java 做视频转换主要用到开源的ffmpeg或者mencoder，还要有MP4Box。

注：由于平时都没有时间写博客，所以思路我就不写了，有问题问我，不一定马上回复。

详细介绍：

ffmpeg：http://www.ffmpeg.org/

mencoder：http://en.wikipedia.org/wiki/MEncoder

MP4Box：http://gpac.wp.mines-telecom.fr/mp4box/mp4box-documentation/

主要实现：

1.获取视频元数据信息
2.视频相互转换
3.视频加文字及图片水印
4.视频截图

思路：

配置文件中定义各转换工具的路径：（相关工具去官网下载）

<!-- ################配置系统用到的转换工具相关参数   开始....--><!-- ##ffmpeg.so文件路径 --><param name="ffmpegPath" value="D:\conver\ffmpeg-win.exe" /><!-- ##memcoder.so文件路径 --><param name="mencoderPath" value="D:\conver\mencoder.exe" /><!-- ##给视频加水印的shell脚本路径 --><param name="shellPath" value="D:\conver\coverVideo.bat" /><!-- ##定义MP4Box工具路径 --><param name="mp4BoxPath" value="D:\conver\MP4Box" /><!-- ##定义图片转换工具路径 --><param name="imgConverPath" value="C:/Program Files/ImageMagick-6.3.9-Q16/convert.exe" /><!-- ################配置系统用到的转换工具相关参数   结束-->

2.获取视频音频的各项属性帮助类

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.List;import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.MatchResult;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.PatternCompiler;
import org.apache.oro.text.regex.PatternMatcher;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;
import com.brainsoon.bsrcm.common.utils.BaseCommonUtil;
import com.brainsoon.bsrcm.system.support.CacConver;/*** 获取视频音频的各项属性帮助类* 如果需要修改或者添加属性，只要扩展下面的二维数组和修改下面getVideoInfo()方法* @author tanghui**/
public class VideoInfoHelps {protected static final Logger logger = Logger.getLogger(VideoInfoHelps.class);public static final String ffmpegPath; // ffmpeg.exe的目录  static{ffmpegPath = BaseCommonUtil.getProRealPath("ffmpegPath");}/*** 根据属性获取视频信息* @param videoPath* @return*/public static VideoInfo getVideoInfo(String videoPath) {VideoInfo videoInfo  = new VideoInfo();if(CacConver.exitFile(videoPath)){String videoType = videoPath.substring(videoPath.lastIndexOf(".")+1, videoPath.length());if(CacConver.isNeedVideoFormat(videoType)){String result =   processVideo(videoPath); if(StringUtils.isNotEmpty(result)){PatternCompiler compiler =new Perl5Compiler();  try {  String regexDuration ="Duration: (.*?), start: (.*?), bitrate: (\\d*) kb\\/s";  String regexVideo ="Video: (.*?), (.*?), (.*?)[,\\s]";  String regexAudio ="Audio: (\\w*), (\\d*) Hz";  Pattern patternDuration = compiler.compile(regexDuration,Perl5Compiler.CASE_INSENSITIVE_MASK);  PatternMatcher matcherDuration = new Perl5Matcher();  if(matcherDuration.contains(result, patternDuration)){  MatchResult re = matcherDuration.getMatch();  videoInfo.setPlayingAllTime( re.group(1));videoInfo.setPlayingStartTime( re.group(2));videoInfo.setBitrateSize( re.group(3));}  Pattern patternVideo = compiler.compile(regexVideo,Perl5Compiler.CASE_INSENSITIVE_MASK);  PatternMatcher matcherVideo = new Perl5Matcher();  if(matcherVideo.contains(result, patternVideo)){  MatchResult re = matcherVideo.getMatch();  videoInfo.setCodeFormat( re.group(1));videoInfo.setVideoFormat( re.group(2));videoInfo.setResolution( re.group(3));}  Pattern patternAudio = compiler.compile(regexAudio,Perl5Compiler.CASE_INSENSITIVE_MASK);  PatternMatcher matcherAudio = new Perl5Matcher();  if(matcherAudio.contains(result, patternAudio)){  MatchResult re = matcherAudio.getMatch();  videoInfo.setAudioCoding(re.group(1));videoInfo.setAudioFrequency( re.group(2));}} catch (MalformedPatternException e) {  logger.error("获取【" + videoPath +"】视频信息失败!");} logger.info("获取【" + videoPath +"】视频信息成功!");}else{logger.info("执行成功！但未获取到【" + videoPath +"】视频信息!");}}else{logger.debug("【" + videoPath + "】文件格式不支持！");}}return videoInfo ;}/***  ffmpeg能解析的格式：（asx，asf，mpg，wmv，3gp，mp4，mov，avi，flv等）  * @param inputPath* @return*/private static String processVideo(String filePath) {   List<String> commend=new java.util.ArrayList<String>();  commend.add(ffmpegPath);//可以设置环境变量从而省去这行  commend.add("-i");  commend.add(filePath);  try {  ProcessBuilder builder = new ProcessBuilder();  builder.command(commend);  builder.redirectErrorStream(true);  Process p= builder.start();  BufferedReader buf = null; // 保存ffmpeg的输出结果流  String line = null;  buf = new BufferedReader(new InputStreamReader(p.getInputStream()));  StringBuffer sb= new StringBuffer();  while ((line = buf.readLine()) != null) {  sb.append(line);  continue;  }  p.waitFor();//这里线程阻塞，将等待外部转换进程运行成功运行结束后，才往下执行  return sb.toString();  } catch (Exception e) { logger.error("ffmpeg解析视频文件【" + filePath +"】失败!");return null;  }  } }

3.其他的工具类

 /*** 等待进程处理* @param p* @return*/@SuppressWarnings("unused")public static int doWaitFor(Process p) {  InputStream in = null;  InputStream err = null;  int exitValue = -1; // returned to caller when p is finished  try {  in = p.getInputStream();  err = p.getErrorStream();  boolean finished = false; // Set to true when p is finished  while (!finished) {  try {  while (in.available() > 0) {  Character c = new Character((char) in.read());  }  while (err.available() > 0) {  Character c = new Character((char) err.read());  }  exitValue = p.exitValue();  finished = true;  } catch (IllegalThreadStateException e) {  Thread.currentThread();Thread.sleep(500);  }  }  } catch (Exception e) {  logger.error("doWaitFor();: unexpected exception - " + e.getMessage());} finally {  try {  if (in != null) {  in.close();  }  } catch (IOException e) {  logger.error("等待进程处理错误");}  if (err != null) {  try {  err.close();  } catch (IOException e) {  logger.error("等待进程处理错误");  }  }  }  return exitValue;  }  /*** 删除文件* @param filepath*/public static void deleteFile(String filepath) {  File file = new File(filepath);  if (file.exists()) {  if (file.delete()) {  logger.info("文件【" + filepath + "】已删除");}  } }  /*** 根据时间返回总秒数 形如：（00:12:12）* @param timeStr* @return*/public static String getSplitStr(String timeStr){String secStr="0";//返回秒if(timeStr != null && !timeStr.equals("") ){String[] str = timeStr.split(":");int subInt0 = Integer.parseInt(str[0]);int subInt1 = Integer.parseInt(str[1]);String str2s = "";if(str[2].length() >2&&str[2].indexOf(".")>0){str2s = str[2].substring(0,str[2].indexOf("."));}else{str2s =  str[2];}int subInt2 = Integer.parseInt(str2s);Long countNum = subInt0 * 3600L + subInt1 * 60 + subInt2;secStr = countNum + "";}return secStr;}/*** 计算两个字符串时间相减 如：("00:22:22")* * @param time1* @param time2* @return*/public static String calTime(String time1, String time2){Long time1Long = Long.parseLong(time1);Long time2Long = Long.parseLong(time2);Long timeLong = time2Long-time1Long;StringBuffer sbuffer = null;if(timeLong > 0){int hour = (int) (timeLong/3600);int minute = (int) ((timeLong-hour*3600)/60);int second =(int) ((timeLong-hour*3600-minute*60)%60);sbuffer = new StringBuffer();if(hour<10){sbuffer.append("0");}sbuffer.append(Integer.toString(hour));sbuffer.append(":");if(minute<10){sbuffer.append("0");}sbuffer.append(Integer.toString(minute));sbuffer.append(":");if(second<10){sbuffer.append("0");}sbuffer.append(Integer.toString(second));return sbuffer.toString();}else{logger.error("时间不能为负数！可能原因是传入的时间位置不对!");return "";}}