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Slightly increase max preview size, preclude very small preview sizes unless no other choice, properly favor large preview sizes in general and correctly prioritize on aspect ratio in all cases

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git-svn-id: https://zxing.googlecode.com/svn/trunk@2259 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
srowen 2012-04-25 19:45:53 +00:00
parent 26d5ff4355
commit 6067089669
1 changed files with 35 additions and 23 deletions
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58
android/src/com/google/zxing/client/android/camera/CameraConfigurationManager.java
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@ -27,7 +27,10 @@ import android.view.WindowManager;
import com.google.zxing.client.android.PreferencesActivity;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
/**
@ -37,8 +40,12 @@ import java.util.List;
final class CameraConfigurationManager {
private static final String TAG = "CameraConfiguration";
private static final int MIN_PREVIEW_PIXELS = 320 * 240; // small screen
private static final int MAX_PREVIEW_PIXELS = 854 * 480; // large/HD screen (Droid 2 in particular)
// This is bigger than the size of a small screen, which is still supported. The routine
// below will still select the default (presumably 320x240) size for these. This prevents
// accidental selection of very low resolution on some devices.
private static final int MIN_PREVIEW_PIXELS = 470 * 320; // normal screen
private static final int MAX_PREVIEW_PIXELS = 800 * 600; // more than large/HD screen
private final Context context;
private Point screenResolution;
@ -136,7 +143,22 @@ final class CameraConfigurationManager {
private Point findBestPreviewSizeValue(Camera.Parameters parameters, Point screenResolution) {
List<Camera.Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes();
// Sort by size, descending
List<Camera.Size> supportedPreviewSizes = new ArrayList<Camera.Size>(parameters.getSupportedPreviewSizes());
Collections.sort(supportedPreviewSizes, new Comparator<Camera.Size>() {
@Override
public int compare(Camera.Size a, Camera.Size b) {
int aPixels = a.height * a.width;
int bPixels = b.height * b.width;
if (bPixels < aPixels) {
return -1;
}
if (bPixels > aPixels) {
return 1;
}
return 0;
}
});
if (Log.isLoggable(TAG, Log.INFO)) {
StringBuilder previewSizesString = new StringBuilder();
@ -147,6 +169,10 @@ final class CameraConfigurationManager {
Log.i(TAG, "Supported preview sizes: " + previewSizesString);
}
Point bestSize = null;
float screenAspectRatio = (float) screenResolution.x / (float) screenResolution.y;
float diff = Float.POSITIVE_INFINITY;
for (Camera.Size supportedPreviewSize : supportedPreviewSizes) {
int realWidth = supportedPreviewSize.width;
int realHeight = supportedPreviewSize.height;
@ -158,27 +184,12 @@ final class CameraConfigurationManager {
int maybeFlippedWidth = isCandidatePortrait ? realHeight : realWidth;
int maybeFlippedHeight = isCandidatePortrait ? realWidth : realHeight;
if (maybeFlippedWidth == screenResolution.x && maybeFlippedHeight == screenResolution.y) {
return new Point(realWidth, realHeight);
}
}
Point bestSize = null;
int diff = Integer.MAX_VALUE;
for (Camera.Size supportedPreviewSize : supportedPreviewSizes) {
int realWidth = supportedPreviewSize.width;
int realHeight = supportedPreviewSize.height;
int pixels = realWidth * realHeight;
if (pixels < MIN_PREVIEW_PIXELS || pixels > MAX_PREVIEW_PIXELS) {
continue;
}
boolean isCandidatePortrait = realWidth < realHeight;
int maybeFlippedWidth = isCandidatePortrait ? realHeight : realWidth;
int maybeFlippedHeight = isCandidatePortrait ? realWidth : realHeight;
int newDiff = Math.abs(screenResolution.x * maybeFlippedHeight - screenResolution.y * maybeFlippedWidth);
if (newDiff == 0) {
return new Point(realWidth, realHeight);
Point exactPoint = new Point(realWidth, realHeight);
Log.i(TAG, "Found preview size exactly matching screen size: " + exactPoint);
return exactPoint;
}
float aspectRatio = (float) maybeFlippedWidth / (float) maybeFlippedHeight;
float newDiff = Math.abs(aspectRatio - screenAspectRatio);
if (newDiff < diff) {
bestSize = new Point(realWidth, realHeight);
diff = newDiff;
@ -191,6 +202,7 @@ final class CameraConfigurationManager {
Log.i(TAG, "No suitable preview sizes, using default: " + bestSize);
}
Log.i(TAG, "Found best approximate preview size: " + bestSize);
return bestSize;
}