I agree that writesf~ works very well but I want to have a simple, visual feedback to know that the recording is taking place. This is for 'complicated' situations: while performing and recording simultaneously in a concert or talking and recording in an interview. In these situations all kinds of (technical) problems might occur, sometimes just before or even during the concert. The recording isn't the most important concern at that moment. After concerts I have noticed that I miss a few channels or some songs. I guess often the problem is that the dsp was switched on and off (for example, when you notice a microphone connected to the sound card isn't reacting) or a name was given to the recording (open message to writesf~) but no 'start' command followed.
That's why I make this patch. My initial idea was: if I just have a green light/button flashing, saying that the recording is proceeding well and the recording files on the hard disk are growing, I just have to watch one simple thing (for the recording part of the concert...).
The growing filesize solution doesn't work but I have another idea: just check if each writesf~ received an 'open' followed by a 'start' message and simultaneously check if the audio signal/connection going to writesf~ is really sending audio. I'll post it tomorrow.
(Another solution could be to visualize the amplitude curve -the waveforms- of the audio going to writesf~ , but personally I don't like this: when you are recording lots of channels - in complicated situations - you have to watch too much curves + you can't see the difference between silence (zero signals~) and a broken connection.)