Python event log analyzer tool: fix of indexing issue.

webrtc/tools/py_event_log_analyzer/rtp_analyzer.py

 #  Copyright (c) 2016 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.
 
 """Displays statistics and plots graphs from RTC protobuf dump."""
 
@@ skipping 262 matching lines @@
 
 def calculate_delay(start, stop, step, points):
   """Quantizes the time coordinates for the delay.
 
   Quantizes points by rounding the timestamps downwards to the nearest
   point in the time sequence start, start+step, start+2*step... Takes
   the average of the delays of points rounded to the same. Returns
   masked array, in which time points with no value are masked.
 
   """
-  grouped_delays = [[] for _ in numpy.arange(start, stop, step)]
+  grouped_delays = [[] for _ in numpy.arange(start, stop + step, step)]
   rounded_value_index = lambda x: int((x - start) / step)
   for point in points:
     grouped_delays[rounded_value_index(point.real_send_time_ms)
                   ].append(point.absdelay)
   regularized_delays = [numpy.average(arr) if arr else -1 for arr in
                         grouped_delays]
   return numpy.ma.masked_values(regularized_delays, -1)
 
 
 def main():
@@ skipping 37 matching lines @@
   print("Statistics:")
   rtp_stats.print_sequence_number_statistics()
   rtp_stats.estimate_frequency(options.query_sample_rate)
   rtp_stats.print_duration_statistics()
   rtp_stats.remove_reordered()
   rtp_stats.compute_bandwidth()
   rtp_stats.plot_statistics()
 
 if __name__ == "__main__":
   main()