// Copyright (c) 2012 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 MEDIA_BASE_AUDIO_RENDERER_H_ #define MEDIA_BASE_AUDIO_RENDERER_H_ #include "base/callback.h" #include "base/time/time.h" #include "media/base/buffering_state.h" #include "media/base/media_export.h" #include "media/base/pipeline_status.h" #include "third_party/abseil-cpp/absl/types/optional.h" namespace media { class CdmContext; class DemuxerStream; class RendererClient; class TimeSource; class MEDIA_EXPORT AudioRenderer { public: AudioRenderer(); AudioRenderer(const AudioRenderer&) = delete; AudioRenderer& operator=(const AudioRenderer&) = delete; // Stop all operations and fire all pending callbacks. virtual ~AudioRenderer(); // Initialize an AudioRenderer with |stream|, executing |init_cb| upon // completion. If initialization fails, only |init_cb| // (not RendererClient::OnError) will be called. // // |cdm_context| can be used to handle encrypted streams. May be null if the // stream is not encrypted. // // AudioRenderer may be reinitialized for playback of a different demuxer // stream by calling Initialize again when the renderer is in a flushed // state (i.e. after Flush call, but before StartPlaying). This is used for // media track switching. virtual void Initialize(DemuxerStream* stream, CdmContext* cdm_context, RendererClient* client, PipelineStatusCallback init_cb) = 0; // Returns the TimeSource associated with audio rendering. virtual TimeSource* GetTimeSource() = 0; // Discard any audio data, executing |callback| when completed. // // Clients should expect |buffering_state_cb| to be called with // BUFFERING_HAVE_NOTHING while flushing is in progress. virtual void Flush(base::OnceClosure callback) = 0; // Starts playback by reading from |stream| and decoding and rendering audio. // // Only valid to call after a successful Initialize() or Flush(). virtual void StartPlaying() = 0; // Sets the output volume. virtual void SetVolume(float volume) = 0; // Set a hint indicating target latency. See comment in renderer.h. // |latency_hint| may be nullopt to indicate the hint has been cleared // (restore UA default). virtual void SetLatencyHint(absl::optional latency_hint) = 0; // Sets a flag indicating that the AudioRenderer should use or avoid pitch // preservation when playing back at speeds other than 1.0. virtual void SetPreservesPitch(bool preserves_pitch) = 0; // Sets a flag indicating whether the audio stream was played with user // activation. virtual void SetWasPlayedWithUserActivation( bool was_played_with_user_activation) = 0; }; } // namespace media #endif // MEDIA_BASE_AUDIO_RENDERER_H_