/**
* @author : Paul Taylor
* <p/>
* Version @version:$Id: MPEGFrameHeader.java 970 2011-05-06 12:34:36Z paultaylor $
* Date :${DATE}
* <p/>
* Jaikoz Copyright Copyright (C) 2003 -2005 JThink Ltd
*/
package org.jaudiotagger.audio.mp3;
import org.jaudiotagger.FileConstants;
import org.jaudiotagger.audio.exceptions.InvalidAudioFrameException;
import org.jaudiotagger.logging.AbstractTagDisplayFormatter;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
/**
* Represents a MPEGFrameHeader, an MP3 is made up of a number of frames each frame starts with a four
* byte frame header.
*/
@SuppressWarnings({"PointlessArithmeticExpression"})
public class MPEGFrameHeader
{
/**
* Constants for MP3 Frame header, each frame has a basic header of
* 4 bytes
*/
private static final int BYTE_1 = 0;
private static final int BYTE_2 = 1;
private static final int BYTE_3 = 2;
private static final int BYTE_4 = 3;
public static final int HEADER_SIZE = 4;
/**
* Sync Value to identify the start of an MPEGFrame
*/
public static final int SYNC_SIZE = 2;
public static final int SYNC_BYTE1 = 0xFF;
public static final int SYNC_BYTE2 = 0xE0;
public static final int SYNC_BIT_ANDSAMPING_BYTE3 = 0xFC;
private static final byte[] header = new byte[HEADER_SIZE];
/**
* Constants for MPEG Version
*/
public static final Map<Integer, String> mpegVersionMap = new HashMap<Integer, String>();
public final static int VERSION_2_5 = 0;
public final static int VERSION_2 = 2;
public final static int VERSION_1 = 3;
static
{
mpegVersionMap.put(VERSION_2_5, "MPEG-2.5");
mpegVersionMap.put(VERSION_2, "MPEG-2");
mpegVersionMap.put(VERSION_1, "MPEG-1");
}
/**
* Constants for MPEG Layer
*/
public static final Map<Integer, String> mpegLayerMap = new HashMap<Integer, String>();
public final static int LAYER_I = 3;
public final static int LAYER_II = 2;
public final static int LAYER_III = 1;
static
{
mpegLayerMap.put(LAYER_I, "Layer 1");
mpegLayerMap.put(LAYER_II, "Layer 2");
mpegLayerMap.put(LAYER_III, "Layer 3");
}
/**
* Slot Size is dependent on Layer
*/
public final static int LAYER_I_SLOT_SIZE = 4;
public final static int LAYER_II_SLOT_SIZE = 1;
public final static int LAYER_III_SLOT_SIZE = 1;
/**
* Bit Rates, the setBitrate varies for different Version and Layer
*/
private static final Map<Integer, Integer> bitrateMap = new HashMap<Integer, Integer>();
static
{
// MPEG-1, Layer I (E)
bitrateMap.put(0x1E, 32);
bitrateMap.put(0x2E, 64);
bitrateMap.put(0x3E, 96);
bitrateMap.put(0x4E, 128);
bitrateMap.put(0x5E, 160);
bitrateMap.put(0x6E, 192);
bitrateMap.put(0x7E, 224);
bitrateMap.put(0x8E, 256);
bitrateMap.put(0x9E, 288);
bitrateMap.put(0xAE, 320);
bitrateMap.put(0xBE, 352);
bitrateMap.put(0xCE, 384);
bitrateMap.put(0xDE, 416);
bitrateMap.put(0xEE, 448);
// MPEG-1, Layer II (C)
bitrateMap.put(0x1C, 32);
bitrateMap.put(0x2C, 48);
bitrateMap.put(0x3C, 56);
bitrateMap.put(0x4C, 64);
bitrateMap.put(0x5C, 80);
bitrateMap.put(0x6C, 96);
bitrateMap.put(0x7C, 112);
bitrateMap.put(0x8C, 128);
bitrateMap.put(0x9C, 160);
bitrateMap.put(0xAC, 192);
bitrateMap.put(0xBC, 224);
bitrateMap.put(0xCC, 256);
bitrateMap.put(0xDC, 320);
bitrateMap.put(0xEC, 384);
// MPEG-1, Layer III (A)
bitrateMap.put(0x1A, 32);
bitrateMap.put(0x2A, 40);
bitrateMap.put(0x3A, 48);
bitrateMap.put(0x4A, 56);
bitrateMap.put(0x5A, 64);
bitrateMap.put(0x6A, 80);
bitrateMap.put(0x7A, 96);
bitrateMap.put(0x8A, 112);
bitrateMap.put(0x9A, 128);
bitrateMap.put(0xAA, 160);
bitrateMap.put(0xBA, 192);
bitrateMap.put(0xCA, 224);
bitrateMap.put(0xDA, 256);
bitrateMap.put(0xEA, 320);
// MPEG-2, Layer I (6)
bitrateMap.put(0x16, 32);
bitrateMap.put(0x26, 48);
bitrateMap.put(0x36, 56);
bitrateMap.put(0x46, 64);
bitrateMap.put(0x56, 80);
bitrateMap.put(0x66, 96);
bitrateMap.put(0x76, 112);
bitrateMap.put(0x86, 128);
bitrateMap.put(0x96, 144);
bitrateMap.put(0xA6, 160);
bitrateMap.put(0xB6, 176);
bitrateMap.put(0xC6, 192);
bitrateMap.put(0xD6, 224);
bitrateMap.put(0xE6, 256);
// MPEG-2, Layer II (4)
bitrateMap.put(0x14, 8);
bitrateMap.put(0x24, 16);
bitrateMap.put(0x34, 24);
bitrateMap.put(0x44, 32);
bitrateMap.put(0x54, 40);
bitrateMap.put(0x64, 48);
bitrateMap.put(0x74, 56);
bitrateMap.put(0x84, 64);
bitrateMap.put(0x94, 80);
bitrateMap.put(0xA4, 96);
bitrateMap.put(0xB4, 112);
bitrateMap.put(0xC4, 128);
bitrateMap.put(0xD4, 144);
bitrateMap.put(0xE4, 160);
// MPEG-2, Layer III (2)
bitrateMap.put(0x12, 8);
bitrateMap.put(0x22, 16);
bitrateMap.put(0x32, 24);
bitrateMap.put(0x42, 32);
bitrateMap.put(0x52, 40);
bitrateMap.put(0x62, 48);
bitrateMap.put(0x72, 56);
bitrateMap.put(0x82, 64);
bitrateMap.put(0x92, 80);
bitrateMap.put(0xA2, 96);
bitrateMap.put(0xB2, 112);
bitrateMap.put(0xC2, 128);
bitrateMap.put(0xD2, 144);
bitrateMap.put(0xE2, 160);
}
/**
* Constants for Channel mode
*/
public static final Map<Integer, String> modeMap = new HashMap<Integer, String>();
public final static int MODE_STEREO = 0;
public final static int MODE_JOINT_STEREO = 1;
public final static int MODE_DUAL_CHANNEL = 2;
public final static int MODE_MONO = 3;
static
{
modeMap.put(MODE_STEREO, "Stereo");
modeMap.put(MODE_JOINT_STEREO, "Joint Stereo");
modeMap.put(MODE_DUAL_CHANNEL, "Dual");
modeMap.put(MODE_MONO, "Mono");
}
/**
* Constants for Emphasis
*/
private static final Map<Integer, String> emphasisMap = new HashMap<Integer, String>();
public final static int EMPHASIS_NONE = 0;
public final static int EMPHASIS_5015MS = 1;
public final static int EMPHASIS_RESERVED = 2;
public final static int EMPHASIS_CCITT = 3;
static
{
emphasisMap.put(EMPHASIS_NONE, "None");
emphasisMap.put(EMPHASIS_5015MS, "5015MS");
emphasisMap.put(EMPHASIS_RESERVED, "Reserved");
emphasisMap.put(EMPHASIS_CCITT, "CCITT");
}
private static final Map<Integer, String> modeExtensionMap = new HashMap<Integer, String>();
private final static int MODE_EXTENSION_NONE = 0;
private final static int MODE_EXTENSION_ONE = 1;
private final static int MODE_EXTENSION_TWO = 2;
private final static int MODE_EXTENSION_THREE = 3;
private static final Map<Integer, String> modeExtensionLayerIIIMap = new HashMap<Integer, String>();
private final static int MODE_EXTENSION_OFF_OFF = 0;
private final static int MODE_EXTENSION_ON_OFF = 1;
private final static int MODE_EXTENSION_OFF_ON = 2;
private final static int MODE_EXTENSION_ON_ON = 3;
static
{
modeExtensionMap.put(MODE_EXTENSION_NONE, "4-31");
modeExtensionMap.put(MODE_EXTENSION_ONE, "8-31");
modeExtensionMap.put(MODE_EXTENSION_TWO, "12-31");
modeExtensionMap.put(MODE_EXTENSION_THREE, "16-31");
modeExtensionLayerIIIMap.put(MODE_EXTENSION_OFF_OFF, "off-off");
modeExtensionLayerIIIMap.put(MODE_EXTENSION_ON_OFF, "on-off");
modeExtensionLayerIIIMap.put(MODE_EXTENSION_OFF_ON, "off-on");
modeExtensionLayerIIIMap.put(MODE_EXTENSION_ON_ON, "on-on");
}
/**
* Sampling Rate in Hz
*/
private static final Map<Integer, Map<Integer, Integer>> samplingRateMap = new HashMap<Integer, Map<Integer, Integer>>();
private static final Map<Integer, Integer> samplingV1Map = new HashMap<Integer, Integer>();
private static final Map<Integer, Integer> samplingV2Map = new HashMap<Integer, Integer>();
private static final Map<Integer, Integer> samplingV25Map = new HashMap<Integer, Integer>();
static
{
samplingV1Map.put(0, 44100);
samplingV1Map.put(1, 48000);
samplingV1Map.put(2, 32000);
samplingV2Map.put(0, 22050);
samplingV2Map.put(1, 24000);
samplingV2Map.put(2, 16000);
samplingV25Map.put(0, 11025);
samplingV25Map.put(1, 12000);
samplingV25Map.put(2, 8000);
samplingRateMap.put(VERSION_1, samplingV1Map);
samplingRateMap.put(VERSION_2, samplingV2Map);
samplingRateMap.put(VERSION_2_5, samplingV25Map);
}
/* Samples Per Frame */
private static final Map<Integer, Map<Integer, Integer>> samplesPerFrameMap = new HashMap<Integer, Map<Integer, Integer>>();
private static final Map<Integer, Integer> samplesPerFrameV1Map = new HashMap<Integer, Integer>();
private static final Map<Integer, Integer> samplesPerFrameV2Map = new HashMap<Integer, Integer>();
private static final Map<Integer, Integer> samplesPerFrameV25Map = new HashMap<Integer, Integer>();
static
{
samplesPerFrameV1Map.put(LAYER_I, 384);
samplesPerFrameV1Map.put(LAYER_II, 1152);
samplesPerFrameV1Map.put(LAYER_III, 1152);
samplesPerFrameV2Map.put(LAYER_I, 384);
samplesPerFrameV2Map.put(LAYER_II, 1152);
samplesPerFrameV2Map.put(LAYER_III, 576);
samplesPerFrameV25Map.put(LAYER_I, 384);
samplesPerFrameV25Map.put(LAYER_II, 1152);
samplesPerFrameV25Map.put(LAYER_III, 576);
samplesPerFrameMap.put(VERSION_1, samplesPerFrameV1Map);
samplesPerFrameMap.put(VERSION_2, samplesPerFrameV2Map);
samplesPerFrameMap.put(VERSION_2_5, samplesPerFrameV25Map);
}
private static final int SCALE_BY_THOUSAND = 1000;
private static final int LAYER_I_FRAME_SIZE_COEFFICIENT = 12;
private static final int LAYER_II_FRAME_SIZE_COEFFICIENT = 144;
private static final int LAYER_III_FRAME_SIZE_COEFFICIENT = 144;
/**
* MP3 Frame Header bit mask
*/
private static final int MASK_MP3_ID = FileConstants.BIT3;
/**
* MP3 version, confusingly for MP3s the version is 1.
*/
private static final int MASK_MP3_VERSION = FileConstants.BIT4 | FileConstants.BIT3;
/**
* MP3 Layer, for MP3s the Layer is 3
*/
private static final int MASK_MP3_LAYER = FileConstants.BIT2 | FileConstants.BIT1;
/**
* Does it include a CRC Checksum at end of header, this can be used to check the header.
*/
private static final int MASK_MP3_PROTECTION = FileConstants.BIT0;
/**
* The setBitrate of this MP3
*/
private static final int MASK_MP3_BITRATE = FileConstants.BIT7 | FileConstants.BIT6 | FileConstants.BIT5 | FileConstants.BIT4;
/**
* The sampling/frequency rate
*/
private static final int MASK_MP3_FREQUENCY = FileConstants.BIT3 + FileConstants.BIT2;
/**
* An extra padding bit is sometimes used to make sure frames are exactly the right length
*/
private static final int MASK_MP3_PADDING = FileConstants.BIT1;
/**
* Private bit set, for application specific
*/
private static final int MASK_MP3_PRIVACY = FileConstants.BIT0;
/**
* Channel Mode, Stero/Mono/Dual Channel
*/
private static final int MASK_MP3_MODE = FileConstants.BIT7 | FileConstants.BIT6;
/**
* MP3 Frame Header bit mask
*/
private static final int MASK_MP3_MODE_EXTENSION = FileConstants.BIT5 | FileConstants.BIT4;
/**
* MP3 Frame Header bit mask
*/
private static final int MASK_MP3_COPY = FileConstants.BIT3;
/**
* MP3 Frame Header bit mask
*/
private static final int MASK_MP3_HOME = FileConstants.BIT2;
/**
* MP3 Frame Header bit mask
*/
private static final int MASK_MP3_EMPHASIS = FileConstants.BIT1 | FileConstants.BIT0;
private byte[] mpegBytes;
/**
* The version of this MPEG frame (see the constants)
*/
private int version;
private String versionAsString;
/**
* Contains the mpeg layer of this frame (see constants)
*/
private int layer;
private String layerAsString;
/**
* Bitrate of this frame
*/
private Integer bitRate;
/**
* Channel Mode of this Frame (see constants)
*/
private int channelMode;
/**
* Channel Mode of this Frame As English String
*/
private String channelModeAsString;
/**
* Emphasis of this frame
*/
private int emphasis;
/**
* Emphasis mode string
*/
private String emphasisAsString;
/**
* Mode Extension
*/
private String modeExtension;
/**
* Flag indicating if this frame has padding byte
*/
private boolean isPadding;
/**
* Flag indicating if this frame contains copyrighted material
*/
private boolean isCopyrighted;
/**
* Flag indicating if this frame contains original material
*/
private boolean isOriginal;
/**
* Flag indicating if this frame is protected
*/
private boolean isProtected;
/**
* Flag indicating if this frame is private
*/
private boolean isPrivate;
private Integer samplingRate;
/**
* Gets the layerVersion attribute of the MPEGFrame object
*
* @return The layerVersion value
*/
public int getLayer()
{
return layer;
}
public String getLayerAsString()
{
return layerAsString;
}
/**
* Gets the copyrighted attribute of the MPEGFrame object
*/
private void setCopyrighted()
{
isCopyrighted = (mpegBytes[BYTE_4] & MASK_MP3_COPY) != 0;
}
/**
* Set the version of this frame as an int value (see constants)
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setVersion() throws InvalidAudioFrameException
{
//MPEG Version
version = (byte) ((mpegBytes[BYTE_2] & MASK_MP3_VERSION) >> 3);
versionAsString = mpegVersionMap.get(version);
if (versionAsString == null)
{
throw new InvalidAudioFrameException("Invalid mpeg version");
}
}
/**
* Sets the original attribute of the MPEGFrame object
*/
private void setOriginal()
{
isOriginal = (mpegBytes[BYTE_4] & MASK_MP3_HOME) != 0;
}
/**
* Sets the protected attribute of the MPEGFrame object
*/
private void setProtected()
{
isProtected = (mpegBytes[BYTE_2] & MASK_MP3_PROTECTION) == 0x00;
}
/**
* Sets the private attribute of the MPEGFrame object
*/
private void setPrivate()
{
isPrivate = (mpegBytes[BYTE_3] & MASK_MP3_PRIVACY) != 0;
}
/**
* Get the setBitrate of this frame
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setBitrate() throws InvalidAudioFrameException
{
/* BitRate, get by checking header setBitrate bits and MPEG Version and Layer */
int bitRateIndex = mpegBytes[BYTE_3] & MASK_MP3_BITRATE | mpegBytes[BYTE_2] & MASK_MP3_ID | mpegBytes[BYTE_2] & MASK_MP3_LAYER;
bitRate = bitrateMap.get(bitRateIndex);
if (bitRate == null)
{
throw new InvalidAudioFrameException("Invalid bitrate");
}
}
/**
* Set the Mpeg channel mode of this frame as a constant (see constants)
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setChannelMode() throws InvalidAudioFrameException
{
channelMode = (mpegBytes[BYTE_4] & MASK_MP3_MODE) >>> 6;
channelModeAsString = modeMap.get(channelMode);
if (channelModeAsString == null)
{
throw new InvalidAudioFrameException("Invalid channel mode");
}
}
/**
* Get the setEmphasis mode of this frame in a string representation
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setEmphasis() throws InvalidAudioFrameException
{
emphasis = mpegBytes[BYTE_4] & MASK_MP3_EMPHASIS;
emphasisAsString = emphasisMap.get(emphasis);
if (getEmphasisAsString() == null)
{
throw new InvalidAudioFrameException("Invalid emphasis");
}
}
/**
* Set whether this frame uses padding bytes
*/
private void setPadding()
{
isPadding = (mpegBytes[BYTE_3] & MASK_MP3_PADDING) != 0;
}
/**
* Get the layer version of this frame as a constant int value (see constants)
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setLayer() throws InvalidAudioFrameException
{
layer = (mpegBytes[BYTE_2] & MASK_MP3_LAYER) >>> 1;
layerAsString = mpegLayerMap.get(layer);
if (layerAsString == null)
{
throw new InvalidAudioFrameException("Invalid Layer");
}
}
/**
* Sets the string representation of the mode extension of this frame
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setModeExtension() throws InvalidAudioFrameException
{
int index = (mpegBytes[BYTE_4] & MASK_MP3_MODE_EXTENSION) >> 4;
if (layer == LAYER_III)
{
modeExtension = modeExtensionLayerIIIMap.get(index);
if (getModeExtension() == null)
{
throw new InvalidAudioFrameException("Invalid Mode Extension");
}
}
else
{
modeExtension = modeExtensionMap.get(index);
if (getModeExtension() == null)
{
throw new InvalidAudioFrameException("Invalid Mode Extension");
}
}
}
/**
* set the sampling rate in Hz of this frame
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private void setSamplingRate() throws InvalidAudioFrameException
{
//Frequency
int index = (mpegBytes[BYTE_3] & MASK_MP3_FREQUENCY) >>> 2;
Map<Integer, Integer> samplingRateMapForVersion = samplingRateMap.get(version);
if (samplingRateMapForVersion == null)
{
throw new InvalidAudioFrameException("Invalid version");
}
samplingRate = samplingRateMapForVersion.get(index);
if (samplingRate == null)
{
throw new InvalidAudioFrameException("Invalid sampling rate");
}
}
/**
* Gets the number of channels
*
* @return The setChannelMode value
*/
public int getNumberOfChannels()
{
switch (channelMode)
{
case MODE_DUAL_CHANNEL:
return 2;
case MODE_JOINT_STEREO:
return 2;
case MODE_MONO:
return 1;
case MODE_STEREO:
return 2;
default:
return 0;
}
}
public int getChannelMode()
{
return channelMode;
}
public String getChannelModeAsString()
{
return channelModeAsString;
}
/**
* Gets the mPEGVersion attribute of the MPEGFrame object
*
* @return The mPEGVersion value
*/
public int getVersion()
{
return version;
}
public String getVersionAsString()
{
return versionAsString;
}
/**
* Gets the paddingLength attribute of the MPEGFrame object
*
* @return The paddingLength value
*/
public int getPaddingLength()
{
if (isPadding())
{
return 1;
}
else
{
return 0;
}
}
public Integer getBitRate()
{
return bitRate;
}
public Integer getSamplingRate()
{
return samplingRate;
}
/*
* Gets this frame length in bytes, value should always be rounded down to the nearest byte (not rounded up)
*
* Calculation is Bitrate (scaled to bps) divided by sampling frequency (in Hz), The larger the bitrate the larger
* the frame but the more samples per second the smaller the value, also have to take into account frame padding
* Have to multiple by a coefficient constant depending upon the layer it is encoded in,
*/
public int getFrameLength()
{
switch (version)
{
case VERSION_2:
case VERSION_2_5:
switch (layer)
{
case LAYER_I:
return (LAYER_I_FRAME_SIZE_COEFFICIENT * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength()) * LAYER_I_SLOT_SIZE;
case LAYER_II:
return (LAYER_II_FRAME_SIZE_COEFFICIENT ) * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength() * LAYER_II_SLOT_SIZE;
case LAYER_III:
if (this.getChannelMode() == MODE_MONO)
{
return (LAYER_III_FRAME_SIZE_COEFFICIENT / 2 ) * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength() * LAYER_III_SLOT_SIZE;
}
else
{
return (LAYER_III_FRAME_SIZE_COEFFICIENT) * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength() * LAYER_III_SLOT_SIZE;
}
default:
throw new RuntimeException("Mp3 Unknown Layer:" + layer);
}
case VERSION_1:
switch (layer)
{
case LAYER_I:
return (LAYER_I_FRAME_SIZE_COEFFICIENT * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength()) * LAYER_I_SLOT_SIZE;
case LAYER_II:
return LAYER_II_FRAME_SIZE_COEFFICIENT * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength() * LAYER_II_SLOT_SIZE;
case LAYER_III:
return LAYER_III_FRAME_SIZE_COEFFICIENT * (getBitRate() * SCALE_BY_THOUSAND) / getSamplingRate() + getPaddingLength() * LAYER_III_SLOT_SIZE;
default:
throw new RuntimeException("Mp3 Unknown Layer:" + layer);
}
default:
throw new RuntimeException("Mp3 Unknown Version:" + version);
}
}
/**
* Get the number of samples in a frame, all frames in a file have a set number of samples as defined by their MPEG Versiona
* and Layer
* @return
*/
public int getNoOfSamples()
{
Integer noOfSamples = samplesPerFrameMap.get(version).get(layer);
return noOfSamples;
}
public boolean isPadding()
{
return isPadding;
}
public boolean isCopyrighted()
{
return isCopyrighted;
}
public boolean isOriginal()
{
return isOriginal;
}
public boolean isProtected()
{
return isProtected;
}
public boolean isPrivate()
{
return isPrivate;
}
public boolean isVariableBitRate()
{
return false;
}
public int getEmphasis()
{
return emphasis;
}
public String getEmphasisAsString()
{
return emphasisAsString;
}
public String getModeExtension()
{
return modeExtension;
}
/**
* Hide Constructor
* @throws org.jaudiotagger.audio.exceptions.InvalidAudioFrameException
*/
private MPEGFrameHeader() throws InvalidAudioFrameException
{
}
/**
* Try and create a new MPEG frame with the given byte array and decodes its contents
* If decoding header causes a problem it is not a valid header
*
* @param b the array of bytes representing this mpeg frame
* @throws InvalidAudioFrameException if does not match expected format
*/
private MPEGFrameHeader(byte[] b) throws InvalidAudioFrameException
{
mpegBytes = b;
setBitrate();
setVersion();
setLayer();
setProtected();
setSamplingRate();
setPadding();
setPrivate();
setChannelMode();
setModeExtension();
setCopyrighted();
setOriginal();
setEmphasis();
}
/**
* Parse the MPEGFrameHeader of an MP3File, file pointer returns at end of the frame header
*
* @param bb the byte buffer containing the header
* @return
* @throws InvalidAudioFrameException if there is no header at this point
*/
public static MPEGFrameHeader parseMPEGHeader(ByteBuffer bb) throws InvalidAudioFrameException
{
int position = bb.position();
bb.get(header, 0, HEADER_SIZE);
bb.position(position);
MPEGFrameHeader frameHeader = new MPEGFrameHeader(header);
return frameHeader;
}
/**
* Gets the MPEGFrame attribute of the MPEGFrame object
*
* @param bb
* @return The mPEGFrame value
*/
public static boolean isMPEGFrame(ByteBuffer bb)
{
int position = bb.position();
return (((bb.get(position) & SYNC_BYTE1) == SYNC_BYTE1)
&& ((bb.get(position + 1) & SYNC_BYTE2) == SYNC_BYTE2)
&& ((bb.get(position + 2) & SYNC_BIT_ANDSAMPING_BYTE3) != SYNC_BIT_ANDSAMPING_BYTE3));
}
/**
* @return a string represntation
*/
public String toString()
{
return " mpeg frameheader:" + " frame length:" + getFrameLength() + " version:" + versionAsString + " layer:" + layerAsString + " channelMode:" + channelModeAsString + " noOfSamples:" + getNoOfSamples() + " samplingRate:" + samplingRate + " isPadding:" + isPadding + " isProtected:" + isProtected + " isPrivate:" + isPrivate + " isCopyrighted:" + isCopyrighted + " isOriginal:" + isCopyrighted + " isVariableBitRate" + this.isVariableBitRate() + " header as binary:" + AbstractTagDisplayFormatter.displayAsBinary(mpegBytes[BYTE_1]) + " " + AbstractTagDisplayFormatter.displayAsBinary(mpegBytes[BYTE_2]) + " " + AbstractTagDisplayFormatter.displayAsBinary(mpegBytes[BYTE_3]) + " " + AbstractTagDisplayFormatter.displayAsBinary(mpegBytes[BYTE_4]);
}
}
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