Add new audio2mozzy.py

The script allows to create mozzi tables from raw files and it's supposed to replace all the "*2mozzy.py" scripts thanks to its high configurability (it also supports int16/int32 tables in case they'll be supported in the future)

extras/python/audio2mozzi.py

@@ -0,0 +1,152 @@
+#!/usr/bin/env python3
+"""
+For converting raw audio files to Mozzi table
+
+To generate waveforms using Audacity:
+Set the project rate to the size of the wavetable you wish to create, which must
+be a power of two (eg. 8192), and set the selection format
+(beneath the editing window) to samples. Then you can generate
+and save 1 second of a waveform and it will fit your table
+length.
+
+To convert samples using Audacity:
+For a recorded audio sample, set the project rate to the
+MOZZI_AUDIO_RATE (16384 in the current version).
+Samples can be any length, as long as they fit in your Arduino.
+Save by exporting with the format set to "Other uncompressed formats",
+"Header: RAW(headerless)" and choose the encoding you prefer (Signed 8/16/32-bit PCM or 32-bit Float).
+
+Alternative to convert samples via CLI using sox (http://sox.sourceforge.net/):
+sox <inputfile> -b <8/16/32> -c 1 -e <floating-point/signed-integer> -r 16384 <outputfile>
+
+Now use the file you just exported, as the "input_file" to convert and
+set the other parameters according to what you chose for conversion.
+"""
+
+import array
+import math
+import random
+import sys
+import textwrap
+from argparse import ArgumentParser
+from pathlib import Path
+
+
+def float2mozzi(args):
+    input_path = args.input_file.expanduser()
+    output_path = (
+        args.output_file.expanduser()
+        if args.output_file is not None
+        else input_path.with_suffix(".h")
+    )
+
+    with input_path.open("rb") as fin, output_path.open("w") as fout:
+        print(f"opened {input_path}")
+        num_input_values = int(
+            input_path.stat().st_size / (args.input_bits / 8)
+        )  # Adjust for number format (table at top of https://docs.python.org/3/library/array.html)
+
+        array_type = ""
+        if args.input_bits == 8:
+            array_type = "b"
+        elif args.input_bits == 16:
+            array_type = "h"
+        elif args.input_bits == 32:
+            array_type = "f" if args.input_encoding == "float" else "i"
+
+        valuesfromfile = array.array(array_type)
+        try:
+            valuesfromfile.fromfile(fin, num_input_values)
+        except EOFError:
+            pass
+        values = valuesfromfile.tolist()
+
+        tablename = (
+            args.table_name
+            if args.table_name is not None
+            else output_path.stem.replace("-", "_").upper()
+        )
+
+        fout.write(f"#ifndef {tablename}_H_\n")
+        fout.write(f"#define {tablename}_H_\n\n")
+        fout.write("#include <Arduino.h>\n")
+        fout.write('#include "mozzi_pgmspace.h"\n\n')
+        fout.write(f"#define {tablename}_NUM_CELLS {len(values)}\n")
+        fout.write(f"#define {tablename}_SAMPLERATE {args.sample_rate}\n\n")
+
+        table = f"CONSTTABLE_STORAGE(int{args.output_bits}_t) {tablename}_DATA [] = {{"
+        max_output_value = 2 << (args.output_bits - 2)  # Halved because signed
+        for value in values:
+            cnt_33 = 0
+            out_value = (
+                math.trunc((value * max_output_value) + 0.5)
+                if args.input_encoding == "float"
+                else value
+            )
+            # Mega2560 boards won't upload if there is 33, 33, 33 in the array, so dither the 3rd 33 if there is one
+            if value == 33:
+                cnt_33 += 1
+                if cnt_33 == 3:
+                    out_value = random.choice((32, 34))
+                    cnt_33 = 0
+            else:
+                cnt_33 = 0
+            table += f"{out_value}, "
+        table += "};"
+        table = textwrap.fill(table, 80)
+        fout.write(table)
+        fout.write("\n\n")
+        fout.write(f"#endif /* {tablename}_H_ */\n")
+        print(f"wrote {table} to {output_path}")
+
+    return 0
+
+
+if __name__ == "__main__":
+    parser = ArgumentParser(
+        description="Script for converting a raw audio file to a Mozzi table",
+    )
+    parser.add_argument(
+        "-e",
+        "--input-encoding",
+        choices=("float", "int"),
+        default="int",
+        help="Input encoding",
+    )
+    parser.add_argument(
+        "--input-bits",
+        type=int,
+        choices=(8, 16, 32),
+        default=8,
+        help="Number of bits for the INPUT encoding",
+    )
+    parser.add_argument(
+        "--output-bits",
+        type=int,
+        choices=(8, 16, 32),
+        default=8,
+        help="Number of bits for each element of the OUTPUT table",
+    )
+    parser.add_argument("input_file", type=Path, help="Path to the input file")
+    parser.add_argument(
+        "-o",
+        "--output-file",
+        type=Path,
+        help="Path to the output file. It will be input_file.h if not provided",
+    )
+    parser.add_argument(
+        "-t",
+        "--table-name",
+        type=str,
+        help="Name of the output table. If not provided, the name of the output will be used",
+    )
+    parser.add_argument(
+        "-s",
+        "--sample-rate",
+        type=int,
+        default=16384,
+        help="Sample rate. Value of 16384 recommended",
+    )
+
+    args_ = parser.parse_args()
+    sys.exit(float2mozzi(args_))