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jsbain/Audio.py

Created Jun 26, 2016
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Audio.py
from objc_util import *
import ctypes
import numpy as np
import matplotlib.image
import io,ui
AVAudioEngine=ObjCClass('AVAudioEngine')
AVAudioSession=ObjCClass('AVAudioSession')
def setup():
error=ctypes.c_void_p(0)
session=AVAudioSession.sharedInstance()
category=session.setCategory('AVAudioSessionCategoryPlayAndRecord',error=ctypes.pointer(error))
if error:
raise Exception('error setting up category')
session.setActive(True, error=ctypes.pointer(error))
if error:
raise Exception('error setting up session active')
engine=AVAudioEngine.new()
return engine
class fftview(ui.View):
def __init__(self,*args,**kwargs):
ui.View.__init__(self,*args,**kwargs)
self.i=ui.ImageView()
self.i.frame=self.bounds
self.i.flex='wh'
self.add_subview(self.i)
self.fps=ui.Label()
self.add_subview(self.fps)
self.fps.text=''
def update(self,im):
self.i.image=im
@ui.in_background
def will_close(self):
print('stopping engine')
engine.pause()
v=fftview(frame=(0,0,500,500))
import time
'''setup a tap block'''
buf=[] #for debugging
bIO=io.BytesIO()
lastt=0
timing=np.zeros((100))
def processBuffer(self,buffer,when, cmd):
try:
global lastt
global timing
#global buf
timing[0]=time.time()
buf=ObjCInstance(buffer )
t=ObjCInstance(when).sampleTime()/44100.
timing[1]=time.time()
fps=1./(t-lastt)
lastt=t
v.fps.text='fps{}'.format(fps)
timing[2]=time.time()
A=np.ctypeslib.as_array(buf.floatChannelData()[0],(4,4096))
timing[3]=time.time()
A=A-A.mean()
#B=np.transpose(np.log10(np.fft.fftshift(abs(np.fft.fft(A,32)))))
timing[4]=time.time()
matplotlib.image.imsave(bIO,A+1,format='png',
cmap=(matplotlib.image.cm.get_cmap('gray',256)),
vmax=2.,vmin=0.)
timing[5]=time.time()
#v.update(ui.Image.from_data(bIO.getvalue()))
m.update_data(ui.Image.from_data(bIO.getvalue()))
timing[6]=time.time()
bIO.seek(0)
#buf.autorelease()
except:
engine.pause()
raise
process_block=ObjCBlock(processBuffer,restype=None,argtypes=[c_void_p,c_void_p,c_void_p,c_void_p])
'''set up audio engine, and install tap, and start'''
engine=setup()
engine.connect_to_format_(engine.inputNode(),
engine.outputNode(),
engine.inputNode().inputFormatForBus_(0))
engine.inputNode().installTapOnBus(0,
bufferSize=64*256,
format=None,
block=process_block)
#v.present('sheet')
engine.prepare()
from scene import *
''' 16384 samples/44100 samp/sec=0.3715 sec per window
due to tex suze limits of 4096, we size as a 4x4096
if we scale u and t such that they are both 1 at max,
then scale by screen width as W*x+(1-W)*t, we get an offset
into the texture.
We then convert this into a u,v coords by multiplying by number of rows, then taking mod and fract
'''
ripple_shader = '''
precision highp float;
varying vec2 v_tex_coord;
// These uniforms are set automatically:
uniform sampler2D u_texture;
uniform float u_time;
uniform vec2 u_sprite_size;
// This uniform is set in response to touch events:
uniform float u_oldtime;
uniform sampler2D u_data;
void main(void) {
vec2 uv=v_tex_coord.xy;
float t = (u_time - u_oldtime)/0.371519/1.;
float W=0.2;//fraction of total buffer to show on screen at once,
float N=4.;//num rows in texture
float shft =N*(W*uv.x + (1.-W)*t);
float u = mod(shft ,1.);
float v = floor(shft)+1./N;
float y = texture2D(u_data, vec2(u,v)).x;
float dy=1./67.;
float col = smoothstep(-dy,0.,uv.y-y)-smoothstep(0.,dy,uv.y-y);
gl_FragColor = vec4(col/2.,col,col/2.,1.);
}
'''
class MyScene (Scene):
def setup(self):
b=io.BytesIO()
matplotlib.image.imsave(b,(np.zeros((320,768),float)),format='png')
self.sprite=SpriteNode(Texture(ui.Image.from_data(b.getvalue())),
parent=self)
self.sprite.shader = Shader(ripple_shader)
self.did_change_size()
def stop(self):
engine.pause()
def update(self):
pass
def did_change_size(self):
# Center the image:
self.sprite.position = self.size/2
def update_data(self,i):
txt=Texture(i)
self.sprite.shader.set_uniform('u_data',txt)
oldtime=self.sprite.shader.get_uniform('u_time')
self.sprite.shader.set_uniform('u_oldtime',oldtime)
m=MyScene()
run(m,show_fps=True,frame_interval=2,anti_alias=True)
engine.startAndReturnError_(None)
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