Add conversion script

scripts/wav_to_wavetable.py

+#!/usr/bin/python
+
+import os
+import sys
+import argparse
+import wave
+
+
+class bcolors:
+    HEADER = "\033[95m"
+    OKBLUE = "\033[94m"
+    OKCYAN = "\033[96m"
+    OKGREEN = "\033[92m"
+    WARNING = "\033[93m"
+    FAIL = "\033[91m"
+    ENDC = "\033[0m"
+    BOLD = "\033[1m"
+    UNDERLINE = "\033[4m"
+
+
+parser = argparse.ArgumentParser(
+    prog="wav_to_wavetable.py",
+    description="converts a wave file into an c-style array of 10 bit signed variables.",
+    epilog="the result in a header file. Copy the result into the \
+                    appropriate place to use the wavetable (replacing the old one).\n\
+                    \n\
+                    If a stereo wav-file is provided this uses the left channel only.",
+)
+
+parser.add_argument("-i", "--input", required=True, help="Path of the input wav file")
+parser.add_argument("-o", "--output", required=True, help="Path for the output")
+parser.add_argument(
+    "-f", "--force", action="store_true", help="overwrite output file if it exists"
+)
+
+args = parser.parse_args()
+
+if not os.path.isfile(args.input):
+    print(
+        f"{bcolors.FAIL}Error:{bcolors.ENDC} The input file at the specified path does not exist:",
+        file=sys.stderr,
+    )
+    print(f"       {args.input}")
+    exit(1)
+
+if os.path.isfile(args.output) and not args.force:
+    print(
+        f"{bcolors.FAIL}Error:{bcolors.ENDC} There is already a file at the specified output path:",
+        file=sys.stderr,
+    )
+    print(f"       {args.input}", file=sys.stderr)
+    print(
+        f"{bcolors.OKGREEN}Hint:{bcolors.ENDC}  Run this command again with the --force flag to overwrite",
+        file=sys.stderr,
+    )
+    exit(1)
+
+path = args.input
+w = wave.open(path, "rb")
+channels = w.getnchannels()
+samplewidth = w.getsampwidth()
+print(f"Audio has {channels} channels and each sample is {samplewidth} bytes wide")
+
+resampled = []
+
+
+def resample(sample: int) -> int:
+    return min(1023, int(sample / 2**14)) - 511
+
+
+for n in range(w.getnframes()):
+    frame = w.readframes(n)
+    if frame != b"":
+        # Convert the frame into a list of integers, assuming little endian encoding
+        frame_data = [
+            int.from_bytes(frame[i : i + samplewidth], "little")
+            for i in range(0, len(frame), samplewidth)
+        ]
+        # If we have more than one channel the samples of each channel
+        # should be interleaved
+        if channels == 1:
+            # Each frame can contain multiple samples
+            for sample in frame_data:
+                # print(sample)
+                # 24 bit - 14 bit = 10 bit
+                resampled.append(resample(sample))
+        elif channels == 2:
+            # Iterate in steps of 2 over the frames and deinterleave
+            # them into the samples for left and right
+            for c in range(0, len(frame_data), 2):
+                left, right = zip(frame_data[c : c + 2])
+                left, right = left[0], right[0]
+                resampled.append(resample(left))
+        else:
+            print(
+                f"{bcolors.FAIL}Error:{bcolors.ENDC} Sorry, we do not support wave files with {channels} channels.. yet",
+                file=sys.stderr,
+            )
+            exit()
+
+print(f"Resampled {len(resampled)} samples")
+# shrink_to = 48000*2
+# resampled = resampled[:shrink_to]
+c_array = f"short wavetable[{len(resampled)}] = {{"
+elements_per_line = 64
+for chunk in range(0, len(resampled), elements_per_line):
+    c_array += ",".join([str(s) for s in resampled[chunk : chunk + elements_per_line]])
+    c_array += ",\n    "
+c_array += "};"
+
+
+with open(args.output, "w") as f:
+    f.write(c_array)
+    f.write("\n")
+
+print(f"Written {len(resampled)} 10 bit samples to {args.output}")