[Chromecast] Add new volume control API to CastMediaShlib

chromecast/public/media/media_pipeline_device_params.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMECAST_PUBLIC_MEDIA_MEDIA_PIPELINE_DEVICE_PARAMS_H_
 #define CHROMECAST_PUBLIC_MEDIA_MEDIA_PIPELINE_DEVICE_PARAMS_H_
 
 #include <string>
 
 namespace chromecast {
 class TaskRunner;
 
 namespace media {
 
+enum class AudioContentType;  // See chromecast/public/volume_control.h
+
 // Supplies creation parameters to platform-specific pipeline backend.
 struct MediaPipelineDeviceParams {
   enum MediaSyncType {
     // Default operation, synchronize playback using PTS with higher latency.
     kModeSyncPts = 0,
     // With this mode, synchronization is disabled and audio/video frames are
     // rendered "right away":
     // - for audio, frames are still rendered based on the sampling frequency
     // - for video, frames are rendered as soon as available at the output of
     //   the video decoder.
     //   The assumption is that no B frames are used when synchronization is
     //   disabled, otherwise B frames would always be skipped.
     kModeIgnorePts = 1,
     // In addition to the constraints above, also do not wait for vsync.
     kModeIgnorePtsAndVSync = 2,
   };
 
   enum AudioStreamType {
     // "Real" audio stream. If this stream underruns, all audio output may pause
     // until more real stream data is available.
     kAudioStreamNormal = 0,
     // Sound-effects audio stream. May be interrupted if a real audio stream
     // is created with a different sample rate. Underruns on an effects stream
     // do not affect output of real audio streams.
     kAudioStreamSoundEffects = 1,
   };
 
-  MediaPipelineDeviceParams(TaskRunner* task_runner_in)
+  MediaPipelineDeviceParams(TaskRunner* task_runner_in,
+                            AudioContentType content_type_in,
+                            const std::string& device_id_in)
       : sync_type(kModeSyncPts),
         audio_type(kAudioStreamNormal),
-        task_runner(task_runner_in) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   MediaPipelineDeviceParams(MediaSyncType sync_type_in,
-                            TaskRunner* task_runner_in)
+                            TaskRunner* task_runner_in,
+                            AudioContentType content_type_in,
+                            const std::string& device_id_in)
       : sync_type(sync_type_in),
         audio_type(kAudioStreamNormal),
-        task_runner(task_runner_in) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   MediaPipelineDeviceParams(MediaSyncType sync_type_in,
                             AudioStreamType audio_type_in,
-                            TaskRunner* task_runner_in)
+                            TaskRunner* task_runner_in,
+                            AudioContentType content_type_in,
+                            const std::string& device_id_in)
       : sync_type(sync_type_in),
         audio_type(audio_type_in),
-        task_runner(task_runner_in) {}
-
-  // |device_id_in| should be from media/audio/audio_device_description.h or
-  // chromecast/media/base/audio_device_ids.h
-  MediaPipelineDeviceParams(MediaSyncType sync_type_in,
-                            AudioStreamType audio_type_in,
-                            const std::string& device_id_in,
-                            TaskRunner* task_runner_in)
-      : sync_type(sync_type_in),
-        audio_type(audio_type_in),
-        device_id(device_id_in),
-        task_runner(task_runner_in) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   const MediaSyncType sync_type;
   const AudioStreamType audio_type;
-  const std::string device_id;
 
   // task_runner allows backend implementations to post tasks to the media
   // thread.  Since all calls from cast_shell into the backend are made on
   // the media thread, this may simplify thread management and safety for
   // some backends.
   TaskRunner* const task_runner;
+
+  // Identifies the content type for volume control.
+  const AudioContentType content_type;
+  const std::string device_id;
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_MEDIA_PIPELINE_DEVICE_PARAMS_H_