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. 4 5 #ifndef REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_ 6 #define REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_ 7 8 #include "base/files/file.h" 9 #include "base/files/file_path.h" 10 #include "base/files/file_path_watcher.h" 11 #include "base/memory/ref_counted.h" 12 #include "base/memory/ref_counted_memory.h" 13 #include "base/message_loop/message_loop.h" 14 #include "base/observer_list_threadsafe.h" 15 #include "base/time/time.h" 16 #include "base/timer/timer.h" 17 #include "remoting/proto/audio.pb.h" 18 19 namespace remoting { 20 21 struct AudioPipeReaderTraits; 22 23 // AudioPipeReader class reads from a named pipe to which an audio server (e.g. 24 // pulseaudio) writes the sound that's being played back and then sends data to 25 // all registered observers. 26 class AudioPipeReader 27 : public base::RefCountedThreadSafe<AudioPipeReader, AudioPipeReaderTraits>, 28 public base::MessageLoopForIO::Watcher { 29 public: 30 // PulseAudio's module-pipe-sink must be configured to use the following 31 // parameters for the sink we read from. 32 static const AudioPacket_SamplingRate kSamplingRate = 33 AudioPacket::SAMPLING_RATE_48000; 34 static const AudioPacket_BytesPerSample kBytesPerSample = 35 AudioPacket::BYTES_PER_SAMPLE_2; 36 static const AudioPacket_Channels kChannels = AudioPacket::CHANNELS_STEREO; 37 38 class StreamObserver { 39 public: 40 virtual void OnDataRead(scoped_refptr<base::RefCountedString> data) = 0; 41 }; 42 43 // |task_runner| specifies the IO thread to use to read data from the pipe. 44 static scoped_refptr<AudioPipeReader> Create( 45 scoped_refptr<base::SingleThreadTaskRunner> task_runner, 46 const base::FilePath& pipe_path); 47 48 // Register or unregister an observer. Each observer receives data on the 49 // thread on which it was registered and guaranteed not to be called after 50 // RemoveObserver(). 51 void AddObserver(StreamObserver* observer); 52 void RemoveObserver(StreamObserver* observer); 53 54 // MessageLoopForIO::Watcher interface. 55 virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE; 56 virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE; 57 58 private: 59 friend class base::DeleteHelper<AudioPipeReader>; 60 friend class base::RefCountedThreadSafe<AudioPipeReader>; 61 friend struct AudioPipeReaderTraits; 62 63 AudioPipeReader(scoped_refptr<base::SingleThreadTaskRunner> task_runner, 64 const base::FilePath& pipe_path); 65 virtual ~AudioPipeReader(); 66 67 void StartOnAudioThread(); 68 void OnDirectoryChanged(const base::FilePath& path, bool error); 69 void TryOpenPipe(); 70 void StartTimer(); 71 void DoCapture(); 72 void WaitForPipeReadable(); 73 74 scoped_refptr<base::SingleThreadTaskRunner> task_runner_; 75 base::FilePath pipe_path_; 76 77 // Watcher for the directory that contains audio pipe we are reading from, to 78 // monitor when pulseaudio creates or deletes it. 79 base::FilePathWatcher file_watcher_; 80 81 base::File pipe_; 82 base::RepeatingTimer<AudioPipeReader> timer_; 83 scoped_refptr<ObserverListThreadSafe<StreamObserver> > observers_; 84 85 // Time when capturing was started. 86 base::TimeTicks started_time_; 87 88 // Stream position of the last capture in bytes with zero position 89 // corresponding to |started_time_|. Must always be a multiple of the sample 90 // size. 91 int64 last_capture_position_; 92 93 // Bytes left from the previous read. 94 std::string left_over_bytes_; 95 96 base::MessageLoopForIO::FileDescriptorWatcher file_descriptor_watcher_; 97 98 DISALLOW_COPY_AND_ASSIGN(AudioPipeReader); 99 }; 100 101 // Destroys |audio_pipe_reader| on the audio thread. 102 struct AudioPipeReaderTraits { 103 static void Destruct(const AudioPipeReader* audio_pipe_reader); 104 }; 105 106 } // namespace remoting 107 108 #endif // REMOTING_HOST_LINUX_AUDIO_PIPE_READER_H_ 109
