ch.randelshofer.media.mp3
Class MP3ElementaryInputStream.Frame

java.lang.Object
  ch.randelshofer.media.mp3.MP3ElementaryInputStream.Frame

Enclosing class:

MP3ElementaryInputStream

public static class MP3ElementaryInputStream.Frame
extends java.lang.Object

An elementary frame.

Constructor Summary

MP3ElementaryInputStream.Frame(int header)
Creates a new frame.

Method Summary

int	getBitRate() Returns the bitrate of the frame.
int	getBitRateCode() Returns the raw bitrate code as it is stored in the header.
long	getBodyOffset() Returns the offset of the frame body in the input stream.
int	getBodySize() Returns the size of the frame body in bytes.
int	getChannelCount() Returns the number of channels.
int	getChannelModeCode() Returns the raw channel mode as stored in the header.
int	getCRC() Returns the CRC of this frame.
long	getFrameOffset() Returns the offset of the frame in the input stream.
int	getFrameSize() Returns the size of the frame in bytes.
int	getHeader()
long	getHeaderOffset() Returns the offset of the header in the input stream.
int	getHeaderSize() Returns the size of the header in bytes.
int	getLayer() Returns the layer number.
int	getLayerCode() Returns the raw layer code as it is stored in the header.
int	getPaddingSize() Padding is used to fit the bit rates exactly.
int	getSampleCount() Returns the number of samples in the frame.
int	getSampleRate() Returns the sample rate in Hz.
int	getSampleRateCode() Returns the raw sample rate code as it is stored in the header.
int	getSampleSize() Returns the sample size in bits.
long	getSideInfoOffset() Returns the offset of the side info in the input stream.
int	getSideInfoSize() Returns the size of the side info in bytes.
int	getVersion() Returns the version number: 1=MPEG 1, 2=MPEG 2, 25=MPEG 2.5; -1=unknown.
int	getVersionCode() Returns the raw version code as it is stored in the header.
boolean	hasCRC() Returns true if this frame has a CRC.
boolean	hasPadding()
byte[]	headerToByteArray() Returns the frame header as a byte array.
int	headerToByteArray(byte[] data, int offset) Writes the frame header into the specified byte array.
void	writeHeader(java.io.OutputStream out) Writes the frame header into the specified output stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

MP3ElementaryInputStream.Frame

public MP3ElementaryInputStream.Frame(int header)

Creates a new frame.

Parameters:

header - The 32-bit Frame header

Method Detail

getHeader

public int getHeader()

getVersion

public int getVersion()

Returns the version number: 1=MPEG 1, 2=MPEG 2, 25=MPEG 2.5; -1=unknown.

getVersionCode

public int getVersionCode()

Returns the raw version code as it is stored in the header. 3=MPEG 1, 2=MPEG 2, 1=reserved, 0=MPEG 2.5.

getLayer

public int getLayer()

Returns the layer number. 1=Layer I, 2=Layer II, 3=Layer III, -1=unknown.

getLayerCode

public int getLayerCode()

Returns the raw layer code as it is stored in the header. 3=Layer I, 2=Layer II, 1=Layer III, 0=reserved.

getBitRate

public int getBitRate()

Returns the bitrate of the frame. Returns -1 if unknown.

getBitRateCode

public int getBitRateCode()

Returns the raw bitrate code as it is stored in the header.

hasCRC

public boolean hasCRC()

Returns true if this frame has a CRC.

getCRC

public int getCRC()

Returns the CRC of this frame. The value is only valid if hasCRC() returns true.

hasPadding

public boolean hasPadding()

getSampleRate

public int getSampleRate()

Returns the sample rate in Hz. Returns -1 if unknown.

getSampleRateCode

public int getSampleRateCode()

Returns the raw sample rate code as it is stored in the header.

getSampleCount

public int getSampleCount()

Returns the number of samples in the frame. It is constant and always 384 samples for Layer I and 1152 samples for Layer II and Layer III. Returns -1 if unknown.

getChannelCount

public int getChannelCount()

Returns the number of channels.

Returns:

1=mono, 2=stereo, joint stereo or dual channel.

getSampleSize

public int getSampleSize()

Returns the sample size in bits. Always 16 bit per sample.

getChannelModeCode

public int getChannelModeCode()

Returns the raw channel mode as stored in the header.

Returns:

0=stereo, 1=joint stereo, 2=dual channel, 3=single channel (mono).

headerToByteArray

public byte[] headerToByteArray()

Returns the frame header as a byte array.

headerToByteArray

public int headerToByteArray(byte[] data,
                             int offset)

Writes the frame header into the specified byte array. Returns the number of bytes written.

writeHeader

public void writeHeader(java.io.OutputStream out)
                 throws java.io.IOException

Writes the frame header into the specified output stream.

Throws:

java.io.IOException

getFrameOffset

public long getFrameOffset()

Returns the offset of the frame in the input stream.

getFrameSize

public int getFrameSize()

Returns the size of the frame in bytes. This size includes the header, the data and the padding.

getHeaderOffset

public long getHeaderOffset()

Returns the offset of the header in the input stream.

getHeaderSize

public int getHeaderSize()

Returns the size of the header in bytes.

getSideInfoOffset

public long getSideInfoOffset()

Returns the offset of the side info in the input stream.

getSideInfoSize

public int getSideInfoSize()

Returns the size of the side info in bytes. It is 17 bytes long in a single channel frame and 32 bytes in dual channel or stereo channel.

getBodyOffset

public long getBodyOffset()

Returns the offset of the frame body in the input stream.

getBodySize

public int getBodySize()

Returns the size of the frame body in bytes. The body includes the side info, the audio data, and the padding.

getPaddingSize

public int getPaddingSize()

Padding is used to fit the bit rates exactly. For an example: 128k 44.1kHz layer II uses a lot of 418 bytes and some of 417 bytes long frames to get the exact 128k bitrate. For Layer I slot is 32 bits long, for Layer II and Layer III slot is 8 bits long.