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/*
* Copyright 2015 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
package org.webrtc;
import static java.lang.Math.abs;
import android.graphics.ImageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
@SuppressWarnings("deprecation")
public class CameraEnumerationAndroid {
private final static String TAG = "CameraEnumerationAndroid";
static final ArrayList<Size> COMMON_RESOLUTIONS = new ArrayList<Size>(Arrays.asList(
// 0, Unknown resolution
new Size(160, 120), // 1, QQVGA
new Size(240, 160), // 2, HQVGA
new Size(320, 240), // 3, QVGA
new Size(400, 240), // 4, WQVGA
new Size(480, 320), // 5, HVGA
new Size(640, 360), // 6, nHD
new Size(640, 480), // 7, VGA
new Size(768, 480), // 8, WVGA
new Size(854, 480), // 9, FWVGA
new Size(800, 600), // 10, SVGA
new Size(960, 540), // 11, qHD
new Size(960, 640), // 12, DVGA
new Size(1024, 576), // 13, WSVGA
new Size(1024, 600), // 14, WVSGA
new Size(1280, 720), // 15, HD
new Size(1280, 1024), // 16, SXGA
new Size(1920, 1080), // 17, Full HD
new Size(1920, 1440), // 18, Full HD 4:3
new Size(2560, 1440), // 19, QHD
new Size(3840, 2160) // 20, UHD
));
public static class CaptureFormat {
// 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 / 1000.0f) + ":" + (max / 1000.0f) + "]";
}
@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 int width;
public final int height;
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.framerate = new FramerateRange(minFramerate, maxFramerate);
}
public CaptureFormat(int width, int height, FramerateRange framerate) {
this.width = width;
this.height = height;
this.framerate = framerate;
}
// Calculates the frame size of this capture format.
public int frameSize() {
return frameSize(width, height, imageFormat);
}
// Calculates the frame size of the specified image format. Currently only
// supporting ImageFormat.NV21.
// The size is width * height * number of bytes per pixel.
public static int frameSize(int width, int height, int imageFormat) {
if (imageFormat != ImageFormat.NV21) {
throw new UnsupportedOperationException("Don't know how to calculate "
+ "the frame size of non-NV21 image formats.");
}
return (width * height * ImageFormat.getBitsPerPixel(imageFormat)) / 8;
}
@Override
public String toString() {
return width + "x" + height + "@" + framerate;
}
@Override
public boolean equals(Object other) {
if (!(other instanceof CaptureFormat)) {
return false;
}
final CaptureFormat otherFormat = (CaptureFormat) other;
return width == otherFormat.width && height == otherFormat.height
&& framerate.equals(otherFormat.framerate);
}
@Override
public int hashCode() {
return 1 + (width * 65497 + height) * 251 + framerate.hashCode();
}
}
// 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);
@Override
public int compare(T t1, T t2) {
return diff(t1) - diff(t2);
}
}
// 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 getClosestSupportedFramerateRange(
List<CaptureFormat.FramerateRange> supportedFramerates, final int requestedFps) {
return Collections.min(
supportedFramerates, new ClosestComparator<CaptureFormat.FramerateRange>() {
// Progressive penalty if the upper bound is further away than `MAX_FPS_DIFF_THRESHOLD`
// from requested.
private static final int MAX_FPS_DIFF_THRESHOLD = 5000;
private static final int MAX_FPS_LOW_DIFF_WEIGHT = 1;
private static final int MAX_FPS_HIGH_DIFF_WEIGHT = 3;
// Progressive penalty if the lower bound is bigger than `MIN_FPS_THRESHOLD`.
private static final int MIN_FPS_THRESHOLD = 8000;
private static final int MIN_FPS_LOW_VALUE_WEIGHT = 1;
private static final int MIN_FPS_HIGH_VALUE_WEIGHT = 4;
// Use one weight for small `value` less than `threshold`, and another weight above.
private int progressivePenalty(int value, int threshold, int lowWeight, int highWeight) {
return (value < threshold) ? value * lowWeight
: threshold * lowWeight + (value - threshold) * highWeight;
}
@Override
int diff(CaptureFormat.FramerateRange range) {
final int minFpsError = progressivePenalty(
range.min, MIN_FPS_THRESHOLD, MIN_FPS_LOW_VALUE_WEIGHT, MIN_FPS_HIGH_VALUE_WEIGHT);
final int maxFpsError = progressivePenalty(Math.abs(requestedFps * 1000 - range.max),
MAX_FPS_DIFF_THRESHOLD, MAX_FPS_LOW_DIFF_WEIGHT, MAX_FPS_HIGH_DIFF_WEIGHT);
return minFpsError + maxFpsError;
}
});
}
public static Size getClosestSupportedSize(
List<Size> supportedSizes, final int requestedWidth, final int requestedHeight) {
return Collections.min(supportedSizes, new ClosestComparator<Size>() {
@Override
int diff(Size size) {
return abs(requestedWidth - size.width) + abs(requestedHeight - size.height);
}
});
}
// Helper method for camera classes.
static void reportCameraResolution(Histogram histogram, Size resolution) {
int index = COMMON_RESOLUTIONS.indexOf(resolution);
// 0 is reserved for unknown resolution, so add 1.
// indexOf returns -1 for unknown resolutions so it becomes 0 automatically.
histogram.addSample(index + 1);
}
}