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/*
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef AUDIO_UTILITY_AUDIO_FRAME_OPERATIONS_H_
#define AUDIO_UTILITY_AUDIO_FRAME_OPERATIONS_H_
#include <stddef.h>
#include "typedefs.h" // NOLINT(build/include)
namespace webrtc {
class AudioFrame;
// TODO(andrew): consolidate this with utility.h and audio_frame_manipulator.h.
// Change reference parameters to pointers. Consider using a namespace rather
// than a class.
class AudioFrameOperations {
public:
// Add samples in |frame_to_add| with samples in |result_frame|
// putting the results in |results_frame|. The fields
// |vad_activity_| and |speech_type_| of the result frame are
// updated. If |result_frame| is empty (|samples_per_channel_|==0),
// the samples in |frame_to_add| are added to it. The number of
// channels and number of samples per channel must match except when
// |result_frame| is empty.
static void Add(const AudioFrame& frame_to_add, AudioFrame* result_frame);
// Upmixes mono |src_audio| to stereo |dst_audio|. This is an out-of-place
// operation, meaning src_audio and dst_audio must point to different
// buffers. It is the caller's responsibility to ensure that |dst_audio| is
// sufficiently large.
static void MonoToStereo(const int16_t* src_audio,
size_t samples_per_channel,
int16_t* dst_audio);
// |frame.num_channels_| will be updated. This version checks for sufficient
// buffer size and that |num_channels_| is mono.
static int MonoToStereo(AudioFrame* frame);
// Downmixes stereo |src_audio| to mono |dst_audio|. This is an in-place
// operation, meaning |src_audio| and |dst_audio| may point to the same
// buffer.
static void StereoToMono(const int16_t* src_audio,
size_t samples_per_channel,
int16_t* dst_audio);
// |frame.num_channels_| will be updated. This version checks that
// |num_channels_| is stereo.
static int StereoToMono(AudioFrame* frame);
// Downmixes 4 channels |src_audio| to stereo |dst_audio|. This is an in-place
// operation, meaning |src_audio| and |dst_audio| may point to the same
// buffer.
static void QuadToStereo(const int16_t* src_audio,
size_t samples_per_channel,
int16_t* dst_audio);
// |frame.num_channels_| will be updated. This version checks that
// |num_channels_| is 4 channels.
static int QuadToStereo(AudioFrame* frame);
// Downmixes 4 channels |src_audio| to mono |dst_audio|. This is an in-place
// operation, meaning |src_audio| and |dst_audio| may point to the same
// buffer.
static void QuadToMono(const int16_t* src_audio,
size_t samples_per_channel,
int16_t* dst_audio);
// |frame.num_channels_| will be updated. This version checks that
// |num_channels_| is 4 channels.
static int QuadToMono(AudioFrame* frame);
// Downmixes |src_channels| |src_audio| to |dst_channels| |dst_audio|.
// This is an in-place operation, meaning |src_audio| and |dst_audio|
// may point to the same buffer. Supported channel combinations are
// Stereo to Mono, Quad to Mono, and Quad to Stereo.
static void DownmixChannels(const int16_t* src_audio,
size_t src_channels,
size_t samples_per_channel,
size_t dst_channels,
int16_t* dst_audio);
// |frame.num_channels_| will be updated. This version checks that
// |num_channels_| and |dst_channels| are valid and performs relevant
// downmix. Supported channel combinations are Stereo to Mono, Quad to Mono,
// and Quad to Stereo.
static int DownmixChannels(size_t dst_channels, AudioFrame* frame);
// Swap the left and right channels of |frame|. Fails silently if |frame| is
// not stereo.
static void SwapStereoChannels(AudioFrame* frame);
// Conditionally zero out contents of |frame| for implementing audio mute:
// |previous_frame_muted| && |current_frame_muted| - Zero out whole frame.
// |previous_frame_muted| && !|current_frame_muted| - Fade-in at frame start.
// !|previous_frame_muted| && |current_frame_muted| - Fade-out at frame end.
// !|previous_frame_muted| && !|current_frame_muted| - Leave frame untouched.
static void Mute(AudioFrame* frame,
bool previous_frame_muted,
bool current_frame_muted);
// Zero out contents of frame.
static void Mute(AudioFrame* frame);
// Halve samples in |frame|.
static void ApplyHalfGain(AudioFrame* frame);
static int Scale(float left, float right, AudioFrame* frame);
static int ScaleWithSat(float scale, AudioFrame* frame);
};
} // namespace webrtc
#endif // AUDIO_UTILITY_AUDIO_FRAME_OPERATIONS_H_