Compiling the distributed source code should result in 3 executable programs being created for use on the "transmit side", and 1 executable program being created for use on the "receive side". Additionally, in the distribution is a tcl executable that takes care of running the 3 "transmit side" programs in sequence, so that the over all result is the creation of a .wav file (to send to a sound card) representing the supplied binary file with the chosen level of redundancy in the outer code.
If you don't have a tcl interpreter installed, you can use the tcl executable as an example of how to run the 3 "transmit side" programs manually. In this case, if you want to get rid of the temporary files, you will have to do that manually as well.
The behavior of the initial release of this software reflects the research environment in which it was developed. In some respects it behaves differently than would software developed for a mass market. These differences in behavior are listed below.
The short coming I expect to cause the most problems is the failure to check the sample rate and number of bits per sample in the .wav file header that is input to the pm7b-demod-decode program. None of the .wav recording programs I am aware of default to the 11,025 Hz, 16-bits per sample required by my program. Even I didn't always remember to select the correct recording mode, before making recordings of HDSSTV transmissions. The good news is that other sample rates and bit depths can be converted to 11,025 Hz and 16 bits, and that recordings made at 22,050 Hz with only 8 bits per sample have decoded just as well as those made at 11,025 Hz and 16 bits per sample. The bad news is that my program will fail, without telling you why, if it is given a .wav file that is not 11,025 Hz with 16 bits per sample.
Overwriting files of the same name, without warning, is not very nice behavior, but BE WARNED, that is the way the initial distribution of my programs work.
A copy of the GNU General Public License Version 2, under which the initial distribution of the HDSSTV software is being released, is included in the distribution.
The GNU General Public License Version 2 does not place constraints on running the software. So, if all you want to do is run you own copy of the software, you don't need to worry about the terms of this license. If, however, you want to distribute, either the original, or a modified version of the software, then the GNU General Public License Version 2 states the conditions under which you may legally do so.
The URL for downloading the initial distribution of this software is listed at the bottom of the image below. As indicated by the .tgz suffix, all of the files have been combined into one file with the "tar" program, then compressed, using the "-z" option to tar.
There are also a couple of ".wav" files useful in setting audio levels. They are distributed separately, along with their documentation.
Questions about this method of digital communication may be e-mailed to:
wyman@svs.net
Links to: