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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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, Florian Bomers
/** * Common conversions etc. * * @author Kara Kytle * @author Florian Bomers */
public final class Toolkit {
Suppresses default constructor, ensuring non-instantiability.
/** * Suppresses default constructor, ensuring non-instantiability. */
private Toolkit() { }
Converts bytes from signed to unsigned.
/** * 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:
  • ArrayIndexOutOfBoundsException – if len is not a multiple of 2.
/** * Swaps bytes. * @throws ArrayIndexOutOfBoundsException 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.
/** * Linear to DB scale conversion. */
static float linearToDB(float linear) { float dB = (float) (Math.log(((linear==0.0)?0.0001:linear))/Math.log(10.0) * 20.0); return dB; }
DB to linear scale conversion.
/** * 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); }
Throws an exception if the buffer size does not represent an integral number of sample frames.
/** * Throws an exception if the buffer size does not represent an integral * number of sample frames. */
static void validateBuffer(final int frameSize, final int bufferSize) { if (bufferSize % frameSize == 0) { return; } throw new IllegalArgumentException(String.format( "Buffer size (%d) does not represent an integral number of " + "sample frames (%d)", bufferSize, frameSize)); } static void isFullySpecifiedAudioFormat(AudioFormat format) { // Our code requires a positive frame size, that's probably is not // necessary for non-linear encodings, but for now // IllegalArgumentException is better than ArithmeticException if (format.getFrameSize() <= 0) { throw new IllegalArgumentException("invalid frame size: " +((format.getFrameSize() == -1) ? "NOT_SPECIFIED":String.valueOf(format.getFrameSize()))); } 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.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; } }