PandoraServer: update a2dp.proto

// Copyright 2022 Google LLC

//

// 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

//

//     https://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.

syntax = "proto3";

option java_outer_classname = "A2dpProto";

package pandora;

import "pandora/host.proto";

// Service to trigger A2DP (Advanced Audio Distribution Profile) procedures.

//

// Requirements for the implementor:

// - Streams must not be automatically opened, even if discovered.

// - The `Host` service must be implemented

//

// References:

// - [A2DP] Bluetooth SIG, Specification of the Bluetooth System,

//    Advanced Audio Distribution, Version 1.3 or Later

// - [AVDTP] Bluetooth SIG, Specification of the Bluetooth System,

//    Audio/Video Distribution Transport Protocol, Version 1.3 or Later

service A2DP {

  // Open a stream from a local **Source** endpoint to a remote **Sink**

  // endpoint.

  //

  // The returned source should be in the AVDTP_OPEN state (see [AVDTP] 9.1).

  // The rpc must block until the stream has reached this state.

  //

  // A cancellation of this call must result in aborting the current

  // AVDTP procedure (see [AVDTP] 9.9).

  rpc OpenSource(OpenSourceRequest) returns (OpenSourceResponse);

  // Open a stream from a local **Sink** endpoint to a remote **Source**

  // endpoint.

  //

  // The returned sink must be in the AVDTP_OPEN state (see [AVDTP] 9.1).

  // The rpc must block until the stream has reached this state.

  //

  // A cancellation of this call must result in aborting the current

  // AVDTP procedure (see [AVDTP] 9.9).

  rpc OpenSink(OpenSinkRequest) returns (OpenSinkResponse);

  // Wait for a stream from a local **Source** endpoint to

  // a remote **Sink** endpoint to open.

  //

  // The returned source should be in the AVDTP_OPEN state (see [AVDTP] 9.1).

  // The rpc must block until the stream has reached this state.

  //

  // If the peer has opened a source prior to this call, the server will

  // return it. The server must return the same source only once.

  rpc WaitSource(WaitSourceRequest) returns (WaitSourceResponse);

  // Wait for a stream from a local **Sink** endpoint to

  // a remote **Source** endpoint to open.

  //

  // The returned sink should be in the AVDTP_OPEN state (see [AVDTP] 9.1).

  // The rpc must block until the stream has reached this state.

  //

  // If the peer has opened a sink prior to this call, the server will

  // return it. The server must return the same sink only once.

  rpc WaitSink(WaitSinkRequest) returns (WaitSinkResponse);

  // Get if the stream is suspended

  rpc IsSuspended(IsSuspendedRequest) returns (IsSuspendedResponse);

  // Start a suspended stream.

  rpc Start(StartRequest) returns (StartResponse);

  // Suspend a started stream.

  rpc Suspend(SuspendRequest) returns (SuspendResponse);

  // Close a stream, the source or sink tokens must not be reused afterwards.

  rpc Close(CloseRequest) returns (CloseResponse);

  // Get the `AudioEncoding` value of a stream

  rpc GetAudioEncoding(GetAudioEncodingRequest) returns (GetAudioEncodingResponse);

  // Playback audio by a `Source`

  rpc PlaybackAudio(stream PlaybackAudioRequest) returns (PlaybackAudioResponse);

  // Capture audio from a `Sink`

  rpc CaptureAudio(CaptureAudioRequest) returns (stream CaptureAudioResponse);

}

// Audio encoding formats.

enum AudioEncoding {

  // Interleaved stereo frames with 16-bit signed little-endian linear PCM

  // samples at 44100Hz sample rate

  PCM_S16_LE_44K1_STEREO = 0;

  // Interleaved stereo frames with 16-bit signed little-endian linear PCM

  // samples at 48000Hz sample rate

  PCM_S16_LE_48K_STEREO = 1;

}

// A Token representing a Source stream (see [A2DP] 2.2).

// It's acquired via an OpenSource on the A2DP service.

message Source {

  // Opaque value filled by the GRPC server, must not

  // be modified nor crafted.

  Connection connection = 1;

}

// A Token representing a Sink stream (see [A2DP] 2.2).

// It's acquired via an OpenSink on the A2DP service.

message Sink {

  // Opaque value filled by the GRPC server, must not

  // be modified nor crafted.

  Connection connection = 1;

}

// Request for the `OpenSource` method.

message OpenSourceRequest {

  // The connection that will open the stream.

  Connection connection = 1;

}

// Response for the `OpenSource` method.

message OpenSourceResponse {

  // Result of the `OpenSource` call:

  // - If successful: a Source

  oneof result {

    Source source = 1;

  }

}

// Request for the `OpenSink` method.

message OpenSinkRequest {

  // The connection that will open the stream.

  Connection connection = 1;

}

// Response for the `OpenSink` method.

message OpenSinkResponse {

  // Result of the `OpenSink` call:

  // - If successful: a Sink

  oneof result {

    Sink sink = 1;

  }

}

// Request for the `WaitSource` method.

message WaitSourceRequest {

  // The connection that is awaiting the stream.

  Connection connection = 1;

}

// Response for the `WaitSource` method.

message WaitSourceResponse {

  // Result of the `WaitSource` call:

  // - If successful: a Source

  oneof result {

    Source source = 1;

  }

}

// Request for the `WaitSink` method.

message WaitSinkRequest {

  // The connection that is awaiting the stream.

  Connection connection = 1;

}

// Response for the `WaitSink` method.

message WaitSinkResponse {

  // Result of the `WaitSink` call:

  // - If successful: a Sink

  oneof result {

    Sink sink = 1;

  }

}

// Request for the `IsSuspended` method.

message IsSuspendedRequest {

  // The stream on which the function will check if it's suspended

  oneof target {

    Sink sink = 1;

    Source source = 2;

  }

}

// Response for the `IsSuspended` method.

message IsSuspendedResponse {

  bool is_suspended = 1;

}

// Request for the `Start` method.

message StartRequest {

  // Target of the start, either a Sink or a Source.

  oneof target {

    Sink sink = 1;

    Source source = 2;

  }

}

// Response for the `Start` method.

message StartResponse {}

// Request for the `Suspend` method.

message SuspendRequest {

  // Target of the suspend, either a Sink or a Source.

  oneof target {

    Sink sink = 1;

    Source source = 2;

  }

}

// Response for the `Suspend` method.

message SuspendResponse {}

// Request for the `Close` method.

message CloseRequest {

  // Target of the close, either a Sink or a Source.

  oneof target {

    Sink sink = 1;

    Source source = 2;

  }

}

// Response for the `Close` method.

message CloseResponse {}

// Request for the `GetAudioEncoding` method.

message GetAudioEncodingRequest {

  // The stream on which the function will read the `AudioEncoding`.

  oneof target {

    Sink sink = 1;

    Source source = 2;

  }

}

// Response for the `GetAudioEncoding` method.

message GetAudioEncodingResponse {

  // Audio encoding of the stream.

  AudioEncoding encoding = 1;

}

// Request for the `PlaybackAudio` method.

message PlaybackAudioRequest {

  // Source that will playback audio.

  Source source = 1;

  // Audio data to playback.

  // The audio data must be encoded in the specified `AudioEncoding` value

  // obtained in response of a `GetAudioEncoding` method call.

  bytes data = 2;

}

// Response for the `PlaybackAudio` method.

message PlaybackAudioResponse {}

// Request for the `CaptureAudio` method.

message CaptureAudioRequest {

  // Sink that will capture audio

  Sink sink = 1;

}

// Response for the `CaptureAudio` method.

message CaptureAudioResponse {

  // Captured audio data.

  // The audio data is encoded in the specified `AudioEncoding` value

  // obained in response of a `GetAudioEncoding` method call.

  bytes data = 1;

}