Camera2: Add distortion correction support

This allows camera devices to correct geometric distortion in their
optics, when requested by the application.

The correction only applies to processed (YUV, JPEG, etc) outputs,
not RAW buffers, or the result metadata.

Test: New CTS test passes
Bug: 74434422
Change-Id: I77a84c1321058ab6637be2fffaca19a27f46dca1

camera/ndk/impl/ACameraMetadata.cpp

@@ -313,6 +313,7 @@ ACameraMetadata::isCaptureRequestTag(const uint32_t tag) {
         case ACAMERA_TONEMAP_GAMMA:
         case ACAMERA_TONEMAP_PRESET_CURVE:
         case ACAMERA_BLACK_LEVEL_LOCK:
+        case ACAMERA_DISTORTION_CORRECTION_MODE:
             return true;
         default:
             return false;

camera/ndk/include/camera/NdkCameraMetadataTags.h

@@ -70,6 +70,7 @@ typedef enum acamera_metadata_section {
     ACAMERA_REPROCESS,
     ACAMERA_DEPTH,
     ACAMERA_LOGICAL_MULTI_CAMERA,
+    ACAMERA_DISTORTION_CORRECTION,
     ACAMERA_SECTION_COUNT,
 
     ACAMERA_VENDOR = 0x8000
@@ -108,6 +109,9 @@ typedef enum acamera_metadata_section_start {
     ACAMERA_LOGICAL_MULTI_CAMERA_START
                                    = ACAMERA_LOGICAL_MULTI_CAMERA
                                                                 << 16,
+    ACAMERA_DISTORTION_CORRECTION_START
+                                   = ACAMERA_DISTORTION_CORRECTION
+                                                                << 16,
     ACAMERA_VENDOR_START           = ACAMERA_VENDOR            << 16
 } acamera_metadata_section_start_t;
 
@@ -5284,6 +5288,63 @@ typedef enum acamera_metadata_tag {
             ACAMERA_LOGICAL_MULTI_CAMERA_START + 1,
     ACAMERA_LOGICAL_MULTI_CAMERA_END,
 
+    /**
+     * <p>Mode of operation for the lens distortion correction block.</p>
+     *
+     * <p>Type: byte (acamera_metadata_enum_android_distortion_correction_mode_t)</p>
+     *
+     * <p>This tag may appear in:
+     * <ul>
+     *   <li>ACameraMetadata from ACameraCaptureSession_captureCallback_result callbacks</li>
+     *   <li>ACaptureRequest</li>
+     * </ul></p>
+     *
+     * <p>The lens distortion correction block attempts to improve image quality by fixing
+     * radial, tangential, or other geometric aberrations in the camera device's optics.  If
+     * available, the ACAMERA_LENS_DISTORTION field documents the lens's distortion parameters.</p>
+     * <p>OFF means no distortion correction is done.</p>
+     * <p>FAST/HIGH_QUALITY both mean camera device determined distortion correction will be
+     * applied. HIGH_QUALITY mode indicates that the camera device will use the highest-quality
+     * correction algorithms, even if it slows down capture rate. FAST means the camera device
+     * will not slow down capture rate when applying correction. FAST may be the same as OFF if
+     * any correction at all would slow down capture rate.  Every output stream will have a
+     * similar amount of enhancement applied.</p>
+     * <p>The correction only applies to processed outputs such as YUV, JPEG, or DEPTH16; it is not
+     * applied to any RAW output.  Metadata coordinates such as face rectangles or metering
+     * regions are also not affected by correction.</p>
+     * <p>Applications enabling distortion correction need to pay extra attention when converting
+     * image coordinates between corrected output buffers and the sensor array. For example, if
+     * the app supports tap-to-focus and enables correction, it then has to apply the distortion
+     * model described in ACAMERA_LENS_DISTORTION to the image buffer tap coordinates to properly
+     * calculate the tap position on the sensor active array to be used with
+     * ACAMERA_CONTROL_AF_REGIONS. The same applies in reverse to detected face rectangles if
+     * they need to be drawn on top of the corrected output buffers.</p>
+     *
+     * @see ACAMERA_CONTROL_AF_REGIONS
+     * @see ACAMERA_LENS_DISTORTION
+     */
+    ACAMERA_DISTORTION_CORRECTION_MODE =                        // byte (acamera_metadata_enum_android_distortion_correction_mode_t)
+            ACAMERA_DISTORTION_CORRECTION_START,
+    /**
+     * <p>List of distortion correction modes for ACAMERA_DISTORTION_CORRECTION_MODE that are
+     * supported by this camera device.</p>
+     *
+     * @see ACAMERA_DISTORTION_CORRECTION_MODE
+     *
+     * <p>Type: byte[n]</p>
+     *
+     * <p>This tag may appear in:
+     * <ul>
+     *   <li>ACameraMetadata from ACameraManager_getCameraCharacteristics</li>
+     * </ul></p>
+     *
+     * <p>No device is required to support this API; such devices will always list only 'OFF'.
+     * All devices that support this API will list both FAST and HIGH_QUALITY.</p>
+     */
+    ACAMERA_DISTORTION_CORRECTION_AVAILABLE_MODES =             // byte[n]
+            ACAMERA_DISTORTION_CORRECTION_START + 1,
+    ACAMERA_DISTORTION_CORRECTION_END,
+
 } acamera_metadata_tag_t;
 
 /**
@@ -7679,6 +7740,29 @@ typedef enum acamera_metadata_enum_acamera_logical_multi_camera_sensor_sync_type
 } acamera_metadata_enum_android_logical_multi_camera_sensor_sync_type_t;
 
 
+// ACAMERA_DISTORTION_CORRECTION_MODE
+typedef enum acamera_metadata_enum_acamera_distortion_correction_mode {
+    /**
+     * <p>No distortion correction is applied.</p>
+     */
+    ACAMERA_DISTORTION_CORRECTION_MODE_OFF                           = 0,
+
+    /**
+     * <p>Lens distortion correction is applied without reducing frame rate
+     * relative to sensor output. It may be the same as OFF if distortion correction would
+     * reduce frame rate relative to sensor.</p>
+     */
+    ACAMERA_DISTORTION_CORRECTION_MODE_FAST                          = 1,
+
+    /**
+     * <p>High-quality distortion correction is applied, at the cost of
+     * possibly reduced frame rate relative to sensor output.</p>
+     */
+    ACAMERA_DISTORTION_CORRECTION_MODE_HIGH_QUALITY                  = 2,
+
+} acamera_metadata_enum_android_distortion_correction_mode_t;
+
+
 #endif /* __ANDROID_API__ >= 24 */
 
 __END_DECLS