/*

 * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.media.sound;

import javax.sound.sampled.AudioFormat;

import javax.sound.sampled.AudioInputStream;

import javax.sound.sampled.AudioSystem;

/**

 * Common conversions etc.

 *

 * @author Kara Kytle

 * @author Florian Bomers

 */

public class Toolkit {

    /**

     * Converts bytes from signed to unsigned.

     */

    static void getUnsigned8(byte[] b, int off, int len) {

        for (int i = off; i < (off+len); i++) {

            b[i] += 128;

        }

    }

    /**

     * Swaps bytes.

     * @throws ArrayOutOfBoundsException if len is not a multiple of 2.

     */

    static void getByteSwapped(byte[] b, int off, int len) {

        byte tempByte;

        for (int i = off; i < (off+len); i+=2) {

            tempByte = b[i];

            b[i] = b[i+1];

            b[i+1] = tempByte;

        }

    }

    /**

     * Linear to DB scale conversion.

     */

    static float linearToDB(float linear) {

        float dB = (float) (Math.log((double)((linear==0.0)?0.0001:linear))/Math.log(10.0) * 20.0);

        return dB;

    }

    /**

     * DB to linear scale conversion.

     */

    static float dBToLinear(float dB) {

        float linear = (float) Math.pow(10.0, dB/20.0);

        return linear;

    }

    /*

     * returns bytes aligned to a multiple of blocksize

     * the return value will be in the range of (bytes-blocksize+1) ... bytes

     */

    static long align(long bytes, int blockSize) {

        // prevent null pointers

        if (blockSize <= 1) {

            return bytes;

        }

        return bytes - (bytes % blockSize);

    }

    static int align(int bytes, int blockSize) {

        // prevent null pointers

        if (blockSize <= 1) {

            return bytes;

        }

        return bytes - (bytes % blockSize);

    }

    /*

     * gets the number of bytes needed to play the specified number of milliseconds

     */

    static long millis2bytes(AudioFormat format, long millis) {

        long result = (long) (millis * format.getFrameRate() / 1000.0f * format.getFrameSize());

        return align(result, format.getFrameSize());

    }

    /*

     * gets the time in milliseconds for the given number of bytes

     */

    static long bytes2millis(AudioFormat format, long bytes) {

        return (long) (bytes / format.getFrameRate() * 1000.0f / format.getFrameSize());

    }

    /*

     * gets the number of bytes needed to play the specified number of microseconds

     */

    static long micros2bytes(AudioFormat format, long micros) {

        long result = (long) (micros * format.getFrameRate() / 1000000.0f * format.getFrameSize());

        return align(result, format.getFrameSize());

    }

    /*

     * gets the time in microseconds for the given number of bytes

     */

    static long bytes2micros(AudioFormat format, long bytes) {

        return (long) (bytes / format.getFrameRate() * 1000000.0f / format.getFrameSize());

    }

    /*

     * gets the number of frames needed to play the specified number of microseconds

     */

    static long micros2frames(AudioFormat format, long micros) {

        return (long) (micros * format.getFrameRate() / 1000000.0f);

    }

    /*

     * gets the time in microseconds for the given number of frames

     */

    static long frames2micros(AudioFormat format, long frames) {

        return (long) (((double) frames) / format.getFrameRate() * 1000000.0d);

    }

    static void isFullySpecifiedAudioFormat(AudioFormat format) {

        if (!format.getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)

            && !format.getEncoding().equals(AudioFormat.Encoding.PCM_UNSIGNED)

            && !format.getEncoding().equals(AudioFormat.Encoding.ULAW)

            && !format.getEncoding().equals(AudioFormat.Encoding.ALAW)) {

            // we don't know how to verify possibly non-linear encodings

            return;

        }

        if (format.getFrameRate() <= 0) {

            throw new IllegalArgumentException("invalid frame rate: "

                                               +((format.getFrameRate()==-1)?

                                                 "NOT_SPECIFIED":String.valueOf(format.getFrameRate())));

        }

        if (format.getSampleRate() <= 0) {

            throw new IllegalArgumentException("invalid sample rate: "

                                               +((format.getSampleRate()==-1)?

                                                 "NOT_SPECIFIED":String.valueOf(format.getSampleRate())));

        }

        if (format.getSampleSizeInBits() <= 0) {

            throw new IllegalArgumentException("invalid sample size in bits: "

                                               +((format.getSampleSizeInBits()==-1)?

                                                 "NOT_SPECIFIED":String.valueOf(format.getSampleSizeInBits())));

        }

        if (format.getFrameSize() <= 0) {

            throw new IllegalArgumentException("invalid frame size: "

                                               +((format.getFrameSize()==-1)?

                                                 "NOT_SPECIFIED":String.valueOf(format.getFrameSize())));

        }

        if (format.getChannels() <= 0) {

            throw new IllegalArgumentException("invalid number of channels: "

                                               +((format.getChannels()==-1)?

                                                 "NOT_SPECIFIED":String.valueOf(format.getChannels())));

        }

    }

    static boolean isFullySpecifiedPCMFormat(AudioFormat format) {

        if (!format.getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)

            && !format.getEncoding().equals(AudioFormat.Encoding.PCM_UNSIGNED)) {

            return false;

        }

        if ((format.getFrameRate() <= 0)

            || (format.getSampleRate() <= 0)

            || (format.getSampleSizeInBits() <= 0)

            || (format.getFrameSize() <= 0)

            || (format.getChannels() <= 0)) {

            return false;

        }

        return true;

    }

    public static AudioInputStream getPCMConvertedAudioInputStream(AudioInputStream ais) {

        // we can't open the device for non-PCM playback, so we have

        // convert any other encodings to PCM here (at least we try!)

        AudioFormat af = ais.getFormat();

        if( (!af.getEncoding().equals(AudioFormat.Encoding.PCM_SIGNED)) &&

            (!af.getEncoding().equals(AudioFormat.Encoding.PCM_UNSIGNED))) {

            try {

                AudioFormat newFormat =

                    new AudioFormat( AudioFormat.Encoding.PCM_SIGNED,

                                     af.getSampleRate(),

                                     16,

                                     af.getChannels(),

                                     af.getChannels() * 2,

                                     af.getSampleRate(),

                                     Platform.isBigEndian());

                ais = AudioSystem.getAudioInputStream(newFormat, ais);

            } catch (Exception e) {

                if (Printer.err) e.printStackTrace();

                ais = null;

            }

        }

        return ais;

    }

}