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// Copyright (C) 2020 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.
#ifndef DEVICE_GOOGLE_ATV_AUDIO_PROXY_PUBLIC_AUDIO_PROXY_H_
#define DEVICE_GOOGLE_ATV_AUDIO_PROXY_PUBLIC_AUDIO_PROXY_H_
#include <stdint.h>
#include <sys/types.h>
#include <time.h>
#ifdef __cplusplus
extern "C" {
#endif
// audio proxy allows the application to implement an audio HAL. It contains two
// components, a client library and a service.
// The client library is defined by this header file. Applications should
// integrate this library to provide audio HAL components. Currently it's only
// IStreamOut.
// The service implements IDevicesFactory and IDevice. It will register itself
// to audio server and forward function calls to client.
// Most of the struct/functions just converts the HIDL definitions into C
// definitions.
// The following enum and typedef are subset of those defined in
// hardware/interfaces/audio/common/$VERSION/types.hal, or
// hardware/interfaces/audio/$VERSION/types.hal.
// The selected subsets are those commonly supported by a normal audio HAL. The
// library won't check the validation of these enums. In other words, Audio
// server can still pass value not defined here to the application.
// AudioFormat
enum {
AUDIO_PROXY_FORMAT_INVALID = 0xFFFFFFFFu,
AUDIO_PROXY_FORMAT_PCM_16_BIT = 0x1u,
AUDIO_PROXY_FORMAT_PCM_8_BIT = 0x2u,
AUDIO_PROXY_FORMAT_PCM_FLOAT = 0x5u,
};
typedef uint32_t audio_proxy_format_t;
// AudioChannelMask
enum {
AUDIO_PROXY_CHANNEL_INVALID = 0xC0000000u,
AUDIO_PROXY_CHANNEL_OUT_MONO = 0x1u,
AUDIO_PROXY_CHANNEL_OUT_STEREO = 0x3u,
};
typedef uint32_t audio_proxy_channel_mask_t;
// AudioDrain
enum {
AUDIO_PROXY_DRAIN_ALL,
AUDIO_PROXY_DRAIN_EARLY_NOTIFY,
};
typedef int32_t audio_proxy_drain_type_t;
// AudioOutputFlag
enum {
AUDIO_PROXY_OUTPUT_FLAG_NONE = 0x0,
AUDIO_PROXY_OUTPUT_FLAG_DIRECT = 0x1,
};
typedef int32_t audio_proxy_output_flags_t;
// AudioConfig
typedef struct {
uint32_t sample_rate;
audio_proxy_channel_mask_t channel_mask;
audio_proxy_format_t format;
uint32_t frame_count;
// Points to extra fields defined in the future versions.
void* extension;
} audio_proxy_config_t;
// Util structure for key value pair.
typedef struct {
const char* key;
const char* val;
} audio_proxy_key_val_t;
typedef void (*audio_proxy_get_parameters_callback_t)(
void*, const audio_proxy_key_val_t*);
// The following struct/functions mirror those definitions in audio HAL. They
// should have the same requirement as audio HAL interfaces, unless specified.
// IStreamOut.
struct audio_proxy_stream_out {
size_t (*get_buffer_size)(const struct audio_proxy_stream_out* stream);
uint64_t (*get_frame_count)(const struct audio_proxy_stream_out* stream);
// Gets all the sample rate supported by the stream. The list is terminated
// by 0. The returned list should have the same life cycle of |stream|.
const uint32_t* (*get_supported_sample_rates)(
const struct audio_proxy_stream_out* stream, audio_proxy_format_t format);
uint32_t (*get_sample_rate)(const struct audio_proxy_stream_out* stream);
// optional.
int (*set_sample_rate)(struct audio_proxy_stream_out* stream, uint32_t rate);
// Gets all the channel mask supported by the stream. The list is terminated
// by AUDIO_PROXY_CHANNEL_INVALID. The returned list should have the same life
// cycle of |stream|.
const audio_proxy_channel_mask_t* (*get_supported_channel_masks)(
const struct audio_proxy_stream_out* stream, audio_proxy_format_t format);
audio_proxy_channel_mask_t (*get_channel_mask)(
const struct audio_proxy_stream_out* stream);
// optional.
int (*set_channel_mask)(struct audio_proxy_stream_out* stream,
audio_proxy_channel_mask_t mask);
// Gets all the audio formats supported by the stream. The list is terminated
// by AUDIO_PROXY_FORMAT_INVALID. The returned list should have the same life
// cycle of |stream|.
const audio_proxy_format_t* (*get_supported_formats)(
const struct audio_proxy_stream_out* stream);
audio_proxy_format_t (*get_format)(
const struct audio_proxy_stream_out* stream);
// optional.
int (*set_format)(struct audio_proxy_stream_out* stream,
audio_proxy_format_t format);
uint32_t (*get_latency)(const struct audio_proxy_stream_out* stream);
int (*standby)(struct audio_proxy_stream_out* stream);
int (*pause)(struct audio_proxy_stream_out* stream);
int (*resume)(struct audio_proxy_stream_out* stream);
// optional.
int (*drain)(struct audio_proxy_stream_out* stream,
audio_proxy_drain_type_t type);
int (*flush)(struct audio_proxy_stream_out* stream);
// Writes |buffer| into |stream|. This is called on an internal thread of this
// library.
ssize_t (*write)(struct audio_proxy_stream_out* self, const void* buffer,
size_t bytes);
// optional.
int (*get_render_position)(const struct audio_proxy_stream_out* stream,
uint32_t* dsp_frames);
// optional.
int (*get_next_write_timestamp)(const struct audio_proxy_stream_out* stream,
int64_t* timestamp);
int (*get_presentation_position)(const struct audio_proxy_stream_out* stream,
uint64_t* frames,
struct timespec* timestamp);
// opional.
int (*set_volume)(struct audio_proxy_stream_out* stream, float left,
float right);
// Sets parameters on |stream|. Both |context| and |param| are terminated
// by key_val_t whose key is null. They are only valid during the function
// call.
int (*set_parameters)(struct audio_proxy_stream_out* stream,
const audio_proxy_key_val_t* context,
const audio_proxy_key_val_t* param);
// Gets parameters from |stream|.
// |context| is key val pairs array terminated by null key
// audio_proxy_key_val_t. |keys| is C string array, terminated by nullptr.
// |on_result| is the callback to deliver the result. It must be called before
// this function returns, with |obj| as the first argument, and the list of
// caller owned list of key value pairs as the second argument.
// |obj| opaque object. Implementation should not touch it.
void (*get_parameters)(const struct audio_proxy_stream_out* stream,
const audio_proxy_key_val_t* context,
const char** keys,
audio_proxy_get_parameters_callback_t on_result,
void* obj);
// optional.
int (*dump)(const struct audio_proxy_stream_out* stream, int fd);
// Pointer to the next version structure, for compatibility.
void* extension;
};
typedef struct audio_proxy_stream_out audio_proxy_stream_out_t;
// Represents an audio HAL bus device.
struct audio_proxy_device {
// Returns the unique address of this device.
const char* (*get_address)(struct audio_proxy_device* device);
// Similar to IDevice::openOutputStream.
int (*open_output_stream)(struct audio_proxy_device* device,
audio_proxy_output_flags_t flags,
audio_proxy_config_t* config,
audio_proxy_stream_out_t** stream_out);
// Close |stream|. No more methods will be called on |stream| after this.
void (*close_output_stream)(struct audio_proxy_device* device,
struct audio_proxy_stream_out* stream);
// Points to next version's struct. Implementation should set this field to
// null if next version struct is not available.
// This allows library to work with applications integrated with older version
// header.
void* extension;
};
typedef struct audio_proxy_device audio_proxy_device_t;
// Provides |device| to the library. It returns 0 on success. This function is
// supposed to be called once per process.
// The service behind this library will register a new audio HAL to the audio
// server, on the first call to the service.
int audio_proxy_register_device(audio_proxy_device_t* device);
#ifdef __cplusplus
}
#endif
#endif // DEVICE_GOOGLE_ATV_AUDIO_PROXY_PUBLIC_AUDIO_PROXY_H_