Camera2: implement high speed video APIs

Bug: 21442271
Change-Id: Ia0ae5bbd3e8c81bad293c29987301a2457817d12

7 files changed, 375 insertions, 19 deletions

diff --git a/core/java/android/hardware/camera2/CaptureRequest.java b/core/java/android/hardware/camera2/CaptureRequest.java
index b2c1c71..bc625dd 100644
--- a/core/java/android/hardware/camera2/CaptureRequest.java
+++ b/core/java/android/hardware/camera2/CaptureRequest.java
@@ -169,6 +169,9 @@ public final class CaptureRequest extends CameraMetadata<CaptureRequest.Key<?>>
     private final HashSet<Surface> mSurfaceSet;
     private final CameraMetadataNative mSettings;
     private boolean mIsReprocess;
+    // If this request is part of constrained high speed request list that was created by
+    // {@link CameraDevice#createConstrainedHighSpeedRequestList}.
+    private boolean mIsPartOfCHSRequestList = false;
     // Each reprocess request must be tied to a reprocessable session ID.
     // Valid only for reprocess requests (mIsReprocess == true).
     private int mReprocessableSessionId;
@@ -197,6 +200,7 @@ public final class CaptureRequest extends CameraMetadata<CaptureRequest.Key<?>>
         mSettings = new CameraMetadataNative(source.mSettings);
         mSurfaceSet = (HashSet<Surface>) source.mSurfaceSet.clone();
         mIsReprocess = source.mIsReprocess;
+        mIsPartOfCHSRequestList = source.mIsPartOfCHSRequestList;
         mReprocessableSessionId = source.mReprocessableSessionId;
         mUserTag = source.mUserTag;
     }
@@ -321,6 +325,35 @@ public final class CaptureRequest extends CameraMetadata<CaptureRequest.Key<?>>
     }
 
     /**
+     * <p>Determine if this request is part of a constrained high speed request list that was
+     * created by {@link CameraDevice#createConstrainedHighSpeedRequestList}. A constrained high
+     * speed request list contains some constrained high speed capture requests with certain
+     * interleaved pattern that is suitable for high speed preview/video streaming. An active
+     * constrained high speed capture session only accepts constrained high speed request lists.
+     * This method can be used to do the sanity check when a constrained high speed capture session
+     * receives a request list via {@link CameraCaptureSession#setRepeatingBurst} or
+     * {@link CameraCaptureSession#captureBurst}.
+     * </p>
+     *
+     *
+     * @return {@code true} if this request is part of a constrained high speed request list,
+     * {@code false} otherwise.
+     *
+     * @hide
+     */
+    public boolean isPartOfCRequestList() {
+        return mIsPartOfCHSRequestList;
+    }
+
+    /**
+     * Returns a copy of the underlying {@link CameraMetadataNative}.
+     * @hide
+     */
+    public CameraMetadataNative getNativeCopy() {
+        return new CameraMetadataNative(mSettings);
+    }
+
+    /**
      * Get the reprocessable session ID this reprocess capture request is associated with.
      *
      * @return the reprocessable session ID this reprocess capture request is associated with
@@ -547,6 +580,18 @@ public final class CaptureRequest extends CameraMetadata<CaptureRequest.Key<?>>
         }
 
         /**
+         * <p>Mark this request as part of a constrained high speed request list created by
+         * {@link CameraDevice#createConstrainedHighSpeedRequestList}. A constrained high speed
+         * request list contains some constrained high speed capture requests with certain
+         * interleaved pattern that is suitable for high speed preview/video streaming.</p>
+         *
+         * @hide
+         */
+        public void setPartOfCHSRequestList(boolean partOfCHSList) {
+            mRequest.mIsPartOfCHSRequestList = partOfCHSList;
+        }
+
+        /**
          * Build a request using the current target Surfaces and settings.
          * <p>Note that, although it is possible to create a {@code CaptureRequest} with no target
          * {@link Surface}s, passing such a request into {@link CameraCaptureSession#capture},
@@ -563,7 +608,6 @@ public final class CaptureRequest extends CameraMetadata<CaptureRequest.Key<?>>
             return new CaptureRequest(mRequest);
         }
 
-
         /**
          * @hide
          */
diff --git a/core/java/android/hardware/camera2/ICameraDeviceUser.aidl b/core/java/android/hardware/camera2/ICameraDeviceUser.aidl
index 375b310..1574f93 100644
--- a/core/java/android/hardware/camera2/ICameraDeviceUser.aidl
+++ b/core/java/android/hardware/camera2/ICameraDeviceUser.aidl
@@ -61,7 +61,7 @@ interface ICameraDeviceUser
      * must be called before any requests can be submitted.
      * <p>
      */
-    int endConfigure();
+    int endConfigure(boolean isConstrainedHighSpeed);
 
     int deleteStream(int streamId);
 
diff --git a/core/java/android/hardware/camera2/impl/CameraCaptureSessionImpl.java b/core/java/android/hardware/camera2/impl/CameraCaptureSessionImpl.java
index ab0f607..cbc85f3 100644
--- a/core/java/android/hardware/camera2/impl/CameraCaptureSessionImpl.java
+++ b/core/java/android/hardware/camera2/impl/CameraCaptureSessionImpl.java
@@ -60,6 +60,7 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
     private final android.hardware.camera2.impl.CameraDeviceImpl mDeviceImpl;
     /** Internal handler; used for all incoming events to preserve total order */
     private final Handler mDeviceHandler;
+    private final boolean mIsConstrainedHighSpeedSession;
 
     /** Drain Sequence IDs which have been queued but not yet finished with aborted/completed */
     private final TaskDrainer<Integer> mSequenceDrainer;
@@ -88,13 +89,14 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
     CameraCaptureSessionImpl(int id, Surface input, List<Surface> outputs,
             CameraCaptureSession.StateCallback callback, Handler stateHandler,
             android.hardware.camera2.impl.CameraDeviceImpl deviceImpl,
-            Handler deviceStateHandler, boolean configureSuccess) {
+            Handler deviceStateHandler, boolean configureSuccess, boolean isConstrainedHighSpeed) {
         if (outputs == null || outputs.isEmpty()) {
             throw new IllegalArgumentException("outputs must be a non-null, non-empty list");
         } else if (callback == null) {
             throw new IllegalArgumentException("callback must not be null");
         }
 
+        mIsConstrainedHighSpeedSession = isConstrainedHighSpeed;
         mId = id;
         mIdString = String.format("Session %d: ", mId);
 
@@ -134,6 +136,30 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
         }
     }
 
+
+    private boolean isConstrainedHighSpeedRequestList(List<CaptureRequest> requestList) {
+        checkCollectionNotEmpty(requestList, "High speed request list");
+        for (CaptureRequest request : requestList) {
+            if (!request.isPartOfCRequestList()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * If the session is constrained high speed session, it only accept constrained high speed
+     * request list.
+     */
+    private void checkConstrainedHighSpeedRequestSanity(List<CaptureRequest> requestList) {
+        if (mIsConstrainedHighSpeedSession) {
+            if (!isConstrainedHighSpeedRequestList(requestList)) {
+                throw new IllegalArgumentException("It is only allowed to submit a constrained "
+                        + "high speed request list to a constrianed high speed session!!!");
+            }
+        }
+    }
+
     @Override
     public CameraDevice getDevice() {
         return mDeviceImpl;
@@ -155,6 +181,10 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
         } else if (request.isReprocess() && request.getReprocessableSessionId() != mId) {
             throw new IllegalArgumentException("capture request was created for another session");
         }
+        if (mIsConstrainedHighSpeedSession) {
+            throw new UnsupportedOperationException("Constrained high speed session doesn't support"
+                    + " this method");
+        }
 
         checkNotClosed();
 
@@ -178,6 +208,8 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
             throw new IllegalArgumentException("Requests must have at least one element");
         }
 
+        checkConstrainedHighSpeedRequestSanity(requests);
+
         for (CaptureRequest request : requests) {
             if (request.isReprocess()) {
                 if (!isReprocessable()) {
@@ -212,7 +244,10 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
         } else if (request.isReprocess()) {
             throw new IllegalArgumentException("repeating reprocess requests are not supported");
         }
-
+        if (mIsConstrainedHighSpeedSession) {
+            throw new UnsupportedOperationException("Constrained high speed session doesn't support"
+                    + " this method");
+        }
 
         checkNotClosed();
 
@@ -236,6 +271,8 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
             throw new IllegalArgumentException("requests must have at least one element");
         }
 
+        checkConstrainedHighSpeedRequestSanity(requests);
+
         for (CaptureRequest r : requests) {
             if (r.isReprocess()) {
                 throw new IllegalArgumentException("repeating reprocess burst requests are not " +
@@ -704,7 +741,8 @@ public class CameraCaptureSessionImpl extends CameraCaptureSession {
                     // everything is idle.
                     try {
                         // begin transition to unconfigured
-                        mDeviceImpl.configureStreamsChecked(null, null);
+                        mDeviceImpl.configureStreamsChecked(/*inputConfig*/null, /*outputs*/null,
+                                /*isConstrainedHighSpeed*/false);
                     } catch (CameraAccessException e) {
                         // OK: do not throw checked exceptions.
                         Log.e(TAG, mIdString + "Exception while unconfiguring outputs: ", e);
diff --git a/core/java/android/hardware/camera2/impl/CameraDeviceImpl.java b/core/java/android/hardware/camera2/impl/CameraDeviceImpl.java
index 16701e5..e975105 100644
--- a/core/java/android/hardware/camera2/impl/CameraDeviceImpl.java
+++ b/core/java/android/hardware/camera2/impl/CameraDeviceImpl.java
@@ -18,6 +18,7 @@ package android.hardware.camera2.impl;
 
 import static android.hardware.camera2.CameraAccessException.CAMERA_IN_USE;
 
+import android.graphics.ImageFormat;
 import android.hardware.camera2.CameraAccessException;
 import android.hardware.camera2.CameraCaptureSession;
 import android.hardware.camera2.CameraCharacteristics;
@@ -35,17 +36,22 @@ import android.hardware.camera2.params.StreamConfigurationMap;
 import android.hardware.camera2.utils.CameraBinderDecorator;
 import android.hardware.camera2.utils.CameraRuntimeException;
 import android.hardware.camera2.utils.LongParcelable;
+import android.hardware.camera2.utils.SurfaceUtils;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.RemoteException;
 import android.util.Log;
+import android.util.Range;
 import android.util.Size;
 import android.util.SparseArray;
 import android.view.Surface;
 
 import java.util.AbstractMap.SimpleEntry;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -326,7 +332,8 @@ public class CameraDeviceImpl extends CameraDevice {
         for (Surface s : outputs) {
             outputConfigs.add(new OutputConfiguration(s));
         }
-        configureStreamsChecked(/*inputConfig*/null, outputConfigs);
+        configureStreamsChecked(/*inputConfig*/null, outputConfigs,
+                /*isConstrainedHighSpeed*/false);
 
     }
 
@@ -344,12 +351,14 @@ public class CameraDeviceImpl extends CameraDevice {
      *
      * @param inputConfig input configuration or {@code null} for no input
      * @param outputs a list of one or more surfaces, or {@code null} to unconfigure
+     * @param isConstrainedHighSpeed If the streams configuration is for constrained high speed output.
      * @return whether or not the configuration was successful
      *
      * @throws CameraAccessException if there were any unexpected problems during configuration
      */
     public boolean configureStreamsChecked(InputConfiguration inputConfig,
-            List<OutputConfiguration> outputs) throws CameraAccessException {
+            List<OutputConfiguration> outputs, boolean isConstrainedHighSpeed)
+                    throws CameraAccessException {
         // Treat a null input the same an empty list
         if (outputs == null) {
             outputs = new ArrayList<OutputConfiguration>();
@@ -422,7 +431,7 @@ public class CameraDeviceImpl extends CameraDevice {
                 }
 
                 try {
-                    mRemoteDevice.endConfigure();
+                    mRemoteDevice.endConfigure(isConstrainedHighSpeed);
                 }
                 catch (IllegalArgumentException e) {
                     // OK. camera service can reject stream config if it's not supported by HAL
@@ -463,7 +472,8 @@ public class CameraDeviceImpl extends CameraDevice {
         for (Surface surface : outputs) {
             outConfigurations.add(new OutputConfiguration(surface));
         }
-        createCaptureSessionInternal(null, outConfigurations, callback, handler);
+        createCaptureSessionInternal(null, outConfigurations, callback, handler,
+                /*isConstrainedHighSpeed*/false);
     }
 
     @Override
@@ -475,7 +485,8 @@ public class CameraDeviceImpl extends CameraDevice {
             Log.d(TAG, "createCaptureSessionByOutputConfiguration");
         }
 
-        createCaptureSessionInternal(null, outputConfigurations, callback, handler);
+        createCaptureSessionInternal(null, outputConfigurations, callback, handler,
+                /*isConstrainedHighSpeed*/false);
     }
 
     @Override
@@ -494,13 +505,14 @@ public class CameraDeviceImpl extends CameraDevice {
         for (Surface surface : outputs) {
             outConfigurations.add(new OutputConfiguration(surface));
         }
-        createCaptureSessionInternal(inputConfig, outConfigurations, callback, handler);
+        createCaptureSessionInternal(inputConfig, outConfigurations, callback, handler,
+                /*isConstrainedHighSpeed*/false);
     }
 
     private void createCaptureSessionInternal(InputConfiguration inputConfig,
             List<OutputConfiguration> outputConfigurations,
-            CameraCaptureSession.StateCallback callback, Handler handler)
-            throws CameraAccessException {
+            CameraCaptureSession.StateCallback callback, Handler handler,
+            boolean isConstrainedHighSpeed) throws CameraAccessException {
         synchronized(mInterfaceLock) {
             if (DEBUG) {
                 Log.d(TAG, "createCaptureSessionInternal");
@@ -508,6 +520,11 @@ public class CameraDeviceImpl extends CameraDevice {
 
             checkIfCameraClosedOrInError();
 
+            if (isConstrainedHighSpeed && inputConfig != null) {
+                throw new IllegalArgumentException("Constrained high speed session doesn't support"
+                        + " input configuration yet.");
+            }
+
             // Notify current session that it's going away, before starting camera operations
             // After this call completes, the session is not allowed to call into CameraDeviceImpl
             if (mCurrentSession != null) {
@@ -520,7 +537,8 @@ public class CameraDeviceImpl extends CameraDevice {
             Surface input = null;
             try {
                  // configure streams and then block until IDLE
-                configureSuccess = configureStreamsChecked(inputConfig, outputConfigurations);
+                configureSuccess = configureStreamsChecked(inputConfig, outputConfigurations,
+                        isConstrainedHighSpeed);
                 if (inputConfig != null) {
                     input = new Surface();
                     mRemoteDevice.getInputSurface(/*out*/input);
@@ -545,7 +563,7 @@ public class CameraDeviceImpl extends CameraDevice {
             CameraCaptureSessionImpl newSession =
                     new CameraCaptureSessionImpl(mNextSessionId++, input,
                             outSurfaces, callback, handler, this, mDeviceHandler,
-                            configureSuccess);
+                            configureSuccess, isConstrainedHighSpeed);
 
             // TODO: wait until current session closes, then create the new session
             mCurrentSession = newSession;
@@ -1907,17 +1925,156 @@ public class CameraDeviceImpl extends CameraDevice {
         return mCharacteristics;
     }
 
+    private void checkConstrainedHighSpeedSurfaces(Collection<Surface> surfaces,
+            Range<Integer> fpsRange) {
+        if (surfaces == null || surfaces.size() == 0 || surfaces.size() > 2) {
+            throw new IllegalArgumentException("Output target surface list must not be null and"
+                    + " the size must be 1 or 2");
+        }
+
+        StreamConfigurationMap config =
+                getCharacteristics().get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
+        List<Size> highSpeedSizes = null;
+        if (fpsRange == null) {
+            highSpeedSizes = Arrays.asList(config.getHighSpeedVideoSizes());
+        } else {
+            // Check the FPS range first if provided
+            Range<Integer>[] highSpeedFpsRanges = config.getHighSpeedVideoFpsRanges();
+            if(!Arrays.asList(highSpeedFpsRanges).contains(fpsRange)) {
+                throw new IllegalArgumentException("Fps range " + fpsRange.toString() + " in the"
+                        + " request is not a supported high speed fps range " +
+                        Arrays.toString(highSpeedFpsRanges));
+            }
+            highSpeedSizes = Arrays.asList(config.getHighSpeedVideoSizesFor(fpsRange));
+        }
+
+        for (Surface surface : surfaces) {
+            // Surface size must be supported high speed sizes.
+            Size surfaceSize = SurfaceUtils.getSurfaceSize(surface);
+            int surfaceFormat = SurfaceUtils.getSurfaceFormat(surface);
+
+            if (surfaceFormat != ImageFormat.PRIVATE) {
+                throw new IllegalArgumentException("Surface format is not for preview or"
+                        + " hardware video encoding" + surfaceFormat);
+            }
+
+            if (!highSpeedSizes.contains(surfaceSize)) {
+                throw new IllegalArgumentException("Surface size " + surfaceSize.toString() + " is"
+                        + " not part of the high speed supported size list " +
+                        Arrays.toString(highSpeedSizes.toArray()));
+            }
+            // Each output surface must be either preview surface or recording surface.
+            if (!SurfaceUtils.isSurfaceForPreview(surface) &&
+                    !SurfaceUtils.isSurfaceForHwVideoEncoder(surface)) {
+                throw new IllegalArgumentException("This output surface is neither preview nor "
+                        + "hardware video encoding surface");
+            }
+            if (SurfaceUtils.isSurfaceForPreview(surface) &&
+                    SurfaceUtils.isSurfaceForHwVideoEncoder(surface)) {
+                throw new IllegalArgumentException("This output surface can not be both preview"
+                        + " and hardware video encoding surface");
+            }
+        }
+
+        // For 2 output surface case, they shouldn't be same type.
+        if (surfaces.size() == 2) {
+            // Up to here, each surface can only be either preview or recording.
+            Iterator<Surface> iterator = surfaces.iterator();
+            boolean isFirstSurfacePreview =
+                    SurfaceUtils.isSurfaceForPreview(iterator.next());
+            boolean isSecondSurfacePreview =
+                    SurfaceUtils.isSurfaceForPreview(iterator.next());
+            if (isFirstSurfacePreview == isSecondSurfacePreview) {
+                throw new IllegalArgumentException("The 2 output surfaces must have different"
+                        + " type");
+            }
+        }
+    }
+
     @Override
     public void createConstrainedHighSpeedCaptureSession(List<Surface> outputs,
             android.hardware.camera2.CameraCaptureSession.StateCallback callback, Handler handler)
             throws CameraAccessException {
-        // TODO: to be implemented
-        throw new UnsupportedOperationException("To be implemented!!!!");
+        if (outputs == null || outputs.size() == 0 || outputs.size() > 2) {
+            throw new IllegalArgumentException(
+                    "Output surface list must not be null and the size must be no more than 2");
+        }
+        checkConstrainedHighSpeedSurfaces(outputs, /*fpsRange*/null);
+
+        List<OutputConfiguration> outConfigurations = new ArrayList<>(outputs.size());
+        for (Surface surface : outputs) {
+            outConfigurations.add(new OutputConfiguration(surface));
+        }
+        createCaptureSessionInternal(null, outConfigurations, callback, handler,
+                /*isConstrainedHighSpeed*/true);
     }
 
     @Override
     public List<CaptureRequest> createConstrainedHighSpeedRequestList(CaptureRequest request)
             throws CameraAccessException {
-        throw new UnsupportedOperationException("To be implemented!!!!");
+        if (request == null) {
+            throw new IllegalArgumentException("Input capture request must not be null");
+        }
+        Collection<Surface> outputSurfaces = request.getTargets();
+        Range<Integer> fpsRange = request.get(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE);
+        checkConstrainedHighSpeedSurfaces(outputSurfaces, fpsRange);
+
+        // Request list size: to limit the preview to 30fps, need use maxFps/30; to maximize
+        // the preview frame rate, should use maxBatch size for that high speed stream
+        // configuration. We choose the former for now.
+        int requestListSize = fpsRange.getUpper() / 30;
+        List<CaptureRequest> requestList = new ArrayList<CaptureRequest>();
+
+        // Prepare the Request builders: need carry over the request controls.
+        // First, create a request builder that will only include preview or recording target.
+        CameraMetadataNative requestMetadata = new CameraMetadataNative(request.getNativeCopy());
+        CaptureRequest.Builder singleTargetRequestBuilder = new CaptureRequest.Builder(
+                requestMetadata, /*reprocess*/false, CameraCaptureSession.SESSION_ID_NONE);
+
+        // Overwrite the capture intent to make sure a good value is set.
+        Surface[] surfaces = (Surface[])outputSurfaces.toArray();
+        if (outputSurfaces.size() == 1 && SurfaceUtils.isSurfaceForHwVideoEncoder(surfaces[0])) {
+            singleTargetRequestBuilder.set(CaptureRequest.CONTROL_CAPTURE_INTENT,
+                    CaptureRequest.CONTROL_CAPTURE_INTENT_PREVIEW);
+        } else {
+            // Video only, or preview + video
+            singleTargetRequestBuilder.set(CaptureRequest.CONTROL_CAPTURE_INTENT,
+                    CaptureRequest.CONTROL_CAPTURE_INTENT_VIDEO_RECORD);
+        }
+        singleTargetRequestBuilder.setPartOfCHSRequestList(/*partOfCHSList*/true);
+
+        // Second, Create a request builder that will include both preview and recording targets.
+        CaptureRequest.Builder doubleTargetRequestBuilder = null;
+        if (outputSurfaces.size() == 2) {
+            doubleTargetRequestBuilder = new CaptureRequest.Builder(
+                    requestMetadata, /*reprocess*/false, CameraCaptureSession.SESSION_ID_NONE);
+            doubleTargetRequestBuilder.set(CaptureRequest.CONTROL_CAPTURE_INTENT,
+                    CaptureRequest.CONTROL_CAPTURE_INTENT_VIDEO_RECORD);
+            doubleTargetRequestBuilder.addTarget(surfaces[0]);
+            doubleTargetRequestBuilder.addTarget(surfaces[1]);
+            doubleTargetRequestBuilder.setPartOfCHSRequestList(/*partOfCHSList*/true);
+            // Make sure singleTargetRequestBuilder contains only recording surface for
+            // preview + recording case.
+            Surface recordingSurface = surfaces[0];
+            if (!SurfaceUtils.isSurfaceForHwVideoEncoder(recordingSurface)) {
+                recordingSurface = surfaces[1];
+            }
+            singleTargetRequestBuilder.addTarget(recordingSurface);
+        } else {
+            // Single output case: either recording or preview.
+            singleTargetRequestBuilder.addTarget(surfaces[0]);
+        }
+
+        // Generate the final request list.
+        for (int i = 0; i < requestListSize; i++) {
+            if (i == 0 && doubleTargetRequestBuilder != null) {
+                // First request should be recording + preview request
+                requestList.add(doubleTargetRequestBuilder.build());
+            } else {
+                requestList.add(singleTargetRequestBuilder.build());
+            }
+        }
+
+        return Collections.unmodifiableList(requestList);
     }
 }
diff --git a/core/java/android/hardware/camera2/legacy/CameraDeviceUserShim.java b/core/java/android/hardware/camera2/legacy/CameraDeviceUserShim.java
index bc0a3a8..e963a0d 100644
--- a/core/java/android/hardware/camera2/legacy/CameraDeviceUserShim.java
+++ b/core/java/android/hardware/camera2/legacy/CameraDeviceUserShim.java
@@ -465,7 +465,7 @@ public class CameraDeviceUserShim implements ICameraDeviceUser {
     }
 
     @Override
-    public int endConfigure() {
+    public int endConfigure(boolean isConstrainedHighSpeed) {
         if (DEBUG) {
             Log.d(TAG, "endConfigure called.");
         }
diff --git a/core/java/android/hardware/camera2/legacy/LegacyCameraDevice.java b/core/java/android/hardware/camera2/legacy/LegacyCameraDevice.java
index 098c2d8..cc9d496 100644
--- a/core/java/android/hardware/camera2/legacy/LegacyCameraDevice.java
+++ b/core/java/android/hardware/camera2/legacy/LegacyCameraDevice.java
@@ -82,6 +82,7 @@ public class LegacyCameraDevice implements AutoCloseable {
     private static final int GRALLOC_USAGE_SW_READ_OFTEN = 0x00000003;
     private static final int GRALLOC_USAGE_HW_TEXTURE = 0x00000100;
     private static final int GRALLOC_USAGE_HW_COMPOSER = 0x00000800;
+    private static final int GRALLOC_USAGE_HW_RENDER = 0x00000200;
     private static final int GRALLOC_USAGE_HW_VIDEO_ENCODER = 0x00010000;
 
     public static final int MAX_DIMEN_FOR_ROUNDING = 1080; // maximum allowed width for rounding
@@ -549,6 +550,42 @@ public class LegacyCameraDevice implements AutoCloseable {
         return flexibleConsumer;
     }
 
+    public static boolean isPreviewConsumer(Surface output) {
+        int usageFlags = detectSurfaceUsageFlags(output);
+        int disallowedFlags = GRALLOC_USAGE_HW_VIDEO_ENCODER | GRALLOC_USAGE_RENDERSCRIPT |
+                GRALLOC_USAGE_SW_READ_OFTEN;
+        int allowedFlags = GRALLOC_USAGE_HW_TEXTURE | GRALLOC_USAGE_HW_COMPOSER |
+                GRALLOC_USAGE_HW_RENDER;
+        boolean previewConsumer = ((usageFlags & disallowedFlags) == 0 &&
+                (usageFlags & allowedFlags) != 0);
+        int surfaceFormat = ImageFormat.UNKNOWN;
+        try {
+            surfaceFormat = detectSurfaceType(output);
+        } catch(BufferQueueAbandonedException e) {
+            throw new IllegalArgumentException("Surface was abandoned", e);
+        }
+
+        return previewConsumer && (surfaceFormat == ImageFormat.PRIVATE);
+    }
+
+    public static boolean isVideoEncoderConsumer(Surface output) {
+        int usageFlags = detectSurfaceUsageFlags(output);
+        int disallowedFlags = GRALLOC_USAGE_HW_TEXTURE | GRALLOC_USAGE_HW_COMPOSER |
+                GRALLOC_USAGE_RENDERSCRIPT | GRALLOC_USAGE_SW_READ_OFTEN;
+        int allowedFlags = GRALLOC_USAGE_HW_VIDEO_ENCODER;
+        boolean videoEncoderConsumer = ((usageFlags & disallowedFlags) == 0 &&
+                (usageFlags & allowedFlags) != 0);
+
+        int surfaceFormat = ImageFormat.UNKNOWN;
+        try {
+            surfaceFormat = detectSurfaceType(output);
+        } catch(BufferQueueAbandonedException e) {
+            throw new IllegalArgumentException("Surface was abandoned", e);
+        }
+
+        return videoEncoderConsumer && (surfaceFormat == ImageFormat.PRIVATE);
+    }
+
     /**
      * Query the surface for its currently configured usage flags
      */
diff --git a/core/java/android/hardware/camera2/utils/SurfaceUtils.java b/core/java/android/hardware/camera2/utils/SurfaceUtils.java
new file mode 100644
index 0000000..79d82a8
--- /dev/null
+++ b/core/java/android/hardware/camera2/utils/SurfaceUtils.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.camera2.utils;
+
+import android.hardware.camera2.legacy.LegacyCameraDevice;
+import android.hardware.camera2.legacy.LegacyExceptionUtils.BufferQueueAbandonedException;
+import android.util.Size;
+import android.view.Surface;
+
+/**
+ * Various Surface utilities.
+ */
+public class SurfaceUtils {
+
+    /**
+     * Check if a surface is for preview consumer.
+     *
+     * @param surface The surface to be checked.
+     * @return true if the surface is for preview consumer, false otherwise.
+     */
+    public static boolean isSurfaceForPreview(Surface surface) {
+        return LegacyCameraDevice.isPreviewConsumer(surface);
+    }
+
+    /**
+     * Check if the surface is for hardware video encoder consumer.
+     *
+     * @param surface The surface to be checked.
+     * @return true if the surface is for hardware video encoder consumer, false otherwise.
+     */
+    public static boolean isSurfaceForHwVideoEncoder(Surface surface) {
+        return LegacyCameraDevice.isVideoEncoderConsumer(surface);
+    }
+
+    /**
+     * Get the Surface size.
+     *
+     * @param surface The surface to be queried for size.
+     * @return Size of the surface.
+     *
+     * @throw IllegalArgumentException if the surface is already abandoned.
+     */
+    public static Size getSurfaceSize(Surface surface) {
+        try {
+            return LegacyCameraDevice.getSurfaceSize(surface);
+        } catch (BufferQueueAbandonedException e) {
+            throw new IllegalArgumentException("Surface was abandoned", e);
+        }
+    }
+
+    /**
+     * Get the Surface format.
+     *
+     * @param surface The surface to be queried for format.
+     * @return format of the surface.
+     *
+     * @throw IllegalArgumentException if the surface is already abandoned.
+     */
+    public static int getSurfaceFormat(Surface surface) {
+        try {
+            return LegacyCameraDevice.detectSurfaceType(surface);
+        } catch (BufferQueueAbandonedException e) {
+            throw new IllegalArgumentException("Surface was abandoned", e);
+        }
+    }
+}