services/audiopolicy/common/include/policy.h

/*
 * 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>

static const audio_format_t gDynamicFormat = AUDIO_FORMAT_DEFAULT;

// For mixed output and inputs, the policy will use max mixer sampling rates.
// Do not limit sampling rate otherwise
#define SAMPLE_RATE_HZ_MAX 192000

// Used when a client opens a capture stream, without specifying a desired sample rate.
#define SAMPLE_RATE_HZ_DEFAULT 48000

// For mixed output and inputs, the policy will use max mixer channel count.
// Do not limit channel count otherwise
#define MAX_MIXER_CHANNEL_COUNT FCC_8

/**
 * A device mask for all audio input devices that are considered "virtual" when evaluating
 * active inputs in getActiveInputs()
 */
#define APM_AUDIO_IN_DEVICE_VIRTUAL_ALL  (AUDIO_DEVICE_IN_REMOTE_SUBMIX)


/**
 * A device mask for all audio input and output devices where matching inputs/outputs on device
 * type alone is not enough: the address must match too
 */
#define APM_AUDIO_DEVICE_OUT_MATCH_ADDRESS_ALL (AUDIO_DEVICE_OUT_REMOTE_SUBMIX|AUDIO_DEVICE_OUT_BUS)

#define APM_AUDIO_DEVICE_IN_MATCH_ADDRESS_ALL (AUDIO_DEVICE_IN_REMOTE_SUBMIX|AUDIO_DEVICE_IN_BUS)

/**
 * Stub audio output device. Used in policy configuration file on platforms without audio outputs.
 * This alias value to AUDIO_DEVICE_OUT_DEFAULT is only used in the audio policy context.
 */
#define AUDIO_DEVICE_OUT_STUB AUDIO_DEVICE_OUT_DEFAULT
/**
 * Stub audio input device. Used in policy configuration file on platforms without audio inputs.
 * This alias value to AUDIO_DEVICE_IN_DEFAULT is only used in the audio policy context.
 */
#define AUDIO_DEVICE_IN_STUB AUDIO_DEVICE_IN_DEFAULT
/**
 * Alias to AUDIO_DEVICE_OUT_DEFAULT defined for clarification when this value is used by volume
 * control APIs (e.g setStreamVolumeIndex().
 */
#define AUDIO_DEVICE_OUT_DEFAULT_FOR_VOLUME AUDIO_DEVICE_OUT_DEFAULT


/**
 * Check if the state given correspond to an in call state.
 * @TODO find a better name for widely call state
 *
 * @param[in] state to consider
 *
 * @return true if given state represents a device in a telephony or VoIP call
 */
static inline bool is_state_in_call(int state)
{
    return (state == AUDIO_MODE_IN_CALL) || (state == AUDIO_MODE_IN_COMMUNICATION);
}

/**
 * Check if the input device given is considered as a virtual device.
 *
 * @param[in] device to consider
 *
 * @return true if the device is a virtual one, false otherwise.
 */
static inline bool is_virtual_input_device(audio_devices_t device)
{
    if ((device & AUDIO_DEVICE_BIT_IN) != 0) {
        device &= ~AUDIO_DEVICE_BIT_IN;
        if ((popcount(device) == 1) && ((device & ~APM_AUDIO_IN_DEVICE_VIRTUAL_ALL) == 0))
            return true;
    }
    return false;
}

/**
 * Check whether the device type is one
 * where addresses are used to distinguish between one connected device and another
 *
 * @param[in] device to consider
 *
 * @return true if the device needs distinguish on address, false otherwise..
 */
static inline bool device_distinguishes_on_address(audio_devices_t device)
{
    return (((device & AUDIO_DEVICE_BIT_IN) != 0) &&
            ((~AUDIO_DEVICE_BIT_IN & device & APM_AUDIO_DEVICE_IN_MATCH_ADDRESS_ALL) != 0)) ||
           (((device & AUDIO_DEVICE_BIT_IN) == 0) &&
            ((device & APM_AUDIO_DEVICE_OUT_MATCH_ADDRESS_ALL) != 0));
}

/**
 * Returns the priority of a given audio source for capture. The priority is used when more than one
 * capture session is active on a given input stream to determine which session drives routing and
 * effect configuration.
 *
 * @param[in] inputSource to consider. Valid sources are:
 * - AUDIO_SOURCE_VOICE_COMMUNICATION
 * - AUDIO_SOURCE_CAMCORDER
 * - AUDIO_SOURCE_MIC
 * - AUDIO_SOURCE_FM_TUNER
 * - AUDIO_SOURCE_VOICE_RECOGNITION
 * - AUDIO_SOURCE_HOTWORD
 *
 * @return the corresponding input source priority or 0 if priority is irrelevant for this source.
 *      This happens when the specified source cannot share a given input stream (e.g remote submix)
 *      The higher the value, the higher the priority.
 */
static inline int32_t source_priority(audio_source_t inputSource)
{
    switch (inputSource) {
    case AUDIO_SOURCE_VOICE_COMMUNICATION:
        return 6;
    case AUDIO_SOURCE_CAMCORDER:
        return 5;
    case AUDIO_SOURCE_MIC:
        return 4;
    case AUDIO_SOURCE_FM_TUNER:
        return 3;
    case AUDIO_SOURCE_VOICE_RECOGNITION:
        return 2;
    case AUDIO_SOURCE_HOTWORD:
        return 1;
    default:
        break;
    }
    return 0;
}

/* Indicates if audio formats are equivalent when considering a match between
 * audio HAL supported formats and client requested formats
 */
static inline bool audio_formats_match(audio_format_t format1,
                                       audio_format_t format2)
{
    if (audio_is_linear_pcm(format1) &&
            (audio_bytes_per_sample(format1) > 2) &&
            audio_is_linear_pcm(format2) &&
            (audio_bytes_per_sample(format2) > 2)) {
        return true;
    }
    return format1 == format2;
}