添加一些关于midi播放的项目

2025-03-24 14:30:56 +08:00
parent e31eb22077
commit 498b4ef13b
699 changed files with 186162 additions and 1 deletions
@@ -0,0 +1,106 @@
+
+from __future__ import print_function
+import threading
+import rtaudio as rt
+
+from math import cos
+
+import struct
+
+
+class audio_generator:
+    def __init__(self):
+        self.idx = -1
+        self.freq = 440.
+    def __call__(self):
+        self.idx += 1
+        if self.idx%48000 == 0:
+            self.freq *= 2**(1/12.)
+        return 0.5*cos(2.*3.1416*self.freq*self.idx/48000.)
+
+
+class callback:
+    def __init__(self, gen):
+        self.gen = gen
+        self.i = 0
+    def __call__(self,playback, capture):
+        [struct.pack_into("f", playback, 4*o, self.gen()) for o in range(256)]
+        self.i = self.i + 256
+        if self.i > 48000*10:
+            print('.')
+            return 1
+
+try:
+    # if we have numpy, replace the above class
+    import numpy as np
+    class callback:
+        def __init__(self, gen):
+            print('Using Numpy.')
+            self.freq = 440.
+            t = np.arange(256, dtype=np.float32) / 48000.0
+            self.phase = 2*np.pi*t
+            self.inc = 2*np.pi*256/48000
+            self.k = 0
+        def __call__(self, playback, capture):
+            # Calculate sinusoid using numpy vector operation, as
+            # opposed to per-sample computations in the generator
+            # above that must be collected and packed one at a time.
+            self.k += 256
+            if self.k > 48000:
+                self.freq *= 2**(1/12.)
+                self.k = 0
+            self.phase += self.inc
+            samples = 0.5*np.cos(self.phase * self.freq)
+
+            # Ensure result is the right size!
+            assert samples.shape[0] == 256
+            assert samples.dtype == np.float32
+
+            # Use numpy array view to do a once-copy into memoryview
+            # (ie. we only do a single byte-wise copy of the final
+            # result into 'playback')
+            usamples = samples.view(dtype=np.uint8)
+            playback_array = np.array(playback, copy=False)
+            np.copyto(playback_array, usamples)
+except ModuleNotFoundError:
+    print('Numpy not available, using struct.')
+
+dac = rt.RtAudio()
+
+n = dac.getDeviceCount()
+print('Number of devices available: ', n)
+
+for i in range(n):
+    try:
+        print(dac.getDeviceInfo(i))
+    except rt.RtError as e:
+        print(e)
+
+
+print('Default output device: ', dac.getDefaultOutputDevice())
+print('Default input device: ', dac.getDefaultInputDevice())
+
+print('is stream open: ', dac.isStreamOpen())
+print('is stream running: ', dac.isStreamRunning())
+
+oParams = {'deviceId': 0, 'nChannels': 1, 'firstChannel': 0}
+iParams = {'deviceId': 0, 'nChannels': 1, 'firstChannel': 0}
+
+try:
+  dac.openStream(oParams,oParams,48000,256,callback(audio_generator()) )
+except rt.RtError as e:
+  print(e)
+else:
+  dac.startStream()
+
+  import time
+  print('latency: ', dac.getStreamLatency())
+
+  while (dac.isStreamRunning()):
+    time.sleep(0.1)
+
+  print(dac.getStreamTime())
+
+  dac.stopStream()
+  dac.abortStream()
+  dac.closeStream()