diff options
Diffstat (limited to 'HAL-afb/HAL-interface/hal-volmap.c')
| -rw-r--r-- | HAL-afb/HAL-interface/hal-volmap.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/HAL-afb/HAL-interface/hal-volmap.c b/HAL-afb/HAL-interface/hal-volmap.c new file mode 100644 index 0000000..de99974 --- /dev/null +++ b/HAL-afb/HAL-interface/hal-volmap.c @@ -0,0 +1,96 @@ +/* + * 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 + */ + +#define _GNU_SOURCE // needed for vasprintf +#include <math.h> +#include "hal-interface.h" + + +typedef enum { + DB_NORMALIZE_LINEAR, + DB_NORMALIZE_MATH, +} 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 DB_NORMALIZE_LINEAR: + normalized = ((double)(value-dbscale->min)/(double)(dbscale->max-dbscale->min))*100; + break; + + case DB_NORMALIZE_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) / 6000.0); + normalized = (normalized - min_norm) / (1 - min_norm); + } + break; + + default: + normalized=0; + } + + return (int)round(normalized*100); +} + +// HAL normalise volume values to 0-100% +PUBLIC struct json_object *GetNormaliseVolume(const alsaHalCtlMapT *halCtls, struct json_object *valuesJ) { + int useNormalizeDB; + + // 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= 0; + + } else { // db_scale looks OK let's use it + if ((halCtls->dbscale->max - halCtls->dbscale->min) <= MAX_LINEAR_DB_SCALE * 100) useNormalizeDB= DB_NORMALIZE_LINEAR; + else useNormalizeDB = DB_NORMALIZE_MATH; + + } + + // loop on values to normalise + int length = json_object_array_length(valuesJ); + json_object *normalisedJ= json_object_new_array(); + for (int idx=0; idx <length; idx++) { + json_object *valueJ = json_object_array_get_idx (valuesJ, idx); + int value = json_object_get_int(valueJ); + + // If Integer scale to 0/100 + if (halCtls->type == SND_CTL_ELEM_TYPE_INTEGER) { + if (useNormalizeDB) value = dbNormalizeVal (useNormalizeDB, halCtls->dbscale, value); + else value = 100* (value - halCtls->minval) / (halCtls->maxval - halCtls->minval); + } + + json_object_array_add(normalisedJ, json_object_new_int(value)); + } + + return (normalisedJ); + + ExitOnError: + return NULL; +} +
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