writing on this bytes container i thought
it could be fun to run a code that plays
array of shorts as 22100Hz audio, (1 channel, 16 bit)

(winanpi has functions for this: waveOut)

i load the vav onto screen when given 16bit
value i draw as a pixel so i got the sound drawed
(as blue-green mess)

44k hz sound better (22k souns a bit like from
casette recorder) but 22k makes more sound to seen
on screen (like 20 seconds instead of 10 seconds)

than i run the playback just from teh screen data
so i can play bitmap data like sorta of bitmap
gramophone (hovever playing bitmaps genarally makes
mostly if not ony some buzzes not much interesting)

so i decided to generate waves (using sin() ) into that
bitmap wav thinking if i divide given second of
playback onto 50 parts of 0.02 second each and if i
generate sinvaves based on a plot w ill draw with a mouse
(1 pixel y distance from bottom of screen = pitch of
20ms fragment that is playbacking) then i should obtain
something interesting (in theory coz in practice
it rather sounds like f1 8-bit bolid speeding engines up
and down)

the question is how to exactly generate those sinvaves
based the plot

right now i got something like (which is probably crap)
(but its total draft writing at the night as a series
of experminets with brain off) (thats why one need
to slow down and rethink it slowly)

int wave_pos =0;

void buffer_add_sinwave(int len, float a, int cycle)
{
for(int i=wave_pos; i<wave_pos+len; i++)
{
if(i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y)
continue;

float t = (i%cycle)*1./cycle;
float s = sin(2*3.14159*t);
// float w = (s+1.001)/2.01;
w=s;
unsigned int val=a*(127*256*w);
big_ofscreen_buffer[i] = val;//+rand()%5;
}

wave_pos+=len;

return;
///////////////////////////////////////
}

int tempo = 22050/44.1;

float volume = 0.3;
int base = 22050/1;

void buffer_add_sinwaves()
{

wave_pos =0;
for(int i=0; i<floats_size;i++)
buffer_add_sinwave(tempo, floats2[i]/frame_size_y, base/floats[i]);
}

two notes
1) i dont in fack know what those 16 bit walues are, they are
unsigned or signed
2) here the frequency it semms i generate cycle (of sinvavw) = 22khz/y
which means for y = 10 i got 2200 pixels wave so its 10 hz
for y=100 i 220 wave - so its 100 hz ?

(i get a little bit (i mean uch) tired of this but it
overally seems somewhat interesting)

fir wrote:
>
> than i run the playback just from teh screen data
> so i can play bitmap data like sorta of bitmap
> gramophone (hovever playing bitmaps genarally makes
> mostly if not ony some buzzes not much interesting)

i mean normal graphical bitmaps sound like buzzes
whan those that are generated from loaded vaw - it is those
who are mess soound like music

so regular imeges give buzes but mess images give music

fir wrote:
> fir wrote:
>>
>> than i run the playback just from teh screen data
>> so i can play bitmap data like sorta of bitmap
>> gramophone (hovever playing bitmaps genarally makes
>> mostly if not ony some buzzes not much interesting)
>
> i mean normal graphical bitmaps sound like buzzes
> whan those that are generated from loaded vaw - it is those
> who are mess soound like music
>
> so regular imeges give buzes but mess images give music

some things showed imo

1) the vaves seem to be 16 bit signed, so drawing it as a bitmap
not fully works cos -min and +max have nearly the same color on screen
(0x8000 is lowest 0x7fff is max)where 0 sound and -1 sound have quite
different colors 0x0000 and 0xffff) - but at least it seems i generati
it right (?)

unsigned short val=amplitude*127*256*sin(t);

i rewritten the code

void buffer_add_sinwave(int len, float amplitude, float hz)
{
for(int i=wave_pos; i<wave_pos+len; i++)
{
if(i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y)
continue;

float cycle = 22050.0/hz;
float t = 2*M_PI*fmod(i,cycle)/cycle;
unsigned short val=amplitude*127*256*sin(t);
big_ofscreen_buffer[i] = val;
}
wave_pos+=len;
return;
}

but there seem to be a problem with high frequenzy at all
and i seem not to understand something

if 20.1 khz is 20100 pixels per second (send to waveOut which is set to
take 20.1khz 16 bit 1 channel) then how i can draw 20.1 khz when
one 'period' 'wave' is 1 pixel ? it seems i could draw at most 10.06 khz
az tost when one wave will be then 2 pixels width - hovever if i draw it
it seem al sound a lot higher

this overally might mean i should possibly sqwitch to 44.2 khz or even more
to ba able to draw 22 kh with 2 pixels or more

istnt it?
(i know maybe nobody here was doing such lowlewel audio but i post it
becouse it seem generally lowlewel in interestuing - and c is big part
about lowlewel imo)

On Tue, 02 Apr 2024 14:29:17 +0200
fir <fir@grunge.pl> wrote:
> fir wrote:
> > fir wrote:
> >>
> >> than i run the playback just from teh screen data
> >> so i can play bitmap data like sorta of bitmap
> >> gramophone (hovever playing bitmaps genarally makes
> >> mostly if not ony some buzzes not much interesting)
> >
> > i mean normal graphical bitmaps sound like buzzes
> > whan those that are generated from loaded vaw - it is those
> > who are mess soound like music
> >
> > so regular imeges give buzes but mess images give music
>
>
> some things showed imo
>
> 1) the vaves seem to be 16 bit signed, so drawing it as a bitmap
> not fully works cos -min and +max have nearly the same color on screen
> (0x8000 is lowest 0x7fff is max)where 0 sound and -1 sound have quite
> different colors 0x0000 and 0xffff) - but at least it seems i generati
> it right (?)
>
> unsigned short val=amplitude*127*256*sin(t);
>
> i rewritten the code
>
> void buffer_add_sinwave(int len, float amplitude, float hz)
> {
> for(int i=wave_pos; i<wave_pos+len; i++)
> {
> if(i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y)
> continue;

Shouldn't this be break ? When
i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y , it will remain
true for all the other values of i in the loop.

>
> float cycle = 22050.0/hz;
> float t = 2*M_PI*fmod(i,cycle)/cycle;
> unsigned short val=amplitude*127*256*sin(t);
> big_ofscreen_buffer[i] = val;
> }
> wave_pos+=len;
> return;
> }

Are big_ofscreen_buffer , big_ofscreen_buffer_size_x , big_ofscreen_buffer_size_y
global variables ?

Spiros Bousbouras wrote:
> On Tue, 02 Apr 2024 14:29:17 +0200
> fir <fir@grunge.pl> wrote:
>> fir wrote:
>>> fir wrote:
>>>>
>>>> than i run the playback just from teh screen data
>>>> so i can play bitmap data like sorta of bitmap
>>>> gramophone (hovever playing bitmaps genarally makes
>>>> mostly if not ony some buzzes not much interesting)
>>>
>>> i mean normal graphical bitmaps sound like buzzes
>>> whan those that are generated from loaded vaw - it is those
>>> who are mess soound like music
>>>
>>> so regular imeges give buzes but mess images give music
>>
>>
>> some things showed imo
>>
>> 1) the vaves seem to be 16 bit signed, so drawing it as a bitmap
>> not fully works cos -min and +max have nearly the same color on screen
>> (0x8000 is lowest 0x7fff is max)where 0 sound and -1 sound have quite
>> different colors 0x0000 and 0xffff) - but at least it seems i generati
>> it right (?)
>>
>> unsigned short val=amplitude*127*256*sin(t);
>>
>> i rewritten the code
>>
>> void buffer_add_sinwave(int len, float amplitude, float hz)
>> {
>> for(int i=wave_pos; i<wave_pos+len; i++)
>> {
>> if(i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y)
>> continue;
>
> Shouldn't this be break ? When
> i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y , it will remain
> true for all the other values of i in the loop.
>
>>
>> float cycle = 22050.0/hz;
>> float t = 2*M_PI*fmod(i,cycle)/cycle;
>> unsigned short val=amplitude*127*256*sin(t);
>> big_ofscreen_buffer[i] = val;
>> }
>> wave_pos+=len;
>> return;
>> }
>
> Are big_ofscreen_buffer , big_ofscreen_buffer_size_x , big_ofscreen_buffer_size_y
> global variables ?
>
yes, what people call it, (coz it is not global but module scope
(exe/dll) in fact)
thsi name is bad should be offscreen buffer but when i code various
experiments i dont care for names to much (than in normal 'design' code)