1/*
2 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef WEBRTC_VOICE_ENGINE_AUDIO_FRAME_OPERATIONS_H_
12#define WEBRTC_VOICE_ENGINE_AUDIO_FRAME_OPERATIONS_H_
13
14#include "webrtc/typedefs.h"
15
16namespace webrtc {
17
18class AudioFrame;
19
20// TODO(andrew): consolidate this with utility.h and audio_frame_manipulator.h.
21// Change reference parameters to pointers. Consider using a namespace rather
22// than a class.
23class AudioFrameOperations {
24 public:
25  // Upmixes mono |src_audio| to stereo |dst_audio|. This is an out-of-place
26  // operation, meaning src_audio and dst_audio must point to different
27  // buffers. It is the caller's responsibility to ensure that |dst_audio| is
28  // sufficiently large.
29  static void MonoToStereo(const int16_t* src_audio, int samples_per_channel,
30                           int16_t* dst_audio);
31  // |frame.num_channels_| will be updated. This version checks for sufficient
32  // buffer size and that |num_channels_| is mono.
33  static int MonoToStereo(AudioFrame* frame);
34
35  // Downmixes stereo |src_audio| to mono |dst_audio|. This is an in-place
36  // operation, meaning |src_audio| and |dst_audio| may point to the same
37  // buffer.
38  static void StereoToMono(const int16_t* src_audio, int samples_per_channel,
39                           int16_t* dst_audio);
40  // |frame.num_channels_| will be updated. This version checks that
41  // |num_channels_| is stereo.
42  static int StereoToMono(AudioFrame* frame);
43
44  // Swap the left and right channels of |frame|. Fails silently if |frame| is
45  // not stereo.
46  static void SwapStereoChannels(AudioFrame* frame);
47
48  // Zeros out the audio and sets |frame.energy| to zero.
49  static void Mute(AudioFrame& frame);
50
51  static int Scale(float left, float right, AudioFrame& frame);
52
53  static int ScaleWithSat(float scale, AudioFrame& frame);
54};
55
56}  // namespace webrtc
57
58#endif  // #ifndef WEBRTC_VOICE_ENGINE_AUDIO_FRAME_OPERATIONS_H_
59