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_MODULES_UTILITY_INCLUDE_AUDIO_FRAME_OPERATIONS_H_ 12 #define WEBRTC_MODULES_UTILITY_INCLUDE_AUDIO_FRAME_OPERATIONS_H_ 13 14 #include "webrtc/typedefs.h" 15 16 namespace webrtc { 17 18 class 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. 23 class 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, size_t 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, size_t 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_MODULES_UTILITY_INCLUDE_AUDIO_FRAME_OPERATIONS_H_ 59