WIP: Android Camera2 capture implementation

webrtc/api/java/android/org/webrtc/CameraEnumerationAndroid.java

Index: webrtc/api/java/android/org/webrtc/CameraEnumerationAndroid.java
diff --git a/webrtc/api/java/android/org/webrtc/CameraEnumerationAndroid.java b/webrtc/api/java/android/org/webrtc/CameraEnumerationAndroid.java
index c5c8be3a5d8e62443fb28ce70c9a8dc82fd0d1c5..87f2adc1431e8376310999a342cf837182893c77 100644
--- a/webrtc/api/java/android/org/webrtc/CameraEnumerationAndroid.java
+++ b/webrtc/api/java/android/org/webrtc/CameraEnumerationAndroid.java
@@ -23,7 +23,7 @@ import java.util.List;
 public class CameraEnumerationAndroid {
   private final static String TAG = "CameraEnumerationAndroid";
   // Synchronized on |CameraEnumerationAndroid.this|.
-  private static Enumerator enumerator = new CameraEnumerator();
+  private static Enumerator enumerator = new Camera1Enumerator();
 
   public interface Enumerator {
     /**
@@ -43,26 +43,90 @@ public class CameraEnumerationAndroid {
   }
 
   public static class CaptureFormat {
-    public final int width;
-    public final int height;
-    public final int maxFramerate;
-    public final int minFramerate;
+    // Class for describing width and height dimensions in pixels.
+    public static class Size {
+      public int width;
+      public int height;
+
+      public Size(int width, int height) {
+        this.width = width;
+        this.height = height;
+      }
+
+      @Override
+      public String toString() {
+        return width + "x" + height;
+      }
+
+      @Override
+      public boolean equals(Object other) {
+        if (!(other instanceof Size)) {
+          return false;
+        }
+        final Size otherSize = (Size) other;
+        return width == otherSize.width && height == otherSize.height;
+      }
+
+      @Override
+      public int hashCode() {
+        // Use prime close to 2^16 to avoid collisions for normal values less than 2^16.
+        return 1 + 65537 * width + height;
+      }
+    }
+
+    // Class to represent a framerate range. The framerate varies because of lightning conditions.
+    // The values are multiplied by 1000, so 1000 represents one frame per second.
+    public static class FramerateRange {
+      public int min;
+      public int max;
+
+      public FramerateRange(int min, int max) {
+        this.min = min;
+        this.max = max;
+      }
+
+      @Override
+      public String toString() {
+        return "[" + min + ":" + max + "]";
+      }
+
+      @Override
+      public boolean equals(Object other) {
+        if (!(other instanceof FramerateRange)) {
+          return false;
+        }
+        final FramerateRange otherFramerate = (FramerateRange) other;
+        return min == otherFramerate.min && max == otherFramerate.max;
+      }
+
+      @Override
+      public int hashCode() {
+        // Use prime close to 2^16 to avoid collisions for normal values less than 2^16.
+        return 1 + 65537 * min + max;
+      }
+    }
+
+    public final Size size;
+    public final FramerateRange framerate;
+
     // TODO(hbos): If VideoCapturer.startCapture is updated to support other image formats then this
     // needs to be updated and VideoCapturer.getSupportedFormats need to return CaptureFormats of
     // all imageFormats.
     public final int imageFormat = ImageFormat.NV21;
 
-    public CaptureFormat(int width, int height, int minFramerate,
-        int maxFramerate) {
-      this.width = width;
-      this.height = height;
-      this.minFramerate = minFramerate;
-      this.maxFramerate = maxFramerate;
+    public CaptureFormat(int width, int height, int minFramerate, int maxFramerate) {
+      this.size = new Size(width, height);
+      this.framerate = new FramerateRange(minFramerate, maxFramerate);
+    }
+
+    public CaptureFormat(Size size, FramerateRange framerate) {
+      this.size = size;
+      this.framerate = framerate;
     }
 
     // Calculates the frame size of this capture format.
     public int frameSize() {
-      return frameSize(width, height, imageFormat);
+      return frameSize(size.width, size.height, imageFormat);
     }
 
     // Calculates the frame size of the specified image format. Currently only
@@ -79,15 +143,21 @@ public class CameraEnumerationAndroid {
 
     @Override
     public String toString() {
-      return width + "x" + height + "@[" + minFramerate + ":" + maxFramerate + "]";
+      return size.toString() + "@" + framerate.toString();
     }
 
-    public boolean isSameFormat(final CaptureFormat that) {
-      if (that == null) {
+    @Override
+    public boolean equals(Object other) {
+      if (!(other instanceof CaptureFormat)) {
         return false;
       }
-      return width == that.width && height == that.height && maxFramerate == that.maxFramerate
-          && minFramerate == that.minFramerate;
+      final CaptureFormat otherFormat = (CaptureFormat) other;
+      return size.equals(otherFormat.size) && framerate.equals(otherFormat.framerate);
+    }
+
+    @Override
+    public int hashCode() {
+      return 1 + 31 * size.hashCode() + framerate.hashCode();
     }
   }
 
@@ -134,7 +204,9 @@ public class CameraEnumerationAndroid {
     return getNameOfDevice(android.hardware.Camera.CameraInfo.CAMERA_FACING_BACK);
   }
 
-  // Helper class for finding the closest supported format for the two functions below.
+  // Helper class for finding the closest supported format for the two functions below. It creates a
+  // comparator based on the difference to some requested parameters, where the element with the
+  // minimum difference is the element that is closest to the requested parameters.
   private static abstract class ClosestComparator<T> implements Comparator<T> {
     // Difference between supported and requested parameter.
     abstract int diff(T supportedParameter);
@@ -145,30 +217,27 @@ public class CameraEnumerationAndroid {
     }
   }
 
-  public static int[] getFramerateRange(android.hardware.Camera.Parameters parameters,
-      final int framerate) {
-    List<int[]> listFpsRange = parameters.getSupportedPreviewFpsRange();
-    if (listFpsRange.isEmpty()) {
-      Logging.w(TAG, "No supported preview fps range");
-      return new int[]{0, 0};
-    }
-    return Collections.min(listFpsRange,
-        new ClosestComparator<int[]>() {
-          @Override int diff(int[] range) {
+  // Prefer a fps range with an upper bound close to |framerate|. Also prefer a fps range with a low
+  // lower bound, to allow the framerate to fluctuate based on lightning conditions.
+  public static CaptureFormat.FramerateRange getClosestSupportedFramerate(
+      List<CaptureFormat.FramerateRange> supportedFramerates, final int requestedFps) {
+    return Collections.min(supportedFramerates,
+        new ClosestComparator<CaptureFormat.FramerateRange>() {
+          @Override
+          int diff(CaptureFormat.FramerateRange range) {
             final int maxFpsWeight = 10;
-            return range[android.hardware.Camera.Parameters.PREVIEW_FPS_MIN_INDEX]
-                + maxFpsWeight * abs(framerate
-                    - range[android.hardware.Camera.Parameters.PREVIEW_FPS_MAX_INDEX]);
+            return range.min + maxFpsWeight * abs(1000 * requestedFps - range.max);
           }
      });
   }
 
-  public static android.hardware.Camera.Size getClosestSupportedSize(
-      List<android.hardware.Camera.Size> supportedSizes, final int requestedWidth,
+  public static CaptureFormat.Size getClosestSupportedSize(
+      List<CaptureFormat.Size> supportedSizes, final int requestedWidth,
       final int requestedHeight) {
     return Collections.min(supportedSizes,
-        new ClosestComparator<android.hardware.Camera.Size>() {
-          @Override int diff(android.hardware.Camera.Size size) {
+        new ClosestComparator<CaptureFormat.Size>() {
+          @Override
+          int diff(CaptureFormat.Size size) {
             return abs(requestedWidth - size.width) + abs(requestedHeight - size.height);
           }
      });