1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_
6 #define CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_
11 #include "base/synchronization/lock.h"
12 #include "content/common/content_export.h"
13 #include "media/audio/audio_parameters.h"
16 class AudioHardwareConfig;
17 class AudioRendererMixer;
18 class AudioRendererMixerInput;
19 class AudioRendererSink;
24 // Manages sharing of an AudioRendererMixer among AudioRendererMixerInputs based
25 // on their AudioParameters configuration. Inputs with the same AudioParameters
26 // configuration will share a mixer while a new AudioRendererMixer will be
27 // lazily created if one with the exact AudioParameters does not exist.
29 // There should only be one instance of AudioRendererMixerManager per render
32 // TODO(dalecurtis): Right now we require AudioParameters to be an exact match
33 // when we should be able to ignore bits per channel since we're only dealing
34 // with floats. However, bits per channel is currently used to interleave the
35 // audio data by AudioOutputDevice::AudioThreadCallback::Process for consumption
36 // via the shared memory. See http://crbug.com/114700.
37 class CONTENT_EXPORT AudioRendererMixerManager {
39 // Construct an instance using the given audio hardware configuration. The
40 // provided |hardware_config| is not owned by AudioRendererMixerManager and
42 explicit AudioRendererMixerManager(
43 media::AudioHardwareConfig* hardware_config);
44 ~AudioRendererMixerManager();
46 // Creates an AudioRendererMixerInput with the proper callbacks necessary to
47 // retrieve an AudioRendererMixer instance from AudioRendererMixerManager.
48 // |source_render_view_id| refers to the RenderView containing the entity
49 // rendering the audio. Caller must ensure AudioRendererMixerManager outlives
50 // the returned input.
51 media::AudioRendererMixerInput* CreateInput(int source_render_view_id);
53 // Returns a mixer instance based on AudioParameters; an existing one if one
54 // with the provided AudioParameters exists or a new one if not.
55 media::AudioRendererMixer* GetMixer(int source_render_view_id,
56 const media::AudioParameters& params);
58 // Remove a mixer instance given a mixer if the only other reference is held
59 // by AudioRendererMixerManager. Every AudioRendererMixer owner must call
60 // this method when it's done with a mixer.
61 void RemoveMixer(int source_render_view_id,
62 const media::AudioParameters& params);
65 friend class AudioRendererMixerManagerTest;
67 // Define a key so that only those AudioRendererMixerInputs from the same
68 // RenderView and with the same AudioParameters can be mixed together.
69 typedef std::pair<int, media::AudioParameters> MixerKey;
71 // Map of MixerKey to <AudioRendererMixer, Count>. Count allows
72 // AudioRendererMixerManager to keep track explicitly (v.s. RefCounted which
73 // is implicit) of the number of outstanding AudioRendererMixers.
74 struct AudioRendererMixerReference {
75 media::AudioRendererMixer* mixer;
78 typedef std::map<MixerKey, AudioRendererMixerReference> AudioRendererMixerMap;
80 // Overrides the AudioRendererSink implementation for unit testing.
81 void SetAudioRendererSinkForTesting(media::AudioRendererSink* sink);
84 AudioRendererMixerMap mixers_;
85 base::Lock mixers_lock_;
87 // Audio hardware configuration. Used to construct output AudioParameters for
88 // each AudioRendererMixer instance.
89 media::AudioHardwareConfig* const hardware_config_;
91 media::AudioRendererSink* sink_for_testing_;
93 DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerManager);
96 } // namespace content
98 #endif // CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_