commit e26da60a20d19b69c0bafd3005985d2c9965c4f3
from: Omar Polo <op@omarpolo.com>
date: Thu Mar 23 14:10:48 2023 UTC

add an audio implementation for ALSA

it still doesn't work correctly, audio is very distorted, but at least
there's some sound.

commit - 06ceb3767eb7e480de05cd50f4fbaf75fb3322a2
commit + e26da60a20d19b69c0bafd3005985d2c9965c4f3
blob - ed6eac93eeae2b298b126764266afb1ebaf7ca0e
blob + dd7865dd031072630bde52cdb3f06d625ba85dea
--- Makefile
+++ Makefile
@@ -94,6 +94,7 @@ ${DISTNAME}.tar.gz: ${DISTFILES}
 # supports it.
 
 -include amused.d
+-include audio_alsa.d
 -include audio_sndio.d
 -include compats.d
 -include control.d
blob - /dev/null
blob + 59128b71c8a1192389220edbb0178e4a416c51b9 (mode 644)
--- /dev/null
+++ audio_alsa.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2023 Omar Polo <op@omarpolo.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <alsa/asoundlib.h>
+
+#include <limits.h>
+
+#include "amused.h"
+#include "log.h"
+
+static snd_pcm_t	*pcm;
+
+int
+audio_open(void (*onmove_cb)(void *, int))
+{
+	const char	*device = "default";
+	int		 err;
+
+	err = snd_pcm_open(&pcm, device, SND_PCM_STREAM_PLAYBACK,
+	    SND_PCM_NONBLOCK);
+	if (err < 0) {
+		log_warnx("playback open error: %s", snd_strerror(err));
+		return -1;
+	}
+
+	/* TODO: set up onmove callback? */
+	return 0;
+}
+
+int
+audio_setup(unsigned int bits, unsigned int rate, unsigned int channels,
+    struct pollfd *pfds)
+{
+	int			 err;
+	snd_pcm_format_t	 fmt;
+
+	if (bits == 8)
+		fmt = SND_PCM_FORMAT_S8;
+	else if (bits == 16)
+		fmt = SND_PCM_FORMAT_S16;
+	else if (bits == 24)
+		fmt = SND_PCM_FORMAT_S24;
+	else if (bits == 32)
+		fmt = SND_PCM_FORMAT_S32;
+	else {
+		log_warnx("can't handle %d bits", bits);
+		return -1;
+	}
+
+	err = snd_pcm_set_params(pcm, fmt, SND_PCM_ACCESS_RW_INTERLEAVED,
+	    channels, rate, 1, 500000 /* 0.5s */);
+	if (err < 0) {
+		log_warnx("invalid params: %s", snd_strerror(err));
+		return -1;
+	}
+
+	err = snd_pcm_prepare(pcm);
+	if (err < 0) {
+		log_warnx("snd_pcm_prepare failed: %s", snd_strerror(err));
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+audio_nfds(void)
+{
+	return snd_pcm_poll_descriptors_count(pcm);
+}
+
+int
+audio_pollfd(struct pollfd *pfds, int events)
+{
+	return snd_pcm_poll_descriptors(pcm, pfds, audio_nfds());
+}
+
+int
+audio_revents(struct pollfd *pfds)
+{
+	int			 err;
+	unsigned short		 revents;
+
+	err = snd_pcm_poll_descriptors_revents(pcm, pfds, audio_nfds(),
+	    &revents);
+	if (err < 0) {
+		log_warnx("snd revents failure: %s", snd_strerror(err));
+		return 0;
+	}
+
+	return revents;
+}
+
+size_t
+audio_write(const void *buf, size_t len)
+{
+	snd_pcm_sframes_t	ret;
+
+	ret = snd_pcm_writei(pcm, buf, len);
+	if (ret < 0) {
+		log_warnx("snd_pcm_writei failed: %s", snd_strerror(ret));
+		return 0;
+	}
+	return ret;
+}
+
+int
+audio_flush(void)
+{
+	int			err;
+
+	err = snd_pcm_drop(pcm);
+	if (err < 0) {
+		log_warnx("snd_pcm_drop: %s", snd_strerror(err));
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+audio_stop(void)
+{
+	int			err;
+
+	err = snd_pcm_drain(pcm);
+	if (err < 0) {
+		log_warnx("snd_pcm_drain: %s", snd_strerror(err));
+		return -1;
+	}
+
+	return 0;
+}