Merge pull request #19 from sthibaul/alsa-volume

Support setting ALSA volume in addition to espeak volume

Makefile

@@ -6,7 +6,7 @@ DEPFLAGS = -MMD
 WARNFLAGS = -Wall
 CFLAGS += ${DEPFLAGS} ${WARNFLAGS}
 
-LDLIBS = -lespeak -lpthread
+LDLIBS = -lespeak -lpthread -lasound -lm
 
 INSTALL = install
 BINMODE = 0755

cli.c

@@ -30,11 +30,15 @@ extern char *pidPath;
 /* default voice */
 extern char *defaultVoice;
 
+/* Whether to drive ALSA volume */
+extern int alsaVolume;
+
 /* command line options */
 const char *shortOptions = "P:V:adhv";
 const struct option longOptions[] = {
 	{"pid-path", required_argument, NULL, 'P'},
 	{"default-voice", required_argument, NULL, 'V'},
+	{"alsa-volume", no_argument, &alsaVolume, 1},
 	{"acsint", no_argument, NULL, 'a'},
 	{"debug", no_argument, NULL, 'd'},
 	{"help", no_argument, NULL, 'h'},
@@ -48,6 +52,7 @@ static void show_help()
 	printf("Options are as follows:\n");
 	printf("  --pid-path=path, -P path\t\tSet path for pid file.\n");
 	printf("  --default-voice=voice, -V voice\tSet default voice.\n");
+	printf("  --alsa-volume\t\t\t\tDrive the ALSA volume.\n");
 	printf("  --debug, -d\t\t\t\tDebug mode (stay in the foreground).\n");
 	printf("  --help, -h\t\t\t\tShow this help.\n");
 	printf("  --version, -v\t\t\t\tDisplay the software version.\n");
@@ -93,6 +98,7 @@ void process_cli(int argc, char **argv)
 			show_version();
 			break;
 		case -1:
+		case 0:
 			break;
 		default:
 			show_help();

espeak.c

@@ -22,6 +22,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <alsa/asoundlib.h>
+#include <math.h>
 
 #include "espeakup.h"
 
@@ -32,6 +34,7 @@ const int defaultRange = 5;
 const int defaultRate = 2;
 const int defaultVolume = 5;
 char *defaultVoice = NULL;
+int alsaVolume = 0;
 
 /* multipliers and offsets */
 const int frequencyMultiplier = 11;
@@ -152,6 +155,86 @@ static espeak_ERROR set_voice(struct synth_t *s, char *voice)
 	return rc;
 }
 
+static void set_alsa_volume(int vol)
+{
+	snd_mixer_t *m;
+	snd_mixer_elem_t *e;
+	int err;
+
+	err = snd_mixer_open(&m, 0);
+	if (err < 0)
+	{
+		fprintf(stderr, "ALSA mixer open error: %s\n", snd_strerror(err));
+		return;
+	}
+
+	err = snd_mixer_attach(m, "default");
+	if (err < 0)
+	{
+		fprintf(stderr, "ALSA mixer attach error: %s\n", snd_strerror(err));
+		return;
+	}
+	err = snd_mixer_selem_register(m, NULL, NULL);
+	if (err < 0)
+	{
+		fprintf(stderr, "ALSA mixer load error: %s\n", snd_strerror(err));
+		return;
+	}
+	err = snd_mixer_load(m);
+	if (err < 0)
+	{
+		fprintf(stderr, "ALSA mixer load error: %s\n", snd_strerror(err));
+		return;
+	}
+
+	/* Turn vol value to volume %.
+	 * We do not want to soften that much with ALSA, espeak is already
+	 * doing it. We want the default value (5) to be the usual default
+	 * volume (80%), and make higher values increase ALSA volume, up to
+	 * 100%. */
+
+	int volume = (vol+1) * 50 / 10 + 50;
+
+	for (e = snd_mixer_first_elem(m); e; e = snd_mixer_elem_next(e))
+	{
+		if (snd_mixer_elem_get_type(e) != SND_MIXER_ELEM_SIMPLE)
+			continue;
+		if (snd_mixer_selem_is_enumerated(e))
+			continue;
+
+		if (snd_mixer_selem_has_playback_switch(e)) {
+			snd_mixer_selem_set_playback_switch_all(e, 1);
+		}
+
+		if (snd_mixer_selem_has_playback_volume(e)) {
+			long min, max, set;
+
+			err = snd_mixer_selem_get_playback_dB_range(e, &min, &max);
+			if (err == 0 && min < max) {
+				if (max - min < 2400) {
+					/* 24dB amplitude is too small for using a logscale */
+					set = min + volume * (max-min) / 100;
+				} else {
+					/* Use a logscale */
+					double volf = volume / 100.;
+					if (min != SND_CTL_TLV_DB_GAIN_MUTE)
+					{
+						double minf = pow(10, (min-max) / 6000.);
+						volf = volf * (1 - minf) + minf;
+					}
+					set = 6000. * log10(volf) + max;
+				}
+				snd_mixer_selem_set_playback_dB_all(e, set, 0);
+			} else {
+				/* No dB setting, try a linear scale */
+				snd_mixer_selem_get_playback_volume_range(e, &min, &max);
+				set = min + volume * (max-min) / 100;
+				snd_mixer_selem_set_playback_volume_all(e, set);
+			}
+		}
+	}
+}
+
 static espeak_ERROR set_volume(struct synth_t *s, int vol,
 							   enum adjust_t adj)
 {
@@ -164,7 +247,11 @@ static espeak_ERROR set_volume(struct synth_t *s, int vol,
 	rc = espeak_SetParameter(espeakVOLUME, (vol + 1) * volumeMultiplier,
 							 0);
 	if (rc == EE_OK)
+	{
 		s->volume = vol;
+		if (alsaVolume)
+			set_alsa_volume(vol);
+	}
 
 	return rc;
 }