80 lines
2.2 KiB
Python
80 lines
2.2 KiB
Python
# Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
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#
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# Use of this source code is governed by a BSD-style license
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# that can be found in the LICENSE file in the root of the source
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# tree. An additional intellectual property rights grant can be found
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# in the file PATENTS. All contributing project authors may
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# be found in the AUTHORS file in the root of the source tree.
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"""Utility functions for calculating statistics.
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"""
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from __future__ import division
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import collections
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import sys
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def count_reordered(sequence_numbers):
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"""Returns number of reordered indices.
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A reordered index is an index `i` for which sequence_numbers[i] >=
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sequence_numbers[i + 1]
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"""
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return sum(1 for (s1, s2) in zip(sequence_numbers,
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sequence_numbers[1:]) if
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s1 >= s2)
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def ssrc_normalized_size_table(data_points):
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"""Counts proportion of data for every SSRC.
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Args:
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data_points: list of pb_parse.DataPoint
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Returns:
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A dictionary mapping from every SSRC in the data points. The
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value of an SSRC `s` is the proportion of sizes of packets with
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SSRC `s` to the total size of all packets.
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"""
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mapping = collections.defaultdict(int)
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for point in data_points:
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mapping[point.ssrc] += point.size
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return normalize_counter(mapping)
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def normalize_counter(counter):
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"""Returns a normalized version of the dictionary `counter`.
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Does not modify `counter`.
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Returns:
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A new dictionary, in which every value in `counter`
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has been divided by the total to sum up to 1.
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"""
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total = sum(counter.values())
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return {key: counter[key] / total for key in counter}
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def unwrap(data, mod):
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"""Returns `data` unwrapped modulo `mod`. Does not modify data.
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Adds integer multiples of mod to all elements of data except the
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first, such that all pairs of consecutive elements (a, b) satisfy
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-mod / 2 <= b - a < mod / 2.
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E.g. unwrap([0, 1, 2, 0, 1, 2, 7, 8], 3) -> [0, 1, 2, 3,
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4, 5, 4, 5]
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"""
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lst = data[:]
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for i in range(1, len(data)):
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lst[i] = lst[i - 1] + (lst[i] - lst[i - 1] +
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mod // 2) % mod - (mod // 2)
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return lst
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# Python 2/3-compatible input function
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if sys.version_info[0] <= 2:
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get_input = raw_input
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else:
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get_input = input
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