blob: 94a37150e4ee716c787b8ec4475eeb1d1dbe84e4 [file] [log] [blame]
/*
* 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 MODULES_AUDIO_CODING_NETEQ_BUFFER_LEVEL_FILTER_H_
#define MODULES_AUDIO_CODING_NETEQ_BUFFER_LEVEL_FILTER_H_
#include <stddef.h>
#include <stdint.h>
#include "rtc_base/constructor_magic.h"
namespace webrtc {
class BufferLevelFilter {
public:
BufferLevelFilter();
virtual ~BufferLevelFilter() {}
virtual void Reset();
// Updates the filter. Current buffer size is `buffer_size_samples`.
// `time_stretched_samples` is subtracted from the filtered value (thus
// bypassing the filter operation).
virtual void Update(size_t buffer_size_samples, int time_stretched_samples);
// Set the filtered buffer level to a particular value directly. This should
// only be used in case of large changes in buffer size, such as buffer
// flushes.
virtual void SetFilteredBufferLevel(int buffer_size_samples);
// The target level is used to select the appropriate filter coefficient.
virtual void SetTargetBufferLevel(int target_buffer_level_ms);
// Returns filtered current level in number of samples.
virtual int filtered_current_level() const {
// Round to nearest whole sample.
return (int64_t{filtered_current_level_} + (1 << 7)) >> 8;
}
private:
int level_factor_; // Filter factor for the buffer level filter in Q8.
int filtered_current_level_; // Filtered current buffer level in Q8.
RTC_DISALLOW_COPY_AND_ASSIGN(BufferLevelFilter);
};
} // namespace webrtc
#endif // MODULES_AUDIO_CODING_NETEQ_BUFFER_LEVEL_FILTER_H_