Hello. I tryed to process image on hadoop and i using HVPI (https://github.com/xmpy/hvpi). It's open source. I using it to extract the frames from video but it not provide a output format to save the frames on HDFS. So i tryed to use the SequencefileOutputFormat to save the frames on HDFS. I readed a book and make some changes to the code work on hadoop 2.7.1. Apparently it's worked but when i tryed to recover the file in another mapreduce job i got EOFException. I thinked there is 3 possibily: 1- My SequenceFileOutputFormat is wrong and save a corrupted file; 2-My SequenceInputFormt is wrong; 3- The HVPI custom type is wrong.   The code to save a  Sequence file:   public static void main(String[] args) throws Exception {   //判断输入参数 if (args.length != 2) {             System.err.println("Usage: <input path> <output path>");         System.exit(-1);   }        Configuration conf = new Configuration();   //设置Master URL   conf.set("fs.defaultFS","hdfs://evoido:9000"); Job job = new Job(conf, "MRVideoReader"); job.setJarByClass(MRVideoReader.class);   Path in = new Path(args[0]); Path out = new Path(args[1]); //reduce task zero job is only map  job.setJobName("Sequence Writer Test"); job.setNumReduceTasks(0); job.setInputFormatClass(VideoInputFormat.class); job.setMapperClass(MRVideoReaderMapper.class);   job.setMapOutputKeyClass(Text.class); //job.setMapOutputValueClass(Text.class); job.setMapOutputValueClass(ImageWritable.class); job.setReducerClass(MRVideoReaderReducer.class);   job.setOutputFormatClass(SequenceFileOutputFormat.class);   job.setJarByClass(MRVideoReader.class);   job.setOutputKeyClass(Text.class); job.setOutputValueClass(ImageWritable.class); //job.setOutputValueClass(Text.class);     FileInputFormat.addInputPath(job,in);     SequenceFileOutputFormat.setOutputPath(job, out);     System.exit(job.waitForCompletion(true)?0:1);   }   The code to read from HDFS:   public static void main(String[] args) throws Exception {   //判断输入参数 if (args.length != 2) {             System.err.println("Usage: <input path> <output path>");         System.exit(-1);   }        Configuration conf = new Configuration();   //设置Master URL   conf.set("fs.defaultFS","hdfs://evoido:9000"); Job job = new Job(conf, "MRVideoReader"); job.setJarByClass(MRVideoReader.class);   Path in = new Path(args[0]); Path out = new Path(args[1]); //reduce task zero job is only map  job.setJobName("Sequence Writer Test"); job.setNumReduceTasks(0); job.setInputFormatClass(SequenceFileInputFormat.class);   job.setMapperClass(MRVideoReaderMapper.class);   job.setMapOutputKeyClass(Text.class); //job.setMapOutputValueClass(Text.class); job.setMapOutputValueClass(ImageWritable.class); job.setReducerClass(MRVideoReaderReducer.class);     job.setOutputFormatClass(TextOutputFormat.class); job.setJarByClass(MRVideoReader.class);   job.setOutputKeyClass(Text.class); job.setOutputValueClass(ImageWritable.class); //job.setOutputValueClass(Text.class);   SequenceFileInputFormat.addInputPath(job, in);   FileOutputFormat.setOutputPath(job, out);       System.exit(job.waitForCompletion(true)?0:1); }   This is the code's piece from the custom type.  Maybe the readFilds or write methods are incorrect.   public void readFields(DataInput in) throws IOException { int len = WritableUtils.readVInt(in); System.out.println("Valor de len:"+len); byte[] temp = new byte[len]; in.readFully(temp, 0, len); ByteArrayInputStream byteStream = new ByteArrayInputStream(temp); // 输入流； bufferedImage = ImageIO.read(byteStream); // 从输入流中，读取图片存入image中，而这里in可以为ByteArrayInputStream(); }     public void write(DataOutput out) throws IOException {     ByteArrayOutputStream byteOutputStream = new ByteArrayOutputStream(); ImageIO.write( bufferedImage, "png", byteOutputStream ); WritableUtils.writeVInt(out, byteOutputStream.size());   }   ... View more