hi Martin, On Sun, 28 Jan 2024 13:27:45 -0600 "Martin McCormick" <marti...@suddenlink.net> wrote:
> Several years ago, I wrote some C code which turns one's > computer's sound interface in to a sound-activated recorder that > I could then connect to radio receivers or microphones and record > when audio started and stop recording when there is nothing but > silence. One essentially sets a sound card to record > continuously but the sound samples go through code that knows > what silence looks like. In short, silence looks like samples > whose numeric value is exactly half-way between the lowest and > highest voltage that the analog-to-digital converter reads, > commonly either 32,767 representing silence, give or take a count > or two due to digital sampling errors or decimal 128, hex 80 for > 8-bit mono audio. > > The Advanced Linux Sound Architecture Project has C library > functions for setting sample rates, mono, stereo, big or little > endianness and 8 or 16-bit audio, whatever one needs for their > application. One can even define samples as signed or unsigned > integers. > > Once one gets a stream of ints which are usually 32-bits > wide for stereo or 16-bit shorts for mono, the sound processing > can begin which C is really good at but perl is just as good at > so if one could get the same alsa modules which are used by aplay > and arecord for setting up one's audio interfaces or sound cards, > the manipulation of those data that was done in C could also be > done in perl without hardly any modification to it at all. > > Perl has just the right mix of low-level logic and > bitwise operators plus a much more easy-to-use string handling > capability which is why I am asking this question. > > I may be looking in the wrong places but, so far, I seem > to be batting zeros when looking for perl and alsa together. > you can try using an FFI, eg: https://metacpan.org/dist/Inline-C/view/lib/Inline/C.pod https://metacpan.org/dist/Inline-Python/view/Python.pod https://metacpan.org/pod/FFI::Platypus > Any good ideas are greatly appreciated, here. > > Martin McCormick > -- Shlomi Fish https://www.shlomifish.org/ Selina Mandrake - The Slayer (Buffy parody) - https://shlom.in/selina If the miller travelled to the market with Emma, they would have each rided their own donkey. Problem solved. — https://www.shlomifish.org/humour/bits/facts/Emma-Watson/ Please reply to list if it's a mailing list post - https://shlom.in/reply . -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
