Add support for 24-bit and 32-bit audio output.

Drivers with 24-bit and 32-bit audio support:
- [x] ALSA
- [ ] BSD
- [ ] CoreAudio
- [ ] NetBSD
- [ ] OSS
- [x] PulseAudio
- [ ] sndio
- [x] Raw file
- [x] WAV file

Drivers that do not support 24-bit or 32-bit:
- [ ] Sound Blaster

Drivers to verify:
- [ ] AHI
- [ ] AIFF file
- [ ] AIX
- [ ] ALSA 0.5
- [ ] BeOS
- [ ] DART
- [ ] HP-UX
- [ ] QNX
- [ ] SGI
- [ ] Solaris

Author: AliceLR

Changelog

@@ -3,10 +3,17 @@ Stable versions
 
 4.2.1 (?):
 	Changes by Alice Rowan
+	- Support 24-bit and 32-bit output for the PulseAudio, ALSA,
+	  WAV, file drivers (requires libxmp 4.7.0+) (FIXME).
 	- Report pan value "---" for instruments/samples without
 	  a default panning value (sub->pan < 0).
 	- Don't unmute muted IT channels unless explicitly unmuted by
 	  the -S/--solo option.
+	- wav: fix incorrect RIFF length in output.
+	- wav: add terminal pad byte after odd length data chunks.
+	- file: fix incorrect handling of -Dendian ("big" would output
+	  little endian, anything else would output big endian).
+	- pulseaudio: support 8-bit output.
 
 4.2.0 (20230615):
 	Changes by Özkan Sezer:

README

@@ -59,7 +59,7 @@ directly to cmatsuoka@gmail.com.
 LICENSE
 
 Extended Module Player
-Copyright (C) 1996-2022 Claudio Matsuoka and Hipolito Carraro Jr
+Copyright (C) 1996-2026 Claudio Matsuoka and Hipolito Carraro Jr
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software

src/common.h

@@ -22,6 +22,11 @@
 
 #include <xmp.h>
 
+/* Allow building with <4.7.0 for now... */
+#if XMP_VERCODE < 0x040700
+#define XMP_FORMAT_32BIT	(1 << 3)
+#endif
+
 struct player_mode {
 	const char *name;
 	const char *desc;
@@ -33,6 +38,7 @@ struct options {
 	int amplify;		/* amplification factor */
 	int rate;		/* sampling rate */
 	int format;		/* sample format */
+	int format_downmix;	/* XMP_FORMAT_32BIT may require downmix to 24 */
 	int max_time;		/* max. replay time */
 	int mix;		/* channel separation */
 	int defpan;		/* default pan */

src/main.c

@@ -1,5 +1,5 @@
 /* Extended Module Player
- * Copyright (C) 1996-2016 Claudio Matsuoka and Hipolito Carraro Jr
+ * Copyright (C) 1996-2026 Claudio Matsuoka and Hipolito Carraro Jr
  *
  * This file is part of the Extended Module Player and is distributed
  * under the terms of the GNU General Public License. See the COPYING
@@ -335,13 +335,21 @@ int main(int argc, char **argv)
 	}
 
 	if (opt.verbose > 0) {
+		int format_bits;
+		if (opt.format & XMP_FORMAT_32BIT) {
+			format_bits = opt.format_downmix == 24 ? 24 : 32;
+		} else if (~opt.format & XMP_FORMAT_8BIT) {
+			format_bits = 16;
+		} else {
+			format_bits = 8;
+		}
+
 		report("Extended Module Player " VERSION "\n"
-			"Copyright (C) 1996-2016 Claudio Matsuoka and Hipolito Carraro Jr\n");
+			"Copyright (C) 1996-2026 Claudio Matsuoka and Hipolito Carraro Jr\n");
 
 		report("Using %s\n", sound->description());
 
-		report("Mixer set to %d Hz, %dbit, %s%s%s\n", opt.rate,
-		    opt.format & XMP_FORMAT_8BIT ? 8 : 16,
+		report("Mixer set to %d Hz, %dbit, %s%s%s\n", opt.rate, format_bits,
 		    opt.interp == XMP_INTERP_LINEAR ? "linear interpolated " :
 		    opt.interp == XMP_INTERP_SPLINE ? "cubic spline interpolated " : "",
 		    opt.format & XMP_FORMAT_MONO ? "mono" : "stereo",

src/options.c

@@ -1,5 +1,5 @@
 /* Extended Module Player
- * Copyright (C) 1996-2016 Claudio Matsuoka and Hipolito Carraro Jr
+ * Copyright (C) 1996-2026 Claudio Matsuoka and Hipolito Carraro Jr
  *
  * This file is part of the Extended Module Player and is distributed
  * under the terms of the GNU General Public License. See the COPYING
@@ -96,7 +96,7 @@ static void usage(char *s, struct options *options)
 "\nMixer options:\n"
 "   -A --amiga             Use Paula simulation mixer in Amiga formats\n"
 "   -a --amplify {0|1|2|3} Amplification factor: 0=Normal, 1=x2, 2=x4, 3=x8\n"
-"   -b --bits {8|16}       Software mixer resolution (8 or 16 bits)\n"
+"   -b --bits {8|16|24|32} Software mixer resolution (8, 16, 24, or 32 bits)\n"
 "   -c --stdout            Mix the module to stdout\n"
 "   -f --frequency rate    Sampling rate in hertz (default 44100)\n"
 "   -i --interpolation {nearest|linear|spline}\n"
@@ -190,8 +190,19 @@ void get_options(int argc, char **argv, struct options *options)
 			options->amplify = atoi(optarg);
 			break;
 		case 'b':
-			if (atoi(optarg) == 8) {
+			options->format &= ~(XMP_FORMAT_8BIT | XMP_FORMAT_32BIT);
+			options->format_downmix = 0;
+			switch (atoi(optarg)) {
+			case 8:
 				options->format |= XMP_FORMAT_8BIT;
+				break;
+			case 24:
+				options->format |= XMP_FORMAT_32BIT;
+				options->format_downmix = 24;
+				break;
+			case 32:
+				options->format |= XMP_FORMAT_32BIT;
+				break;
 			}
 			break;
 		case 'C':
@@ -385,6 +396,11 @@ void get_options(int argc, char **argv, struct options *options)
 	if (options->rate > 48000)
 		options->rate = 48000;	/* Max. rate 48 kHz */
 
+	if (xmp_vercode < 0x040700) {
+		options->format &= ~XMP_FORMAT_32BIT;
+		options->format_downmix = 0;
+	}
+
 	/* apply guess if no driver selected */
 	if (!options->driver_id)
 		options->driver_id = driver_guess;

src/sound.c

@@ -1,5 +1,5 @@
 /* Extended Module Player
- * Copyright (C) 1996-2016 Claudio Matsuoka and Hipolito Carraro Jr
+ * Copyright (C) 1996-2026 Claudio Matsuoka and Hipolito Carraro Jr
  *
  * This file is part of the Extended Module Player and is distributed
  * under the terms of the GNU General Public License. See the COPYING
@@ -101,16 +101,103 @@ const struct sound_driver *select_sound_driver(struct options *options)
 	return NULL;
 }
 
-/* Convert little-endian 16 bit samples to big-endian */
-void convert_endian(unsigned char *p, int l)
+/* Downmix 32-bit to 24-bit aligned (in-place) */
+void downmix_32_to_24_aligned(unsigned char *buffer, int buffer_bytes)
+{
+	unsigned *buf32 = (unsigned *)buffer;
+	int i;
+
+	for (i = 0; i < buffer_bytes; i += 4) {
+		*buf32 >>= 8;
+		buf32++;
+	}
+}
+
+/* Downmix 32-bit to 24-bit unaligned (in-place).
+ * Returns the new number of useful bytes in the buffer. */
+int downmix_32_to_24_unaligned(unsigned char *buffer, int buffer_bytes)
+{
+	unsigned char *out = buffer;
+	int buffer_samples = buffer_bytes >> 2;
+	int i;
+
+	/* Big endian 32-bit (22 11 00 XX) -> 24-bit (22 11 00)
+	 * Little endian 32-bit (XX 00 11 22) -> 24-bit (00 11 22)
+	 * Skip the first byte for little endian to allow reusing the same loop.
+	 */
+	if (!is_big_endian()) {
+		buffer++;
+	}
+
+	for (i = 0; i < buffer_samples; i++) {
+		out[0] = buffer[0];
+		out[1] = buffer[1];
+		out[2] = buffer[2];
+		out += 3;
+		buffer += 4;
+	}
+
+	return buffer_samples * 3;
+}
+
+
+/* Convert native endian 16-bit samples for file IO */
+void convert_endian_16bit(unsigned char *buffer, int buffer_bytes)
 {
 	unsigned char b;
 	int i;
 
-	for (i = 0; i < l; i++) {
-		b = p[0];
-		p[0] = p[1];
-		p[1] = b;
-		p += 2;
+	for (i = 0; i < buffer_bytes; i += 2) {
+		b = buffer[0];
+		buffer[0] = buffer[1];
+		buffer[1] = b;
+		buffer += 2;
+	}
+}
+
+/* Convert native endian 24-bit unaligned samples for file IO */
+void convert_endian_24bit(unsigned char *buffer, int buffer_bytes)
+{
+	unsigned char b;
+	int i;
+
+	for (i = 0; i < buffer_bytes; i += 3) {
+		b = buffer[0];
+		buffer[0] = buffer[2];
+		buffer[2] = b;
+		buffer += 3;
+	}
+}
+
+/* Convert native endian 32-bit samples for file IO */
+void convert_endian_32bit(unsigned char *buffer, int buffer_bytes)
+{
+	unsigned char a, b;
+	int i;
+
+	for (i = 0; i < buffer_bytes; i+= 4) {
+		a = buffer[0];
+		b = buffer[1];
+		buffer[0] = buffer[3];
+		buffer[1] = buffer[2];
+		buffer[2] = b;
+		buffer[3] = a;
+		buffer += 4;
+	}
+}
+
+/* Convert native endian 16-bit, 24-bit, or 32-bit samples for file IO */
+void convert_endian(unsigned char *buffer, int buffer_bytes, int bits)
+{
+	switch (bits) {
+	case 16:
+		convert_endian_16bit(buffer, buffer_bytes);
+		break;
+	case 24:
+		convert_endian_24bit(buffer, buffer_bytes);
+		break;
+	case 32:
+		convert_endian_32bit(buffer, buffer_bytes);
+		break;
 	}
 }

src/sound.h

@@ -58,13 +58,19 @@ extern const struct sound_driver *const sound_driver_list[];
 #define chkparm2(x,y,z,w) { if (!strcmp(s, x)) { \
 	if (2 > sscanf(token, y, z, w)) parm_error(); } }
 
-static inline int is_big_endian(void) {
+static inline int is_big_endian(void)
+{
 	unsigned short w = 0x00ff;
 	return (*(char *)&w == 0x00);
 }
 
 void init_sound_drivers(void);
 const struct sound_driver *select_sound_driver(struct options *);
-void convert_endian(unsigned char *, int);
+void downmix_32_to_24_aligned(unsigned char *, int);
+int downmix_32_to_24_unaligned(unsigned char *, int);
+void convert_endian_16bit(unsigned char *, int);
+void convert_endian_24bit(unsigned char *, int);
+void convert_endian_32bit(unsigned char *, int);
+void convert_endian(unsigned char *, int, int);
 
 #endif

src/sound_ahi.c

@@ -92,6 +92,7 @@ static int init(struct options *options) {
                         if (AHIBuf[1]) {
                             /* driver is initialized before calling libxmp, so this is OK : */
                             options->format &= ~XMP_FORMAT_UNSIGNED;/* no unsigned with AHI */
+                            options->format &= ~XMP_FORMAT_32BIT;
                             return 0;
                         }
                     }

src/sound_aiff.c

@@ -99,6 +99,7 @@ static int init(struct options *options)
 	} else {
 		fd = stdout;
 	}
+	options->format &= ~XMP_FORMAT_32BIT;
 
 	fwrite(hed, 1, 54, fd);
 
@@ -107,8 +108,8 @@ static int init(struct options *options)
 
 static void play(void *b, int len) 
 {
-	if (swap_endian && bits == 16) {
-		convert_endian((unsigned char *)b, len);
+	if (swap_endian) {
+		convert_endian((unsigned char *)b, len, bits);
 	}
 	fwrite(b, 1, len, fd);
 	size += len;

src/sound_aix.c

@@ -1,5 +1,5 @@
 /* Extended Module Player
- * Copyright (C) 1996-2016 Claudio Matsuoka and Hipolito Carraro Jr
+ * Copyright (C) 1996-2026 Claudio Matsuoka and Hipolito Carraro Jr
  *
  * This file is part of the Extended Module Player and is distributed
  * under the terms of the GNU General Public License. See the COPYING
@@ -83,6 +83,8 @@ static int init(struct options *options)
 		close(audio_fd);
 		return -1;
 	}
+	options->format &= ~XMP_FORMAT_32BIT;
+
 	return 0;
 }