[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/CameraDeviceInfo.java
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@@ -52,6 +52,12 @@
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     int getFirstFrontCameraId();
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     /**
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+     * @return The first (lowest) ID of the external cameras or {@code NO_DEVICE}
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+     *         if not available.
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+     */
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+    int getFirstExternalCameraId();
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+
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+    /**
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      * Device characteristics for a single camera.
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      */
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     public abstract class Characteristics {
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@@ -68,6 +74,11 @@
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         public abstract boolean isFacingFront();
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         /**
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+         * @return Whether the camera faces the device's screen.
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+         *                 */
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+        public abstract boolean isFacingExternal();
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+
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+        /**
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          * @return The camera sensor orientation, or the counterclockwise angle
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          *          from its natural position that the device must be held at
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          *          for the sensor to be right side up (in degrees, always a