Camera: Avoid over-delaying frames in PreviewFrameSpacer
There could be 1 or 2 ms between calculating the timeToWait and
queueBuffer(). As a result currently we are over-delaying each
frame for about 1ms. This over-delay can accumulate and recover
once the maximum 10ms limit is reached or 2 frames are queued.
To compensate, wait up to until (mLastPresentTime + captureInterval - 2ms)
So that the presentation intervals don't always exceed captureInternal.
Bug: 251183098
Test: Camera CTS, vendor testing
Test: testPreviewJitterSurfaceTexture
Change-Id: I2728d0516686950141c8e6d41e041d8d6dc00c8a
diff --git a/services/camera/libcameraservice/device3/PreviewFrameSpacer.cpp b/services/camera/libcameraservice/device3/PreviewFrameSpacer.cpp
index b3cb178..83caa00 100644
--- a/services/camera/libcameraservice/device3/PreviewFrameSpacer.cpp
+++ b/services/camera/libcameraservice/device3/PreviewFrameSpacer.cpp
@@ -69,7 +69,9 @@
}
// Cache the frame to match readout time interval, for up to kMaxFrameWaitTime
- nsecs_t expectedQueueTime = mLastCameraPresentTime + readoutInterval;
+ // Because the code between here and queueBuffer() takes time to execute, make sure the
+ // presentationInterval is slightly shorter than readoutInterval.
+ nsecs_t expectedQueueTime = mLastCameraPresentTime + readoutInterval - kFrameAdjustThreshold;
nsecs_t frameWaitTime = std::min(kMaxFrameWaitTime, expectedQueueTime - currentTime);
if (frameWaitTime > 0 && mPendingBuffers.size() < 2) {
mBufferCond.waitRelative(mLock, frameWaitTime);
@@ -78,9 +80,9 @@
}
currentTime = systemTime();
}
- ALOGV("%s: readoutInterval %" PRId64 ", queueInterval %" PRId64 ", waited for %" PRId64
+ ALOGV("%s: readoutInterval %" PRId64 ", waited for %" PRId64
", timestamp %" PRId64, __FUNCTION__, readoutInterval,
- currentTime - mLastCameraPresentTime, frameWaitTime, buffer.timestamp);
+ mPendingBuffers.size() < 2 ? frameWaitTime : 0, buffer.timestamp);
mPendingBuffers.pop();
queueBufferToClientLocked(buffer, currentTime);
return true;
diff --git a/services/camera/libcameraservice/device3/PreviewFrameSpacer.h b/services/camera/libcameraservice/device3/PreviewFrameSpacer.h
index cb9690c..f46de3d 100644
--- a/services/camera/libcameraservice/device3/PreviewFrameSpacer.h
+++ b/services/camera/libcameraservice/device3/PreviewFrameSpacer.h
@@ -86,6 +86,7 @@
static constexpr nsecs_t kWaitDuration = 5000000LL; // 50ms
static constexpr nsecs_t kFrameIntervalThreshold = 80000000LL; // 80ms
static constexpr nsecs_t kMaxFrameWaitTime = 10000000LL; // 10ms
+ static constexpr nsecs_t kFrameAdjustThreshold = 2000000LL; // 2ms
};
}; //namespace camera3