1 files changed, 137 insertions, 0 deletions
diff --git a/services/audiopolicy/common/include/Volume.h b/services/audiopolicy/common/include/Volume.h
new file mode 100755
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--- /dev/null
+++ b/services/audiopolicy/common/include/Volume.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <system/audio.h>
+#include <utils/Log.h>
+
+class VolumeCurvePoint
+{
+public:
+    int mIndex;
+    float mDBAttenuation;
+};
+
+class Volume
+{
+public:
+    /**
+     * 4 points to define the volume attenuation curve, each characterized by the volume
+     * index (from 0 to 100) at which they apply, and the attenuation in dB at that index.
+     * we use 100 steps to avoid rounding errors when computing the volume in volIndexToAmpl()
+     *
+     * @todo shall become configurable
+     */
+    enum {
+        VOLMIN = 0,
+        VOLKNEE1 = 1,
+        VOLKNEE2 = 2,
+        VOLMAX = 3,
+
+        VOLCNT = 4
+    };
+
+    /**
+     * device categories used for volume curve management.
+     */
+    enum device_category {
+        DEVICE_CATEGORY_HEADSET,
+        DEVICE_CATEGORY_SPEAKER,
+        DEVICE_CATEGORY_EARPIECE,
+        DEVICE_CATEGORY_EXT_MEDIA,
+        DEVICE_CATEGORY_CNT
+    };
+
+    /**
+     * extract one device relevant for volume control from multiple device selection
+     *
+     * @param[in] device for which the volume category is associated
+     *
+     * @return subset of device required to limit the number of volume category per device
+     */
+    static audio_devices_t getDeviceForVolume(audio_devices_t device)
+    {
+        if (device == AUDIO_DEVICE_NONE) {
+            // this happens when forcing a route update and no track is active on an output.
+            // In this case the returned category is not important.
+            device =  AUDIO_DEVICE_OUT_SPEAKER;
+        } else if (popcount(device) > 1) {
+            // Multiple device selection is either:
+            //  - speaker + one other device: give priority to speaker in this case.
+            //  - one A2DP device + another device: happens with duplicated output. In this case
+            // retain the device on the A2DP output as the other must not correspond to an active
+            // selection if not the speaker.
+            //  - HDMI-CEC system audio mode only output: give priority to available item in order.
+            if (device & AUDIO_DEVICE_OUT_SPEAKER) {
+                device = AUDIO_DEVICE_OUT_SPEAKER;
+            } else if (device & AUDIO_DEVICE_OUT_HDMI_ARC) {
+                device = AUDIO_DEVICE_OUT_HDMI_ARC;
+            } else if (device & AUDIO_DEVICE_OUT_AUX_LINE) {
+                device = AUDIO_DEVICE_OUT_AUX_LINE;
+            } else if (device & AUDIO_DEVICE_OUT_SPDIF) {
+                device = AUDIO_DEVICE_OUT_SPDIF;
+            } else {
+                device = (audio_devices_t)(device & AUDIO_DEVICE_OUT_ALL_A2DP);
+            }
+        }
+
+        /*SPEAKER_SAFE is an alias of SPEAKER for purposes of volume control*/
+        if (device == AUDIO_DEVICE_OUT_SPEAKER_SAFE)
+            device = AUDIO_DEVICE_OUT_SPEAKER;
+
+        ALOGW_IF(popcount(device) != 1,
+                 "getDeviceForVolume() invalid device combination: %08x",
+                 device);
+
+        return device;
+    }
+
+    /**
+     * returns the category the device belongs to with regard to volume curve management
+     *
+     * @param[in] device to check upon the category to whom it belongs to.
+     *
+     * @return device category.
+     */
+    static device_category getDeviceCategory(audio_devices_t device)
+    {
+        switch(getDeviceForVolume(device)) {
+        case AUDIO_DEVICE_OUT_EARPIECE:
+            return DEVICE_CATEGORY_EARPIECE;
+        case AUDIO_DEVICE_OUT_WIRED_HEADSET:
+        case AUDIO_DEVICE_OUT_WIRED_HEADPHONE:
+        case AUDIO_DEVICE_OUT_BLUETOOTH_SCO:
+        case AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET:
+        case AUDIO_DEVICE_OUT_BLUETOOTH_A2DP:
+        case AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES:
+            return DEVICE_CATEGORY_HEADSET;
+        case AUDIO_DEVICE_OUT_LINE:
+        case AUDIO_DEVICE_OUT_AUX_DIGITAL:
+            /*USB?  Remote submix?*/
+            return DEVICE_CATEGORY_EXT_MEDIA;
+        case AUDIO_DEVICE_OUT_SPEAKER:
+        case AUDIO_DEVICE_OUT_BLUETOOTH_SCO_CARKIT:
+        case AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_SPEAKER:
+        case AUDIO_DEVICE_OUT_USB_ACCESSORY:
+        case AUDIO_DEVICE_OUT_USB_DEVICE:
+        case AUDIO_DEVICE_OUT_REMOTE_SUBMIX:
+        default:
+            return DEVICE_CATEGORY_SPEAKER;
+        }
+    }
+
+};