/*
 *	Page.java
 *
 *	This file is part of Tritonus: http://www.tritonus.org/
 */

/*
 *  Copyright (c) 2000 - 2001 by Matthias Pfisterer
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as published
 *   by the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
|<---            this code is formatted to fit into 80 columns             --->|
*/

package org.tritonus.lowlevel.pogg;

import org.tritonus.share.TDebug;



/** Wrapper for ogg_page.
 */
public class Page
{
	private static final int[] crc_lookup =
	{
		0x00000000,0x04c11db7,0x09823b6e,0x0d4326d9,
		0x130476dc,0x17c56b6b,0x1a864db2,0x1e475005,
		0x2608edb8,0x22c9f00f,0x2f8ad6d6,0x2b4bcb61,
		0x350c9b64,0x31cd86d3,0x3c8ea00a,0x384fbdbd,
		0x4c11db70,0x48d0c6c7,0x4593e01e,0x4152fda9,
		0x5f15adac,0x5bd4b01b,0x569796c2,0x52568b75,
		0x6a1936c8,0x6ed82b7f,0x639b0da6,0x675a1011,
		0x791d4014,0x7ddc5da3,0x709f7b7a,0x745e66cd,
		0x9823b6e0,0x9ce2ab57,0x91a18d8e,0x95609039,
		0x8b27c03c,0x8fe6dd8b,0x82a5fb52,0x8664e6e5,
		0xbe2b5b58,0xbaea46ef,0xb7a96036,0xb3687d81,
		0xad2f2d84,0xa9ee3033,0xa4ad16ea,0xa06c0b5d,
		0xd4326d90,0xd0f37027,0xddb056fe,0xd9714b49,
		0xc7361b4c,0xc3f706fb,0xceb42022,0xca753d95,
		0xf23a8028,0xf6fb9d9f,0xfbb8bb46,0xff79a6f1,
		0xe13ef6f4,0xe5ffeb43,0xe8bccd9a,0xec7dd02d,
		0x34867077,0x30476dc0,0x3d044b19,0x39c556ae,
		0x278206ab,0x23431b1c,0x2e003dc5,0x2ac12072,
		0x128e9dcf,0x164f8078,0x1b0ca6a1,0x1fcdbb16,
		0x018aeb13,0x054bf6a4,0x0808d07d,0x0cc9cdca,
		0x7897ab07,0x7c56b6b0,0x71159069,0x75d48dde,
		0x6b93dddb,0x6f52c06c,0x6211e6b5,0x66d0fb02,
		0x5e9f46bf,0x5a5e5b08,0x571d7dd1,0x53dc6066,
		0x4d9b3063,0x495a2dd4,0x44190b0d,0x40d816ba,
		0xaca5c697,0xa864db20,0xa527fdf9,0xa1e6e04e,
		0xbfa1b04b,0xbb60adfc,0xb6238b25,0xb2e29692,
		0x8aad2b2f,0x8e6c3698,0x832f1041,0x87ee0df6,
		0x99a95df3,0x9d684044,0x902b669d,0x94ea7b2a,
		0xe0b41de7,0xe4750050,0xe9362689,0xedf73b3e,
		0xf3b06b3b,0xf771768c,0xfa325055,0xfef34de2,
		0xc6bcf05f,0xc27dede8,0xcf3ecb31,0xcbffd686,
		0xd5b88683,0xd1799b34,0xdc3abded,0xd8fba05a,
		0x690ce0ee,0x6dcdfd59,0x608edb80,0x644fc637,
		0x7a089632,0x7ec98b85,0x738aad5c,0x774bb0eb,
		0x4f040d56,0x4bc510e1,0x46863638,0x42472b8f,
		0x5c007b8a,0x58c1663d,0x558240e4,0x51435d53,
		0x251d3b9e,0x21dc2629,0x2c9f00f0,0x285e1d47,
		0x36194d42,0x32d850f5,0x3f9b762c,0x3b5a6b9b,
		0x0315d626,0x07d4cb91,0x0a97ed48,0x0e56f0ff,
		0x1011a0fa,0x14d0bd4d,0x19939b94,0x1d528623,
		0xf12f560e,0xf5ee4bb9,0xf8ad6d60,0xfc6c70d7,
		0xe22b20d2,0xe6ea3d65,0xeba91bbc,0xef68060b,
		0xd727bbb6,0xd3e6a601,0xdea580d8,0xda649d6f,
		0xc423cd6a,0xc0e2d0dd,0xcda1f604,0xc960ebb3,
		0xbd3e8d7e,0xb9ff90c9,0xb4bcb610,0xb07daba7,
		0xae3afba2,0xaafbe615,0xa7b8c0cc,0xa379dd7b,
		0x9b3660c6,0x9ff77d71,0x92b45ba8,0x9675461f,
		0x8832161a,0x8cf30bad,0x81b02d74,0x857130c3,
		0x5d8a9099,0x594b8d2e,0x5408abf7,0x50c9b640,
		0x4e8ee645,0x4a4ffbf2,0x470cdd2b,0x43cdc09c,
		0x7b827d21,0x7f436096,0x7200464f,0x76c15bf8,
		0x68860bfd,0x6c47164a,0x61043093,0x65c52d24,
		0x119b4be9,0x155a565e,0x18197087,0x1cd86d30,
		0x029f3d35,0x065e2082,0x0b1d065b,0x0fdc1bec,
		0x3793a651,0x3352bbe6,0x3e119d3f,0x3ad08088,
		0x2497d08d,0x2056cd3a,0x2d15ebe3,0x29d4f654,
		0xc5a92679,0xc1683bce,0xcc2b1d17,0xc8ea00a0,
		0xd6ad50a5,0xd26c4d12,0xdf2f6bcb,0xdbee767c,
		0xe3a1cbc1,0xe760d676,0xea23f0af,0xeee2ed18,
		0xf0a5bd1d,0xf464a0aa,0xf9278673,0xfde69bc4,
		0x89b8fd09,0x8d79e0be,0x803ac667,0x84fbdbd0,
		0x9abc8bd5,0x9e7d9662,0x933eb0bb,0x97ffad0c,
		0xafb010b1,0xab710d06,0xa6322bdf,0xa2f33668,
		0xbcb4666d,0xb8757bda,0xb5365d03,0xb1f740b4
	};


	private byte[]	m_abHeader;
	private int		m_nHeaderLength;
	private byte[]	m_abBody;
	private int		m_nBodyLength;


	public Page()
	{
		if (TDebug.TraceOggNative) { TDebug.out("Page.<init>(): begin"); }
		if (TDebug.TraceOggNative) { TDebug.out("Page.<init>(): end"); }
	}



	private native int malloc();

	// TODO: remove calls to this method
	public void free()
	{
	}


	/** Calls ogg_page_version().
	 */
	public int getVersion()
	{
		return m_abHeader[4] & 0xFF;
	}


	/** Calls ogg_page_continued().
	 */
	public boolean isContinued()
	{
		return (m_abHeader[5] & 0x01) != 0;
	}



	/** Calls ogg_page_packets().
	 */
/* returns the number of packets that are completed on this page (if
   the leading packet is begun on a previous page, but ends on this
   page, it's counted */

/* NOTE:
If a page consists of a packet begun on a previous page, and a new
packet begun (but not completed) on this page, the return will be:
  ogg_page_packets(page)   ==1, 
  ogg_page_continued(page) !=0

If a page happens to be a single packet that was begun on a
previous page, and spans to the next page (in the case of a three or
more page packet), the return will be: 
  ogg_page_packets(page)   ==0, 
  ogg_page_continued(page) !=0
*/
	public int getPackets()
	{
		int n = m_abHeader[26] & 0xFF;
		int count = 0;
		for (int i = 0; i < n; i++)
			if ((m_abHeader[27 + i] & 0xFF) < 255)
				count++;
		return count;
	}



	/** Calls ogg_page_bos().
	 */
	public boolean isBos()
	{
		return (m_abHeader[5] & 0x02) != 0;
	}



	/** Calls ogg_page_eos().
	 */
	public boolean isEos()
	{
		return (m_abHeader[5] & 0x04) != 0;
	}



	/** Calls ogg_page_granulepos().
	 */
	public long getGranulePos()
	{
		long granulepos = m_abHeader[13]&(0xff);
		granulepos = (granulepos<<8)|(m_abHeader[12] & 0xFF);
		granulepos = (granulepos<<8)|(m_abHeader[11] & 0xFF);
		granulepos = (granulepos<<8)|(m_abHeader[10] & 0xFF);
		granulepos = (granulepos<<8)|(m_abHeader[9] & 0xFF);
		granulepos = (granulepos<<8)|(m_abHeader[8] & 0xFF);
		granulepos = (granulepos<<8)|(m_abHeader[7] & 0xFF);
		granulepos = (granulepos<<8)|(m_abHeader[6] & 0xFF);
		return granulepos;
	}



	/** Calls ogg_page_serialno().
	 */
	public int getSerialNo()
	{
		return m_abHeader[14] |
			(m_abHeader[15] << 8) |
			(m_abHeader[16] << 16) |
			(m_abHeader[17] << 24);
	}



	/** Calls ogg_page_pageno().
	 */
	public int getPageNo()
	{
		return m_abHeader[18] |
			(m_abHeader[19] << 8) |
			(m_abHeader[20] << 16) |
			(m_abHeader[21] << 24);
	}



	/** Calls ogg_page_checksum_set().
	 */
	public void setChecksum()
	{
		int crc_reg = 0;

		/* safety; needed for API behavior, but not framing code */
		m_abHeader[22]=0;
		m_abHeader[23]=0;
		m_abHeader[24]=0;
		m_abHeader[25]=0;

		for(int i = 0; i < m_nHeaderLength; i++)
			crc_reg = (crc_reg << 8) ^ crc_lookup[((crc_reg >>> 24) & 0xff) ^ (m_abHeader[i] & 0xFF)];
		for(int i = 0; i < m_nBodyLength; i++)
			crc_reg = (crc_reg << 8) ^ crc_lookup[((crc_reg >>> 24) & 0xff) ^ (m_abBody[i] & 0xFF)];
    
		m_abHeader[22] = (byte) (crc_reg & 0xff);
		m_abHeader[23] = (byte) ((crc_reg >> 8) & 0xff);
		m_abHeader[24] = (byte) ((crc_reg >> 16) & 0xff);
		m_abHeader[25] = (byte) ((crc_reg >> 24) & 0xff);
	}




	public byte[] getHeader()
	{
		byte[] abHeader = new byte[m_nHeaderLength];
		System.arraycopy(m_abHeader, 0, abHeader, 0, m_nHeaderLength);
		return abHeader;
	}



	public byte[] getBody()
	{
		byte[] abBody = new byte[m_nBodyLength];
		System.arraycopy(m_abBody, 0, abBody, 0, m_nBodyLength);
		return abBody;
	}



	public void setData(byte[] abHeader, int nHeaderOffset,
						int nHeaderLength,
						byte[] abBody, int nBodyOffset,
						int nBodyLength)
	{
		m_abHeader = new byte[nHeaderLength];
		System.arraycopy(abHeader, nHeaderOffset, m_abHeader, 0, nHeaderLength);
		m_nHeaderLength = nHeaderLength;
		m_abBody = new byte[nBodyLength];
		System.arraycopy(abBody, nBodyOffset, m_abBody, 0, nBodyLength);
		m_nBodyLength = nBodyLength;
	}
}





/*** Page.java ***/
