[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;
+
 // 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)

[alokp, 2017/02/24 17:34:26]

Do we need both - content_type and device_id?

[kmackay, 2017/02/24 19:01:06]

Ben is planning to use device_id in the short term, to do separate filtering for
things that fall into the same volume control group (see his CL). The idea is
that it more closely identifies the actual stream source, but OEM's don't need
to care about it if they don't want to. Also it's nice to have in in the params
rather than passing it around as a second param everywhere.

       : 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) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   const MediaSyncType sync_type;
   const AudioStreamType audio_type;
 
   // 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;
+
+  const AudioContentType content_type;
+  const std::string device_id;
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_MEDIA_PIPELINE_DEVICE_PARAMS_H_