I wasn't criticising the fact that you use a pre-rendered audio file (in fact that's the proper way to do it, as there's no need to recompute the SSTV audio eve

I wasn't criticising the fact that you use a pre-rendered audio file (in fact that's the proper way to do it, as there's no need to recompute the SSTV audio every single time), merely the fact that it's just one-way SSTV instead of something more exciting like implementing an actual modem.