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/Camera3Device.cpp

diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index aeffd24..55acec4 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -2649,7 +2649,7 @@
 
 status_t Camera3Device::registerInFlight(uint32_t frameNumber,
         int32_t numBuffers, CaptureResultExtras resultExtras, bool hasInput,
-        bool hasAppCallback, nsecs_t maxExpectedDuration,
+        bool hasAppCallback, nsecs_t minExpectedDuration, nsecs_t maxExpectedDuration,
         const std::set<std::set<String8>>& physicalCameraIds,
         bool isStillCapture, bool isZslCapture, bool rotateAndCropAuto,
         const std::set<std::string>& cameraIdsWithZoom,
@@ -2659,8 +2659,9 @@
 
     ssize_t res;
     res = mInFlightMap.add(frameNumber, InFlightRequest(numBuffers, resultExtras, hasInput,
-            hasAppCallback, maxExpectedDuration, physicalCameraIds, isStillCapture, isZslCapture,
-            rotateAndCropAuto, cameraIdsWithZoom, requestTimeNs, outputSurfaces));
+            hasAppCallback, minExpectedDuration, maxExpectedDuration, physicalCameraIds,
+            isStillCapture, isZslCapture, rotateAndCropAuto, cameraIdsWithZoom, requestTimeNs,
+            outputSurfaces));
     if (res < 0) return res;
 
     if (mInFlightMap.size() == 1) {
@@ -3216,13 +3217,16 @@
     return true;
 }
 
-nsecs_t Camera3Device::RequestThread::calculateMaxExpectedDuration(const camera_metadata_t *request) {
-    nsecs_t maxExpectedDuration = kDefaultExpectedDuration;
+std::pair<nsecs_t, nsecs_t> Camera3Device::RequestThread::calculateExpectedDurationRange(
+        const camera_metadata_t *request) {
+    std::pair<nsecs_t, nsecs_t> expectedRange(
+            InFlightRequest::kDefaultMinExpectedDuration,
+            InFlightRequest::kDefaultMaxExpectedDuration);
     camera_metadata_ro_entry_t e = camera_metadata_ro_entry_t();
     find_camera_metadata_ro_entry(request,
             ANDROID_CONTROL_AE_MODE,
             &e);
-    if (e.count == 0) return maxExpectedDuration;
+    if (e.count == 0) return expectedRange;
 
     switch (e.data.u8[0]) {
         case ANDROID_CONTROL_AE_MODE_OFF:
@@ -3230,13 +3234,15 @@
                     ANDROID_SENSOR_EXPOSURE_TIME,
                     &e);
             if (e.count > 0) {
-                maxExpectedDuration = e.data.i64[0];
+                expectedRange.first = e.data.i64[0];
+                expectedRange.second = expectedRange.first;
             }
             find_camera_metadata_ro_entry(request,
                     ANDROID_SENSOR_FRAME_DURATION,
                     &e);
             if (e.count > 0) {
-                maxExpectedDuration = std::max(e.data.i64[0], maxExpectedDuration);
+                expectedRange.first = std::max(e.data.i64[0], expectedRange.first);
+                expectedRange.second = expectedRange.first;
             }
             break;
         default:
@@ -3244,12 +3250,13 @@
                     ANDROID_CONTROL_AE_TARGET_FPS_RANGE,
                     &e);
             if (e.count > 1) {
-                maxExpectedDuration = 1e9 / e.data.u8[0];
+                expectedRange.first = 1e9 / e.data.i32[1];
+                expectedRange.second = 1e9 / e.data.i32[0];
             }
             break;
     }
 
-    return maxExpectedDuration;
+    return expectedRange;
 }
 
 bool Camera3Device::RequestThread::skipHFRTargetFPSUpdate(int32_t tag,
@@ -3864,11 +3871,13 @@
                 isZslCapture = true;
             }
         }
+        auto expectedDurationRange = calculateExpectedDurationRange(settings);
         res = parent->registerInFlight(halRequest->frame_number,
                 totalNumBuffers, captureRequest->mResultExtras,
                 /*hasInput*/halRequest->input_buffer != NULL,
                 hasCallback,
-                calculateMaxExpectedDuration(settings),
+                /*min*/expectedDurationRange.first,
+                /*max*/expectedDurationRange.second,
                 requestedPhysicalCameras, isStillCapture, isZslCapture,
                 captureRequest->mRotateAndCropAuto, mPrevCameraIdsWithZoom,
                 (mUseHalBufManager) ? uniqueSurfaceIdMap :