![](/img/trans.png)
[英]Is there any way to change background image color in JavaFX ImageView?
[英]Is there any way to export a JavaFX animation to image frames?
我想要完成的事情:
制作 JavaFX animation 最終將在 video.mp4 (或任何其他擴展名)中進行協調
一種方法:
在 animation 播放期間,將 30fps(或 60fps)導出為靜止圖像(即 png 圖像)。 之后使用一些工具處理圖像並創建視頻。
那么如何創建 JavaFX window 的框架呢?
免責聲明
以下解決方案僅作為概念證明提供,沒有附帶解釋,沒有評論支持,不保證它會為您工作,不保證它不會出現錯誤(它可能有一些小錯誤),並且沒有promise 適用於任何用途。
解決方案策略
Capture 使用 James 和 mipa 評論中建議的技術:
創建一個未顯示在包含 animation 的 window 中的場景。 不要 play() animation,而是重復調用 animation 上的 jumpTo(...) 來創建每一幀,對結果進行快照,然后寫入文件。
JPEG 是一種有損編碼方法,此示例的 output 有點模糊(可能是由於可以調整的默認 ImageIO 設置)。
如果需要,可以將每幀 output 轉換為無損格式(如 png)的單獨文件,而不是 mjpeg,然后通過第三方處理軟件運行以創建另一種視頻格式,如 mp4。
MjpegCaptureAndPlayApp.java
package com.example.mjpeg;
import javafx.animation.Animation;
import javafx.animation.TranslateTransition;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;
import java.nio.file.Files;
public class MjpegCaptureAndPlayApp extends Application {
final private double W = 100, H = 100;
private MjpegPlayer player;
@Override
public void start(Stage stage) throws Exception {
String movieFile = Files.createTempFile("mjpeg-capture", "mjpeg").toString();
CaptureAnimation captureAnimation = createCaptureAnimation();
MjpegCapture mjpegCapture = new MjpegCapture(
movieFile,
captureAnimation.root(),
captureAnimation.animation()
);
mjpegCapture.capture();
player = new MjpegPlayer(movieFile);
StackPane viewer = new StackPane(player.getViewer());
viewer.setPrefSize(W, H);
VBox layout = new VBox(20);
layout.setStyle("-fx-background-color: cornsilk;");
layout.setPadding(new Insets(10));
layout.setAlignment(Pos.CENTER);
layout.getChildren().setAll(
viewer,
player.getControls()
);
stage.setScene(new Scene(layout));
stage.show();
player.getTimeline().playFromStart();
}
@Override
public void stop() throws Exception {
if (player != null) {
player.dispose();
}
}
record CaptureAnimation(Parent root, Animation animation) {}
private CaptureAnimation createCaptureAnimation() {
Pane root = new Pane();
root.setMinSize(Pane.USE_PREF_SIZE, Pane.USE_PREF_SIZE);
root.setPrefSize(W, H);
root.setMaxSize(Pane.USE_PREF_SIZE, Pane.USE_PREF_SIZE);
Circle circle = new Circle(W / 10, Color.PURPLE);
root.getChildren().add(circle);
TranslateTransition translateTransition = new TranslateTransition(
Duration.seconds(5),
circle
);
translateTransition.setFromX(0);
translateTransition.setToX(W);
translateTransition.setFromY(H/2);
translateTransition.setToY(H/2);
translateTransition.setAutoReverse(true);
translateTransition.setCycleCount(2);
// move to start pos.
circle.setTranslateX(0);
circle.setTranslateY(H/2);
return new CaptureAnimation(root, translateTransition);
}
public static void main(String[] args) {
launch(args);
}
}
MjpegCapture.java
package com.example.mjpeg;
import javafx.animation.Animation;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.image.WritableImage;
import javafx.util.Duration;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
public class MjpegCapture {
private final Duration SECS_PER_FRAME = Duration.seconds(1.0 / 24);
private final String videoFilename;
private final Parent root;
private final Animation animation;
public MjpegCapture(String videoFilename, Parent root, Animation animation) {
this.videoFilename = videoFilename;
this.root = root;
this.animation = animation;
}
public void capture() throws IOException {
VideoStreamOutput videoStreamOutput = new VideoStreamOutput(videoFilename);
animation.playFromStart();
Duration curPos = Duration.ZERO;
SnapshotParameters snapshotParameters = new SnapshotParameters();
// transparent fill not supported by jpeg I believe so not enabled.
//snapshotParameters.setFill(Color.TRANSPARENT);
Scene scene = new Scene(root);
// force a layout pass so that we can measure the height and width of the root node.
scene.snapshot(null);
int w = (int) scene.getWidth();
int h = (int) scene.getHeight();
WritableImage fxImage = new WritableImage(w, h);
boolean complete;
ByteArrayOutputStream outputBuffer = new ByteArrayOutputStream();
do {
animation.jumpTo(curPos);
root.snapshot(snapshotParameters, fxImage);
// Get buffered image:
// uses ugly, inefficient workaround from:
// https://stackoverflow.com/a/19605733/1155209
BufferedImage image = SwingFXUtils.fromFXImage(fxImage, null);
// Remove alpha-channel from buffered image:
BufferedImage imageRGB = new BufferedImage(
image.getWidth(),
image.getHeight(),
BufferedImage.OPAQUE);
Graphics2D graphics = imageRGB.createGraphics();
graphics.drawImage(image, 0, 0, null);
ImageIO.write(imageRGB, "jpg", outputBuffer);
videoStreamOutput.writeNextFrame(outputBuffer.toByteArray());
outputBuffer.reset();
complete = curPos.greaterThanOrEqualTo(animation.getTotalDuration());
if (curPos.add(SECS_PER_FRAME).greaterThan(animation.getTotalDuration())) {
curPos = animation.getTotalDuration();
} else {
curPos = curPos.add(SECS_PER_FRAME);
}
} while(!complete);
videoStreamOutput.close();
}
}
MjpegPlayer.java
package com.example.mjpeg;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.geometry.Pos;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.HBox;
import javafx.util.Duration;
import java.io.ByteArrayInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Arrays;
public class MjpegPlayer {
private final String videoFilename;
private final Timeline timeline;
private final ImageView viewer = new ImageView();
private final HBox controls;
private VideoStream videoStream;
public MjpegPlayer(String filename) throws FileNotFoundException {
videoFilename = filename;
videoStream = new VideoStream(filename);
timeline = createTimeline(viewer);
controls = createControls(timeline);
}
private Timeline createTimeline(ImageView viewer) {
final Timeline timeline = new Timeline();
final byte[] buf = new byte[15000];
timeline.getKeyFrames().setAll(
new KeyFrame(Duration.ZERO, event -> {
try {
int len = videoStream.readNextFrame(buf);
if (len == -1) {
timeline.stop();
return;
}
viewer.setImage(
new Image(
new ByteArrayInputStream(
Arrays.copyOf(buf, len)
)
)
);
} catch (Exception e) {
e.printStackTrace();
}
}),
new KeyFrame(Duration.seconds(1.0 / 24))
);
timeline.setCycleCount(Timeline.INDEFINITE);
return timeline;
}
private HBox createControls(final Timeline timeline) {
Button play = new Button("Play");
play.setOnAction(event -> timeline.play());
Button pause = new Button("Pause");
pause.setOnAction(event -> timeline.pause());
Button restart = new Button("Restart");
restart.setOnAction(event -> {
try {
timeline.stop();
videoStream = new VideoStream(videoFilename);
timeline.playFromStart();
} catch (Exception e) {
e.printStackTrace();
}
});
HBox controls = new HBox(10);
controls.setAlignment(Pos.CENTER);
controls.getChildren().setAll(
play,
pause,
restart
);
return controls;
}
public void dispose() throws IOException {
videoStream.close();
}
public String getVideoFilename() {
return videoFilename;
}
public Timeline getTimeline() {
return timeline;
}
public ImageView getViewer() {
return viewer;
}
public HBox getControls() {
return controls;
}
}
視頻流.java
package com.example.mjpeg;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
class VideoStream {
private final FileInputStream fis; //video file
VideoStream(String filename) throws FileNotFoundException {
fis = new FileInputStream(filename);
}
int readNextFrame(byte[] frame) throws Exception {
int length;
String lengthAsString;
byte[] lengthAsBytes = new byte[5];
//read current frame length
fis.read(lengthAsBytes, 0, 5);
//transform lengthAsBytes to integer
lengthAsString = new String(lengthAsBytes);
try {
length = Integer.parseInt(lengthAsString);
} catch (Exception e) {
return -1;
}
return (fis.read(frame, 0, length));
}
void close() throws IOException {
fis.close();
}
}
視頻流輸出.java
package com.example.mjpeg;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
class VideoStreamOutput {
private FileOutputStream fos; //video file
private int frameNum; //current frame nb
public VideoStreamOutput(String filename) throws FileNotFoundException {
fos = new FileOutputStream(filename);
frameNum = 0;
}
public void writeNextFrame(byte[] frame) throws IOException {
frameNum++;
String lengthAsString = String.format("%05d", frame.length);
byte[] lengthAsBytes = lengthAsString.getBytes(StandardCharsets.US_ASCII);
fos.write(lengthAsBytes);
fos.write(frame);
System.out.println(frameNum + ": " + lengthAsString);
}
public void close() throws IOException {
fos.flush();
fos.close();
}
}
模塊信息.java
module com.example.mjpeg {
requires javafx.controls;
requires javafx.swing;
requires java.desktop;
exports com.example.mjpeg;
}
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