Remove automake support

Makefile

@@ -1,29 +0,0 @@
-CC = gcc
-BIN = /usr/bin
-INCLUDES = -I.
-PALETTE_DIR=\"$(PWD)/palettes\"
-CFLAGS = -O3 -Wall -Wextra -Wno-missing-field-initializers -DPALETTE_DIR=$(PALETTE_DIR) $(INCLUDES)
-OBJS = src/main.o src/image.o src/dsp.o src/filter.o src/libs/reg.o src/pngio.o src/libs/median.o src/color.o src/libs/argparse.o
-
-aptdec:	$(OBJS)
-	$(CC) -o $@ $(OBJS) -lm -lsndfile -lpng
-	echo "Using the Makefile with GNU automake is now deprecated and will be removed soon, please use CMake instead."
-
-src/libs/reg.o: src/libs/reg.c
-src/libs/argparse.o: src/libs/argparse.c
-src/color.o:    src/color.c
-src/main.o:     src/main.c
-src/libs/median.o: src/libs/median.c
-src/dsp.o:      src/dsp.c
-src/filter.o:   src/filter.c
-src/image.o:    src/image.c
-src/pngio.o:    src/pngio.c
-
-clean:
-	rm -f src/*.o aptdec
-
-install:
-	install -m 755 aptdec $(BIN)
-
-uninstall:
-	rm $(BIN)/aptdec

README.md

@@ -1,11 +1,8 @@
-![Aptdec logo](textlogo.png)
+![Aptdec Logo](textlogo.png)
 
 Copyright (c) 2004-2009 Thierry Leconte (F4DWV), Xerbo (xerbo@protonmail.com) 2019-2022
 
-![x86 Release](https://github.com/Xerbo/aptdec/workflows/x86%20Release/badge.svg?branch=master)
-![x86 Debug](https://github.com/Xerbo/aptdec/workflows/x86%20Debug/badge.svg?branch=devel)
-![x86 Win Release](https://github.com/Xerbo/aptdec/workflows/x86%20Win%20Release/badge.svg?branch=master)
-![x86 Win Debug](https://github.com/Xerbo/aptdec/workflows/x86%20Win%20Debug/badge.svg?branch=devel)
+[![Build](https://github.com/Xerbo/aptdec/actions/workflows/build.yml/badge.svg?branch=master)](https://github.com/Xerbo/aptdec/actions/workflows/build.yml)
 
 ## Introduction
 
@@ -27,13 +24,11 @@ The input audio format can be anything supported by `libsndfile` (although only
 ```sh
 sudo apt install cmake git gcc libsndfile-dev libpng-dev
 git clone https://github.com/Xerbo/aptdec.git && cd aptdec
-mkdir build && cd build
-cmake -DCMAKE_BUILD_TYPE=Release ..
-make
+cmake -B build
+cmake --build build
+# Resulting binary is build/aptdec
 ```
 
-Using the Makefile with GNU automake is now deprecated and will be removed soon.
-
 ## Examples
 
 To create an image from `gqrx_20200527_115730_137914960.wav` (output filename will be `gqrx_20200527_115730_137914960-r.png`)
@@ -118,16 +113,7 @@ To stop the decode and calibrate the image simply kill the `sox` process.
 
 Palettes are just simple PNG images, 256x256px in size with 24bit RGB color. The X axis represents the value of Channel A and the Y axis the value of Channel B.
 
-## Compiling with cmake
-
-Thanks to the help of [Aang23](https://github.com/Aang23) aptdec is moving towards cmake + cpack for builds.
-
-To use cmake to build instead of GNU automake:
-```
-mkdir build && cd build
-cmake ..
-make
-```
+## Building for Windows
 
 You can cross build for Windows from Linux with the `build_windows.sh` script, you will need the following:
 ```