From 2dfae80f6ba1dc0cefc525a5e01fceacdc2d46bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ju=CC=88rgen=20Hock?= <juergen.hock@jurihock.de>
Date: Fri, 29 Mar 2024 22:49:27 +0100
Subject: [PATCH] Add tuning frequency estimation prototype #1

---
 src/sandbox/synth.py  | 52 +++++++++++++++-------------
 src/sandbox/tuning.py | 80 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+), 24 deletions(-)
 create mode 100644 src/sandbox/tuning.py

diff --git a/src/sandbox/synth.py b/src/sandbox/synth.py
index 8a95a64..a1df599 100644
--- a/src/sandbox/synth.py
+++ b/src/sandbox/synth.py
@@ -12,28 +12,6 @@
 import click
 
 
-@click.command(
-                               context_settings={'help_option_names': ['-h', '--help']},
-                               no_args_is_help=True)
-@click.argument('file',        nargs=1,
-                               required=True,
-                               type=click.Path(exists=False, file_okay=True, dir_okay=False, path_type=Path))
-@click.option('-a', '--a4',
-                               default=440,
-                               show_default=True,
-                               help='Tuning frequency.')
-@click.option('-b', '--bpm',
-                               default=120,
-                               show_default=True,
-                               help='Beats per minute.')
-@click.option('-g', '--prog',
-                               default=0,
-                               show_default=True,
-                               help='MIDI program number.')
-@click.option('-p', '--play',
-                               default=False,
-                               is_flag=True,
-                               help='Play generated file.')
 def synth(file: Union[str, PathLike], *, a4:   int  = 440,
                                          bpm:  int  = 120,
                                          prog: int  = 0,
@@ -59,7 +37,6 @@ def synth(file: Union[str, PathLike], *, a4:   int  = 440,
         track.append(Message('note_off', note=note, velocity=100, time=240))
 
     track.append(MetaMessage('end_of_track'))
-
     midi.save(file.with_suffix('.mid'))
 
     scale  = create_edo_scale(12)
@@ -84,6 +61,33 @@ def synth(file: Union[str, PathLike], *, a4:   int  = 440,
         run(['play', file], check=True)
 
 
+@click.command(
+                               context_settings={'help_option_names': ['-h', '--help']},
+                               no_args_is_help=True)
+@click.argument('file',        nargs=1,
+                               required=True,
+                               type=click.Path(exists=False, file_okay=True, dir_okay=False, path_type=Path))
+@click.option('-a', '--a4',
+                               default=440,
+                               show_default=True,
+                               help='Tuning frequency.')
+@click.option('-b', '--bpm',
+                               default=120,
+                               show_default=True,
+                               help='Beats per minute.')
+@click.option('-p', '--prog',
+                               default=0,
+                               show_default=True,
+                               help='MIDI program number.')
+@click.option('-y', '--play',
+                               default=False,
+                               is_flag=True,
+                               help='Play generated file.')
+def main(file, a4, bpm, prog, play):
+
+    synth(file, a4=a4, bpm=bpm, prog=prog, play=play)
+
+
 if __name__ == '__main__':
 
-    synth()  # pylint: disable=no-value-for-parameter
+    main()  # pylint: disable=no-value-for-parameter
diff --git a/src/sandbox/tuning.py b/src/sandbox/tuning.py
new file mode 100644
index 0000000..4dd3fc2
--- /dev/null
+++ b/src/sandbox/tuning.py
@@ -0,0 +1,80 @@
+# pylint: disable=import-error
+# pylint: disable=fixme
+
+import matplotlib.pyplot as plot
+import numpy as np
+import numpy.lib.stride_tricks as tricks
+import soundfile
+
+from qdft import Chroma
+from synth import synth
+
+CP = 440
+test = f'test.{CP}.wav'
+synth(test, a4=CP)
+
+samples, samplerate = soundfile.read(test)
+
+samples = np.mean(samples, axis=-1) \
+          if len(np.shape(samples)) > 1 \
+          else np.asarray(samples)
+
+print(f'samples {len(samples)} {len(samples)/samplerate}s')
+length = int(np.ceil(samples.size / samplerate) * samplerate)
+samples.resize(length)
+print(f'samples {len(samples)} {len(samples)/samplerate}s')
+
+chunks  = tricks.sliding_window_view(samples, samplerate)[::samplerate]
+chroma  = Chroma(samplerate, feature='hz')
+
+chromagram = np.empty((0, chroma.size))
+
+for i, chunk in enumerate(chunks):
+
+    if not i:
+        print('0%')
+
+    chromagram = np.vstack((chromagram, chroma.chroma(chunk)))
+
+    print(f'{int(100 * (i + 1) / len(chunks))}%')
+
+# TODO chroma.qdft.latencies in the next release
+latency = int(np.max(chroma.qdft.periods[0] - chroma.qdft.offsets))
+print(f'latency {latency}')
+
+print(f'old shape {chromagram.shape}')
+chromagram = chromagram[latency:]
+print(f'new shape {chromagram.shape}')
+
+cp0 = chroma.concertpitch
+cp1 = np.full(len(chromagram), cp0, float)
+
+r = np.real(chromagram)
+f = np.imag(chromagram)
+
+i = np.arange(len(chromagram))
+j = np.argmax(r, axis=-1)
+
+for n, m in zip(i, j):
+
+    # TODO peak picking
+    s = np.round(12 * np.log2(f[n, m] / cp1[n-1]))
+
+    cp1[n] = (f[n, m] * 2**(s/12)) / (2**(s/6))
+    cp1[n] = cp1[n-1] if np.isnan(cp1[n]) else cp1[n]
+
+# TODO better estimation precision
+stats = np.ceil([
+    cp1[0],
+    cp1[-1],
+    np.mean(cp1),
+    np.median(cp1)
+])
+
+print(f'fist {stats[0]} last {stats[1]} avg {stats[2]} med {stats[3]}')
+
+plot.figure(test)
+plot.plot(cp1)
+plot.show()
+
+assert stats[-1] == CP