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
