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1/*
2 *  Copyright 2015 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#import "ARDBitrateTracker.h"
12
13#import <QuartzCore/QuartzCore.h>
14
15@implementation ARDBitrateTracker {
16  CFTimeInterval _prevTime;
17  NSInteger _prevByteCount;
18}
19
20@synthesize bitrate = _bitrate;
21
22+ (NSString *)bitrateStringForBitrate:(double)bitrate {
23  if (bitrate > 1e6) {
24    return [NSString stringWithFormat:@"%.2fMbps", bitrate * 1e-6];
25  } else if (bitrate > 1e3) {
26    return [NSString stringWithFormat:@"%.0fKbps", bitrate * 1e-3];
27  } else {
28    return [NSString stringWithFormat:@"%.0fbps", bitrate];
29  }
30}
31
32- (NSString *)bitrateString {
33  return [[self class] bitrateStringForBitrate:_bitrate];
34}
35
36- (void)updateBitrateWithCurrentByteCount:(NSInteger)byteCount {
37  CFTimeInterval currentTime = CACurrentMediaTime();
38  if (_prevTime && (byteCount > _prevByteCount)) {
39    _bitrate = (byteCount - _prevByteCount) * 8 / (currentTime - _prevTime);
40  }
41  _prevByteCount = byteCount;
42  _prevTime = currentTime;
43}
44
45@end
46