Audio output debug recording.

content/browser/renderer_host/media/audio_debug_file_writer.h

 // Copyright 2015 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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_DEBUG_FILE_WRITER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_DEBUG_FILE_WRITER_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/files/file.h"
 #include "base/macros.h"
 #include "base/sequence_checker.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/browser_thread.h"
 #include "media/audio/audio_file_writer.h"
 #include "media/base/audio_parameters.h"
 
 namespace media {
 
 class AudioBus;
 
 }  // namespace media
 
 namespace content {
 
-// Writes audio input data used for debugging purposes. All operations are
-// non-blocking.
+// Writes audio data to a 16 bit PCM WAVE file used for debugging purposes. All
+// operations are non-blocking.
 class CONTENT_EXPORT AudioDebugFileWriter
     : public NON_EXPORTED_BASE(media::AudioFileWriter) {
  public:
   explicit AudioDebugFileWriter(const media::AudioParameters& params);
   ~AudioDebugFileWriter() override;
 
+  // Number of channels and sample rate are used from |params|, the other
+  // parameters are ignored. The number of channels in the data passed to
+  // Write() must match |params|.
+  static std::unique_ptr<media::AudioFileWriter> Create(
+      const media::AudioParameters& params);
+
   void Start(const base::FilePath& file) override;
   void Stop() override;
   void Write(std::unique_ptr<media::AudioBus> data) override;
   bool WillWrite() override;
+  std::string GetExtension() override;

[o1ka, 2017/02/09 13:04:02]

GetFileNameExtension() would be more descriptive.

[Henrik Grunell, 2017/02/10 09:00:56]

Agree, changed.

 
  private:
   class AudioFileWriter;
   using AudioFileWriterUniquePtr =
       std::unique_ptr<AudioFileWriter, BrowserThread::DeleteOnFileThread>;
   AudioFileWriterUniquePtr file_writer_;
   const media::AudioParameters params_;
   base::SequenceChecker client_sequence_checker_;
 };
 
 }  // namspace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_DEBUG_FILE_WRITER_H_