ch.randelshofer.media.eightsvx
Class EightSVXDecoder

java.lang.Object
  ch.randelshofer.media.eightsvx.EightSVXDecoder

All Implemented Interfaces:

IFFVisitor

public class EightSVXDecoder
extends java.lang.Object
implements IFFVisitor

Creates a collection of EightSVXAudioClip objects by reading an IFF 8SVX file.

8SVX Type Definitions

 #define ID_8SVX MakeID('8', 'S', 'V', 'X')
 #define ID_VHDR MakeID('V', 'H', 'D', 'R')

 typedef LONG Fixed;     // A Fixed-point value, 16 bits to the left of
 // the point and 16 to the right. A Fixed is a number
 // of 2^16ths, i.e., 65536ths.
 #define Unity 0x10000L  // Unity = Fixed 1.0 = maximum volume

 // sCompression: Choice of compression algorithm applied to the samples.
 #define sCmpNone   0  // not compressed
 #define sCmpFibDelta 1  // Fibonacci-delta encoding.
 // Can be more kinds in the future.

 typedef struct {
 ULONG oneShotHiSamples,   // # samples in the high octave 1-shot part
 repeatHiSamples,   // # samples in the high octave repeat part
 samplesPerHiCycle; // # samples/cycle in high octave, else 0
 UWORD samplesPerSec;     // data sampling rate
 UBYTE ctOctave,          // # octaves of waveform
 sCompression;      // data compression technique used
 Fixed volume;            // playback volume form 0 to Unity (full
 // volume). Map this value into the output
 // hardware's dynamic range.
 } Voice8Header;

 #define ID_NAME MakeID('N', 'A', 'M', 'E')
 // NAME chunk contains a CHAR[], the voice's name.

 #define ID_Copyright MakeID('(', 'c', ')', ' ')
 // "(c) " chunk contains a CHAR[], the FORM's copyright notice.

 #define ID_AUTH MakeID('A', 'U', 'T', 'H')
 // AUTH chunk contains a CHAR[], the author's name.

 #define ID_ANNO MakeID('A', 'N', 'N', 'O')
 // ANNO chunk contains a CHAR[], author's text annotations.

 #define ID_ATAK MakeID('A', 'T', 'A', 'K')
 #define ID_RLSE MakeID('R', 'L', 'S', 'E')

 typedef struct {
 UWORD duration; // segment duration in milliseconds, > 0
 Fixed dest;     // destination volume factor
 } EGPoint;

 // ATAK and RLSE chunks contain an EGPoint[], piecewise-linear envelope.
 // The envelope defines a function of time returning Fixed values. It's
 // used to scale the nominal volume specified in the Voice8Header.

 #define RIGHT    4L
 #define LEFT     2L
 #define STEREO   6L

 #define ID_CHAN MakeID('C', 'H', 'A', 'N')
 typedef sampletype LONG;

 #define ID_PAN MakeID('P', 'A', 'N', ' ')
 typedef sposition Fixed; // 0 <= sposition <= Unity
 // Unity refers to the maximum possible volume.


 #define ID_BODY MakeID('B', 'O', 'D', 'Y')
 typedef character BYTE; // 8 bit signed number, -128 thru 127.
 // BODY chunk contains a BYTE[], array of audio data samples
 

8SVX Regular Expression

 8SVX       ::= "FORM" #{ "8SVX" VHDR [NAME] [Copyright] [AUTH] ANNO* [ATAK] [RLSE] [CHAN] [PAN] BODY }

 VHDR       ::= "VHDR" #{ Voice8Header }
 NAME       ::= "NAME" #{ CHAR* } [0]
 Copyright  ::= "(c) " #{ CHAR* } [0]
 AUTH       ::= "AUTH" #{ CHAR* } [0]
 ANNO       ::= "ANNO" #{ CHAR* } [0]

 ATAK       ::= "ATAK" #{ EGPoint* }
 RLSE       ::= "RLSE" #{ EGPoint* }
 CHAN       ::= "CHAN" #{ sampletype }
 PAN        ::= "PAN " #{ sposition }
 BODY       ::= "BODY" #{ BYTE* } [0]
 

The token "#" represents a ckSize LONG count of the following {braced} data bytes. E.g., a VHDR's "#" should equal sizeof(Voicd8Header). Literal items are shown in "quotes", [square bracket items] are optional, and "*" means 0 ore more replications. A sometimes-needed pad byte is shown als "[0]".

Version:

1.0 1999-10-19

Author:

Werner Randelshofer, Hausmatt 10, CH-6405 Immensee, Switzerland

Field Summary

static int	ANNO_ID
static int	AUTH_ID
static int	BODY_ID
static int	CHAN_ID
static int	COPYRIGHT_ID
static int	EIGHT_SVX_ID
static int	NAME_ID
static int	VHDR_ID

Constructor Summary

EightSVXDecoder()

EightSVXDecoder(java.io.InputStream in)
Creates a new Audio Source from the specified InputStream.

Method Summary

void	addAudioClip(java.applet.AudioClip clip)
protected void	decodeANNO(EightSVXAudioClip sample, IFFChunk[] chunks)
protected void	decodeAUTH(EightSVXAudioClip sample, IFFChunk chunk)
protected void	decodeBODY(EightSVXAudioClip sample, IFFChunk chunk)
protected void	decodeCHAN(EightSVXAudioClip sample, IFFChunk chunk)
protected void	decodeCOPYRIGHT(EightSVXAudioClip sample, IFFChunk chunk)
protected void	decodeNAME(EightSVXAudioClip sample, IFFChunk chunk)
protected void	decodeVHDR(EightSVXAudioClip sample, IFFChunk chunk) The Voice 8 Header (VHDR) property chunk holds the playback parameters for the sampled waveform.
void	enterGroup(IFFChunk group) Visits the start of an IFF GroupChunkExpression.
java.util.Vector	getSamples()
void	leaveGroup(IFFChunk group)
void	registerChunks(IFFParser iff)
void	visitChunk(IFFChunk group, IFFChunk chunk)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EIGHT_SVX_ID

public static final int EIGHT_SVX_ID

VHDR_ID

public static final int VHDR_ID

NAME_ID

public static final int NAME_ID

COPYRIGHT_ID

public static final int COPYRIGHT_ID

ANNO_ID

public static final int ANNO_ID

AUTH_ID

public static final int AUTH_ID

CHAN_ID

public static final int CHAN_ID

BODY_ID

public static final int BODY_ID

Constructor Detail

EightSVXDecoder

public EightSVXDecoder(java.io.InputStream in)
                throws java.io.IOException

Creates a new Audio Source from the specified InputStream. Pre condition InputStream must contain IFF 8SVX data. Post condition - Obligation -

Parameters:

in - The input stream.

Throws:

java.io.IOException

EightSVXDecoder

public EightSVXDecoder()

Method Detail

getSamples

public java.util.Vector getSamples()

registerChunks

public void registerChunks(IFFParser iff)

enterGroup

public void enterGroup(IFFChunk group)

Visits the start of an IFF GroupChunkExpression. Altough this method is declared as public it may only be called from an IFFParser that has been invoked by this class. Pre condition Vector must not be null. This method espects only FORM groups of type 8SVX. Post condition - Obligation -

Specified by:

enterGroup in interface IFFVisitor

Parameters:

group - Group Chunk to be visited.

Throws:

ParseException - When an error has been encountered.

leaveGroup

public void leaveGroup(IFFChunk group)

Specified by:

leaveGroup in interface IFFVisitor

visitChunk

public void visitChunk(IFFChunk group,
                       IFFChunk chunk)
                throws ParseException

Specified by:

visitChunk in interface IFFVisitor

Throws:

ParseException

addAudioClip

public void addAudioClip(java.applet.AudioClip clip)

decodeVHDR

protected void decodeVHDR(EightSVXAudioClip sample,
                          IFFChunk chunk)
                   throws ParseException

The Voice 8 Header (VHDR) property chunk holds the playback parameters for the sampled waveform.

 typedef LONG Fixed;     // A Fixed-point value, 16 bits to the left of
 // the point and 16 to the right. A Fixed is a number
 // of 2^16ths, i.e., 65536ths.
 #define Unity 0x10000L  // Unity = Fixed 1.0 = maximum volume

 // sCompression: Choice of compression algorithm applied to the samples.
 #define sCmpNone   0  // not compressed
 #define sCmpFibDelta 1  // Fibonacci-delta encoding.
 // Can be more kinds in the future.

 typedef struct {
 ULONG oneShotHiSamples,   // # samples in the high octave 1-shot part
 repeatHiSamples,   // # samples in the high octave repeat part
 samplesPerHiCycle; // # samples/cycle in high octave, else 0
 UWORD samplesPerSec;     // data sampling rate
 UBYTE ctOctave,          // # octaves of waveform
 sCompression;      // data compression technique used
 Fixed volume;            // playback volume form 0 to Unity (full
 // volume). Map this value into the output
 // hardware's dynamic range.
 } Voice8Header;
 

Throws:

ParseException

decodeCHAN

protected void decodeCHAN(EightSVXAudioClip sample,
                          IFFChunk chunk)
                   throws ParseException

Throws:

ParseException

decodeNAME

protected void decodeNAME(EightSVXAudioClip sample,
                          IFFChunk chunk)
                   throws ParseException

Throws:

ParseException

decodeCOPYRIGHT

protected void decodeCOPYRIGHT(EightSVXAudioClip sample,
                               IFFChunk chunk)
                        throws ParseException

Throws:

ParseException

decodeAUTH

protected void decodeAUTH(EightSVXAudioClip sample,
                          IFFChunk chunk)
                   throws ParseException

Throws:

ParseException

decodeANNO

protected void decodeANNO(EightSVXAudioClip sample,
                          IFFChunk[] chunks)
                   throws ParseException

Throws:

ParseException

decodeBODY

protected void decodeBODY(EightSVXAudioClip sample,
                          IFFChunk chunk)
                   throws ParseException

Throws:

ParseException