Re-implement audio capturing based on the AudioService API (fixes issue #2755)

include/cef_audio_handler.h

@@ -0,0 +1,111 @@
+// Copyright (c) 2019 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// The contents of this file must follow a specific format in order to
+// support the CEF translator tool. See the translator.README.txt file in the
+// tools directory for more information.
+//
+
+#ifndef CEF_INCLUDE_CEF_AUDIO_HANDLER_H_
+#define CEF_INCLUDE_CEF_AUDIO_HANDLER_H_
+#pragma once
+
+#include "include/cef_base.h"
+#include "include/cef_browser.h"
+
+///
+// Implement this interface to handle audio events.
+///
+/*--cef(source=client)--*/
+class CefAudioHandler : public virtual CefBaseRefCounted {
+ public:
+  typedef cef_channel_layout_t ChannelLayout;
+
+  ///
+  // Called on the UI thread to allow configuration of audio stream parameters.
+  // Return true to proceed with audio stream capture, or false to cancel it.
+  // All members of |params| can optionally be configured here, but they are
+  // also pre-filled with some sensible defaults.
+  ///
+  /*--cef()--*/
+  virtual bool GetAudioParameters(CefRefPtr<CefBrowser> browser,
+                                  CefAudioParameters& params) {
+    return true;
+  }
+
+  ///
+  // Called on a browser audio capture thread when the browser starts
+  // streaming audio. OnAudioSteamStopped will always be called after
+  // OnAudioStreamStarted; both methods may be called multiple times
+  // for the same browser. |params| contains the audio parameters like
+  // sample rate and channel layout. |channels| is the number of channels.
+  ///
+  /*--cef()--*/
+  virtual void OnAudioStreamStarted(CefRefPtr<CefBrowser> browser,
+                                    const CefAudioParameters& params,
+                                    int channels) = 0;
+
+  ///
+  // Called on the audio stream thread when a PCM packet is received for the
+  // stream. |data| is an array representing the raw PCM data as a floating
+  // point type, i.e. 4-byte value(s). |frames| is the number of frames in the
+  // PCM packet. |pts| is the presentation timestamp (in milliseconds since the
+  // Unix Epoch) and represents the time at which the decompressed packet should
+  // be presented to the user. Based on |frames| and the |channel_layout| value
+  // passed to OnAudioStreamStarted you can calculate the size of the |data|
+  // array in bytes.
+  ///
+  /*--cef()--*/
+  virtual void OnAudioStreamPacket(CefRefPtr<CefBrowser> browser,
+                                   const float** data,
+                                   int frames,
+                                   int64 pts) = 0;
+
+  ///
+  // Called on the UI thread when the stream has stopped. OnAudioSteamStopped
+  // will always be called after OnAudioStreamStarted; both methods may be
+  // called multiple times for the same stream.
+  ///
+  /*--cef()--*/
+  virtual void OnAudioStreamStopped(CefRefPtr<CefBrowser> browser) = 0;
+
+  ///
+  // Called on the UI or audio stream thread when an error occurred. During the
+  // stream creation phase this callback will be called on the UI thread while
+  // in the capturing phase it will be called on the audio stream thread. The
+  // stream will be stopped immediately.
+  ///
+  /*--cef()--*/
+  virtual void OnAudioStreamError(CefRefPtr<CefBrowser> browser,
+                                  const CefString& message) = 0;
+};
+
+#endif  // CEF_INCLUDE_CEF_AUDIO_HANDLER_H_