/*

 * 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

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 */

package com.sun.media.sound;

import java.io.File;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.IOException;

import java.io.DataInputStream;

import java.net.URL;

import javax.sound.sampled.AudioFileFormat;

import javax.sound.sampled.AudioInputStream;

import javax.sound.sampled.UnsupportedAudioFileException;

import javax.sound.sampled.spi.AudioFileReader;

/**

 * Abstract File Reader class.

 *

 * @author Jan Borgersen

 */

abstract class SunFileReader extends AudioFileReader {

    // buffer size for temporary input streams

    protected static final int bisBufferSize = 4096;

    /**

     * Constructs a new SunFileReader object.

     */

    public SunFileReader() {

    }

    // METHODS TO IMPLEMENT AudioFileReader

    /**

     * Obtains the audio file format of the input stream provided.  The stream must

     * point to valid audio file data.  In general, audio file providers may

     * need to read some data from the stream before determining whether they

     * support it.  These parsers must

     * be able to mark the stream, read enough data to determine whether they

     * support the stream, and, if not, reset the stream's read pointer to its original

     * position.  If the input stream does not support this, this method may fail

     * with an IOException.

     * @param stream the input stream from which file format information should be

     * extracted

     * @return an <code>AudioFileFormat</code> object describing the audio file format

     * @throws UnsupportedAudioFileException if the stream does not point to valid audio

     * file data recognized by the system

     * @throws IOException if an I/O exception occurs

     * @see InputStream#markSupported

     * @see InputStream#mark

     */

    abstract public AudioFileFormat getAudioFileFormat(InputStream stream) throws UnsupportedAudioFileException, IOException;

    /**

     * Obtains the audio file format of the URL provided.  The URL must

     * point to valid audio file data.

     * @param url the URL from which file format information should be

     * extracted

     * @return an <code>AudioFileFormat</code> object describing the audio file format

     * @throws UnsupportedAudioFileException if the URL does not point to valid audio

     * file data recognized by the system

     * @throws IOException if an I/O exception occurs

     */

    abstract public AudioFileFormat getAudioFileFormat(URL url) throws UnsupportedAudioFileException, IOException;

    /**

     * Obtains the audio file format of the File provided.  The File must

     * point to valid audio file data.

     * @param file the File from which file format information should be

     * extracted

     * @return an <code>AudioFileFormat</code> object describing the audio file format

     * @throws UnsupportedAudioFileException if the File does not point to valid audio

     * file data recognized by the system

     * @throws IOException if an I/O exception occurs

     */

    abstract public AudioFileFormat getAudioFileFormat(File file) throws UnsupportedAudioFileException, IOException;

    /**

     * Obtains an audio stream from the input stream provided.  The stream must

     * point to valid audio file data.  In general, audio file providers may

     * need to read some data from the stream before determining whether they

     * support it.  These parsers must

     * be able to mark the stream, read enough data to determine whether they

     * support the stream, and, if not, reset the stream's read pointer to its original

     * position.  If the input stream does not support this, this method may fail

     * with an IOException.

     * @param stream the input stream from which the <code>AudioInputStream</code> should be

     * constructed

     * @return an <code>AudioInputStream</code> object based on the audio file data contained

     * in the input stream.

     * @throws UnsupportedAudioFileException if the stream does not point to valid audio

     * file data recognized by the system

     * @throws IOException if an I/O exception occurs

     * @see InputStream#markSupported

     * @see InputStream#mark

     */

    abstract public AudioInputStream getAudioInputStream(InputStream stream) throws UnsupportedAudioFileException, IOException;

    /**

     * Obtains an audio stream from the URL provided.  The URL must

     * point to valid audio file data.

     * @param url the URL for which the <code>AudioInputStream</code> should be

     * constructed

     * @return an <code>AudioInputStream</code> object based on the audio file data pointed

     * to by the URL

     * @throws UnsupportedAudioFileException if the URL does not point to valid audio

     * file data recognized by the system

     * @throws IOException if an I/O exception occurs

     */

    abstract public AudioInputStream getAudioInputStream(URL url) throws UnsupportedAudioFileException, IOException;

    /**

     * Obtains an audio stream from the File provided.  The File must

     * point to valid audio file data.

     * @param file the File for which the <code>AudioInputStream</code> should be

     * constructed

     * @return an <code>AudioInputStream</code> object based on the audio file data pointed

     * to by the File

     * @throws UnsupportedAudioFileException if the File does not point to valid audio

     * file data recognized by the system

     * @throws IOException if an I/O exception occurs

     */

    abstract public AudioInputStream getAudioInputStream(File file) throws UnsupportedAudioFileException, IOException;

    // HELPER METHODS

    /**

     * rllong

     * Protected helper method to read 64 bits and changing the order of

     * each bytes.

     * @param DataInputStream

     * @return 32 bits swapped value.

     * @exception IOException

     */

    protected int rllong(DataInputStream dis) throws IOException {

        int b1, b2, b3, b4 ;

        int i = 0;

        i = dis.readInt();

        b1 = ( i & 0xFF ) << 24 ;

        b2 = ( i & 0xFF00 ) << 8;

        b3 = ( i & 0xFF0000 ) >> 8;

        b4 = ( i & 0xFF000000 ) >>> 24;

        i = ( b1 | b2 | b3 | b4 );

        return i;

    }

    /**

     * big2little

     * Protected helper method to swap the order of bytes in a 32 bit int

     * @param int

     * @return 32 bits swapped value

     */

    protected int big2little(int i) {

        int b1, b2, b3, b4 ;

        b1 = ( i & 0xFF ) << 24 ;

        b2 = ( i & 0xFF00 ) << 8;

        b3 = ( i & 0xFF0000 ) >> 8;

        b4 = ( i & 0xFF000000 ) >>> 24;

        i = ( b1 | b2 | b3 | b4 );

        return i;

    }

    /**

     * rlshort

     * Protected helper method to read 16 bits value. Swap high with low byte.

     * @param DataInputStream

     * @return the swapped value.

     * @exception IOException

     */

    protected short rlshort(DataInputStream dis)  throws IOException {

        short s=0;

        short high, low;

        s = dis.readShort();

        high = (short)(( s & 0xFF ) << 8) ;

        low = (short)(( s & 0xFF00 ) >>> 8);

        s = (short)( high | low );

        return s;

    }

    /**

     * big2little

     * Protected helper method to swap the order of bytes in a 16 bit short

     * @param int

     * @return 16 bits swapped value

     */

    protected short big2littleShort(short i) {

        short high, low;

        high = (short)(( i & 0xFF ) << 8) ;

        low = (short)(( i & 0xFF00 ) >>> 8);

        i = (short)( high | low );

        return i;

    }

        /** Calculates the frame size for PCM frames.

         * Note that this method is appropriate for non-packed samples.

         * For instance, 12 bit, 2 channels will return 4 bytes, not 3.

         * @param sampleSizeInBits the size of a single sample in bits

         * @param channels the number of channels

         * @return the size of a PCM frame in bytes.

         */

        protected static int calculatePCMFrameSize(int sampleSizeInBits,

                                                                                        int channels) {

                return ((sampleSizeInBits + 7) / 8) * channels;

        }

}