Frame.java

/*
 * myLib - https://github.com/taktod/myLib
 * Copyright (c) 2014 ttProject. All rights reserved.
 * 
 * Licensed under The MIT license.
 */
package com.ttProject.frame.adpcmswf.type;

import java.nio.ByteBuffer;

import org.apache.log4j.Logger;

import com.ttProject.frame.adpcmswf.AdpcmswfFrame;
import com.ttProject.nio.channels.IReadChannel;
import com.ttProject.unit.extra.Bit;
import com.ttProject.unit.extra.BitConnector;
import com.ttProject.unit.extra.BitLoader;
import com.ttProject.unit.extra.bit.Bit16;
import com.ttProject.unit.extra.bit.Bit2;
import com.ttProject.unit.extra.bit.Bit6;
import com.ttProject.util.BufferUtil;

/**
 * frame of adpcmswf
 * とりあえずsampleNumだけ取得したい。
 * adpcmCodeSizeを取得してから
 * (byte数 - 0埋めbits) / (adpcmCodeSize + 2) / (channel数) + 1でsampleNumを取得したい。
 * 最終byteを確認して0でうまっている部分はできるだけ排除
 * にすれば、より正確になりそう。
 * @author taktod
 */
public class Frame extends AdpcmswfFrame {
	/** logger */
	@SuppressWarnings("unused")
	private Logger logger = Logger.getLogger(Frame.class);
	
	private Bit2  adpcmCodeSize = new Bit2();
	private Bit16 initSample1   = new Bit16();
	private Bit6  initialIndex1 = new Bit6();
	private Bit16 initSample2   = null;
	private Bit6  initialIndex2 = null;
	private Bit   extraBit      = null;
	private ByteBuffer buffer = null;
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void minimumLoad(IReadChannel channel) throws Exception {
		setSize(channel.size());
		BitLoader loader = new BitLoader(channel);
		loader.load(adpcmCodeSize,
				initSample1, initialIndex1);
		if(getChannel() == 2) {
			initSample2 = new Bit16();
			initialIndex2 = new Bit6();
			loader.load(initSample2, initialIndex2);
		}
		// extra data size.
		extraBit = loader.getExtraBit();
		setReadPosition(channel.position());
		// left bit count.(to calcurate sampleNum for frame.)
		double leftBitCount = (channel.size() - channel.position()) * 8 + (extraBit != null ? extraBit.getBitCount() : 0);
		if(getChannel() == 2) {
			// stereo
			setSampleNum((int)Math.ceil(leftBitCount / (adpcmCodeSize.get() + 2) / 2));
		}
		else {
			// monoral
			setSampleNum((int)Math.ceil(leftBitCount / (adpcmCodeSize.get() + 2)));
		}
		super.update();
	}
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void load(IReadChannel channel) throws Exception {
		channel.position(getReadPosition());
		buffer = BufferUtil.safeRead(channel, getSize() - getReadPosition());
		super.update();
	}
	/**
	 * {@inheritDoc}
	 */
	@Override
	protected void requestUpdate() throws Exception {
		if(buffer == null) {
			throw new Exception("data body is unload yet.");
		}
		BitConnector connector = new BitConnector();
		super.setData(BufferUtil.connect(
			connector.connect(
				adpcmCodeSize,
				initSample1,
				initialIndex1,
				initSample2,
				initialIndex2,
				extraBit
			),
			buffer
		));
	}
	/**
	 * {@inheritDoc}
	 */
	@Override
	public ByteBuffer getPackBuffer() throws Exception{
		return getData();
	}
}