Audio output debug recording.

media/audio/audio_debug_recording_helper.h

+// Copyright 2017 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_DEBUG_RECORDING_HELPER_H_
+#define MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_HELPER_H_
+
+#include <memory>
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "media/audio/audio_file_writer.h"
+#include "media/base/audio_parameters.h"
+
+namespace base {
+class FilePath;
+class SingleThreadTaskRunner;
+}
+
+namespace media {
+
+class AudioBus;
+
+// Interface for feeding data to a recorder.
+class AudioDebugRecorder {
+ public:
+  virtual ~AudioDebugRecorder() {}
+
+  // If debug recording is enabled, copies audio data and makes sure it's
+  // written on the right thread. Otherwise ignores the data. Can be called on
+  // any thread.
+  virtual void OnData(const AudioBus* source) = 0;
+};
+
+// A helper class for those who want to use AudioFileWriter. It handles
+// copying AudioBus data, thread jump (MaybeWrite() can be called on any
+// thread), and creating and deleting the AudioFileWriter at enable and disable.
+class AudioDebugRecordingHelper : public AudioDebugRecorder {
+ public:
+  AudioDebugRecordingHelper(
+      const AudioParameters& params,
+      const CreateAudioFileWriterCallback& create_audio_file_writer_callback,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  ~AudioDebugRecordingHelper() override;
+
+  // Enable and disable debug recording. When enabled, |audio_manager_| is asked
+  // to create a DebugWriter. Extension "wav" will be added to |file_name|.
+  void EnableDebugRecording(const base::FilePath& file_name);
+  void DisableDebugRecording();
+
+  // Pass-through to AudioFileWriter::WillWrite(). Can be called on any thread.
+  // Must not be called after DisableDebugRecording().
+  bool WillWrite();
+
+  // AudioDebugRecorder implementation.
+  void OnData(const AudioBus* source) override;
+
+ private:
+  // Writes debug data to |debug_writer_|.
+  void DoWrite(std::unique_ptr<media::AudioBus> data);
+
+  const AudioParameters params_;
+  CreateAudioFileWriterCallback create_audio_file_writer_callback_;
+  std::unique_ptr<AudioFileWriter> debug_writer_;
+
+  // The task runner for accessing |debug_writer_|.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  base::WeakPtrFactory<AudioDebugRecordingHelper> weak_factory_;
+  DISALLOW_COPY_AND_ASSIGN(AudioDebugRecordingHelper);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_AUDIO_DEBUG_RECORDING_HELPER_H_