org.yestech.multimedia.video.mpeg4.DataStream Maven / Gradle / Ivy
/*
* Copyright LGPL3
* YES Technology Association
* http://yestech.org
*
* http://www.opensource.org/licenses/lgpl-3.0.html
*/
package org.yestech.multimedia.video.mpeg4;
import java.io.IOException;
import java.io.EOFException;
import java.io.InputStream;
/**
* DataStream
*/
public final class DataStream {
/** The MPEG4 input stream. */
private InputStream is;
/** The current offset (position) in the stream. */
private long offset = 0;
/**
* Constructs an DataStream object using the specified MPEG4 input stream.
* @param is the MPEG4 input stream.
*/
public DataStream(InputStream is) {
super();
this.is = is;
}
public long readBytes(int n) throws IOException {
int c = -1;
long result = 0;
while((n-- > 0) && ((c = is.read()) != -1)) {
result <<= 8;
result += c & 0xff;
offset ++;
}
if(c == -1)
throw new EOFException();
return result;
}
public String readString(int n) throws IOException {
char c = (char)-1;
StringBuffer sb = new StringBuffer();
while((n-- > 0) && ((c = (char)is.read()) != -1)) {
sb.append(c);
offset ++;
}
if(c == -1) {
throw new EOFException();
}
return sb.toString();
}
public void skipBytes(long n) throws IOException {
offset += n;
is.skip(n);
}
public long getOffset() {
return offset;
}
}