Add QP stats to the statsview in AppRTCMobile for ios.

webrtc/examples/objc/AppRTCMobile/ARDStatsBuilder.m

 /*
  *  Copyright 2015 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.
  */
 
@@ skipping 23 matching lines @@
   NSString *_videoEncodeMs;
   NSString *_videoInputFps;
   NSString *_videoInputHeight;
   NSString *_videoInputWidth;
   NSString *_videoSendCodec;
   NSString *_videoSendBitrate;
   NSString *_videoSendFps;
   NSString *_videoSendHeight;
   NSString *_videoSendWidth;
 
+  // QP stats.
+  int _videoQPSum;
+  int _framesEncoded;
+  int _oldVideoQPSum;
+  int _oldFramesEncoded;
+
   // Video receive stats.
   NSString *_videoDecodeMs;
   NSString *_videoDecodedFps;
   NSString *_videoOutputFps;
   NSString *_videoRecvBitrate;
   NSString *_videoRecvFps;
   NSString *_videoRecvHeight;
   NSString *_videoRecvWidth;
 
   // Audio send stats.
@@ skipping 16 matching lines @@
 }
 
 - (instancetype)init {
   if (self = [super init]) {
     _audioSendBitrateTracker = [[ARDBitrateTracker alloc] init];
     _audioRecvBitrateTracker = [[ARDBitrateTracker alloc] init];
     _connSendBitrateTracker = [[ARDBitrateTracker alloc] init];
     _connRecvBitrateTracker = [[ARDBitrateTracker alloc] init];
     _videoSendBitrateTracker = [[ARDBitrateTracker alloc] init];
     _videoRecvBitrateTracker = [[ARDBitrateTracker alloc] init];
+    _videoQPSum = 0;
+    _framesEncoded = 0;
   }
   return self;
 }
 
 - (NSString *)statsString {
   NSMutableString *result = [NSMutableString string];
   NSString *systemStatsFormat = @"(cpu)%ld%%\n";
   [result appendString:[NSString stringWithFormat:systemStatsFormat,
       (long)ARDGetCpuUsagePercentage()]];
 
   // Connection stats.
   NSString *connStatsFormat = @"CN %@ms | %@->%@/%@ | (s)%@ | (r)%@\n";
   [result appendString:[NSString stringWithFormat:connStatsFormat,
       _connRtt,
       _localCandType, _remoteCandType, _transportType,
       _connSendBitrate, _connRecvBitrate]];
 
   // Video send stats.
   NSString *videoSendFormat = @"VS (input) %@x%@@%@fps | (sent) %@x%@@%@fps\n"
-                               "VS (enc) %@/%@ | (sent) %@/%@ | %@ms | %@\n";
+                               "VS (enc) %@/%@ | (sent) %@/%@ | %@ms | %@\n"
+                               "AvgQP (past %d encoded frames) = %d\n ";
+  int avgqp = [self calculateAvgQP];
+
   [result appendString:[NSString stringWithFormat:videoSendFormat,
       _videoInputWidth, _videoInputHeight, _videoInputFps,
       _videoSendWidth, _videoSendHeight, _videoSendFps,
       _actualEncBitrate, _targetEncBitrate,
       _videoSendBitrate, _availableSendBw,
       _videoEncodeMs,
-      _videoSendCodec]];
+      _videoSendCodec,
+      _framesEncoded - _oldFramesEncoded, avgqp]];
 
   // Video receive stats.
   NSString *videoReceiveFormat =
       @"VR (recv) %@x%@@%@fps | (decoded)%@ | (output)%@fps | %@/%@ | %@ms\n";
   [result appendString:[NSString stringWithFormat:videoReceiveFormat,
       _videoRecvWidth, _videoRecvHeight, _videoRecvFps,
       _videoDecodedFps,
       _videoOutputFps,
       _videoRecvBitrate, _availableRecvBw,
       _videoDecodeMs]];
@@ skipping 24 matching lines @@
     }
   } else if ([reportType isEqualToString:@"VideoBwe"]) {
     [self parseBweStatsReport:statsReport];
   } else if ([reportType isEqualToString:@"googCandidatePair"]) {
     [self parseConnectionStatsReport:statsReport];
   }
 }
 
 #pragma mark - Private
 
+- (int)calculateAvgQP {
+  int deltaFramesEncoded = _framesEncoded - _oldFramesEncoded;
+  int deltaQPSum = _videoQPSum - _oldVideoQPSum;
+
+  return deltaFramesEncoded ? deltaQPSum / deltaFramesEncoded : deltaQPSum;

[magjed_webrtc, 2016/12/16 12:33:17]

I prefer explicit comparison with 0, i.e. 'deltaFramesEncoded > 0'.

[magjed_webrtc, 2016/12/16 12:33:17]

Is deltaQPSum meaningful when deltaFramesEncoded==0?

[daniela-webrtc, 2016/12/16 13:06:19]

Valid point. What would make more sense for avgQP in that case? -1?

[magjed_webrtc, 2016/12/19 08:56:57]

0 is also fine. I think it will be 0 with the current code, but then I prefer an
explicit 0.

+}
+
 - (void)parseBweStatsReport:(RTCLegacyStatsReport *)statsReport {
   [statsReport.values enumerateKeysAndObjectsUsingBlock:^(
       NSString *key, NSString *value, BOOL *stop) {
     if ([key isEqualToString:@"googAvailableSendBandwidth"]) {
       _availableSendBw =
           [ARDBitrateTracker bitrateStringForBitrate:value.doubleValue];
     } else if ([key isEqualToString:@"googAvailableReceiveBandwidth"]) {
       _availableRecvBw =
           [ARDBitrateTracker bitrateStringForBitrate:value.doubleValue];
     } else if ([key isEqualToString:@"googActualEncBitrate"]) {
@@ skipping 73 matching lines @@
     } else if ([key isEqualToString:@"googFrameWidthSent"]) {
       _videoSendWidth = value;
     } else if ([key isEqualToString:@"googFrameRateSent"]) {
       _videoSendFps = value;
     } else if ([key isEqualToString:@"googAvgEncodeMs"]) {
       _videoEncodeMs = value;
     } else if ([key isEqualToString:@"bytesSent"]) {
       NSInteger byteCount = value.integerValue;
       [_videoSendBitrateTracker updateBitrateWithCurrentByteCount:byteCount];
       _videoSendBitrate = _videoSendBitrateTracker.bitrateString;
+    } else if ([key isEqualToString:@"qpSum"]) {
+      _oldVideoQPSum = _videoQPSum;
+      _videoQPSum = value.integerValue;
+    } else if ([key isEqualToString:@"framesEncoded"]) {
+      _oldFramesEncoded = _framesEncoded;
+      _framesEncoded = value.integerValue;
     }
   }];
 }
 
 - (void)parseRecvSsrcStatsReport:(RTCLegacyStatsReport *)statsReport {
   NSDictionary *values = statsReport.values;
   if ([values objectForKey:@"googFrameWidthReceived"]) {
     // Video track.
     [self parseVideoRecvStatsReport:statsReport];
   } else if ([values objectForKey:@"audioOutputLevel"]) {
@@ skipping 37 matching lines @@
     } else if ([key isEqualToString:@"bytesReceived"]) {
       NSInteger byteCount = value.integerValue;
       [_videoRecvBitrateTracker updateBitrateWithCurrentByteCount:byteCount];
       _videoRecvBitrate = _videoRecvBitrateTracker.bitrateString;
     }
   }];
 }
 
 @end