diff --git a/core/api/current.txt b/core/api/current.txt
index fa65288409abd..d589a27e4e379 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -17787,6 +17787,7 @@ package android.hardware.camera2 {
     method public void onCaptureSequenceAborted(@NonNull android.hardware.camera2.CameraCaptureSession, int);
     method public void onCaptureSequenceCompleted(@NonNull android.hardware.camera2.CameraCaptureSession, int, long);
     method public void onCaptureStarted(@NonNull android.hardware.camera2.CameraCaptureSession, @NonNull android.hardware.camera2.CaptureRequest, long, long);
+    method public void onReadoutStarted(@NonNull android.hardware.camera2.CameraCaptureSession, @NonNull android.hardware.camera2.CaptureRequest, long, long);
   }
 
   public abstract static class CameraCaptureSession.StateCallback {
@@ -18780,6 +18781,7 @@ package android.hardware.camera2.params {
     method public int getSurfaceGroupId();
     method @NonNull public java.util.List<android.view.Surface> getSurfaces();
     method public int getTimestampBase();
+    method public boolean isReadoutTimestampUsed();
     method public void removeSensorPixelModeUsed(int);
     method public void removeSurface(@NonNull android.view.Surface);
     method public void setDynamicRangeProfile(long);
@@ -18787,6 +18789,7 @@ package android.hardware.camera2.params {
     method public void setPhysicalCameraId(@Nullable String);
     method public void setStreamUseCase(long);
     method public void setTimestampBase(int);
+    method public void useReadoutTimestamp(boolean);
     method public void writeToParcel(android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.hardware.camera2.params.OutputConfiguration> CREATOR;
     field public static final int MIRROR_MODE_AUTO = 0; // 0x0
diff --git a/core/java/android/hardware/camera2/CameraCaptureSession.java b/core/java/android/hardware/camera2/CameraCaptureSession.java
index 8e4a10879ce51..ff6e8975f8daf 100644
--- a/core/java/android/hardware/camera2/CameraCaptureSession.java
+++ b/core/java/android/hardware/camera2/CameraCaptureSession.java
@@ -1245,10 +1245,28 @@ public abstract class CameraCaptureSession implements AutoCloseable {
          * the start of exposure, particularly when autoexposure is changing exposure duration
          * between frames.</p>
          *
-         * <p>This timestamp may not match {@link CaptureResult#SENSOR_TIMESTAMP the result
-         * timestamp field}. It will, however, match the timestamp of buffers sent to the
-         * output surfaces with {@link OutputConfiguration#TIMESTAMP_BASE_READOUT_SENSOR}
-         * timestamp base.</p>
+         * <p>The timestamps match the timestamps of the output surfaces with readout timestamp
+         * enabled (via {@link OutputConfiguration#useReadoutTimestamp}) if:</p>
+         * <ul>
+         * <li> Timestamp base is {@link OutputConfiguration#TIMESTAMP_BASE_DEFAULT} and the
+         * output
+         *   <ul>
+         *   <li> is not a SurfaceView surface, and </li>
+         *   <li> is not a MediaRecoder, MediaCodec, or ImageReader surface with {@link
+         *   android.hardware.HardwareBuffer#USAGE_VIDEO_ENCODE} usage flag or the device's {@link
+         *   CameraCharacteristics#SENSOR_INFO_TIMESTAMP_SOURCE} is {@code UNKNOWN}</li>
+         *   </ul>
+         * </li>
+         * <li> Timestamp base is {@link OutputConfiguration#TIMESTAMP_BASE_SENSOR},</li>
+         * <li> Timestamp base is {@link OutputConfiguration#TIMESTAMP_BASE_MONOTONIC} and the
+         *  device's {@link CameraCharacteristics#SENSOR_INFO_TIMESTAMP_SOURCE} is {@code
+         *  UNKNOWN},</li>
+         * <li> Timestamp base is {@link OutputConfiguration#TIMESTAMP_BASE_REALTIME} and the
+         *  device's {@link CameraCharacteristics#SENSOR_INFO_TIMESTAMP_SOURCE} is {@code REALTIME}
+         * </li>
+         * </ul>
+         * <p>Otherwise, the timestamps won't match the timestamp of the output surfaces. See
+         * the possible parameters for {@link OutputConfiguration#setTimestampBase} for details.</p>
          *
          * <p>This callback will be called only if {@link
          * CameraCharacteristics#SENSOR_READOUT_TIMESTAMP} is
@@ -1261,8 +1279,6 @@ public abstract class CameraCaptureSession implements AutoCloseable {
          *                  the timestamp at the input image's start of readout for a
          *                  reprocess request, in nanoseconds.
          * @param frameNumber the frame number for this capture
-         *
-         * @hide
          */
         public void onReadoutStarted(@NonNull CameraCaptureSession session,
                 @NonNull CaptureRequest request, long timestamp, long frameNumber) {
diff --git a/core/java/android/hardware/camera2/CameraCharacteristics.java b/core/java/android/hardware/camera2/CameraCharacteristics.java
index a6f7e945bef80..320af06f34a33 100644
--- a/core/java/android/hardware/camera2/CameraCharacteristics.java
+++ b/core/java/android/hardware/camera2/CameraCharacteristics.java
@@ -4588,22 +4588,26 @@ public final class CameraCharacteristics extends CameraMetadata<CameraCharacteri
 
     /**
      * <p>Whether or not the camera device supports readout timestamp and
-     * onReadoutStarted callback.</p>
-     * <p>If this tag is HARDWARE, the camera device calls onReadoutStarted in addition to the
-     * onCaptureStarted callback for each capture. The timestamp passed into the callback
-     * is the start of camera image readout rather than the start of the exposure. In
-     * addition, the application can configure an
-     * {@link android.hardware.camera2.params.OutputConfiguration } with
-     * TIMESTAMP_BASE_READOUT_SENSOR timestamp base, in which case, the timestamp of the
-     * output surface matches the timestamp from the corresponding onReadoutStarted callback.</p>
+     * {@code onReadoutStarted} callback.</p>
+     * <p>If this tag is {@code HARDWARE}, the camera device calls
+     * {@link CameraCaptureSession.CaptureCallback#onReadoutStarted } in addition to the
+     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted } callback for each capture.
+     * The timestamp passed into the callback is the start of camera image readout rather than
+     * the start of the exposure. The timestamp source of
+     * {@link CameraCaptureSession.CaptureCallback#onReadoutStarted } is the same as that of
+     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted }.</p>
+     * <p>In addition, the application can switch an output surface's timestamp from start of
+     * exposure to start of readout by calling
+     * {@link android.hardware.camera2.params.OutputConfiguration#useReadoutTimestamp }.</p>
      * <p>The readout timestamp is beneficial for video recording, because the encoder favors
      * uniform timestamps, and the readout timestamps better reflect the cadence camera sensors
      * output data.</p>
-     * <p>If this tag is HARDWARE, the camera device produces the start-of-exposure and
-     * start-of-readout together. As a result, the onReadoutStarted is called right after
-     * onCaptureStarted. The difference in start-of-readout and start-of-exposure is the sensor
-     * exposure time, plus certain constant offset. The offset is usually due to camera sensor
-     * level crop, and it remains constant for a given camera sensor mode.</p>
+     * <p>Note that the camera device produces the start-of-exposure and start-of-readout callbacks
+     * together. As a result, the {@link CameraCaptureSession.CaptureCallback#onReadoutStarted }
+     * is called right after {@link CameraCaptureSession.CaptureCallback#onCaptureStarted }. The
+     * difference in start-of-readout and start-of-exposure is the sensor exposure time, plus
+     * certain constant offset. The offset is usually due to camera sensor level crop, and it is
+     * generally constant over time for the same set of output resolutions and capture settings.</p>
      * <p><b>Possible values:</b></p>
      * <ul>
      *   <li>{@link #SENSOR_READOUT_TIMESTAMP_NOT_SUPPORTED NOT_SUPPORTED}</li>
diff --git a/core/java/android/hardware/camera2/CameraMetadata.java b/core/java/android/hardware/camera2/CameraMetadata.java
index b2428b1d80a38..67dcd93757e13 100644
--- a/core/java/android/hardware/camera2/CameraMetadata.java
+++ b/core/java/android/hardware/camera2/CameraMetadata.java
@@ -1700,9 +1700,8 @@ public abstract class CameraMetadata<TKey> {
 
     /**
      * <p>This camera device supports the onReadoutStarted callback as well as outputting
-     * readout timestamp for streams with TIMESTAMP_BASE_READOUT_SENSOR timestamp base. The
-     * readout timestamp is generated by the camera hardware and it has the same accuracy
-     * and timing characteristics of the start-of-exposure time.</p>
+     * readout timestamps. The readout timestamp is generated by the camera hardware and it
+     * has the same accuracy and timing characteristics of the start-of-exposure time.</p>
      * @see CameraCharacteristics#SENSOR_READOUT_TIMESTAMP
      */
     public static final int SENSOR_READOUT_TIMESTAMP_HARDWARE = 1;
diff --git a/core/java/android/hardware/camera2/params/OutputConfiguration.java b/core/java/android/hardware/camera2/params/OutputConfiguration.java
index f4b87b9f5ae91..65df5d1d43597 100644
--- a/core/java/android/hardware/camera2/params/OutputConfiguration.java
+++ b/core/java/android/hardware/camera2/params/OutputConfiguration.java
@@ -191,7 +191,9 @@ public final class OutputConfiguration implements Parcelable {
      *
      * <p>The timestamps of the output images are in the time base as specified by {@link
      * CameraCharacteristics#SENSOR_INFO_TIMESTAMP_SOURCE}. The application can look up the
-     * corresponding result metadata for a particular output image using this timestamp.</p>
+     * corresponding result metadata by matching the timestamp with a {@link
+     * CameraCaptureSession.CaptureCallback#onCaptureStarted}, or with a {@link
+     * CameraCaptureSession.CaptureCallback#onReadoutStarted} if readout timestamp is used.</p>
      */
     public static final int TIMESTAMP_BASE_SENSOR = 1;
 
@@ -204,7 +206,8 @@ public final class OutputConfiguration implements Parcelable {
      *
      * <p>If the camera device's {@link CameraCharacteristics#SENSOR_INFO_TIMESTAMP_SOURCE} is
      * REALTIME, timestamps with this time base cannot directly match the timestamps in
-     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted} or the sensor timestamps in
+     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted}, {@link
+     * CameraCaptureSession.CaptureCallback#onReadoutStarted}, or the sensor timestamps in
      * {@link android.hardware.camera2.CaptureResult}.</p>
      */
     public static final int TIMESTAMP_BASE_MONOTONIC = 2;
@@ -218,7 +221,8 @@ public final class OutputConfiguration implements Parcelable {
      *
      * <p>If the camera device's {@link CameraCharacteristics#SENSOR_INFO_TIMESTAMP_SOURCE} is
      * UNKNOWN, timestamps with this time base cannot directly match the timestamps in
-     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted} or the sensor timestamps in
+     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted}, {@link
+     * CameraCaptureSession.CaptureCallback#onReadoutStarted}, or the sensor timestamps in
      * {@link android.hardware.camera2.CaptureResult}.</p>
      *
      * <p>If using a REALTIME timestamp base on a device that supports only
@@ -243,7 +247,8 @@ public final class OutputConfiguration implements Parcelable {
      * displayed right away.</p>
      *
      * <p>Timestamps with this time base cannot directly match the timestamps in
-     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted} or the sensor timestamps in
+     * {@link CameraCaptureSession.CaptureCallback#onCaptureStarted}, {@link
+     * CameraCaptureSession.CaptureCallback#onReadoutStarted}, or the sensor timestamps in
      * {@link android.hardware.camera2.CaptureResult}. This timestamp base shouldn't be used if the
      * timestamp needs to be used for audio-video synchronization.</p>
      */
@@ -252,18 +257,7 @@ public final class OutputConfiguration implements Parcelable {
     /**
      * Timestamp is the start of readout in the same time domain as TIMESTAMP_BASE_SENSOR.
      *
-     * <p>The start of the camera sensor readout after exposure. For a rolling shutter camera
-     * sensor, the timestamp is typically equal to the start of exposure time +
-     * exposure time + certain fixed offset. The fixed offset could be due to camera sensor
-     * level crop. The benefit of using readout time is that when camera runs in a fixed
-     * frame rate, the timestamp intervals between frames are constant.</p>
-     *
-     * <p>This timestamp is in the same time domain as in TIMESTAMP_BASE_SENSOR, with the exception
-     * that one is start of exposure, and the other is start of readout.</p>
-     *
-     * <p>This timestamp base is supported only if {@link
-     * CameraCharacteristics#SENSOR_READOUT_TIMESTAMP} is
-     * {@link CameraMetadata#SENSOR_READOUT_TIMESTAMP_HARDWARE}.</p>
+     * <p>NOTE: do not use! Use useReadoutTimestamp instead.</p>
      *
      * @hide
      */
@@ -579,6 +573,8 @@ public final class OutputConfiguration implements Parcelable {
         mStreamUseCase = CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_DEFAULT;
         mTimestampBase = TIMESTAMP_BASE_DEFAULT;
         mMirrorMode = MIRROR_MODE_AUTO;
+        mUseReadoutTimestamp = false;
+        mIsReadoutSensorTimestampBase = false;
     }
 
     /**
@@ -679,6 +675,8 @@ public final class OutputConfiguration implements Parcelable {
         mDynamicRangeProfile = DynamicRangeProfiles.STANDARD;
         mColorSpace = ColorSpaceProfiles.UNSPECIFIED;
         mStreamUseCase = CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_DEFAULT;
+        mUseReadoutTimestamp = false;
+        mIsReadoutSensorTimestampBase = false;
     }
 
     /**
@@ -1048,7 +1046,15 @@ public final class OutputConfiguration implements Parcelable {
             throw new IllegalArgumentException("Not a valid timestamp base value " +
                     timestampBase);
         }
-        mTimestampBase = timestampBase;
+
+        if (timestampBase == TIMESTAMP_BASE_READOUT_SENSOR) {
+            mTimestampBase = TIMESTAMP_BASE_SENSOR;
+            mUseReadoutTimestamp = true;
+            mIsReadoutSensorTimestampBase = true;
+        } else {
+            mTimestampBase = timestampBase;
+            mIsReadoutSensorTimestampBase = false;
+        }
     }
 
     /**
@@ -1060,7 +1066,11 @@ public final class OutputConfiguration implements Parcelable {
      * @return The currently set timestamp base
      */
     public @TimestampBase int getTimestampBase() {
-        return mTimestampBase;
+        if (mIsReadoutSensorTimestampBase) {
+            return TIMESTAMP_BASE_READOUT_SENSOR;
+        } else {
+            return mTimestampBase;
+        }
     }
 
     /**
@@ -1099,6 +1109,37 @@ public final class OutputConfiguration implements Parcelable {
         return mMirrorMode;
     }
 
+    /**
+     * Use the camera sensor's readout time for the image timestamp.
+     *
+     * <p>The start of the camera sensor readout after exposure. For a rolling shutter camera
+     * sensor, the timestamp is typically equal to {@code (the start of exposure time) +
+     * (exposure time) + (certain fixed offset)}. The fixed offset can vary per session, depending
+     * on the underlying sensor configuration. The benefit of using readout time is that when
+     * camera runs in a fixed frame rate, the timestamp intervals between frames are constant.</p>
+     *
+     * <p>Readout timestamp is supported only if {@link
+     * CameraCharacteristics#SENSOR_READOUT_TIMESTAMP} is
+     * {@link CameraMetadata#SENSOR_READOUT_TIMESTAMP_HARDWARE}.</p>
+     *
+     * <p>As long as readout timestamp is supported, if the timestamp base isi
+     * {@link #TIMESTAMP_BASE_CHOREOGRAPHER_SYNCED}, or if the timestamp base is DEFAULT for a
+     * SurfaceView output, the image timestamps for the output are always readout time regardless
+     * of whether this function is called.</p>
+     *
+     * @param on The output image timestamp is the start of exposure time if false, and
+     *           the start of readout time if true.
+     */
+    public void useReadoutTimestamp(boolean on) {
+        mUseReadoutTimestamp = on;
+    }
+
+    /** Whether readout timestamp is used for this OutputConfiguration.
+     */
+    public boolean isReadoutTimestampUsed() {
+        return mUseReadoutTimestamp;
+    }
+
     /**
      * Create a new {@link OutputConfiguration} instance with another {@link OutputConfiguration}
      * instance.
@@ -1130,6 +1171,7 @@ public final class OutputConfiguration implements Parcelable {
         this.mStreamUseCase = other.mStreamUseCase;
         this.mTimestampBase = other.mTimestampBase;
         this.mMirrorMode = other.mMirrorMode;
+        this.mUseReadoutTimestamp = other.mUseReadoutTimestamp;
     }
 
     /**
@@ -1157,6 +1199,7 @@ public final class OutputConfiguration implements Parcelable {
 
         int timestampBase = source.readInt();
         int mirrorMode = source.readInt();
+        boolean useReadoutTimestamp = source.readInt() == 1;
 
         mSurfaceGroupId = surfaceSetId;
         mRotation = rotation;
@@ -1185,6 +1228,7 @@ public final class OutputConfiguration implements Parcelable {
         mStreamUseCase = streamUseCase;
         mTimestampBase = timestampBase;
         mMirrorMode = mirrorMode;
+        mUseReadoutTimestamp = useReadoutTimestamp;
     }
 
     /**
@@ -1305,6 +1349,7 @@ public final class OutputConfiguration implements Parcelable {
         dest.writeLong(mStreamUseCase);
         dest.writeInt(mTimestampBase);
         dest.writeInt(mMirrorMode);
+        dest.writeInt(mUseReadoutTimestamp ? 1 : 0);
     }
 
     /**
@@ -1338,7 +1383,8 @@ public final class OutputConfiguration implements Parcelable {
                     mIsMultiResolution != other.mIsMultiResolution ||
                     mStreamUseCase != other.mStreamUseCase ||
                     mTimestampBase != other.mTimestampBase ||
-                    mMirrorMode != other.mMirrorMode)
+                    mMirrorMode != other.mMirrorMode ||
+                    mUseReadoutTimestamp != other.mUseReadoutTimestamp)
                 return false;
             if (mSensorPixelModesUsed.size() != other.mSensorPixelModesUsed.size()) {
                 return false;
@@ -1381,7 +1427,7 @@ public final class OutputConfiguration implements Parcelable {
                     mPhysicalCameraId == null ? 0 : mPhysicalCameraId.hashCode(),
                     mIsMultiResolution ? 1 : 0, mSensorPixelModesUsed.hashCode(),
                     mDynamicRangeProfile, mColorSpace, mStreamUseCase,
-                    mTimestampBase, mMirrorMode);
+                    mTimestampBase, mMirrorMode, mUseReadoutTimestamp ? 1 : 0);
         }
 
         return HashCodeHelpers.hashCode(
@@ -1391,7 +1437,7 @@ public final class OutputConfiguration implements Parcelable {
                 mPhysicalCameraId == null ? 0 : mPhysicalCameraId.hashCode(),
                 mIsMultiResolution ? 1 : 0, mSensorPixelModesUsed.hashCode(),
                 mDynamicRangeProfile, mColorSpace, mStreamUseCase, mTimestampBase,
-                mMirrorMode);
+                mMirrorMode, mUseReadoutTimestamp ? 1 : 0);
     }
 
     private static final String TAG = "OutputConfiguration";
@@ -1433,4 +1479,8 @@ public final class OutputConfiguration implements Parcelable {
     private int mTimestampBase;
     // Mirroring mode
     private int mMirrorMode;
+    // Use readout timestamp
+    private boolean mUseReadoutTimestamp;
+    // Whether the timestamp base is set to READOUT_SENSOR
+    private boolean mIsReadoutSensorTimestampBase;
 }