/* * CVS identifier: * * $Id: LayersInfo.java,v 1.1.1.1 2002/07/22 09:26:49 grosbois Exp $ * * Class:                   LayersInfo * * Description:             Specification of a layer * * * * COPYRIGHT: *  * This software module was originally developed by Rapha雔 Grosbois and * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel * Askel鰂 (Ericsson Radio Systems AB); and Bertrand Berthelot, David * Bouchard, F閘ix Henry, Gerard Mozelle and Patrice Onno (Canon Research * Centre France S.A) in the course of development of the JPEG2000 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This * software module is an implementation of a part of the JPEG 2000 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio * Systems AB and Canon Research Centre France S.A (collectively JJ2000 * Partners) agree not to assert against ISO/IEC and users of the JPEG * 2000 Standard (Users) any of their rights under the copyright, not * including other intellectual property rights, for this software module * with respect to the usage by ISO/IEC and Users of this software module * or modifications thereof for use in hardware or software products * claiming conformance to the JPEG 2000 Standard. Those intending to use * this software module in hardware or software products are advised that * their use may infringe existing patents. The original developers of * this software module, JJ2000 Partners and ISO/IEC assume no liability * for use of this software module or modifications thereof. No license * or right to this software module is granted for non JPEG 2000 Standard * conforming products. JJ2000 Partners have full right to use this * software module for his/her own purpose, assign or donate this * software module to any third party and to inhibit third parties from * using this software module for non JPEG 2000 Standard conforming * products. This copyright notice must be included in all copies or * derivative works of this software module. *  * Copyright (c) 1999/2000 JJ2000 Partners. * */package jj2000.j2k.entropy.encoder;/** * This class stores the specification of a layer distribution in the bit * stream. The specification is made of optimization points and a number of * extra layers to add between the optimization points. Each optimization * point creates a layer which is optimized by the rate allocator to the * specified target bitrate. The extra layers are added by the rate allocator * between the optimized layers, with the difference that they are not * optimized (i.e. they have no precise target bitrate). * * <p>The overall target bitrate for the bit stream is always added as the * last optimization point without any extra layers after it. If there are * some optimization points whose target bitrate is larger than the overall * target bitrate, the overall target bitrate will still appear as the last * optimization point, even though it does not follow the increasing target * bitrate order of the other optimization points. The rate allocator is * responsible for eliminating layers that have target bitrates larger than * the overall target bitrate.</p> * * <p>Optimization points can be added with the addOptPoint() method. It takes * the target bitrate for the optimized layer and the number of extra layers * to add after it.</p> * * <p>Information about the total number of layers, total number of * optimization points, target bitrates, etc. can be obtained with the other * methods.</p> * */public class LayersInfo {    /** The initial size for the arrays: 10 */    private final static int SZ_INIT = 10;    /** The size increment for the arrays */    private final static int SZ_INCR = 5;    /** The total number of layers */    // Starts at 1: overall target bitrate is always an extra optimized layer    int totlyrs = 1;    /** The overall target bitrate, for the whole bit stream */    float totbrate;    /** The number of optimized layers, or optimization points, without     * counting the extra one coming from the overall target bitrate */    int nopt;    /** The target bitrate to which specified layers should be optimized. */    float optbrate[] = new float[SZ_INIT];    /** The number of extra layers to be added after an optimized layer. After     * the layer that is optimized to optbrate[i], extralyrs[i] extra layers     * should be added. These layers are allocated between the bitrate     * optbrate[i] and the next optimized bitrate optbrate[i+1] or, if it does     * not exist, the overall target bitrate. */    int extralyrs[] = new int[SZ_INIT];    /**     * Creates a new LayersInfo object. The overall target bitrate 'brate' is     * always an extra optimization point, with no extra layers are after     * it. Note that any optimization points that are added with addOptPoint()     * are always added before the overall target bitrate.     *     * @param brate The overall target bitrate for the bit stream     * */    public LayersInfo(float brate) {        if (brate <= 0) {            throw new IllegalArgumentException("Overall target bitrate must "+                                               "be a positive number");        }        totbrate = brate;    }    /**     * Returns the overall target bitrate for the entire bit stream.     *     * @return The overall target bitrate     * */    public float getTotBitrate() {        return totbrate;    }         /**     * Returns the total number of layers, according to the layer     * specification of this object and the overall target bitrate.     *     * @return The total number of layers, according to the layer spec.     * */    public int getTotNumLayers() {        return totlyrs;    }    /**     * Returns the number of layers to optimize, or optimization points, as     * specified by this object.     *     * @return The number of optimization points     * */    public int getNOptPoints() {        // overall target bitrate is counted as extra        return nopt+1;    }    /**     * Returns the target bitrate of the optmimization point 'n'.     *     * @param n The optimization point index (starts at 0).     *     * @return The target bitrate (in bpp) for the optimization point 'n'.     * */    public float getTargetBitrate(int n) {        // overall target bitrate is counted as extra        return (n < nopt) ? optbrate[n] : totbrate;    }    /**     * Returns the number of extra layers to add after the optimization point     * 'n', but before optimization point 'n+1'. If there is no optimization     * point 'n+1' then they should be added before the overall target     * bitrate.     *     * @param n The optimization point index (starts at 0).     *     * @return The number of extra (unoptimized) layers to add after the     * optimization point 'n'     * */    public int getExtraLayers(int n) {        // overall target bitrate is counted as extra        return (n < nopt) ? extralyrs[n] : 0;    }        /**     * Adds a new optimization point, with target bitrate 'brate' and with     * 'elyrs' (unoptimized) extra layers after it. The target bitrate 'brate'     * must be larger than the previous optimization point. The arguments are     * checked and IllegalArgumentException is thrown if they are not correct.     *     * @param brate The target bitrate for the optimized layer.     *     * @param elyrs The number of extra (unoptimized) layers to add after the     * optimized layer.     * */    public void addOptPoint(float brate, int elyrs) {        // Check validity of arguments        if (brate <= 0) {            throw new                IllegalArgumentException("Target bitrate must be positive");        }        if (elyrs < 0) {            throw new IllegalArgumentException("The number of extra layers "+                                               "must be 0 or more");        }        if (nopt > 0 && optbrate[nopt-1]>=brate) {            throw new                IllegalArgumentException("New optimization point must have "+                                         "a target bitrate higher than the "+                                         "preceding one");        }        // Check room for new optimization point        if (optbrate.length == nopt) { // Need more room            float tbr[] = optbrate;            int tel[] = extralyrs;            // both arrays always have same size            optbrate = new float[optbrate.length+SZ_INCR];            extralyrs = new int[extralyrs.length+SZ_INCR];            System.arraycopy(tbr,0,optbrate,0,nopt);            System.arraycopy(tel,0,extralyrs,0,nopt);        }        // Add new optimization point        optbrate[nopt] = brate;        extralyrs[nopt] = elyrs;        nopt++;        // Update total number of layers        totlyrs += 1+elyrs;    }}