1，安装ffmpeg
2，java代码：摘自 https://blog.csdn.net/javaer_lee/article/details/79425201
package test;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
public class ConvertVideo {
private static String inputPath = "";
private static String outputPath = "";
private static String ffmpegPath = "";
public static void main(String args[]) throws IOException {
getPath();
if (!checkfile(inputPath)) {
System.out.println(inputPath + " is not file");
return;
}
if (process()) {
System.out.println("ok");
}
}
private static void getPath() { // 先获取当前项目路径，在获得源文件、目标文件、转换器的路径
File diretory = new File("");
try {
String currPath = diretory.getAbsolutePath();
inputPath = "E:\\1.mp4";
outputPath = "E:\\6.mp4";
ffmpegPath = "C:\\Users\\chenwei\\Desktop\\ffmpeg-20190104-b9523f2-win64-static\\bin\\";
System.out.println(currPath);
}
catch (Exception e) {
System.out.println("getPath出错");
}
}
private static boolean process() {
int type = checkContentType();
boolean status = false;
if (type == 0) {
System.out.println("直接转成flv格式");
status = processFLV(inputPath);// 直接转成flv格式
} else if (type == 1) {
String avifilepath = processAVI(type);
if (avifilepath == null)
return false;// 没有得到avi格式
status = processFLV(avifilepath);// 将avi转成flv格式
}
return status;
}
private static int checkContentType() {
String type = inputPath.substring(inputPath.lastIndexOf(".") + 1, inputPath.length())
.toLowerCase();
// ffmpeg能解析的格式：（asx，asf，mpg，wmv，3gp，mp4，mov，avi，flv等）
if (type.equals("avi")) {
return 0;
} else if (type.equals("mpg")) {
return 0;
} else if (type.equals("wmv")) {
return 0;
} else if (type.equals("3gp")) {
return 0;
} else if (type.equals("mov")) {
return 0;
} else if (type.equals("mp4")) {
return 0;
} else if (type.equals("asf")) {
return 0;
} else if (type.equals("asx")) {
return 0;
} else if (type.equals("flv")) {
return 0;
}
// 对ffmpeg无法解析的文件格式(wmv9，rm，rmvb等),
// 可以先用别的工具（mencoder）转换为avi(ffmpeg能解析的)格式.
else if (type.equals("wmv9")) {
return 1;
} else if (type.equals("rm")) {
return 1;
} else if (type.equals("rmvb")) {
return 1;
}
return 9;
}
private static boolean checkfile(String path) {
File file = new File(path);
if (!file.isFile()) {
return false;
}
return true;
}
// 对ffmpeg无法解析的文件格式(wmv9，rm，rmvb等), 可以先用别的工具（mencoder）转换为avi(ffmpeg能解析的)格式.
private static String processAVI(int type) {
List<String> commend = new ArrayList<String>();
commend.add(ffmpegPath + "mencoder");
commend.add(inputPath);
commend.add("-oac");
commend.add("lavc");
commend.add("-lavcopts");
commend.add("acodec=mp3:abitrate=64");
commend.add("-ovc");
commend.add("xvid");
commend.add("-xvidencopts");
commend.add("bitrate=1000");
commend.add("-of");
commend.add("mp4");
commend.add("-o");
commend.add(outputPath + "a.mp4");
try {
ProcessBuilder builder = new ProcessBuilder();
Process process = builder.command(commend).redirectErrorStream(true).start();
new PrintStream(process.getInputStream());
new PrintStream(process.getErrorStream());
process.waitFor();
return outputPath + "a.mp4";
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
// ffmpeg能解析的格式：（asx，asf，mpg，wmv，3gp，mp4，mov，avi，flv等）
private static boolean processFLV(String oldfilepath) {
if (!checkfile(inputPath)) {
System.out.println(oldfilepath + " is not file");
return false;
}
List<String> command = new ArrayList<String>();
command.add(ffmpegPath + "ffmpeg");
command.add("-i");
command.add(oldfilepath);
command.add("-ab");
command.add("56");
command.add("-ar");
command.add("22050");
command.add("-qscale");
command.add("8");
command.add("-r");
command.add("15");
command.add("-s");
command.add("600x500");
command.add(outputPath + "a.mp4");
try {
// 方案1
Process videoProcess = Runtime.getRuntime().exec(ffmpegPath + "ffmpeg -i " + oldfilepath
+ " -vcodec libx264 -r 29.97 -b 768k -ar 24000 -ab 64k -s 1280x720 "
+ outputPath + "a.mp4");
// 方案2
// Process videoProcess = new ProcessBuilder(command).redirectErrorStream(true).start();
//
// new PrintStream(videoProcess.getErrorStream()).start();
//
// new PrintStream(videoProcess.getInputStream()).start();
//
// videoProcess.waitFor();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
}
class PrintStream extends Thread
{
java.io.InputStream __is = null;
public PrintStream(java.io.InputStream is)
{
__is = is;
}
public void run()
{
try
{
while(this != null)
{
int _ch = __is.read();
if(_ch != -1)
System.out.print((char)_ch);
else break;
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
原文地址：https://www.cnblogs.com/cw828/p/10224750.html