back into an image.



			=Transmitting SSTV Signals=

			Luckily, the qsstv software makes it just as easy to transmit signals as it is to receive them. It also makes recording signals to an MP3 or wav file very easy, so it's also possible to create your own SSTV signals in audio files and post them for others to decode. You can also port those files over to a computer with an SDR to transmit them over the air (within legal limits, of course.)

	=Flags=		=Flags=

Admin: /* Receiving SSTV Signals */

2016-08-11T21:18:39Z

Receiving SSTV Signals

← Older revision		Revision as of 21:18, 11 August 2016
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	=Receiving SSTV Signals=		=Receiving SSTV Signals=

	To receive slow scan television signals, qsstv uses audio in. This is possible because SSTV is designed to use about the same bandwidth as a voice signal (3 kHz) so can be played by and picked up by a sound card. Therefore there are several ways to get signals to qsstv:		To receive slow scan television signals, qsstv uses audio in. This is possible because SSTV is designed to use about the same bandwidth as a voice signal (3 kHz) so can be played by and picked up by a sound card.

			==Receiving methods==

			qsstv is able to use the sound card to receive signals, in place of a radio receiver. Therefore, there are several ways to get signals to qsstv:
	* Connecting audio out to audio in (in software, on same computer)		* Connecting audio out to audio in (in software, on same computer)
	* Connecting audio out (device 1) to audio in (device 2)		* Connecting audio out (device 1) to audio in (device 2)
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	The third method is a variation on the previous method - if you have a handheld radio, say, and are tuning into an SSTV signal, you can hold the speaker up to a microphone, and the entire contents of the signal will be transferred from the speaker to the microphone. (Remember - this is only a 3 kHz wide signal, so there's no "hidden" information that's lost this way.)		The third method is a variation on the previous method - if you have a handheld radio, say, and are tuning into an SSTV signal, you can hold the speaker up to a microphone, and the entire contents of the signal will be transferred from the speaker to the microphone. (Remember - this is only a 3 kHz wide signal, so there's no "hidden" information that's lost this way.)

			===Connecting audio out to audio in===

			After installing qsstv on a Kali Linux laptop, I was able to connect the audio out to the audio in via software. This was done using the <code>pavucontrol</code> utility, which provides a more advanced sound configuration interface than the Sound control panel.

			Run <code>pavucontrol</code> on the command line to open the control panel. Click Input Devices, then pick Monitors from the drop down on the bottom. Play some sound and make sure the "Monitor of Built-In Audio Analog Stereo" indicator is bouncing and moving with the sound. Then start up qsstv program, then click the Recording tab of the pavucontrol control panel. Change the recording input device for the qsstv program to the "Monitor of Built-In Audio Analog Stereo" device, which will hook up the audio in (which the qsstv program is listening to) to the audio out (which is what the wav/mp3 player is playing, and what is coming out of the speakers).

			Now when you play a wav or mp3 file with an SSTV signal in it, you'll hear it coming out of the speakers, but that will also be sent to the qsstv audio inputs, where it will be fed to the SSTV demodulator, and translated from audio back into an image.

	=Flags=		=Flags=

Admin: /* Installing */

2016-08-11T21:12:50Z

Installing

← Older revision		Revision as of 21:12, 11 August 2016
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	(also see: [[Kali/Fixes]])		(also see: [[Kali/Fixes]])




			=Receiving SSTV Signals=

			To receive slow scan television signals, qsstv uses audio in. This is possible because SSTV is designed to use about the same bandwidth as a voice signal (3 kHz) so can be played by and picked up by a sound card. Therefore there are several ways to get signals to qsstv:
			* Connecting audio out to audio in (in software, on same computer)
			* Connecting audio out (device 1) to audio in (device 2)
			* Microphone

			I used the first method, as I was testing out the SSTV functionality with pre-recorded SSTV signals. I was playing these wav/mp3 files to audio out, then capturing that audio out and sending it to audio in, so that qsstv could hear it too.

			The second method - connecting audio out of one device to audio in of another device - is useful if you are running a radio receiver. This setup would enable you to receive SSTV signals with the radio, then pipe that audio to the computer's audio in, where qsstv could hear it too.

			The third method is a variation on the previous method - if you have a handheld radio, say, and are tuning into an SSTV signal, you can hold the speaker up to a microphone, and the entire contents of the signal will be transferred from the speaker to the microphone. (Remember - this is only a 3 kHz wide signal, so there's no "hidden" information that's lost this way.)

	=Flags=		=Flags=

Admin at 21:06, 11 August 2016

2016-08-11T21:06:08Z

← Older revision		Revision as of 21:06, 11 August 2016
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			Before we begin: qsstv in action...

			<html>
			<iframe src="https://player.vimeo.com/video/178526302" width="640" height="400" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
			<p><a href="https://vimeo.com/178526302">Slow Scan Television</a> from <a href="https://vimeo.com/charlesreid1">charlesreid1</a> on <a href="https://vimeo.com">Vimeo</a>.</p>
			</html>

	=Overview=		=Overview=

Admin: /* sstv */

2016-08-11T20:33:18Z

sstv

← Older revision		Revision as of 20:33, 11 August 2016
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	A sample SSTV signal is provided on Wikipedia: https://upload.wikimedia.org/wikipedia/commons/c/ce/SSTV_sunset_audio.ogg		A sample SSTV signal is provided on Wikipedia: https://upload.wikimedia.org/wikipedia/commons/c/ce/SSTV_sunset_audio.ogg

			See the [[SSTV]] page for details.

	==qsstv==		==qsstv==