Take all fork improvements and merge into upstream

Makefile

@@ -3,7 +3,7 @@ CFLAGS = -Wall -O2
 LDLIBS = -lm
 
 PYTHON = python3
-PLAY = ffplay -v fatal -nodisp -autoexit -f s32le -ar 48000 -ch_layout mono -i pipe:0
+PLAY = ffplay -v fatal -nodisp -autoexit -f s32le -ar 48000 -ch_layout mono
 
 effects = flanger echo fm phaser discont am distortion tube growlingbass
 flanger_defaults = 0.6 0.6 0.6 0.6
@@ -22,7 +22,7 @@ default:
 	@echo "Pick one of" $(effects)
 
 play: output.raw
-	$(PLAY) < output.raw
+	$(PLAY) $<
 
 visualize: input.raw output.raw magnitude.raw outmagnitude.raw
 	$(PYTHON) visualize.py input.raw output.raw magnitude.raw outmagnitude.raw
@@ -33,7 +33,7 @@ visualize: input.raw output.raw magnitude.raw outmagnitude.raw
 $(effects): input.raw convert
 	./convert $@ $($@_defaults) input.raw output.raw
 	ffmpeg -y -v fatal -f s32le -ar 48000 -ac 1 -i output.raw -f mp3 $@.mp3
-	$(PLAY) < output.raw
+	$(PLAY) output.raw
 
 convert.o: CFLAGS += -ffast-math -fsingle-precision-constant -Wfloat-conversion # -Wdouble-promotion
 convert.o: $(HEADERS)
@@ -53,7 +53,11 @@ input.raw: BassForLinus.mp3
 	ffmpeg -y -v fatal -i $< -f s32le -ar 48000 -ac 1 $@
 
 SeymourDuncan: convert
-	for i in ~/Wav/Seymour\ Duncan/*; do ffmpeg -y -v fatal -i "$$i" -f s32le -ar 48000 -ac 1 pipe:1 | ./convert phaser $(phaser_defaults) | $(PLAY) ; done
+	@if [ ! -d ~/Wav/Seymour\ Duncan ]; then echo "Directory ~/Wav/Seymour Duncan not found"; exit 0; fi
+	for i in ~/Wav/Seymour\ Duncan/*; do \
+		[ -f "$$i" ] || continue; \
+		ffmpeg -y -v fatal -i "$$i" -f s32le -ar 48000 -ac 1 pipe:1 | ./convert phaser $(phaser_defaults) | $(PLAY) -i pipe:0 ; \
+	done
 
 gensin.h: gensin
 	./gensin > gensin.h

README.md

@@ -3,7 +3,7 @@
 The digital [RP2354 and TAC5112-based guitar
 pedal](https://github.com/torvalds/GuitarPedal) actually does work, even
 if I'm not thrilled about some of my analog interface choices (ie the
-pots in particular, and I'm growing to hate the clicky footswitch even
+potentiometers in particular, and I'm growing to hate the clicky footswitch even
 if I do love how it also doubles as a boot selector switch for
 programming). 
 
@@ -40,3 +40,77 @@ much -- than I do about python.  It started out as my typical "google
 and do the monkey-see-monkey-do" kind of programming, but then I cut out
 the middle-man -- me -- and just used Google Antigravity to do the audio
 sample visualizer.
+
+
+## Building and Running
+
+### Dependencies
+
+- GCC
+- FFmpeg and FFplay (for audio format conversion and playback)
+- Python 3 with NumPy and Matplotlib (for visualization only)
+
+On macOS with Homebrew:
+```
+brew install ffmpeg
+pip3 install numpy matplotlib
+```
+
+On Debian/Ubuntu:
+```
+apt install gcc ffmpeg python3-numpy python3-matplotlib
+```
+
+Or install Python dependencies via:
+```bash
+pip install -r requirements.txt
+```
+
+Or using [uv](https://docs.astral.sh/uv/):
+```bash
+uv sync
+```
+
+### Build
+
+Compile the audio processor:
+```
+make convert
+```
+
+### Running Effects
+
+The workflow converts an MP3 to raw 48kHz mono 32-bit audio, processes it through an effect, and plays the result.
+
+Available effects: `flanger`, `echo`, `fm`, `am`, `phaser`, `discont`, `distortion`, `tube`, `growlingbass`
+
+To run an effect (uses `BassForLinus.mp3` as input by default):
+```
+make flanger
+make echo
+make distortion
+# etc.
+```
+
+This will process the audio, save the output as `<effect>.mp3`, and play it back.
+
+To use your own input file:
+```
+ffmpeg -y -i yourfile.mp3 -f s32le -ar 48000 -ac 1 input.raw
+./convert flanger 0.6 0.6 0.6 0.6 input.raw output.raw
+ffmpeg -y -f s32le -ar 48000 -ac 1 -i output.raw output.mp3
+```
+
+### Visualization
+
+To visualize the input/output waveforms:
+```
+make visualize
+```
+
+### Tests
+
+Run the unit tests:
+```
+make test
+```

convert.c

@@ -89,7 +89,7 @@ static void *modify_pots(void *arg)
 		if (n <= 0)
 			return NULL;
 		switch (buf[0]) {
-		case 'p':
+		case 'p': {
 			unsigned int idx = buf[1]-'0';
 			unsigned int d1 = buf[2]-'0';
 			unsigned int d2 = buf[3]-'0';
@@ -98,6 +98,7 @@ static void *modify_pots(void *arg)
 			pots[idx] = (d1*10+d2) / 100.0;
 			eff->describe(pots);
 			break;
+			}
 		}
 	}
 }
@@ -125,6 +126,8 @@ int main(int argc, char **argv)
 		float val = strtof(arg, &endptr);
 		if (endptr != arg) {
 			if (potnr < 4) {
+				if (!isfinite(val))
+					val = 0.5;
 				pots[potnr++] = val;
 				continue;
 			}
@@ -184,6 +187,11 @@ int main(int argc, char **argv)
 	if (output < 0)
 		output = 1;
 
+	if (!eff) {
+		fprintf(stderr, "No effect specified\n");
+		exit(1);
+	}
+
 #ifdef F_SETPIPE_SZ
 	// Limit the output buffer size if we are
 	// writing to a pipe. At least on Linux,

pyproject.toml

@@ -0,0 +1,10 @@
+[project]
+name = "audionoisefork"
+version = "0.1.0"
+description = "A Python toolkit to visualize noise characteristics in audio signals"
+readme = "README.md"
+requires-python = ">=3.12"
+dependencies = [
+    "matplotlib>=3.10.8",
+    "numpy>=2.4.1",
+]

requirements.txt

@@ -0,0 +1,2 @@
+numpy
+matplotlib