NAudio.Wave.Mp3Frame Class Reference

Represents an MP3 Frame. More...

Collaboration diagram for NAudio.Wave.Mp3Frame:

Static Public Member Functions
static Mp3Frame	LoadFromStream (Stream input)
	Loads an MP3 frame from the given input stream and returns the frame.
static Mp3Frame	LoadFromStream (Stream input, bool readData)
	Reads an MP3Frame from a stream.

Properties
int	SampleRate [get, private set]
	Sample rate of this frame.
int	FrameLength [get, private set]
	Frame length in bytes.
int	BitRate [get, private set]
	Bit Rate.
byte[]	RawData [get, private set]
	Raw frame data (includes header bytes)
MpegVersion	MpegVersion [get, private set]
	MPEG Version.
MpegLayer	MpegLayer [get, private set]
	MPEG Layer.
ChannelMode	ChannelMode [get, private set]
	Channel Mode.
int	SampleCount [get, private set]
	The number of samples in this frame.
int	ChannelExtension [get, private set]
	The channel extension bits.
int	BitRateIndex [get, private set]
	The bitrate index (directly from the header)
bool	Copyright [get, private set]
	Whether the Copyright bit is set.
bool	CrcPresent [get, private set]
	Whether a CRC is present.
long	FileOffset [get, private set]
	Not part of the MP3 frame itself - indicates where in the stream we found this header.

Private Member Functions
	Mp3Frame ()
	Constructs an MP3 frame.

Static Private Member Functions
static bool	IsValidHeader (byte[] headerBytes, Mp3Frame frame)
	Checks if the provided header bytes and Mp3Frame are valid and returns a boolean value indicating the result.

Static Private Attributes
static readonly int[,,]	bitRates
static readonly int[,]	samplesPerFrame
static readonly int[]	sampleRatesVersion1 = new int[] {44100, 48000, 32000}
static readonly int[]	sampleRatesVersion2 = new int[] {22050, 24000, 16000}
static readonly int[]	sampleRatesVersion25 = new int[] {11025, 12000, 8000}
const int	MaxFrameLength = 16*1024

Detailed Description

Represents an MP3 Frame.

Constructor & Destructor Documentation

Mp3Frame()

NAudio.Wave.Mp3Frame.Mp3Frame ( )

inlineprivate

Constructs an MP3 frame.

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Member Function Documentation

IsValidHeader()

static bool NAudio.Wave.Mp3Frame.IsValidHeader ( byte[] headerBytes, Mp3Frame frame )

inlinestaticprivate

Checks if the provided header bytes and Mp3Frame are valid and returns a boolean value indicating the result.

Parameters

headerBytes	The header bytes of the Mp3Frame.
frame	The Mp3Frame to be validated.

Returns

True if the header bytes and Mp3Frame are valid; otherwise, false.

This method checks if the provided header bytes and Mp3Frame are valid according to the MPEG audio format specifications. It validates various properties of the Mp3Frame such as MPEG version, layer, bit rate, sample rate, channel mode, frame length, etc. If any of the properties are invalid, the method returns false; otherwise, it returns true.

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LoadFromStream() [1/2]

static Mp3Frame NAudio.Wave.Mp3Frame.LoadFromStream ( Stream input )

inlinestatic

Loads an MP3 frame from the given input stream and returns the frame.

Parameters

input	The input stream from which to load the MP3 frame.
readData	A boolean value indicating whether to read the frame data from the input stream.

Returns

The loaded MP3 frame.

This method reads the header bytes from the input stream and validates them to identify an MP3 frame. If the header is not valid, it shifts down by one and tries again until a valid header is found. Once a valid header is found, it reads the frame data from the input stream based on the frame length. If readData is false, it skips reading the frame data and moves the input stream position accordingly.

Exceptions

EndOfStreamException

Thrown when an unexpected end of stream is encountered before the frame is complete.

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LoadFromStream() [2/2]

static Mp3Frame NAudio.Wave.Mp3Frame.LoadFromStream ( Stream input, bool readData )

inlinestatic

Reads an MP3Frame from a stream.

http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm has some good info also see http://www.codeproject.com/KB/audio-video/mpegaudioinfo.aspx

Returns

A valid MP3 frame, or null if none found

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Member Data Documentation

bitRates

readonly int [,,] NAudio.Wave.Mp3Frame.bitRates

staticprivate

Initial value:

= new int[,,] {
            {
                
                { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448 }, 
                { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384 }, 
                { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320 }, 
            },
            {
                
                { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256 }, 
                { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 }, 
                { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 }, 
            }
        }

MaxFrameLength

const int NAudio.Wave.Mp3Frame.MaxFrameLength = 16*1024

staticprivate

sampleRatesVersion1

readonly int [] NAudio.Wave.Mp3Frame.sampleRatesVersion1 = new int[] {44100, 48000, 32000}

staticprivate

sampleRatesVersion2

readonly int [] NAudio.Wave.Mp3Frame.sampleRatesVersion2 = new int[] {22050, 24000, 16000}

staticprivate

sampleRatesVersion25

readonly int [] NAudio.Wave.Mp3Frame.sampleRatesVersion25 = new int[] {11025, 12000, 8000}

staticprivate

samplesPerFrame

readonly int [,] NAudio.Wave.Mp3Frame.samplesPerFrame

staticprivate

Initial value:

= new int[,] {
            {   
                384,    
                1152,   
                1152    
            },
            {   
                384,    
                1152,   
                576     
            }
        }

Property Documentation

BitRate

int NAudio.Wave.Mp3Frame.BitRate

getprivate set

Bit Rate.

BitRateIndex

int NAudio.Wave.Mp3Frame.BitRateIndex

getprivate set

The bitrate index (directly from the header)

ChannelExtension

int NAudio.Wave.Mp3Frame.ChannelExtension

getprivate set

The channel extension bits.

ChannelMode

ChannelMode NAudio.Wave.Mp3Frame.ChannelMode

getprivate set

Channel Mode.

Copyright

bool NAudio.Wave.Mp3Frame.Copyright

getprivate set

Whether the Copyright bit is set.

CrcPresent

bool NAudio.Wave.Mp3Frame.CrcPresent

getprivate set

Whether a CRC is present.

FileOffset

long NAudio.Wave.Mp3Frame.FileOffset

getprivate set

Not part of the MP3 frame itself - indicates where in the stream we found this header.

FrameLength

int NAudio.Wave.Mp3Frame.FrameLength

getprivate set

Frame length in bytes.

MpegLayer

MpegLayer NAudio.Wave.Mp3Frame.MpegLayer

getprivate set

MPEG Layer.

MpegVersion

MpegVersion NAudio.Wave.Mp3Frame.MpegVersion

getprivate set

MPEG Version.

RawData

byte [] NAudio.Wave.Mp3Frame.RawData

getprivate set

Raw frame data (includes header bytes)

SampleCount

int NAudio.Wave.Mp3Frame.SampleCount

getprivate set

The number of samples in this frame.

SampleRate

int NAudio.Wave.Mp3Frame.SampleRate

getprivate set

Sample rate of this frame.

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The documentation for this class was generated from the following file:

• /Users/sumansaurabh/Documents/my-startup/xeno-rat/Plugins/LiveMicrophone/lib/NAudio.Core/FileFormats/Mp3/Mp3Frame.cs