mpac.java

优秀的MPEG2-TS流分析软件

/*
 * @(#)MPAC.java - mono<->stereo converter M1L2,48khz losless
 *
 * Copyright (c) 2002-2005 by dvb.matt, All rights reserved.
 * 
 * This file is part of X, a free Java based demux utility.
 * X is intended for educational purposes only, as a non-commercial test project.
 * It may not be used otherwise. Most parts are only experimental.
 * 
 * The part of audio parsing was derived from the MPEG/Audio
 * Software Simulation Group's audio codec in a special modified manner.
 *
 *
 * This program is free software; you can redistribute it free of charge
 * and/or modify it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*
 * rewritten Oct 2003 by dvb.matt
 */

package net.sourceforge.dvb.projectx.audio;

import net.sourceforge.dvb.projectx.common.X;
import net.sourceforge.dvb.projectx.common.Resource;

public class MPAC
{

	//mpeg-1 27 subbands
	private final short alloc27[][] = {
		{ 0,1,3,5,6,7,8,9,10,11,12,13,14,15,16,17 },
		{ 0,1,3,5,6,7,8,9,10,11,12,13,14,15,16,17 },
		{ 0,1,3,5,6,7,8,9,10,11,12,13,14,15,16,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,3,4,5,6,17 },
		{ 0,1,2,17 },
		{ 0,1,2,17 },
		{ 0,1,2,17 },
		{ 0,1,2,17 }
	};

	private final short bal27mp1[] = { 4,4,4,4,4,4,4,4,4,4,4,3,3,3,3,3,3,3,3,3,3,3,3,2,2,2,2 };
	private final short getbits[] = { 0,5,7,3,10,4,5,6,7,8,9,10,11,12,13,14,15,16 };
	private final short grouping[] = { 0,3,5,0,9,0,0,0,0,0,0,0,0,0,0,0,0,0 };
	private final int MPA_48M1L2[] = { 0,768,1152,1344,1536,1920,2304,2688,3072,3840,4608,5376,6144,7680,9216,16384 };
	private final int STEREO = 0;
	private final int JSTEREO = 1;
	private final int DUAL = 2;
	private final int SINGLE = 3;

	private int maxBitSize = 0;
	private short Bal[] = new short[0];
	private short Allocation[][];
	private int Sizes[];
	private int BRindex[] = new int[3];
	private int Restart = 0;
	private int error_flag = 0;
	private Audio Audio;

	//init
	public MPAC()
	{
		Audio = new Audio();
		Sizes = MPA_48M1L2;
		java.util.Arrays.sort(Sizes);
		maxBitSize = Sizes[14];
		Bal = bal27mp1;
		Allocation = alloc27;
	}

	/******************************************
	 * modify mpegaudio frame 48khz 56..384kbps M1L2; *
	 ******************************************/
	public byte[][] modifyframe(byte[] AudioFrame, long[] options)
	{
		byte newAudioFrames[][] = new byte[2][AudioFrame.length];

		for (int a=0; a < 3; a++)  //0-s, 1-l, 2-r
			BRindex[a]=(int)(0xF & options[17]>>>(4 + (a<<2)));

		Restart = 0;
		error_flag = 0;

		int transcode = (int)options[10];

		//secure, but most was already done by X.java
		if (Audio.MPA_parseHeader(AudioFrame,0)!=1 || Audio.ID!=1 || Audio.Layer!=2 || Audio.Sampling_frequency!=48000 || 
			Audio.Bitrate<56000 || (Audio.Mode==SINGLE && Audio.Bitrate>192000) || (Audio.Mode!=SINGLE && Audio.Bitrate<112000))
		{
			System.arraycopy(AudioFrame,0,newAudioFrames[0],0,AudioFrame.length);
			System.arraycopy(AudioFrame,0,newAudioFrames[1],0,AudioFrame.length); // copy frame

			X.Msg(Resource.getString("audio.msg.convert.disabled", "" + (options[17]>>>18)));

			options[17] |= 0x1000CL;

			return newAudioFrames;
		}

		Audio.MPA_deleteCRC(AudioFrame);

		switch(transcode)
		{
			case 1:  //single channel to dual(A)
			case 2:  //single channel to stereo
			case 3:  //single channel to jstereo
				if (Audio.Channel == 1)
					newAudioFrames = createByteArrays(makeTwoChannel(createBitArray(AudioFrame), transcode, 0));

				else
					newAudioFrames = adaptSourceFrame(AudioFrame, newAudioFrames, transcode);  //check to pass BR

				break;

			case 4: //dual-stereo-jointstereo to 2 x mono
				if (Audio.Channel == 2)
					newAudioFrames = createByteArrays(splitTwoChannel(createBitArray(AudioFrame),transcode));

				else
					newAudioFrames = adaptSourceFrame(AudioFrame, newAudioFrames, transcode);  //check to pass BR
		}

		options[17] &= ~0xFFFCL;

		for (int a=0; a < 3; a++)  //0-s, 1-l, 2-r
			options[17] |= BRindex[a]<<(4 + (a<<2));

		options[17] |= Restart<<2;

		if (error_flag > 0)
			X.Msg(Resource.getString("audio.msg.convert.error", "" + error_flag, "" + (options[17]>>>18)));

		return newAudioFrames;
	}

	private void setError(int error)
	{
		error_flag |= error;
	}

	//check to pass BR
	private byte[][] adaptSourceFrame(byte AudioFrame[], byte input[][], int transcode)
	{
		System.arraycopy(AudioFrame, 0, input[0], 0, AudioFrame.length);
		System.arraycopy(AudioFrame, 0, input[1], 0, AudioFrame.length); // copy frame

		int size[] = new int[2];
		size[1] = size[0] = (0xF0 & AudioFrame[2])>>>4;

		if (transcode < 4)
		{
			if (size[0] == BRindex[0]) //same size
				return input;

			else if (size[0] > BRindex[0])
			{ //restart with new size
				if (BRindex[0] != 0)
					Restart |= 3;

				BRindex[0] = size[0];

				return input;
			}
		}

		else
		{
			if (size[0] == BRindex[1] && size[1] == BRindex[2]) //same size
				return input;

			else
			{ //restart with new size
				if (size[0] > BRindex[1])
				{  //fill to size L
					if (BRindex[1] != 0)
						Restart |= 1;

					BRindex[1] = size[0];
				}

				if (size[1] > BRindex[2])
				{  //fill to size R
					if (BRindex[2] != 0)
						Restart |= 2;
					BRindex[2] = size[1];
				}

				if (Restart > 0)
					return input;
			}
		}

		byte output[][]=new byte[2][0];

		for (int ch=0; ch<2; ch++)
		{
			output[ch] = new byte[Sizes[BRindex[ch + (transcode>>>2)]]>>>3];

			System.arraycopy(input[ch], 0, output[ch], 0, input[ch].length);

			output[ch][2] &= (byte)~0xF0;
			output[ch][2] |= (byte)BRindex[ch + (transcode>>>2)]<<4;

			if (transcode < 4)
				break;

			else if (BRindex[ch+1] > 10)
				output[ch] = createByteArray(makeTwoChannel(createBitArray(output[ch]), 3, ch + 1));
		}

		return output;
	}

	//bytearray to bitarray
	private boolean[] createBitArray(byte input[])
	{
		boolean output[] = new boolean[maxBitSize]; //max=1152bytes=9216bits

		for (int a=0; a < input.length; a++)
			for (int b=0; b < 8; b++)
				if ( ((0x80>>>b) & input[a]) != 0 ) 
					output[b + (a<<3)] = true;

		return output;
	}

	//1ch_bitarray to 1ch_bytearray, frame in bitform must already be compliant, but will be shortened in this method to the indexed BR
	private byte[] createByteArray(boolean input[])
	{
		int size = getSizeFromIndex(input)>>>3;
		byte output[] = new byte[size];

		for (int a=0; a < size; a++)
			for (int b=0; b < 8; b++)
				output[a] |= input[b + (a<<3)] ? 0x80>>>b : 0;

		return output;
	}

	//1ch_bitarray to 2ch_bytearray, frame in bitform must already be compliant, but will be shortened in this method to the indexed BR
	private byte[][] createByteArrays(boolean input[])
	{
		int size = getSizeFromIndex(input)>>>3;
		byte output[][] = { new byte[size], new byte[0] };

		for (int a=0; a < size; a++)
			for (int b=0; b < 8; b++)
				output[0][a] |= input[b + (a<<3)] ? 0x80>>>b : 0;

		return output;
	}

	//2ch_bitarray to 2ch_bytearray, frame in bitform must already be compliant, but will be shortened in this method to the indexed BR
	private byte[][] createByteArrays(boolean input[][])
	{
		int size[] = new int[2];

		for (int ch=0; ch < 2; ch++)
			size[ch] = getSizeFromIndex(input[ch])>>>3;

		byte output[][] = { new byte[size[0]], new byte[size[1]] };

		for (int ch=0; ch < 2; ch++)
			for (int a=0; a < size[ch]; a++)
				for (int b=0; b < 8; b++)
					output[ch][a] |= input[ch][b + (a<<3)] ? 0x80>>>b : 0;

		return output;
	}

	//read out BR_index in bitlength
	private int getSizeFromIndex(boolean input[])
	{
		int size = 0;

		for (int a=0; a<4; a++)
			size |= input[a + 16] ? 8>>>a : 0;

		size = Sizes[size];

		return size;
	}

	//set Bitrate index
	private void setBitRateIndex(boolean input[], int size, int channel)
	{
		if ( (size = java.util.Arrays.binarySearch(Sizes, size)) < 0);
			size = Math.abs(size) - 1;

		if (channel == 0 && size < 7)
			size = 7;

		if (channel > 0 && size < 3)
			size = 3;

		size = updateCBRIndex(size, channel);

		for (int a=0; a < 4; a++)
			input[a + 16] = (size & 8>>a) != 0 ? true : false;
	}

	//update Bitrate index for CBR
	private int updateCBRIndex(int size, int channel)
	{
		if (BRindex[channel] == 0)  // if 0 set first BR
			BRindex[channel] = size;

		else if (BRindex[channel] >= size)
			size = BRindex[channel];

		else
		{
			Restart |= (3 - channel);
			BRindex[channel] = size;
		}

		return size;
	}

	//set channelmode
	private void setChannelMode(boolean input[], int mode)
	{
		mode <<= 2;

		for (int a=0; a < 4; a++)
			input[a + 24] = (mode & 8>>a) != 0 ? true : false;
	}