New rtc dump analyzing tool in Python

tools/py_event_log_analyzer/misc.py

Index: tools/py_event_log_analyzer/misc.py
diff --git a/tools/py_event_log_analyzer/misc.py b/tools/py_event_log_analyzer/misc.py
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index 0000000000000000000000000000000000000000..cbba7c7e6de585eb59265e51dd2102c596a2aafe
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+++ b/tools/py_event_log_analyzer/misc.py
@@ -0,0 +1,66 @@
+#  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.
+
+"""Utility functions for calculating statistics.
+"""
+
+from __future__ import division
+import collections
+import sys
+
+
+def count_reordered(sequence_numbers):
+  """Returns number of indices `i` for which
+  sequence_numbers[i] >= sequence_numbers[i+1]
+  """
+  return sum(1 for (s1, s2) in zip(sequence_numbers,
+                                   sequence_numbers[1:]) if
+             s1 >= s2)
+
+
+def ssrc_normalized_size_table(data_points):
+  """Returns mapping from a SSRC to its relative occurance proportion in
+  the data.
+  """
+  d = collections.defaultdict(int)
+  for pt in data_points:
+    d[pt.ssrc] += pt.size
+  return normalize_counter(d)
+
+
+def normalize_counter(counter):
+  """Returns a normalized (i.e. divided by total to sum up to 1) version
+  of the input dictionary `counter`. Does not modify `counter`.
+
+  """
+  total = sum(counter.values())
+  return {key: counter[key] / total for key in counter}

[kwiberg-webrtc, 2016/05/31 10:41:35]

return {key: val / total for (key, val) in counter.items()}

Is simpler and might also be faster, since you don't have to do dict lookups.
(But in Python 2 you probably end up losing performance for using items instead
of iteritems.)

+
+
+def unwrap(data, mod):
+  """Returns `data` unwrapped modulo `mod`. Does not modify data.
+
+  Adds integer multiples of mod to all elements of data except the
+  first, such that all pairs of consecutive elements (a, b) satisfy
+  -mod / 2 <= b - a < mod / 2.
+
+  E.g. unwrap([0, 1, 2, 0, 1, 2, 7, 8], 3) -> [0, 1, 2, 3,
+  4, 5, 4, 5]
+
+  """
+  lst = data[:]
+  for i in range(1, len(data)):
+    lst[i] = (data[i - 1] +
+              (data[i] - data[i - 1] + mod // 2) % mod - mod // 2)
+  return lst
+
+# Python 2/3-compatible input function
+if sys.version_info[0] <= 2:
+  get_input = raw_input
+else:
+  get_input = input