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# 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 CountReordered(sequence_numbers):
"""Returns number of reordered indices.
A reordered index is an index `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 SsrcNormalizedSizeTable(data_points):
"""Counts proportion of data for every SSRC.
Args:
data_points: list of pb_parse.DataPoint
Returns:
A dictionary mapping from every SSRC in the data points. The
value of an SSRC `s` is the proportion of sizes of packets with
SSRC `s` to the total size of all packets.
"""
mapping = collections.defaultdict(int)
for point in data_points:
mapping[point.ssrc] += point.size
return NormalizeCounter(mapping)
def NormalizeCounter(counter):
"""Returns a normalized version of the dictionary `counter`.
Does not modify `counter`.
Returns:
A new dictionary, in which every value in `counter`
has been divided by the total to sum up to 1.
"""
total = sum(counter.values())
return {key: counter[key] / total for key in counter}
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] = lst[i - 1] + (lst[i] - lst[i - 1] + mod // 2) % mod - (mod //
2)
return lst
def SsrcDirections(data_points):
ssrc_is_incoming = {}
for point in data_points:
ssrc_is_incoming[point.ssrc] = point.incoming
return ssrc_is_incoming
# Python 2/3-compatible input function
if sys.version_info[0] <= 2:
get_input = raw_input # pylint: disable=invalid-name
else:
get_input = input # pylint: disable=invalid-name