/***************************************
* ViPER-MPEG *
* The Video Processing *
* Evaluation Resource *
* MPEG-1 Decoder *
* Distributed under the LGPL license *
* Terms available at gnu.org. *
* *
* Copyright University of Maryland, *
* College Park. *
***************************************/
package edu.umd.cfar.lamp.mpeg1.system;
import java.io.*;
import edu.columbia.ee.flavor.*;
import edu.umd.cfar.lamp.mpeg1.*;
/**
* Corresponds to system_header() in ISO/IEC 11172-1.
*/
public class SystemHeader implements Parsable
{
int rate_bound = 0;
int audio_bound = 0;
boolean fixed_flag = false;
boolean CSPS_flag = false;
boolean system_audio_lock_flag = false;
boolean system_video_lock_flag = false;
int video_bound = 0;
public void parse(Bitstream bitstream) throws IOException
{
if (bitstream.getbits(32) != SystemStartCodes.SYSTEM_HEADER_START_CODE)
throw new ParsingException("Expected system_header_start_code not found.");
int header_length = bitstream.getbits(16);
if (bitstream.getbits(1) != 1)
throw new ParsingException("Expected marker bit not found.");
rate_bound = bitstream.getbits(22);
if (bitstream.getbits(1) != 1)
throw new ParsingException("Expected marker bit not found.");
audio_bound = bitstream.getbits(6);
fixed_flag = (bitstream.getbits(1) == 1);
CSPS_flag = (bitstream.getbits(1) == 1);
system_audio_lock_flag = (bitstream.getbits(1) == 1);
system_video_lock_flag = (bitstream.getbits(1) == 1);
if (bitstream.getbits(1) != 1)
throw new ParsingException("Expected marker bit not found.");
video_bound = bitstream.getbits(5);
bitstream.skipbits(8); // reserved byte, should be 0xFF, but may be changed in future versions of ISO/IEC 11172
while (bitstream.nextbits(1) == 1)
{
int stream_id = bitstream.getbits(8);
if (bitstream.getbits(2) != 3)
throw new ParsingException("Expected constant 11 not found.");
boolean STD_buffer_bound_scale = (bitstream.getbits(1) == 1);
int STD_buffer_size_bound = bitstream.getbits(13);
}
}
}