Question

How I can start reading from a specific byte? I have following code:

        try {
            while ( (len = f.read(buffer)) > 0 ) {}         
        }

For example, I want to start to read at byte 50.

Answer 1

You should use the skip method.
http://developer.android.com/reference/java/io/InputStream.html#skip(long)

You can skip the number of bytes you want.

int nbToSkip = 50
while (nbToSkip > 0) {
   int nbSkipped = f.skip( nbToSkip );
   nbToSkip -= nbSkipped ; 
}