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NetEq: Convert AverageIAT from int to float calculations

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With this change, the calculations inside AverageIAT are changed to be
in double-precision floating point instead of in fixed point. Also,
the method's name is changed to EstimatedClockDriftPpm to better
reflect what it returns.

A few unit tests had to be updated because of minor numerical
differences.

Also removing the UBSan suppression related to this issue.

BUG=webrtc:5889

Review-Url: https://codereview.webrtc.org/2408653002
Cr-Commit-Position: refs/heads/master@{#14628}
This commit is contained in:
henrik.lundin
2016-10-13 03:35:55 -07:00
committed by Commit bot
parent c9ec8758db
commit 0d8385770b
6 changed files with 23 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
webrtc/modules/audio_coding/neteq/delay_manager.cc
View File

@ -319,22 +319,17 @@ void DelayManager::Reset() {
last_pack_cng_or_dtmf_ = 1;
}
int DelayManager::AverageIAT() const {
int32_t sum_q24 = 0;
// Using an int for the upper limit of the following for-loop so the
// loop-counter can be int. Otherwise we need a cast where |sum_q24| is
// updated.
const int iat_vec_size = static_cast<int>(iat_vector_.size());
assert(iat_vector_.size() == 65); // Algorithm is hard-coded for this size.
for (int i = 0; i < iat_vec_size; ++i) {
// Shift 6 to fit worst case: 2^30 * 64.
sum_q24 += (iat_vector_[i] >> 6) * i;
double DelayManager::EstimatedClockDriftPpm() const {
double sum = 0.0;
// Calculate the expected value based on the probabilities in |iat_vector_|.
for (size_t i = 0; i < iat_vector_.size(); ++i) {
sum += static_cast<double>(iat_vector_[i]) * i;
}
// Subtract the nominal inter-arrival time 1 = 2^24 in Q24.
sum_q24 -= (1 << 24);
// Multiply with 1000000 / 2^24 = 15625 / 2^18 to get in parts-per-million.
// Shift 7 to Q17 first, then multiply with 15625 and shift another 11.
return ((sum_q24 >> 7) * 15625) >> 11;
// The probabilities in |iat_vector_| are in Q30. Divide by 1 << 30 to convert
// to Q0; subtract the nominal inter-arrival time (1) to make a zero
// clockdrift represent as 0; mulitply by 1000000 to produce parts-per-million
// (ppm).
return (sum / (1 << 30) - 1) * 1e6;
}
bool DelayManager::PeakFound() const {

2
webrtc/modules/audio_coding/neteq/delay_manager.h
View File

@ -72,7 +72,7 @@ class DelayManager {
// the nominal frame time, the return value is zero. A positive value
// corresponds to packet spacing being too large, while a negative value means
// that the packets arrive with less spacing than expected.
virtual int AverageIAT() const;
virtual double EstimatedClockDriftPpm() const;
// Returns true if peak-mode is active. That is, delay peaks were observed
// recently. This method simply asks for the same information from the

2
webrtc/modules/audio_coding/neteq/mock/mock_delay_manager.h
View File

@ -35,8 +35,6 @@ class MockDelayManager : public DelayManager {
int(int length_ms));
MOCK_METHOD0(Reset,
void());
MOCK_CONST_METHOD0(AverageIAT,
int());
MOCK_CONST_METHOD0(PeakFound,
bool());
MOCK_METHOD1(UpdateCounters,

20
webrtc/modules/audio_coding/neteq/neteq_unittest.cc
View File

@ -448,10 +448,10 @@ TEST_F(NetEqDecodingTest, MAYBE_TestBitExactness) {
"52797b781758a1d2303140b80b9c5030c9093d6b");
const std::string network_stats_checksum = PlatformChecksum(
"9c5bb9e74a583be89313b158a19ea10d41bf9de6",
"e948ec65cf18852ba2a197189a3186635db34c3b",
"9c5bb9e74a583be89313b158a19ea10d41bf9de6",
"9c5bb9e74a583be89313b158a19ea10d41bf9de6");
"f59b3dfdb9b1b8bbb61abedd7c8cf3fc47c21f5f",
"c8b2a93842e48d014f7e6efe10ae96cb3892b129",
"f59b3dfdb9b1b8bbb61abedd7c8cf3fc47c21f5f",
"f59b3dfdb9b1b8bbb61abedd7c8cf3fc47c21f5f");
const std::string rtcp_stats_checksum = PlatformChecksum(
"b8880bf9fed2487efbddcb8d94b9937a29ae521d",
@ -484,10 +484,10 @@ TEST_F(NetEqDecodingTest, MAYBE_TestOpusBitExactness) {
"9d7d52bc94e941d106aa518f324f16a58d231586");
const std::string network_stats_checksum = PlatformChecksum(
"191af29ed3b8b6dd4c4cc94dc3f33bdf48f055ef",
"191af29ed3b8b6dd4c4cc94dc3f33bdf48f055ef",
"191af29ed3b8b6dd4c4cc94dc3f33bdf48f055ef",
"191af29ed3b8b6dd4c4cc94dc3f33bdf48f055ef");
"d8379381d5a619f0616bb3c0a8a9eea1704a8ab8",
"d8379381d5a619f0616bb3c0a8a9eea1704a8ab8",
"d8379381d5a619f0616bb3c0a8a9eea1704a8ab8",
"d8379381d5a619f0616bb3c0a8a9eea1704a8ab8");
const std::string rtcp_stats_checksum = PlatformChecksum(
"e37c797e3de6a64dda88c9ade7a013d022a2e1e0",
@ -577,7 +577,7 @@ TEST_F(NetEqDecodingTest, TestAverageInterArrivalTimeNegative) {
NetEqNetworkStatistics network_stats;
ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
EXPECT_EQ(-103196, network_stats.clockdrift_ppm);
EXPECT_EQ(-103192, network_stats.clockdrift_ppm);
}
TEST_F(NetEqDecodingTest, TestAverageInterArrivalTimePositive) {
@ -605,7 +605,7 @@ TEST_F(NetEqDecodingTest, TestAverageInterArrivalTimePositive) {
NetEqNetworkStatistics network_stats;
ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
EXPECT_EQ(110946, network_stats.clockdrift_ppm);
EXPECT_EQ(110953, network_stats.clockdrift_ppm);
}
void NetEqDecodingTest::LongCngWithClockDrift(double drift_factor,

3
webrtc/modules/audio_coding/neteq/statistics_calculator.cc
View File

@ -223,7 +223,8 @@ void StatisticsCalculator::GetNetworkStatistics(
stats->preferred_buffer_size_ms = (delay_manager.TargetLevel() >> 8) *
ms_per_packet;
stats->jitter_peaks_found = delay_manager.PeakFound();
stats->clockdrift_ppm = delay_manager.AverageIAT();
stats->clockdrift_ppm =
rtc::saturated_cast<int32_t>(delay_manager.EstimatedClockDriftPpm());
stats->packet_loss_rate =
CalculateQ14Ratio(lost_timestamps_, timestamps_since_last_report_);