android_device_peter_gsi/bluetooth/audio/hw/stream_apis.h
Peter Cai c71693def3 gsi: Initial implementation of sysbta, a system-side bluetooth audio HAL
On platform release T, the legacy `audio.a2dp.default` HAL no longer
exists, and cannot be trivially restored for generic system-side A2DP
audio support. Rather than trying to cling on to its existence (which
does not even work anymore even if one did so), it is time to come up
with a new solution.

This commit introduces a system-side implementation of the generic
bluetooth audio HAL. The HAL itself is modelled after the default
bluetooth audio HAL, while substantial components of the default audio
HAL are also included as it has to also implement the audio HAL
interfaces.

The audio HAL implementation is delegated to `audio.sysbta.default`,
forked from `audio.bluetooth.default` from the Bluetooth apex package.
It then communicates with the bluetooth audio HAL interfaces, which need
to live in the same process (in this case, the process of the sysbta
HAL). This is why we cannot just load `audio.sysbta.default` into the
default audio HAL or the audioserver process directly, but rather have
to include our own simplistic audio HAL implementation.

For now, the audio HAL implementation only includes one for the 6.0
version, but technically, an interface for *every* audio HAL version
needs to exist. This, along with other messiness in the sysbta
implementation, will be addressed in a future commit.

Note that to actually make use of the sysbta audio hal, patches in
frameworks/av and packages/modules/Bluetooth are required to introduce
support for the property `persist.bluetooth.system_audio_hal.enabled`.
2022-08-24 15:47:06 -04:00

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/*
* Copyright 2019 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 <hardware/audio.h>
#include <system/audio.h>
#include <list>
#include "device_port_proxy.h"
#include "device_port_proxy_hidl.h"
constexpr unsigned int kBluetoothDefaultSampleRate = 44100;
constexpr audio_format_t kBluetoothDefaultAudioFormatBitsPerSample =
AUDIO_FORMAT_PCM_16_BIT;
constexpr unsigned int kBluetoothDefaultInputBufferMs = 20;
constexpr unsigned int kBluetoothDefaultInputStateTimeoutMs = 20;
constexpr unsigned int kBluetoothDefaultOutputBufferMs = 10;
constexpr unsigned int kBluetoothSpatializerOutputBufferMs = 10;
constexpr audio_channel_mask_t kBluetoothDefaultOutputChannelModeMask =
AUDIO_CHANNEL_OUT_STEREO;
constexpr audio_channel_mask_t kBluetoothDefaultInputChannelModeMask =
AUDIO_CHANNEL_IN_MONO;
enum class BluetoothStreamState : uint8_t {
DISABLED = 0, // This stream is closing or set param "suspend=true"
STANDBY,
STARTING,
STARTED,
SUSPENDING,
UNKNOWN,
};
std::ostream& operator<<(std::ostream& os, const BluetoothStreamState& state);
struct BluetoothStreamOut {
// Must be the first member so it can be cast from audio_stream
// or audio_stream_out pointer
audio_stream_out stream_out_{};
std::unique_ptr<::android::bluetooth::audio::BluetoothAudioPort>
bluetooth_output_;
bool is_aidl;
int64_t last_write_time_us_;
// Audio PCM Configs
uint32_t sample_rate_;
audio_channel_mask_t channel_mask_;
audio_format_t format_;
size_t preferred_data_interval_us;
// frame is the number of samples per channel
// frames count per tick
size_t frames_count_;
// total frames written, reset on standby
uint64_t frames_rendered_;
// total frames written after opened, never reset
uint64_t frames_presented_;
mutable std::mutex mutex_;
};
struct BluetoothAudioDevice {
// Important: device must be first as an audio_hw_device* may be cast to
// BluetoothAudioDevice* when the type is implicitly known.
audio_hw_device audio_device_{};
// protect against device->output and stream_out from being inconsistent
std::mutex mutex_;
std::list<BluetoothStreamOut*> opened_stream_outs_ =
std::list<BluetoothStreamOut*>(0);
};
struct BluetoothStreamIn {
// Must be the first member so it can be cast from audio_stream
// or audio_stream_in pointer
audio_stream_in stream_in_;
std::unique_ptr<::android::bluetooth::audio::BluetoothAudioPort>
bluetooth_input_;
bool is_aidl;
int64_t last_read_time_us_;
// Audio PCM Configs
uint32_t sample_rate_;
audio_channel_mask_t channel_mask_;
audio_format_t format_;
size_t preferred_data_interval_us;
// frame is the number of samples per channel
// frames count per tick
size_t frames_count_;
// total frames read after opened, never reset
uint64_t frames_presented_;
mutable std::mutex mutex_;
};
int adev_open_output_stream(struct audio_hw_device* dev,
audio_io_handle_t handle, audio_devices_t devices,
audio_output_flags_t flags,
struct audio_config* config,
struct audio_stream_out** stream_out,
const char* address __unused);
void adev_close_output_stream(struct audio_hw_device* dev,
struct audio_stream_out* stream);
size_t adev_get_input_buffer_size(const struct audio_hw_device* dev,
const struct audio_config* config);
int adev_open_input_stream(struct audio_hw_device* dev,
audio_io_handle_t handle, audio_devices_t devices,
struct audio_config* config,
struct audio_stream_in** stream_in,
audio_input_flags_t flags __unused,
const char* address __unused,
audio_source_t source __unused);
void adev_close_input_stream(struct audio_hw_device* dev,
struct audio_stream_in* in);