diff options
Diffstat (limited to 'src/modules/audio_processing/utility/delay_estimator.h')
| -rw-r--r-- | src/modules/audio_processing/utility/delay_estimator.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/modules/audio_processing/utility/delay_estimator.h b/src/modules/audio_processing/utility/delay_estimator.h new file mode 100644 index 0000000000..a376dfeb61 --- /dev/null +++ b/src/modules/audio_processing/utility/delay_estimator.h @@ -0,0 +1,128 @@ +/* + * Copyright (c) 2011 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. + */ + +// Performs delay estimation on binary converted spectra. +// The return value is 0 - OK and -1 - Error, unless otherwise stated. + +#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_DELAY_ESTIMATOR_H_ +#define WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_DELAY_ESTIMATOR_H_ + +#include "typedefs.h" + +typedef struct { + // Pointer to bit counts. + int32_t* mean_bit_counts; + int* far_bit_counts; + + // Array only used locally in ProcessBinarySpectrum() but whose size is + // determined at run-time. + int32_t* bit_counts; + + // Binary history variables. + uint32_t* binary_far_history; + uint32_t* binary_near_history; + + // Delay estimation variables. + int32_t minimum_probability; + int last_delay_probability; + + // Delay memory. + int last_delay; + + // Buffer size. + int history_size; + + // Near-end buffer size. + int near_history_size; +} BinaryDelayEstimator; + +// Releases the memory allocated by WebRtc_CreateBinaryDelayEstimator(...). +// Input: +// - handle : Pointer to the delay estimation instance. +// +int WebRtc_FreeBinaryDelayEstimator(BinaryDelayEstimator* handle); + +// Refer to WebRtc_CreateDelayEstimator() in delay_estimator_wrapper.h. +int WebRtc_CreateBinaryDelayEstimator(BinaryDelayEstimator** handle, + int max_delay, + int lookahead); + +// Initializes the delay estimation instance created with +// WebRtc_CreateBinaryDelayEstimator(...). +// Input: +// - handle : Pointer to the delay estimation instance. +// +// Output: +// - handle : Initialized instance. +// +int WebRtc_InitBinaryDelayEstimator(BinaryDelayEstimator* handle); + +// Estimates and returns the delay between the binary far-end and binary near- +// end spectra. The value will be offset by the lookahead (i.e. the lookahead +// should be subtracted from the returned value). +// Inputs: +// - handle : Pointer to the delay estimation instance. +// - binary_far_spectrum : Far-end binary spectrum. +// - binary_near_spectrum : Near-end binary spectrum of the current block. +// +// Output: +// - handle : Updated instance. +// +// Return value: +// - delay : >= 0 - Calculated delay value. +// -1 - Error. +// -2 - Insufficient data for estimation. +// +int WebRtc_ProcessBinarySpectrum(BinaryDelayEstimator* handle, + uint32_t binary_far_spectrum, + uint32_t binary_near_spectrum); + +// Returns the last calculated delay updated by the function +// WebRtc_ProcessBinarySpectrum(...). +// +// Input: +// - handle : Pointer to the delay estimation instance. +// +// Return value: +// - delay : >= 0 - Last calculated delay value +// -1 - Error +// -2 - Insufficient data for estimation. +// +int WebRtc_binary_last_delay(BinaryDelayEstimator* handle); + +// Returns the history size used in the far-end buffers to calculate the delay +// over. +// +// Input: +// - handle : Pointer to the delay estimation instance. +// +// Return value: +// - history_size : > 0 - Far-end history size. +// -1 - Error. +// +int WebRtc_history_size(BinaryDelayEstimator* handle); + +// Updates the |mean_value| recursively with a step size of 2^-|factor|. This +// function is used internally in the Binary Delay Estimator as well as the +// Fixed point wrapper. +// +// Inputs: +// - new_value : The new value the mean should be updated with. +// - factor : The step size, in number of right shifts. +// +// Input/Output: +// - mean_value : Pointer to the mean value. +// +void WebRtc_MeanEstimatorFix(int32_t new_value, + int factor, + int32_t* mean_value); + + +#endif // WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_DELAY_ESTIMATOR_H_ |