| // 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_AUDIO_AUDIO_SYNC_READER_H_ |
| #define MEDIA_AUDIO_AUDIO_SYNC_READER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <memory> |
| #include <string> |
| |
| #include "base/callback.h" |
| #include "base/compiler_specific.h" |
| #include "base/macros.h" |
| #include "base/memory/shared_memory_mapping.h" |
| #include "base/memory/unsafe_shared_memory_region.h" |
| #include "base/process/process.h" |
| #include "base/sync_socket.h" |
| #include "base/time/time.h" |
| #include "build/build_config.h" |
| #include "media/audio/audio_output_controller.h" |
| #include "media/base/audio_bus.h" |
| #include "media/base/media_export.h" |
| |
| #if defined(OS_POSIX) |
| #include "base/file_descriptor_posix.h" |
| #endif |
| |
| namespace media { |
| |
| // A AudioOutputController::SyncReader implementation using SyncSocket. This |
| // is used by AudioOutputController to provide a low latency data source for |
| // transmitting audio packets between the browser process and the renderer |
| // process. |
| class MEDIA_EXPORT AudioSyncReader : public AudioOutputController::SyncReader { |
| public: |
| // Create() automatically initializes the AudioSyncReader correctly, |
| // and should be strongly preferred over calling the constructor directly! |
| AudioSyncReader( |
| base::RepeatingCallback<void(const std::string&)> log_callback, |
| const AudioParameters& params, |
| base::UnsafeSharedMemoryRegion shared_memory_region, |
| base::WritableSharedMemoryMapping shared_memory_mapping, |
| std::unique_ptr<base::CancelableSyncSocket> socket); |
| |
| ~AudioSyncReader() override; |
| |
| // Returns null on failure. |
| static std::unique_ptr<AudioSyncReader> Create( |
| base::RepeatingCallback<void(const std::string&)> log_callback, |
| const AudioParameters& params, |
| base::CancelableSyncSocket* foreign_socket); |
| |
| // Transfers shared memory region ownership to a caller. It shouldn't be |
| // called more than once. |
| base::UnsafeSharedMemoryRegion TakeSharedMemoryRegion(); |
| |
| void set_max_wait_timeout_for_test(base::TimeDelta time) { |
| maximum_wait_time_ = time; |
| } |
| |
| // AudioOutputController::SyncReader implementations. |
| void RequestMoreData(base::TimeDelta delay, |
| base::TimeTicks delay_timestamp, |
| int prior_frames_skipped) override; |
| void Read(AudioBus* dest) override; |
| void Close() override; |
| |
| private: |
| // Blocks until data is ready for reading or a timeout expires. Returns false |
| // if an error or timeout occurs. |
| bool WaitUntilDataIsReady(); |
| |
| const base::RepeatingCallback<void(const std::string&)> log_callback_; |
| |
| base::UnsafeSharedMemoryRegion shared_memory_region_; |
| base::WritableSharedMemoryMapping shared_memory_mapping_; |
| |
| // Mutes all incoming samples. This is used to prevent audible sound |
| // during automated testing. |
| const bool mute_audio_; |
| |
| // Denotes that the most recent socket error has been logged. Used to avoid |
| // log spam. |
| bool had_socket_error_; |
| |
| // Socket for transmitting audio data. |
| std::unique_ptr<base::CancelableSyncSocket> socket_; |
| |
| const uint32_t output_bus_buffer_size_; |
| |
| // Shared memory wrapper used for transferring audio data to Read() callers. |
| std::unique_ptr<AudioBus> output_bus_; |
| |
| // Track the number of times the renderer missed its real-time deadline and |
| // report a UMA stat during destruction. |
| size_t renderer_callback_count_; |
| size_t renderer_missed_callback_count_; |
| size_t trailing_renderer_missed_callback_count_; |
| |
| // The maximum amount of time to wait for data from the renderer. Calculated |
| // from the parameters given at construction. |
| base::TimeDelta maximum_wait_time_; |
| |
| // The index of the audio buffer we're expecting to be sent from the renderer; |
| // used to block with timeout for audio data. |
| uint32_t buffer_index_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AudioSyncReader); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_AUDIO_AUDIO_SYNC_READER_H_ |