Android Video Capture: use tightest fps Range available on allocate()

media/base/android/java/src/org/chromium/media/VideoCapture.java

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.media;
 
 import android.content.Context;
 import android.graphics.ImageFormat;
 import android.graphics.SurfaceTexture;
 import android.opengl.GLES20;
@@ skipping 104 matching lines @@
             return false;
         }
 
         // getSupportedPreviewFpsRange() returns a List with at least one
         // element, but when camera is in bad state, it can return null pointer.
         List<int[]> listFpsRange = parameters.getSupportedPreviewFpsRange();
         if (listFpsRange == null || listFpsRange.size() == 0) {
             Log.e(TAG, "allocate: no fps range found");
             return false;
         }
-        int frameRateInMs = frameRate * 1000;
-        // Use the first range as default.
-        int[] fpsMinMax = listFpsRange.get(0);
-        int newFrameRate = (fpsMinMax[0] + 999) / 1000;
+        // Use the first range as the default chosen range.
+        int[] chosenFpsRange = listFpsRange.get(0);
+        int chosenFrameRate = (chosenFpsRange[0] + 999) / 1000;
+        int fpsRangeSize = Integer.MAX_VALUE;
+        // API fps ranges are scaled up x1000 to avoid floating point.
+        int frameRateScaled = frameRate * 1000;
         for (int[] fpsRange : listFpsRange) {
-            if (fpsRange[0] <= frameRateInMs && frameRateInMs <= fpsRange[1]) {
-                fpsMinMax = fpsRange;
-                newFrameRate = frameRate;
-                break;
+            if (fpsRange[0] <= frameRateScaled && frameRateScaled <= fpsRange[1] &&
+                    (fpsRange[1] - fpsRange[0]) <= fpsRangeSize) {
+                chosenFpsRange = fpsRange;
+                chosenFrameRate = frameRate;
+                fpsRangeSize = fpsRange[1] - fpsRange[0];
             }
         }
-        frameRate = newFrameRate;
-        Log.d(TAG, "allocate: fps set to " + frameRate);
+        Log.d(TAG, "allocate: fps set to " + chosenFrameRate + ", [" +
+                chosenFpsRange[0] + "-" + chosenFpsRange[1] + "]");
 
         // Calculate size.
         List<android.hardware.Camera.Size> listCameraSize =
                 parameters.getSupportedPreviewSizes();
         int minDiff = Integer.MAX_VALUE;
         int matchedWidth = width;
         int matchedHeight = height;
         for (android.hardware.Camera.Size size : listCameraSize) {
             int diff = Math.abs(size.width - width) +
                        Math.abs(size.height - height);
@@ skipping 16 matching lines @@
         Log.d(TAG, "allocate: matched (" + matchedWidth + "x" + matchedHeight + ")");
 
         if (parameters.isVideoStabilizationSupported()) {
             Log.d(TAG, "Image stabilization supported, currently: " +
                   parameters.getVideoStabilization() + ", setting it.");
             parameters.setVideoStabilization(true);
         } else {
             Log.d(TAG, "Image stabilization not supported.");
         }
 
-        setCaptureParameters(matchedWidth, matchedHeight, frameRate, parameters);
+        setCaptureParameters(matchedWidth, matchedHeight, chosenFrameRate, parameters);
         parameters.setPreviewSize(mCaptureFormat.mWidth,
                                   mCaptureFormat.mHeight);
-        parameters.setPreviewFpsRange(fpsMinMax[0], fpsMinMax[1]);
+        parameters.setPreviewFpsRange(chosenFpsRange[0], chosenFpsRange[1]);
         parameters.setPreviewFormat(mCaptureFormat.mPixelFormat);
         try {
             mCamera.setParameters(parameters);
         } catch (RuntimeException ex) {
             Log.e(TAG, "setParameters: " + ex);
             return false;
         }
 
         // Set SurfaceTexture. Android Capture needs a SurfaceTexture even if
         // it is not going to be used.
@@ skipping 184 matching lines @@
         android.hardware.Camera.CameraInfo cameraInfo = new android.hardware.Camera.CameraInfo();
         try {
             android.hardware.Camera.getCameraInfo(id, cameraInfo);
         } catch (RuntimeException ex) {
             Log.e(TAG, "getCameraInfo: android.hardware.Camera.getCameraInfo: " + ex);
             return null;
         }
         return cameraInfo;
     }
 }