Store images/videos into Hadoop HDFS

Question

I would like to store some videos/images into Hadoop HDFS, but I heard that HDFS accepts only files like as a text.

To be sure, can we store videos/images into HDFS?

Answer 1

It is absolutely possible without doing anything extra. Hadoop provides us the facility to read/write binary files. So, practically anything which can be converted into bytes can be stored into HDFS(images, videos etc). To do that Hadoop provides something called as SequenceFiles. SequenceFile is a flat file consisting of binary key/value pairs. The SequenceFile provides a Writer, Reader and Sorter classes for writing, reading and sorting respectively. So, you could convert your image/video file into a SeuenceFile and store it into the HDFS. Here is small piece of code that will take an image file and convert it into a SequenceFile, where name of the file is the key and image content is the value :

public class ImageToSeq {
    public static void main(String args[]) throws Exception {

        Configuration confHadoop = new Configuration();     
        confHadoop.addResource(new Path("/hadoop/projects/hadoop-1.0.4/conf/core-site.xml"));
        confHadoop.addResource(new Path("/hadoop/projects/hadoop-1.0.4/conf/hdfs-site.xml"));   
        FileSystem fs = FileSystem.get(confHadoop);
        Path inPath = new Path("/mapin/1.png");
        Path outPath = new Path("/mapin/11.png");
        FSDataInputStream in = null;
        Text key = new Text();
        BytesWritable value = new BytesWritable();
        SequenceFile.Writer writer = null;
        try{
            in = fs.open(inPath);
            byte buffer[] = new byte[in.available()];
            in.read(buffer);
            writer = SequenceFile.createWriter(fs, confHadoop, outPath, key.getClass(),value.getClass());
            writer.append(new Text(inPath.getName()), new BytesWritable(buffer));
        }catch (Exception e) {
            System.out.println("Exception MESSAGES = "+e.getMessage());
        }
        finally {
            IOUtils.closeStream(writer);
            System.out.println("last line of the code....!!!!!!!!!!");
        }
    }
}

And if your intention is to just dump the files as it is, you could simply do this :

bin/hadoop fs -put /src_image_file /dst_image_file

And if your intent is more than just storing the files, you might find HIPI useful. HIPI is a library for Hadoop's MapReduce framework that provides an API for performing image processing tasks in a distributed computing environment.

HTH