Some attempts to block referencing of DCPs when it is not possible.

[dcpomatic.git] / hacks / fft.py

diff --git a/hacks/fft.py b/hacks/fft.py
new file mode 100644 (file)
index 0000000..ab700a5
--- /dev/null
+++ b/hacks/fft.py
@@ -0,0 +1,50 @@
+#!/usr/bin/python
+
+import wave
+import sys
+import struct
+from pylab import *
+import numpy
+
+f = wave.open(sys.argv[1], 'rb')
+width = f.getsampwidth()
+peak = pow(2, width * 8) / 2
+channels = f.getnchannels()
+frames = f.getnframes()
+print '%d bytes per sample' % width
+print '%d channels' % channels
+print '%d frames' % frames
+data = []
+for i in range(0, channels):
+    data.append([])
+
+for i in range(0, frames):
+    frame = f.readframes(1)
+    for j in range(0, channels):
+        v = 0
+        for k in range(0, width):
+            v |= ord(frame[j * width + k]) << (k * 8)
+        if v >= peak:
+            v = v - 2 * peak
+        data[j].append(v)
+
+f.close()
+
+names = ['L', 'R', 'C', 'Lfe', 'Ls', 'Rs']
+dyn_range = 20 * log10(pow(2, 23))
+
+for i in range(0, channels):
+    s = numpy.fft.fft(data[i])
+#    subplot(channels, 1, i + 1)
+    # 138.5 is a fudge factor:
+    semilogx(arange(0, frames / 2, 0.5), 20 * log10(abs(s) + 0.1) - dyn_range, label = names[i])
+    xlim(100, frames / 4)
+plt.gca().xaxis.grid(True, which='major')
+plt.gca().xaxis.grid(True, which='minor')
+plt.gca().yaxis.grid(True)
+legend(loc = 'lower right')
+show()
+
+#plot(abs(numpy.fft.fft(data[0])))
+#plot(data[0])
+#show()