[1/4]解决USB摄像头打开相机预览界面绿屏

liyujie

2025-08-28 b3810562527858a3b3d98ffa6e9c9c5b0f4a9a8e

 android/frameworks/ex/camera2/portability/src/com/android/ex/camera2/portability/AndroidCameraAgentImpl.java
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@@ -39,6 +39,7 @@
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 import java.io.IOException;
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 import java.util.Collections;
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+import java.util.HashMap;
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 import java.util.List;
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 import java.util.StringTokenizer;
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@@ -126,29 +127,31 @@
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     }
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     private static class AndroidCameraDeviceInfo implements CameraDeviceInfo {
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-        private final Camera.CameraInfo[] mCameraInfos;
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+        private final HashMap<Integer, Camera.CameraInfo> mCameraInfos;
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         private final int mNumberOfCameras;
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         private final int mFirstBackCameraId;
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         private final int mFirstFrontCameraId;
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+        private final int mFirstExternalCameraId;
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-        private AndroidCameraDeviceInfo(Camera.CameraInfo[] info, int numberOfCameras,
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-                int firstBackCameraId, int firstFrontCameraId) {
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-
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+        private AndroidCameraDeviceInfo(HashMap<Integer, Camera.CameraInfo> info, int numberOfCameras,
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+                int firstBackCameraId, int firstFrontCameraId, int firstExternalCameraId) {
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             mCameraInfos = info;
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             mNumberOfCameras = numberOfCameras;
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             mFirstBackCameraId = firstBackCameraId;
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             mFirstFrontCameraId = firstFrontCameraId;
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+            mFirstExternalCameraId = firstExternalCameraId;
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         }
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         public static AndroidCameraDeviceInfo create() {
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             int numberOfCameras;
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-            Camera.CameraInfo[] cameraInfos;
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+            HashMap<Integer, Camera.CameraInfo> cameraInfos;
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             try {
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                 numberOfCameras = Camera.getNumberOfCameras();
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-                cameraInfos = new Camera.CameraInfo[numberOfCameras];
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+                Log.d(TAG, "create with number " + numberOfCameras);
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+                cameraInfos = new HashMap<Integer, Camera.CameraInfo>();
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                 for (int i = 0; i < numberOfCameras; i++) {
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-                    cameraInfos[i] = new Camera.CameraInfo();
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-                    Camera.getCameraInfo(i, cameraInfos[i]);
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+                    cameraInfos.put(i, new Camera.CameraInfo());
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+                    Camera.getCameraInfo(i, cameraInfos.get(i));
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                 }
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             } catch (RuntimeException ex) {
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                 Log.e(TAG, "Exception while creating CameraDeviceInfo", ex);
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@@ -157,28 +160,29 @@
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             int firstFront = NO_DEVICE;
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             int firstBack = NO_DEVICE;
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+            int firstExternal = NO_DEVICE;
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             // Get the first (smallest) back and first front camera id.
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             for (int i = numberOfCameras - 1; i >= 0; i--) {
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-                if (cameraInfos[i].facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
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+                if (cameraInfos.get(i).facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
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                     firstBack = i;
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-                } else {
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-                    if (cameraInfos[i].facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
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-                        firstFront = i;
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-                    }
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+                } else if (cameraInfos.get(i).facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
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+                    firstFront = i;
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+                }
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+                else if (cameraInfos.get(i).facing == Camera.CameraInfo.CAMERA_FACING_EXTERNAL) {
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+                    firstExternal = i;
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                 }
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             }
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-            return new AndroidCameraDeviceInfo(cameraInfos, numberOfCameras, firstBack, firstFront);
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+            return new AndroidCameraDeviceInfo(cameraInfos, numberOfCameras, firstBack, firstFront, firstExternal);
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         }
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         @Override
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         public Characteristics getCharacteristics(int cameraId) {
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-            if (mCameraInfos == null || mCameraInfos.length == 0 || mCameraInfos.length <= cameraId) {
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-                return null;
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-            }
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-            Camera.CameraInfo info = mCameraInfos[cameraId];
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+            Camera.CameraInfo info = mCameraInfos.get(cameraId);
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             if (info != null) {
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                 return new AndroidCharacteristics(info);
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+            } else if (!mCameraInfos.isEmpty()){
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+                return new AndroidCharacteristics(mCameraInfos.get(0));
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             } else {
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                 return null;
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             }
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@@ -199,6 +203,11 @@
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             return mFirstFrontCameraId;
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         }
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+        @Override
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+        public int getFirstExternalCameraId() {
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+            return mFirstExternalCameraId;
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+        }
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+
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         private static class AndroidCharacteristics extends Characteristics {
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             private Camera.CameraInfo mCameraInfo;
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@@ -217,6 +226,11 @@
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             }
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             @Override
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+            public boolean isFacingExternal() {
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+                return mCameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_EXTERNAL;
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+            }
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+
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+            @Override
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             public int getSensorOrientation() {
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                 return mCameraInfo.orientation;
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             }