commit 00abbeb745c1efcf7a2db82ae8d861f3372d725e
author Shuzhen Wang <shuzhenwang@google.com> Fri Feb 25 17:14:42 2022 -0800
committer Shuzhen Wang <shuzhenwang@google.com> Fri Mar 25 10:36:20 2022 -0700
tree ca74a27efa1140d9aa2c674c94183f79657c91e0
parent a0b269f3c8d0ced48dc0fce35cb1b3ef08af8fd8

Camera: Switch to query function for display sync

The query function has the benefit of:
- Simpler code
- No need to use ndk, thus reduce size of cameraserver process
- Better latency compared to callbacks

The additional inflight preview buffers are still necessary so that
producer doesn't get starved.

Test: GoogleCamera app video mode preview, OpenCamera
Test: Camera CTS
Bug: 221499182
Change-Id: I8de42e5747afca79e85841705b9296de0fd668c7

services/camera/libcameraservice/device3/Camera3OutputStream.h

diff --git a/services/camera/libcameraservice/device3/Camera3OutputStream.h b/services/camera/libcameraservice/device3/Camera3OutputStream.h
index 7b12efc..6ea7ef7 100644
--- a/services/camera/libcameraservice/device3/Camera3OutputStream.h
+++ b/services/camera/libcameraservice/device3/Camera3OutputStream.h
@@ -21,13 +21,13 @@
 #include <utils/RefBase.h>
 #include <gui/IProducerListener.h>
 #include <gui/Surface.h>
+#include <gui/DisplayEventReceiver.h>
 
 #include "utils/LatencyHistogram.h"
 #include "Camera3Stream.h"
 #include "Camera3IOStreamBase.h"
 #include "Camera3OutputStreamInterface.h"
 #include "Camera3BufferManager.h"
-#include "PreviewFrameScheduler.h"
 
 namespace android {
 
@@ -240,12 +240,16 @@
     virtual status_t setBatchSize(size_t batchSize = 1) override;
 
     /**
+     * Notify the stream on change of min frame durations.
+     */
+    virtual void onMinDurationChanged(nsecs_t duration) override;
+
+    /**
      * Apply ZSL related consumer usage quirk.
      */
     static void applyZSLUsageQuirk(int format, uint64_t *consumerUsage /*inout*/);
 
     void setImageDumpMask(int mask) { mImageDumpMask = mask; }
-    bool shouldLogError(status_t res);
 
   protected:
     Camera3OutputStream(int id, camera_stream_type_t type,
@@ -278,7 +282,7 @@
 
     status_t getEndpointUsageForSurface(uint64_t *usage,
             const sp<Surface>& surface) const;
-    status_t configureConsumerQueueLocked(bool allowPreviewScheduler);
+    status_t configureConsumerQueueLocked(bool allowDisplaySync);
 
     // Consumer as the output of camera HAL
     sp<Surface> mConsumer;
@@ -392,13 +396,24 @@
 
     void returnPrefetchedBuffersLocked();
 
+    // Synchronize camera timestamp to display, and the return value
+    // can be used as presentation timestamp
+    nsecs_t syncTimestampToDisplayLocked(nsecs_t t);
+
     static const int32_t kDequeueLatencyBinSize = 5; // in ms
     CameraLatencyHistogram mDequeueBufferLatency;
 
     int mImageDumpMask = 0;
 
-    // The preview stream scheduler for re-timing frames
-    std::unique_ptr<PreviewFrameScheduler> mPreviewFrameScheduler;
+    nsecs_t mMinExpectedDuration = 0;
+    bool mSyncToDisplay = false;
+    DisplayEventReceiver mDisplayEventReceiver;
+    nsecs_t mLastCaptureTime = 0;
+    nsecs_t mLastPresentTime = 0;
+    nsecs_t mCaptureToPresentOffset = 0;
+    static constexpr size_t kDisplaySyncExtraBuffer = 2;
+    static constexpr nsecs_t kSpacingResetIntervalNs = 1000000000LL; // 1 second
+    static constexpr nsecs_t kTimelineThresholdNs = 1000000LL; // 1 millisecond
 }; // class Camera3OutputStream
 
 } // namespace camera3