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Merged
qiin2333 merged 1 commit into from
Jul 22, 2026
Merged

fix(render): preserve PTS burst frames #71

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5 changes: 1 addition & 4 deletions nativelib/src/main/cpp/native_render.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -438,7 +438,6 @@ void NativeRender::ResetPresentationStatsLocked() {
precisePhaseShiftCount_ = 0;
preciseRebufferCount_ = 0;
preciseResyncCount_ = 0;
preciseQueueFullCount_ = 0;
preciseApiFailureCount_ = 0;
preciseMaxTargetLeadNs_ = 0;
presentationDiagnostics_.Reset();
Expand Down Expand Up @@ -577,7 +576,6 @@ NativeRender::FrameSubmitResult NativeRender::SubmitFrame(const DecodedFrame& fr
plan.event == PresentationEvent::DUPLICATE_PTS) {
preciseResyncCount_++;
}
if (plan.event == PresentationEvent::QUEUE_FULL) preciseQueueFullCount_++;
if (plan.action == PresentationAction::SCHEDULE) {
preciseMaxTargetLeadNs_ = std::max(
preciseMaxTargetLeadNs_, plan.targetTimeNs - decodedAtNs);
Expand All @@ -591,7 +589,7 @@ NativeRender::FrameSubmitResult NativeRender::SubmitFrame(const DecodedFrame& fr
const PresentationTimingStats& timing =
presentationDiagnostics_.GetStats();
OH_LOG_INFO(LOG_APP,
"Host-paced stats: frames=%{public}lld, scheduled=%{public}lld, dropped=%{public}lld, late=%{public}lld, catchUp=%{public}lld, phaseShift=%{public}lld, rebuffer=%{public}lld, resync=%{public}lld, queueFull=%{public}lld, apiFailure=%{public}lld, lead=%{public}lldus, maxLead=%{public}lldus, sameSlot=%{public}lld, slotRegression=%{public}lld, targetRegression=%{public}lld, maxRegression=%{public}lldus, maxQueueSlots=%{public}lld, vsyncPeriod=%{public}lldus, vsyncAge=%{public}lldus, vsyncSampleFailure=%{public}lld",
"Host-paced stats: frames=%{public}lld, scheduled=%{public}lld, dropped=%{public}lld, late=%{public}lld, catchUp=%{public}lld, phaseShift=%{public}lld, rebuffer=%{public}lld, resync=%{public}lld, apiFailure=%{public}lld, lead=%{public}lldus, maxLead=%{public}lldus, sameSlot=%{public}lld, slotRegression=%{public}lld, targetRegression=%{public}lld, maxRegression=%{public}lldus, maxQueueSlots=%{public}lld, vsyncPeriod=%{public}lldus, vsyncAge=%{public}lldus, vsyncSampleFailure=%{public}lld",
static_cast<long long>(totalFrames),
static_cast<long long>(preciseScheduledCount_),
static_cast<long long>(preciseDroppedCount_),
Expand All @@ -600,7 +598,6 @@ NativeRender::FrameSubmitResult NativeRender::SubmitFrame(const DecodedFrame& fr
static_cast<long long>(precisePhaseShiftCount_),
static_cast<long long>(preciseRebufferCount_),
static_cast<long long>(preciseResyncCount_),
static_cast<long long>(preciseQueueFullCount_),
static_cast<long long>(preciseApiFailureCount_),
static_cast<long long>(ptsScheduler_.GetInitialLeadNs() / 1000),
static_cast<long long>(preciseMaxTargetLeadNs_ / 1000),
Expand Down
1 change: 0 additions & 1 deletion nativelib/src/main/cpp/native_render.h
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Original file line number Diff line number Diff line change
Expand Up @@ -185,7 +185,6 @@ class NativeRender {
int64_t precisePhaseShiftCount_ = 0;
int64_t preciseRebufferCount_ = 0;
int64_t preciseResyncCount_ = 0;
int64_t preciseQueueFullCount_ = 0;
int64_t preciseApiFailureCount_ = 0;
int64_t preciseMaxTargetLeadNs_ = 0;

Expand Down
40 changes: 0 additions & 40 deletions nativelib/src/main/cpp/presentation_scheduler.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -25,15 +25,6 @@ constexpr double kNtscTripleBurstFps = 119.88;
constexpr int64_t kDriftDeadbandNs = 2 * kNanosecondsPerMillisecond;
constexpr int64_t kMaxDriftCorrectionPerFrameNs = 20 * kNanosecondsPerMicrosecond;

PresentationEvent ReanchorEventForRetry(PresentationEvent event) {
if (event == PresentationEvent::DISCONTINUITY ||
event == PresentationEvent::REBUFFER ||
event == PresentationEvent::DUPLICATE_PTS) {
return event;
}
return PresentationEvent::CATCH_UP;
}

int64_t FloorDiv(int64_t value, int64_t divisor) {
int64_t quotient = value / divisor;
if (value % divisor < 0) {
Expand Down Expand Up @@ -95,8 +86,6 @@ void PtsPresentationScheduler::Reset() {
driftErrorEmaNs_ = 0;
phaseShiftDebtNs_ = 0;
lastScheduledTargetNs_ = 0;
reanchorRetryPending_ = false;
pendingReanchorEvent_ = PresentationEvent::CATCH_UP;
}

PresentationPlan PtsPresentationScheduler::AnchorFrame(
Expand All @@ -108,8 +97,6 @@ PresentationPlan PtsPresentationScheduler::AnchorFrame(
lastPtsUs_ = ptsUs;
driftErrorEmaNs_ = 0;
phaseShiftDebtNs_ = 0;
reanchorRetryPending_ = false;
pendingReanchorEvent_ = PresentationEvent::CATCH_UP;

return ScheduleTarget(
anchorTargetNs_, decodedAtNs, event, latenessNs, slotClock);
Expand All @@ -134,21 +121,6 @@ PresentationPlan PtsPresentationScheduler::ScheduleTarget(
}
}

// Start the existing cadence budget at the first slot that still has the
// submit margin. Being close to a VSync must not reduce burst capacity.
const int64_t firstEligibleSlotNs = CeilToSlot(
requiredTargetNs, slotClock.anchorNs, slotClock.periodNs);
const int64_t maxScheduledSlotNs = firstEligibleSlotNs +
GetAdditionalQueueSlots(slotClock.periodNs) * slotClock.periodNs;
if (scheduledSlotNs > maxScheduledSlotNs) {
reanchorRetryPending_ = true;
pendingReanchorEvent_ = ReanchorEventForRetry(event);
PresentationPlan plan;
plan.event = PresentationEvent::QUEUE_FULL;
plan.latenessNs = latenessNs;
return plan;
}

lastScheduledTargetNs_ = scheduledSlotNs;

PresentationPlan plan;
Expand Down Expand Up @@ -184,13 +156,6 @@ bool PtsPresentationScheduler::IsPresentationQueueEmpty(
return lastOccupiedSlotNs <= slotClock.currentSlotNs;
}

int64_t PtsPresentationScheduler::GetAdditionalQueueSlots(
int64_t vsyncPeriodNs) const {
const int64_t cadenceBudgetNs = std::max<int64_t>(
0, maxFutureLeadNs_ - initialLeadNs_);
return cadenceBudgetNs / vsyncPeriodNs;
}

void PtsPresentationScheduler::ApplySlowDriftCorrection(
int64_t decodedAtNs, int64_t& targetTimeNs) {
int64_t leadErrorNs = targetTimeNs - decodedAtNs - initialLeadNs_;
Expand Down Expand Up @@ -229,11 +194,6 @@ PresentationPlan PtsPresentationScheduler::PlanFrame(
const SlotClock slotClock = ResolveSlotClock(decodedAtNs, vsyncTiming);
const bool queueEmpty = IsPresentationQueueEmpty(slotClock);

if (reanchorRetryPending_) {
return AnchorFrame(
ptsUs, decodedAtNs, pendingReanchorEvent_, slotClock);
}

if (!initialized_) {
return AnchorFrame(
ptsUs, decodedAtNs, PresentationEvent::INITIAL_ANCHOR, slotClock);
Expand Down
4 changes: 0 additions & 4 deletions nativelib/src/main/cpp/presentation_scheduler.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,7 +27,6 @@ enum class PresentationEvent {
REBUFFER,
DUPLICATE_PTS,
INVALID_PTS,
QUEUE_FULL,
};

struct PresentationVsyncTiming {
Expand Down Expand Up @@ -74,7 +73,6 @@ class PtsPresentationScheduler {
int64_t decodedAtNs,
const PresentationVsyncTiming& vsyncTiming) const;
bool IsPresentationQueueEmpty(const SlotClock& slotClock) const;
int64_t GetAdditionalQueueSlots(int64_t vsyncPeriodNs) const;

int64_t frameIntervalNs_ = 16666667LL;
int64_t initialLeadNs_ = 2000000LL;
Expand All @@ -89,8 +87,6 @@ class PtsPresentationScheduler {
int64_t driftErrorEmaNs_ = 0;
int64_t phaseShiftDebtNs_ = 0;
int64_t lastScheduledTargetNs_ = 0;
bool reanchorRetryPending_ = false;
PresentationEvent pendingReanchorEvent_ = PresentationEvent::CATCH_UP;
};

#endif // PRESENTATION_SCHEDULER_H
99 changes: 55 additions & 44 deletions nativelib/src/test/cpp/presentation_scheduler_test.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -106,7 +106,7 @@ void TestSustained120FpsPeriodicJitterDoesNotDrop() {
assert(phaseShiftCount >= 20);
}

void Test120FpsBurstUsesThreeUniqueSlots() {
void Test120FpsBurstPreservesAllFrames() {
PtsPresentationScheduler scheduler;
scheduler.Configure(120.0);
const PresentationVsyncTiming timing = Timing(120.0);
Expand All @@ -116,44 +116,55 @@ void Test120FpsBurstUsesThreeUniqueSlots() {
const PresentationPlan second = scheduler.PlanFrame(8334, decodedAtNs, timing);
const PresentationPlan third = scheduler.PlanFrame(16667, decodedAtNs, timing);
const PresentationPlan fourth = scheduler.PlanFrame(25000, decodedAtNs, timing);
const PresentationPlan fifth = scheduler.PlanFrame(33333, decodedAtNs, timing);

AssertOnVsyncSlot(first, timing);
AssertOnVsyncSlot(second, timing);
AssertOnVsyncSlot(third, timing);
AssertOnVsyncSlot(fourth, timing);
AssertOnVsyncSlot(fifth, timing);
assert(second.targetTimeNs - first.targetTimeNs == timing.periodNs);
assert(third.targetTimeNs - second.targetTimeNs == timing.periodNs);
assert(fourth.action == PresentationAction::DROP);
assert(fourth.event == PresentationEvent::QUEUE_FULL);
assert(fourth.targetTimeNs - third.targetTimeNs == timing.periodNs);
assert(fifth.targetTimeNs - fourth.targetTimeNs == timing.periodNs);
}

void TestQueueFullRetriesAtNextAvailableSlot() {
void TestRepeated120FpsBurstsDrainBetweenCallbacks() {
PtsPresentationScheduler scheduler;
scheduler.Configure(120.0);
const PresentationVsyncTiming timing = Timing(120.0);
const int64_t burstTimeNs = kStartNs + kMs;

const PresentationPlan first = scheduler.PlanFrame(0, burstTimeNs, timing);
scheduler.PlanFrame(8334, burstTimeNs, timing);
const PresentationPlan third = scheduler.PlanFrame(16667, burstTimeNs, timing);
const PresentationPlan full = scheduler.PlanFrame(25000, burstTimeNs, timing);
const PresentationPlan stillFull = scheduler.PlanFrame(
33333, burstTimeNs, timing);
const PresentationPlan recovered = scheduler.PlanFrame(
41667, first.targetTimeNs + kMs, timing);
const PresentationPlan next = scheduler.PlanFrame(
50000, first.targetTimeNs + timing.periodNs + kMs, timing);

assert(full.event == PresentationEvent::QUEUE_FULL);
assert(stillFull.action == PresentationAction::DROP);
assert(stillFull.event == PresentationEvent::QUEUE_FULL);
assert(recovered.action == PresentationAction::SCHEDULE);
assert(recovered.event == PresentationEvent::CATCH_UP);
assert(recovered.targetTimeNs == third.targetTimeNs + timing.periodNs);
assert(next.action == PresentationAction::SCHEDULE);
assert(next.targetTimeNs == recovered.targetTimeNs + timing.periodNs);
const int64_t firstDecodedAtNs = kStartNs + kMs;
constexpr double kPtsIntervalUs = 1000000.0 / 120.0;
constexpr int kBurstSize = 5;

PresentationPlan previous;
for (int burst = 0; burst < 120; ++burst) {
const int firstFrame = burst * kBurstSize;
const int64_t decodedAtNs =
firstDecodedAtNs + firstFrame * timing.periodNs;
for (int offset = 0; offset < kBurstSize; ++offset) {
const int frame = firstFrame + offset;
const int64_t ptsUs = static_cast<int64_t>(
std::llround(frame * kPtsIntervalUs));
const PresentationPlan current = scheduler.PlanFrame(
ptsUs, decodedAtNs, timing);

AssertOnVsyncSlot(current, timing);
if (frame > 0) {
assert(current.targetTimeNs ==
previous.targetTimeNs + timing.periodNs);
}
previous = current;
}
}

const int64_t lastDecodedAtNs = firstDecodedAtNs +
(120 - 1) * kBurstSize * timing.periodNs;
assert(previous.targetTimeNs - lastDecodedAtNs <=
kBurstSize * timing.periodNs);
}

void Test90FpsPairBurstUsesTwoSlots() {
void Test90FpsBurstPreservesAllFrames() {
PtsPresentationScheduler scheduler;
scheduler.Configure(90.0);
const PresentationVsyncTiming timing = Timing(90.0);
Expand All @@ -165,12 +176,12 @@ void Test90FpsPairBurstUsesTwoSlots() {

AssertOnVsyncSlot(first, timing);
AssertOnVsyncSlot(second, timing);
AssertOnVsyncSlot(third, timing);
assert(second.targetTimeNs - first.targetTimeNs == timing.periodNs);
assert(third.action == PresentationAction::DROP);
assert(third.event == PresentationEvent::QUEUE_FULL);
assert(third.targetTimeNs - second.targetTimeNs == timing.periodNs);
}

void Test60FpsDoesNotGrowPresentationQueue() {
void Test60FpsBurstPreservesAllFrames() {
PtsPresentationScheduler scheduler;
scheduler.Configure(60.0);
const PresentationVsyncTiming timing = Timing(60.0);
Expand All @@ -182,11 +193,10 @@ void Test60FpsDoesNotGrowPresentationQueue() {
33333, first.targetTimeNs + kMs, timing);

AssertOnVsyncSlot(first, timing);
assert(burst.action == PresentationAction::DROP);
assert(burst.event == PresentationEvent::QUEUE_FULL);
assert(recovered.action == PresentationAction::SCHEDULE);
assert(recovered.event == PresentationEvent::CATCH_UP);
assert(recovered.targetTimeNs == first.targetTimeNs + timing.periodNs);
AssertOnVsyncSlot(burst, timing);
AssertOnVsyncSlot(recovered, timing);
assert(burst.targetTimeNs == first.targetTimeNs + timing.periodNs);
assert(recovered.targetTimeNs == burst.targetTimeNs + timing.periodNs);
}

void TestSmallLateFrameShiftsWholeTimeline() {
Expand Down Expand Up @@ -238,22 +248,23 @@ void TestDiscontinuityUsesNextAvailableSlot() {
assert(reanchored.targetTimeNs == first.targetTimeNs + timing.periodNs);
}

void TestDuplicatePtsRecoversAfterQueuedSlot() {
void TestDuplicatePtsReanchorsWithoutDropping() {
PtsPresentationScheduler scheduler;
scheduler.Configure(60.0);
const PresentationVsyncTiming timing = Timing(60.0);
const int64_t decodedAtNs = kStartNs + kMs;

const PresentationPlan first = scheduler.PlanFrame(1000, decodedAtNs, timing);
const PresentationPlan full = scheduler.PlanFrame(1000, decodedAtNs, timing);
const PresentationPlan duplicate = scheduler.PlanFrame(1000, decodedAtNs, timing);
const PresentationPlan reanchored = scheduler.PlanFrame(
1000, first.targetTimeNs + kMs, timing);

assert(full.action == PresentationAction::DROP);
assert(full.event == PresentationEvent::QUEUE_FULL);
assert(duplicate.action == PresentationAction::SCHEDULE);
assert(duplicate.event == PresentationEvent::DUPLICATE_PTS);
assert(reanchored.action == PresentationAction::SCHEDULE);
assert(reanchored.event == PresentationEvent::DUPLICATE_PTS);
assert(reanchored.targetTimeNs == first.targetTimeNs + timing.periodNs);
assert(duplicate.targetTimeNs == first.targetTimeNs + timing.periodNs);
assert(reanchored.targetTimeNs == duplicate.targetTimeNs + timing.periodNs);
}

void TestNtscCadenceSkipsARealSlotWithoutRegression() {
Expand Down Expand Up @@ -318,14 +329,14 @@ int main() {
TestRefreshRateTierBudgets();
TestTransient120FpsJitterUsesTemporaryPhaseShift();
TestSustained120FpsPeriodicJitterDoesNotDrop();
Test120FpsBurstUsesThreeUniqueSlots();
TestQueueFullRetriesAtNextAvailableSlot();
Test90FpsPairBurstUsesTwoSlots();
Test60FpsDoesNotGrowPresentationQueue();
Test120FpsBurstPreservesAllFrames();
TestRepeated120FpsBurstsDrainBetweenCallbacks();
Test90FpsBurstPreservesAllFrames();
Test60FpsBurstPreservesAllFrames();
TestSmallLateFrameShiftsWholeTimeline();
TestSevereLateFrameReanchorsImmediately();
TestDiscontinuityUsesNextAvailableSlot();
TestDuplicatePtsRecoversAfterQueuedSlot();
TestDuplicatePtsReanchorsWithoutDropping();
TestNtscCadenceSkipsARealSlotWithoutRegression();
TestObservedVsyncPhaseCannotReuseFallbackSlot();
TestInvalidPtsDropsWithoutScheduling();
Expand Down
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