springboot (JavaCV) realizes the Nth frame of video interception and saves the picture
Now the display list of video websites is displayed with img tags, and gif is used for animations, but when we upload videos, there is no video cover, so we need to automatically generate and save the cover when uploading to the server
This blog uses the jar package to upload video files and capture the first frame of the video, and save it to Alibaba Cloud's OSS (you can also save it locally to get anywhere else).
JavaCV is an open source visual processing library, based on the GPLv2 protocol, a set of jar packages encapsulated by various commonly used computer vision libraries,
It encapsulates the interfaces of libraries commonly used by computer vision programmers such as OpenCV, libdc1394, OpenKinect, videoInput, and ARToolKitPlus.
The advantage of this method is that there is no need to install a plug-in on the server, and the video interception can be realized directly in the code.
We need to intercept the first frame of the video, mainly using ffmpeg and opencv.
1. Introduce the jar package.
The latest javacv version of maven I use is 1.4.3. It should support jdk1.7 and above. My project still uses jdk1.8.
However, it should be noted that in the process of use, when maven imports jar, it will import all platform versions
The size of all imports is about 500 megabytes (not recommended)
<!--视频截取第一帧-->
<dependency>
<groupId>org.bytedeco</groupId>
<artifactId>javacv</artifactId>
<version>1.4.3</version>
</dependency>
<dependency>
<groupId>org.bytedeco.javacpp-presets</groupId>
<artifactId>ffmpeg-platform</artifactId>
<version>4.0.2-1.4.3</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>RELEASE</version>
</dependency>
Two, java code implementation
public class ImgTools {
//util调用application.properties
private final static ResourceBundle RESOURCE_BUNDLE = ResourceBundle.getBundle("application");
private final static String aliyuVideonImg = RESOURCE_BUNDLE.getString("aliyun.video.img");
// public static void main(String[] args) throws Exception {
// ImgTools imgTools = new ImgTools();
// System.out.println(imgTools.randomGrabberFFmpegVideoImage
// ("视频地址，可以是网络视频，也可以是本地视频"));
// }
/**
* 获取视频缩略图
*
* @param filePath：视频路径
* @throws Exception
*/
public String randomGrabberFFmpegVideoImage(String filePath) throws Exception {
String targetFilePath = "";
FFmpegFrameGrabber ff = FFmpegFrameGrabber.createDefault(filePath);
ff.start();
//判断是否是竖屏小视频
String rotate = ff.getVideoMetadata("rotate");
int ffLength = ff.getLengthInFrames();
Frame f;
int i = 0;
int index = 3;//截取图片第几帧
while (i < ffLength) {
f = ff.grabImage();
if (i == index) {
if (null != rotate && rotate.length() > 1) {
targetFilePath = doExecuteFrame(f, true); //获取缩略图
} else {
targetFilePath = doExecuteFrame(f, false); //获取缩略图
}
break;
}
i++;
}
ff.stop();
return targetFilePath; //返回的是视频第N帧
}
/**
* 截取缩略图，存入阿里云OSS（按自己的上传类型自定义转换文件格式）
*
* @param f
* @return
* @throws Exception
*/
public String doExecuteFrame(Frame f, boolean bool) throws Exception {
if (null == f || null == f.image) {
return "";
}
Java2DFrameConverter converter = new Java2DFrameConverter();
BufferedImage bi = converter.getBufferedImage(f);
if (bool == true) {
Image image = (Image) bi;
bi = rotate(image, 90);//图片旋转90度
}
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(bi, "png", os);
byte[] sdf = os.toByteArray();
InputStream input = new ByteArrayInputStream(os.toByteArray());
MultipartFile multipartFile = new MockMultipartFile("temp.jpg", "temp.jpg", "temp.jpg", input);
Aliyunoss aliyunoss = new Aliyunoss();
//如需了解阿里云OSS，请详读我的另一篇博客（"https://blog.csdn.net/weixin_44401989/article/details/105732856"）
String url = aliyunoss.uploadAli(multipartFile, aliyuVideonImg);
return url;
}
/**
* 图片旋转角度
*
* @param src 源图片
* @param angel 角度
* @return 目标图片
*/
public static BufferedImage rotate(Image src, int angel) {
int src_width = src.getWidth(null);
int src_height = src.getHeight(null);
// calculate the new image size
Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(
src_width, src_height)), angel);
BufferedImage res = null;
res = new BufferedImage(rect_des.width, rect_des.height,
BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = res.createGraphics();
// transform(这里先平移、再旋转比较方便处理；绘图时会采用这些变化，绘图默认从画布的左上顶点开始绘画，源图片的左上顶点与画布左上顶点对齐，然后开始绘画，修改坐标原点后，绘画对应的画布起始点改变，起到平移的效果；然后旋转图片即可)
//平移（原理修改坐标系原点，绘图起点变了，起到了平移的效果，如果作用于旋转，则为旋转中心点）
g2.translate((rect_des.width - src_width) / 2, (rect_des.height - src_height) / 2);
//旋转（原理transalte(dx,dy)->rotate(radians)->transalte(-dx,-dy);修改坐标系原点后，旋转90度，然后再还原坐标系原点为(0,0),但是整个坐标系已经旋转了相应的度数 ）
g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);
// //先旋转（以目标区域中心点为旋转中心点，源图片左上顶点对准目标区域中心点，然后旋转）
// g2.translate(rect_des.width/2,rect_des.height/ 2);
// g2.rotate(Math.toRadians(angel));
// //再平移（原点恢复到源图的左上顶点处（现在的右上顶点处），否则只能画出1/4）
// g2.translate(-src_width/2,-src_height/2);
g2.drawImage(src, null, null);
return res;
}
/**
* 计算转换后目标矩形的宽高
*
* @param src 源矩形
* @param angel 角度
* @return 目标矩形
*/
private static Rectangle CalcRotatedSize(Rectangle src, int angel) {
double cos = Math.abs(Math.cos(Math.toRadians(angel)));
double sin = Math.abs(Math.sin(Math.toRadians(angel)));
int des_width = (int) (src.width * cos) + (int) (src.height * sin);
int des_height = (int) (src.height * cos) + (int) (src.width * sin);
return new java.awt.Rectangle(new Dimension(des_width, des_height));
}
}
public class ImgTools {
//util调用application.properties
private final static ResourceBundle RESOURCE_BUNDLE = ResourceBundle.getBundle("application");
private final static String aliyuVideonImg = RESOURCE_BUNDLE.getString("aliyun.video.img");
// public static void main(String[] args) throws Exception {
// ImgTools imgTools = new ImgTools();
// System.out.println(imgTools.randomGrabberFFmpegVideoImage
// ("视频地址，可以是网络视频，也可以是本地视频"));
// }
/**
* 获取视频缩略图
*
* @param filePath：视频路径
* @throws Exception
*/
public String randomGrabberFFmpegVideoImage(String filePath) throws Exception {
String targetFilePath = "";
FFmpegFrameGrabber ff = FFmpegFrameGrabber.createDefault(filePath);
ff.start();
//判断是否是竖屏小视频
String rotate = ff.getVideoMetadata("rotate");
int ffLength = ff.getLengthInFrames();
Frame f;
int i = 0;
int index = 3;//截取图片第几帧
while (i < ffLength) {
f = ff.grabImage();
if (i == index) {
if (null != rotate && rotate.length() > 1) {
targetFilePath = doExecuteFrame(f, true); //获取缩略图
} else {
targetFilePath = doExecuteFrame(f, false); //获取缩略图
}
break;
}
i++;
}
ff.stop();
return targetFilePath; //返回的是视频第N帧
}
/**
* 截取缩略图，存入阿里云OSS（按自己的上传类型自定义转换文件格式）
*
* @param f
* @return
* @throws Exception
*/
public String doExecuteFrame(Frame f, boolean bool) throws Exception {
if (null == f || null == f.image) {
return "";
}
Java2DFrameConverter converter = new Java2DFrameConverter();
BufferedImage bi = converter.getBufferedImage(f);
if (bool == true) {
Image image = (Image) bi;
bi = rotate(image, 90);//图片旋转90度
}
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(bi, "png", os);
byte[] sdf = os.toByteArray();
InputStream input = new ByteArrayInputStream(os.toByteArray());
MultipartFile multipartFile = new MockMultipartFile("temp.jpg", "temp.jpg", "temp.jpg", input);
Aliyunoss aliyunoss = new Aliyunoss();
//如需了解阿里云OSS，请详读我的另一篇博客（"https://blog.csdn.net/weixin_44401989/article/details/105732856"）
String url = aliyunoss.uploadAli(multipartFile, aliyuVideonImg);
return url;
}
/**
* 图片旋转角度
*
* @param src 源图片
* @param angel 角度
* @return 目标图片
*/
public static BufferedImage rotate(Image src, int angel) {
int src_width = src.getWidth(null);
int src_height = src.getHeight(null);
// calculate the new image size
Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(
src_width, src_height)), angel);
BufferedImage res = null;
res = new BufferedImage(rect_des.width, rect_des.height,
BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = res.createGraphics();
// transform(这里先平移、再旋转比较方便处理；绘图时会采用这些变化，绘图默认从画布的左上顶点开始绘画，源图片的左上顶点与画布左上顶点对齐，然后开始绘画，修改坐标原点后，绘画对应的画布起始点改变，起到平移的效果；然后旋转图片即可)
//平移（原理修改坐标系原点，绘图起点变了，起到了平移的效果，如果作用于旋转，则为旋转中心点）
g2.translate((rect_des.width - src_width) / 2, (rect_des.height - src_height) / 2);
//旋转（原理transalte(dx,dy)->rotate(radians)->transalte(-dx,-dy);修改坐标系原点后，旋转90度，然后再还原坐标系原点为(0,0),但是整个坐标系已经旋转了相应的度数 ）
g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);
// //先旋转（以目标区域中心点为旋转中心点，源图片左上顶点对准目标区域中心点，然后旋转）
// g2.translate(rect_des.width/2,rect_des.height/ 2);
// g2.rotate(Math.toRadians(angel));
// //再平移（原点恢复到源图的左上顶点处（现在的右上顶点处），否则只能画出1/4）
// g2.translate(-src_width/2,-src_height/2);
g2.drawImage(src, null, null);
return res;
}
/**
* 计算转换后目标矩形的宽高
*
* @param src 源矩形
* @param angel 角度
* @return 目标矩形
*/
private static Rectangle CalcRotatedSize(Rectangle src, int angel) {
double cos = Math.abs(Math.cos(Math.toRadians(angel)));
double sin = Math.abs(Math.sin(Math.toRadians(angel)));
int des_width = (int) (src.width * cos) + (int) (src.height * sin);
int des_height = (int) (src.height * cos) + (int) (src.width * sin);
return new java.awt.Rectangle(new Dimension(des_width, des_height));
}
}