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authorFulup Ar Foll <fulup@iot.bzh>2017-10-24 22:13:32 +0200
committerFulup Ar Foll <fulup@iot.bzh>2017-10-24 22:13:32 +0200
commit6498bf70a861d18b177a622091f82ab4fadf216d (patch)
tree7853d3f2203b3218b3a07b9e1723fcde86b3aa48 /hal-volume.c
parent2fd0fa8c77dbaaf40ba0812e43b6637ff1d1d76e (diff)
Initial working version as independent repo
Diffstat (limited to 'hal-volume.c')
-rw-r--r--hal-volume.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/hal-volume.c b/hal-volume.c
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index 0000000..997ce98
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+++ b/hal-volume.c
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+/*
+ * Copyright (C) 2016 "IoT.bzh"
+ * Author Fulup Ar Foll <fulup@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * references:
+ * alsa-util/amixer.c + alsa-lib/simple.c
+ * snd_tlv_convert_from_dB
+ * nt snd_tlv_convert_to_dB
+ * snd_tlv_get_dB_range
+ */
+
+#define _GNU_SOURCE // needed for vasprintf
+#include <math.h>
+#include "hal-interface.h"
+
+typedef enum {
+ NORMALIZE_NONE = 0,
+ NORMALIZE_DB_LINEAR,
+ NORMALIZE_DB_MATH,
+ NORMALIZE_LINEAR,
+} enumRandeModeDB_T;
+
+
+// Return Value express from 0-100%
+
+STATIC int dbNormalizeVal(enumRandeModeDB_T normaliseMode, const alsaHalDBscaleT *dbscale, int value) {
+ double normalized, min_norm;
+
+ // To get real DB from TLV DB values should be divided by 100
+ switch (normaliseMode) {
+ case NORMALIZE_DB_LINEAR:
+ normalized = ((double) (value - dbscale->min) / (double) (dbscale->max - dbscale->min));
+ break;
+
+ case NORMALIZE_DB_MATH:
+ normalized = exp10((double) (value - dbscale->max) / 6000.0);
+ if (dbscale->min != SND_CTL_TLV_DB_GAIN_MUTE) {
+ min_norm = exp10((double) (dbscale->min - dbscale->max) / 20);
+ normalized = (normalized - min_norm) / (1 - min_norm);
+ }
+
+ break;
+
+ default:
+ normalized = 0;
+ }
+
+ return (int) round(normalized * 100);
+}
+
+// HAL normalise volume values to 0-100%
+
+PUBLIC json_object *volumeNormalise(ActionSetGetT action, const alsaHalCtlMapT *halCtls, json_object *valuesJ) {
+ enumRandeModeDB_T useNormalizeDB;
+ int length;
+
+ // If Integer look for DBscale
+ if (halCtls->type == SND_CTL_ELEM_TYPE_INTEGER) {
+
+ // If not valid db_scale let's use raw_scale
+ if (!halCtls->dbscale || (halCtls->dbscale->min >= halCtls->dbscale->max)) {
+
+ // dbscale is invalid let's try raw range
+ if (halCtls->minval >= halCtls->maxval) goto ExitOnError;
+
+ // Use Raw Scale Model
+ useNormalizeDB = NORMALIZE_LINEAR;
+
+ } else { // db_scale looks OK let's use it
+ if ((halCtls->dbscale->max - halCtls->dbscale->min) <= MAX_LINEAR_DB_SCALE * 100) useNormalizeDB = NORMALIZE_DB_LINEAR;
+ else useNormalizeDB = NORMALIZE_LINEAR; // Fulup not sure how to handle this useNormalizeDB=NORMALIZE_DB_MATH;
+ }
+ } else useNormalizeDB = NORMALIZE_NONE;
+
+
+ // loop on values to normalise
+ enum json_type jtype = json_object_get_type(valuesJ);
+ if (jtype == json_type_array) length = json_object_array_length(valuesJ);
+ else length = 1;
+
+ json_object *normalisedJ = json_object_new_array();
+ for (int idx = 0; idx < length; idx++) {
+ int value;
+
+ if (jtype == json_type_array) {
+ json_object *valueJ = json_object_array_get_idx(valuesJ, idx);
+ value = json_object_get_int(valueJ);
+ } else {
+ value = json_object_get_int(valuesJ);
+ }
+
+ // If Integer scale to 0/100
+ if (halCtls->type == SND_CTL_ELEM_TYPE_INTEGER) {
+
+ switch (action) {
+
+ case ACTION_GET:
+ switch (useNormalizeDB) {
+ case NORMALIZE_LINEAR:
+ value = 100 * (value - halCtls->minval) / (halCtls->maxval - halCtls->minval);
+ break;
+ case NORMALIZE_DB_MATH: //ToBeDone
+ value = dbNormalizeVal(useNormalizeDB, halCtls->dbscale, value);
+ break;
+ case NORMALIZE_NONE:
+ default:
+ value = value;
+ }
+ break;
+
+ case ACTION_SET:
+ switch (useNormalizeDB) {
+ case NORMALIZE_LINEAR:
+ value = (value * (halCtls->maxval - halCtls->minval)) / 100;
+ break;
+ case NORMALIZE_DB_MATH: //ToBeDone
+ value = dbNormalizeVal(useNormalizeDB, halCtls->dbscale, value);
+ break;
+ case NORMALIZE_NONE:
+ default:
+ value = value;
+ }
+ break;
+
+ default:
+ AFB_NOTICE("volumeNormalise: invalid action value=%d", (int) action);
+ goto ExitOnError;
+ }
+ }
+
+ json_object_array_add(normalisedJ, json_object_new_int(value));
+ }
+
+ return (normalisedJ);
+
+ExitOnError:
+ return NULL;
+}