Re: [9fans] sound, graphics, tuner

[John Floren <slawmaster@gmail.com>]

On Sat, Jan 15, 2011 at 10:50 AM, Rudolf Sykora <rudolf.sykora@gmail.com> wrote:
>> Read N PCM samples from the sound card, this is just a read from the
>> audio in file, easy part.
>> The samples you can read from http://plan9.bell-labs.com/magic/man2html/3/audio
>> audio(3) or a similar interfaces provided by usb/audio usb(4).
>
> Ok. To start with, audio(3) seems to support soundblaster-16-compatibles.
> What about others? I guess mine could be AC'97 on one of my notebooks
> (there fortunately seems to be some support for this one elsewhere,
> too), while god knows what on another. Connected to this:
> How do I find from within plan 9 what soundcard/hardware I have?
>
>> This last part, I would use draw
>> http://plan9.bell-labs.com/magic/man2html/2/draw
>> draw(2). You can use control
>> http://plan9.bell-labs.com/magic/man2html/2/control control(2)
>> to add sliders but for what you are doing just drawing rectangles and
>> lines should be fine.
>
> Ok. I ask because some widget sets already have an analog-like gauge
> I'd like to use, e.g. Tk::gauge. (What'd be the situation in Inferno?
> They have some Tk, don't they?)
>
> Thanks
> Ruda
>
>

If you're tuning a wind instrument, you could just print out the
frequency of middle C and then display the calculated frequency coming
into the microphone below it.

For a guitar tuner, just print out more frequencies (EADGBE)... this
is the lazy man's way to do it, but it would be a way to test it at
first, at least.

If I wanted to make it fancy and graphical, I'd have a horizontal
line, bisected in the center by a vertical line representing the
target frequency, then draw another moving vertical line to represent
the current frequency.


John