Question

In TCP i am receiving media stream from an IP camera as RAW. According to there advise, i need to write that as file. And then i can play it with media player such as VLC.

But when i write this to a file, and play with media players it never play corrupted.

After comparing the original file i see my Java writing it in wrong characters. And there sample file shows different. What or how do i fix such file writing issue, here is how i am writing it:

byte[] buf=new byte[1024];
int bytes_read = 0;
try {  
    bytes_read = sock.getInputStream().read(buf, 0, buf.length);                
    String data = new String(buf, 0, bytes_read);                   
    System.err.println("DATA: " +  bytes_read + " bytes, data=" +data);

        BufferedWriter out = new BufferedWriter(
            new FileWriter("capture.ogg", true));
        out.write(data);
        out.close();

} catch (IOException e) {
    e.printStackTrace(System.err);
}

Answer 1

You’re doing it right… at least until the part where you turn your byte[] into a String:

That step only really makes sense if your byte[] represents textual data in the first place! Which it doesn’t!

Whenever you handle binary data or don’t actually care what the data represents you must avoid using String/Reader/Writer to handle that data. Instead do use byte[]/InputStream/OutputStream.

Also, you must read from the socket in a loop, because nothing guarantees that you’ve read everything:

byte[] buf=new byte[1024];
int bytes_read;
OutputStream out = new FileOutputStream("capture.ogg", true);
InputStream in = sock.getInputStream();
while ((bytes_read = in.read(buf)) != -1) {
    out.write(buf, 0, bytes_read);
}
out.close();