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Reland of VCMCodecTimer: Change filter from max to 95th percentile (patchset #1 id:1 of https://codereview.webrtc.org/1808693002/ )

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This CL is expected to lower goog_max_decode_ms and total_delay_incl_network/receiver_time for screenshare.

Reason for revert:
This CL did not cause the unexpected goog_encode_usage_percent and goog_avg_encode_ms perf changes.

Original issue's description:
> Revert of VCMCodecTimer: Change filter from max to 95th percentile (patchset #5 id:180001 of https://codereview.webrtc.org/1742323002/ )
>
> Reason for revert:
> Caused unexpected perf stats changes, see http://crbug/594575.
>
> Original issue's description:
> > VCMCodecTimer: Change filter from max to 95th percentile
> >
> > The purpose with this change is to make the filter more robust against anomalies. googMaxDecodeMs is expected to drop a litte by this.
> >
> > BUG=b/27306053
> >
> > Committed: https://crrev.com/4bf0c717740d1834e810ea5f32b3c4306c64235f
> > Cr-Commit-Position: refs/heads/master@{#11952}
>
> TBR=stefan@webrtc.org,philipel@webrtc.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=594575,b/27306053
>
> Committed: https://crrev.com/c4a74e95b545f4752d4e72961ac03c1380d4bc1f
> Cr-Commit-Position: refs/heads/master@{#12018}

TBR=stefan@webrtc.org,philipel@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=594575,b/27306053

Review URL: https://codereview.webrtc.org/1824763003

Cr-Commit-Position: refs/heads/master@{#12087}
This commit is contained in:
magjed
2016-03-22 05:12:09 -07:00
committed by Commit bot
parent 81cbd92444
commit 2943f015b6
11 changed files with 306 additions and 119 deletions
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102
webrtc/modules/video_coding/codec_timer.cc
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@ -10,87 +10,47 @@
#include "webrtc/modules/video_coding/codec_timer.h"
#include <assert.h>
namespace webrtc {
namespace {
// The first kIgnoredSampleCount samples will be ignored.
static const int32_t kIgnoredSampleCount = 5;
const int kIgnoredSampleCount = 5;
// Return the |kPercentile| value in RequiredDecodeTimeMs().
const float kPercentile = 0.95f;
// The window size in ms.
const int64_t kTimeLimitMs = 10000;
} // anonymous namespace
VCMCodecTimer::VCMCodecTimer()
: _filteredMax(0), _ignoredSampleCount(0), _shortMax(0), _history() {
Reset();
}
: ignored_sample_count_(0), filter_(kPercentile) {}
void VCMCodecTimer::Reset() {
_filteredMax = 0;
_ignoredSampleCount = 0;
_shortMax = 0;
for (int i = 0; i < MAX_HISTORY_SIZE; i++) {
_history[i].shortMax = 0;
_history[i].timeMs = -1;
}
}
// Update the max-value filter
void VCMCodecTimer::MaxFilter(int32_t decodeTime, int64_t nowMs) {
if (_ignoredSampleCount >= kIgnoredSampleCount) {
UpdateMaxHistory(decodeTime, nowMs);
ProcessHistory(nowMs);
} else {
_ignoredSampleCount++;
}
}
void VCMCodecTimer::UpdateMaxHistory(int32_t decodeTime, int64_t now) {
if (_history[0].timeMs >= 0 && now - _history[0].timeMs < SHORT_FILTER_MS) {
if (decodeTime > _shortMax) {
_shortMax = decodeTime;
}
} else {
// Only add a new value to the history once a second
if (_history[0].timeMs == -1) {
// First, no shift
_shortMax = decodeTime;
} else {
// Shift
for (int i = (MAX_HISTORY_SIZE - 2); i >= 0; i--) {
_history[i + 1].shortMax = _history[i].shortMax;
_history[i + 1].timeMs = _history[i].timeMs;
}
}
if (_shortMax == 0) {
_shortMax = decodeTime;
}
_history[0].shortMax = _shortMax;
_history[0].timeMs = now;
_shortMax = 0;
}
}
void VCMCodecTimer::ProcessHistory(int64_t nowMs) {
_filteredMax = _shortMax;
if (_history[0].timeMs == -1) {
void VCMCodecTimer::AddTiming(int64_t decode_time_ms, int64_t now_ms) {
// Ignore the first |kIgnoredSampleCount| samples.
if (ignored_sample_count_ < kIgnoredSampleCount) {
++ignored_sample_count_;
return;
}
for (int i = 0; i < MAX_HISTORY_SIZE; i++) {
if (_history[i].timeMs == -1) {
break;
}
if (nowMs - _history[i].timeMs > MAX_HISTORY_SIZE * SHORT_FILTER_MS) {
// This sample (and all samples after this) is too old
break;
}
if (_history[i].shortMax > _filteredMax) {
// This sample is the largest one this far into the history
_filteredMax = _history[i].shortMax;
}
// Insert new decode time value.
filter_.Insert(decode_time_ms);
history_.emplace(decode_time_ms, now_ms);
// Pop old decode time values.
while (!history_.empty() &&
now_ms - history_.front().sample_time_ms > kTimeLimitMs) {
filter_.Erase(history_.front().decode_time_ms);
history_.pop();
}
}
// Get the maximum observed time within a time window
int32_t VCMCodecTimer::RequiredDecodeTimeMs(FrameType /*frameType*/) const {
return _filteredMax;
// Get the 95th percentile observed decode time within a time window.
int64_t VCMCodecTimer::RequiredDecodeTimeMs() const {
return filter_.GetPercentileValue();
}
VCMCodecTimer::Sample::Sample(int64_t decode_time_ms, int64_t sample_time_ms)
: decode_time_ms(decode_time_ms), sample_time_ms(sample_time_ms) {}
} // namespace webrtc