PWAVFile Class Reference

#include <pwavfile.h>

Inheritance diagram for PWAVFile:


Construction
enum	{ fmt_PCM = 1, fmt_MSADPCM = 2, fmt_ALaw = 6, fmt_uLaw = 7, fmt_VOXADPCM = 0x10, fmt_IMAADPCM = 0x11, fmt_GSM = 0x31, fmt_G728 = 0x41, fmt_G723 = 0x42, fmt_MSG7231 = 0x42, fmt_G726 = 0x64, fmt_G722 = 0x65, fmt_G729 = 0x83, fmt_VivoG7231 = 0x111, PCM_WavFile = fmt_PCM, G7231_WavFile = fmt_VivoG7231, fmt_NotKnown = 0x10000 }
	PWAVFile (unsigned format=fmt_PCM)
	PWAVFile (OpenMode mode, int opts=ModeDefault, unsigned format=fmt_PCM)
	PWAVFile (const PFilePath &name, OpenMode mode=ReadWrite, int opts=ModeDefault, unsigned format=fmt_PCM)
	PWAVFile (const PString &format, const PFilePath &name, OpenMode mode=PFile::ReadWrite, int opts=PFile::ModeDefault)
	~PWAVFile ()
static PWAVFile *	format (const PString &format)
static PWAVFile *	format (const PString &format, PFile::OpenMode mode, int opts=PFile::ModeDefault)
Public Member Functions
PBoolean	RawRead (void *buf, PINDEX len)
PBoolean	RawWrite (const void *buf, PINDEX len)
PBoolean	FileRead (void *buf, PINDEX len)
PBoolean	FileWrite (const void *buf, PINDEX len)
off_t	RawGetPosition () const
PBoolean	RawSetPosition (off_t pos, FilePositionOrigin origin)
off_t	RawGetDataLength ()
void	SetLastReadCount (PINDEX v)
Overrides from class PFile
virtual PBoolean	Read (void *buf, PINDEX len)
virtual PBoolean	Write (const void *buf, PINDEX len)
virtual PBoolean	Open (OpenMode mode=ReadWrite, int opts=ModeDefault)
virtual PBoolean	Open (const PFilePath &name, OpenMode mode=ReadWrite, int opts=ModeDefault)
virtual PBoolean	Close ()
virtual PBoolean	SetPosition (off_t pos, FilePositionOrigin origin=Start)
virtual off_t	GetPosition () const
Member variable access
virtual PBoolean	SetFormat (unsigned fmt)
virtual PBoolean	SetFormat (const PString &format)
virtual unsigned	GetFormat () const
virtual PString	GetFormatAsString () const
virtual unsigned	GetChannels () const
virtual void	SetChannels (unsigned v)
virtual unsigned	GetSampleRate () const
virtual void	SetSampleRate (unsigned v)
virtual unsigned	GetSampleSize () const
virtual void	SetSampleSize (unsigned v)
virtual unsigned	GetBytesPerSecond () const
virtual void	SetBytesPerSecond (unsigned v)
off_t	GetHeaderLength () const
virtual off_t	GetDataLength ()
PBoolean	IsValid () const
PString	GetFormatString () const
void	SetAutoconvert ()
Public Attributes
PWAV::FMTChunk	wavFmtChunk
PBYTEArray	extendedHeader
Protected Member Functions
void	Construct ()
void	SelectFormat (unsigned fmt)
void	SelectFormat (const PString &format)
PBoolean	ProcessHeader ()
PBoolean	GenerateHeader ()
PBoolean	UpdateHeader ()
Protected Attributes
PBYTEArray	wavHeaderData
PBoolean	isValidWAV
unsigned int	origFmt
PWAVFileFormat *	formatHandler
PBoolean	autoConvert
PWAVFileConverter *	autoConverter
off_t	lenHeader
off_t	lenData
PBoolean	header_needs_updating
Friends
class	PWAVFileConverter

Detailed Description

A class representing a WAV audio file.

Member Enumeration Documentation

anonymous enum

When a file is opened for writing, we can specify if this is a PCM wav file or a G.723.1 wav file.

Enumerator:

fmt_PCM	PCM, 8kHz, 16 bit, mono.
fmt_MSADPCM	MS-ADPCM, 8kHz, mono.
fmt_ALaw	A-Law 8kHz.
fmt_uLaw	u-Law 8kHz
fmt_VOXADPCM	OKI ADPCM.
fmt_IMAADPCM	IMA-ADPCM, 8kHz mono.
fmt_GSM	GSM.
fmt_G728	RFC2361.
fmt_G723	RFC2361.
fmt_MSG7231	Microsoft G.723.1.
fmt_G726	RFC2361.
fmt_G722	RFC2361.
fmt_G729	RFC2361.
fmt_VivoG7231	VivoActive G.723.1.
PCM_WavFile
G7231_WavFile
fmt_NotKnown

Constructor & Destructor Documentation

PWAVFile::PWAVFile ( unsigned format = fmt_PCM )

Create a WAV file object but do not open it. It does not initially have a valid file name. However, an attempt to open the file using the PFile::Open()# function will generate a unique temporary file.

If a WAV file is being created, the type parameter can be used to create a PCM Wave file or a G.723.1 Wave file by using WaveType enum#

Parameters:

format

Type of WAV File to create

PWAVFile::PWAVFile	(	OpenMode	mode,
		int	opts = `ModeDefault`,
		unsigned	format = `fmt_PCM`
	)

Create a unique temporary file name, and open the file in the specified mode and using the specified options. Note that opening a new, unique, temporary file name in ReadOnly mode will always fail. This would only be usefull in a mode and options that will create the file.

If a WAV file is being created, the type parameter can be used to create a PCM Wave file or a G.723.1 Wave file by using WaveType enum#

The PChannel::IsOpen()# function may be used after object construction to determine if the file was successfully opened.

Parameters:

mode	Mode in which to open the file.
opts	OpenOptions enum# for open operation.
format	Type of WAV File to create

PWAVFile::PWAVFile	(	const PFilePath &	name,
		OpenMode	mode = `ReadWrite`,
		int	opts = `ModeDefault`,
		unsigned	format = `fmt_PCM`
	)

Create a WAV file object with the specified name and open it in the specified mode and with the specified options. If a WAV file is being created, the type parameter can be used to create a PCM Wave file or a G.723.1 Wave file by using WaveType enum#

The PChannel::IsOpen()# function may be used after object construction to determine if the file was successfully opened.

Parameters:

name	Name of file to open.
mode	Mode in which to open the file.
opts	OpenOptions enum# for open operation.
format	Type of WAV File to create

PWAVFile::PWAVFile	(	const PString &	format,
		const PFilePath &	name,
		OpenMode	mode = `PFile::ReadWrite`,
		int	opts = `PFile::ModeDefault`
	)

Parameters:

format	Type of WAV File to create
name	Name of file to open.
mode	Mode in which to open the file.
opts	OpenOptions enum# for open operation.

PWAVFile::~PWAVFile ( )

Close the file before destruction.

Member Function Documentation

static PWAVFile* PWAVFile::format ( const PString & format ) [static]

Parameters:

format

Type of WAV File to create

static PWAVFile* PWAVFile::format	(	const PString &	format,
		PFile::OpenMode	mode,
		int	opts = `PFile::ModeDefault`
	)			`[static]`

Parameters:

format	Type of WAV File to create
mode	Mode in which to open the file.
opts	OpenOptions enum# for open operation.

virtual PBoolean PWAVFile::Read	(	void *	buf,
		PINDEX	len
	)			`[virtual]`

Call PFile::Read() to read in audio data and perform necessary processing such as byte-order swaping.

Returns:: PTrue indicates that at least one character was read from the channel. PFalse means no bytes were read due to timeout or some other I/O error.

Parameters:

buf	Pointer to a block of memory to receive the read bytes.
len	Maximum number of bytes to read into the buffer.

Reimplemented from PFile.

virtual PBoolean PWAVFile::Write	(	const void *	buf,
		PINDEX	len
	)			`[virtual]`

Call PFile::Write() to write out audio data and perform necessary processing such as byte-order swaping.

Returns:: PTrue indicates that at least one character was written to the channel. PFalse means no bytes were written due to timeout or some other I/O error.

Parameters:

buf	Pointer to a block of memory to receive the write bytes.
len	Maximum number of bytes to write to the channel.

Reimplemented from PFile.

virtual PBoolean PWAVFile::Open	(	OpenMode	mode = `ReadWrite`,
		int	opts = `ModeDefault`
	)			`[virtual]`

Open the current file in the specified mode and with the specified options. If the file object already has an open file then it is closed.

If there has not been a filename attached to the file object (via SetFilePath()#, the name# parameter or a previous open) then a new unique temporary filename is generated.

Returns:: PTrue if the file was successfully opened.

Parameters:

mode	Mode in which to open the file.
opts	Options for open operation.

Reimplemented from PFile.

virtual PBoolean PWAVFile::Open	(	const PFilePath &	name,
		OpenMode	mode = `ReadWrite`,
		int	opts = `ModeDefault`
	)			`[virtual]`

Open the specified WAV file name in the specified mode and with the specified options. If the file object already has an open file then it is closed. This reads (and validates) the header for existing files. For new files, it creates a new file (and header) using the type of WAV file specified in the class constructor.

Note: if mode# is StandardInput, StandardOutput or StandardError, then the name# parameter is ignored.

Returns:: PTrue if the file was successfully opened.

Parameters:

name	Name of file to open.
mode	Mode in which to open the file.
opts	OpenOptions enum# for open operation.

Reimplemented from PFile.

virtual PBoolean PWAVFile::Close ( ) [virtual]

Close the file channel. If a WAV file has been written to, this will update the header to contain the correct size information.

Returns:: PTrue if close was OK.

Reimplemented from PFile.

virtual PBoolean PWAVFile::SetPosition	(	off_t	pos,
		FilePositionOrigin	origin = `Start`
	)			`[virtual]`

Set the current active position in the file for the next read or write operation. The pos# variable is a signed number which is added to the specified origin. For origin == PFile::Start# only positive values for pos# are meaningful. For origin == PFile::End# only negative values for pos# are meaningful.

Note that for a WAV file, the origin of the file is right after the header. That is, the WAV header is not included when perform SetPosition().

Returns:: PTrue if the new file position was set.

Parameters:

pos	New position to set.
origin	Origin for position change.

Reimplemented from PFile.

virtual off_t PWAVFile::GetPosition ( ) const [virtual]

Get the current active position in the file for the next read or write operation. The WAV header is excluded from calculation the position.

Returns:: current file position relative to the end of the WAV header.

Reimplemented from PFile.

virtual PBoolean PWAVFile::SetFormat ( unsigned fmt ) [virtual]

Find out the format of the WAV file. Eg 0x01 for PCM, 0x42 or 0x111 for G.723.1.

virtual PBoolean PWAVFile::SetFormat ( const PString & format ) [virtual]

virtual unsigned PWAVFile::GetFormat ( ) const [virtual]

Find out the format of the WAV file. Eg 0x01 for PCM, 0x42 or 0x111 for G.723.1.

virtual PString PWAVFile::GetFormatAsString ( ) const [virtual]

virtual unsigned PWAVFile::GetChannels ( ) const [virtual]

Find out the number of channels the WAV file has. Typically this is 1 for mono and 2 for stereo.

virtual void PWAVFile::SetChannels ( unsigned v ) [virtual]

virtual unsigned PWAVFile::GetSampleRate ( ) const [virtual]

Find out the sample rate of the WAV file in Hz.

virtual void PWAVFile::SetSampleRate ( unsigned v ) [virtual]

virtual unsigned PWAVFile::GetSampleSize ( ) const [virtual]

Find out how may bits there are per sample, eg 8 or 16.

virtual void PWAVFile::SetSampleSize ( unsigned v ) [virtual]

virtual unsigned PWAVFile::GetBytesPerSecond ( ) const [virtual]

Find out how may bytes there are per second

virtual void PWAVFile::SetBytesPerSecond ( unsigned v ) [virtual]

off_t PWAVFile::GetHeaderLength ( ) const

Find out the size of WAV header presented in the file.

virtual off_t PWAVFile::GetDataLength ( ) [virtual]

Find out how many bytes of audio data there are.

PBoolean PWAVFile::IsValid ( ) const [inline]

Determine if the WAV file is a valid wave file.

Returns:: PTrue indicates that the WAV file is valid PFalse indicates that the WAV file is invalid

PString PWAVFile::GetFormatString ( ) const [inline]

Return a string that describes the WAV format

void PWAVFile::SetAutoconvert ( )

enable autoconversion between PCM-16 and the native format

PBoolean PWAVFile::RawRead	(	void *	buf,
		PINDEX	len
	)

PBoolean PWAVFile::RawWrite	(	const void *	buf,
		PINDEX	len
	)

PBoolean PWAVFile::FileRead	(	void *	buf,
		PINDEX	len
	)

PBoolean PWAVFile::FileWrite	(	const void *	buf,
		PINDEX	len
	)

off_t PWAVFile::RawGetPosition ( ) const

PBoolean PWAVFile::RawSetPosition	(	off_t	pos,
		FilePositionOrigin	origin
	)

off_t PWAVFile::RawGetDataLength ( )

void PWAVFile::SetLastReadCount ( PINDEX v ) [inline]

void PWAVFile::Construct ( ) [protected]

Reimplemented from PChannel.

void PWAVFile::SelectFormat ( unsigned fmt ) [protected]

void PWAVFile::SelectFormat ( const PString & format ) [protected]

PBoolean PWAVFile::ProcessHeader ( ) [protected]

PBoolean PWAVFile::GenerateHeader ( ) [protected]

PBoolean PWAVFile::UpdateHeader ( ) [protected]

Friends And Related Function Documentation

friend class PWAVFileConverter [friend]

Member Data Documentation

PWAV::FMTChunk PWAVFile::wavFmtChunk

PBYTEArray PWAVFile::extendedHeader

PBYTEArray PWAVFile::wavHeaderData [protected]

PBoolean PWAVFile::isValidWAV [protected]

unsigned int PWAVFile::origFmt [protected]

PWAVFileFormat* PWAVFile::formatHandler [protected]

PBoolean PWAVFile::autoConvert [protected]

PWAVFileConverter* PWAVFile::autoConverter [protected]

off_t PWAVFile::lenHeader [protected]

off_t PWAVFile::lenData [protected]

PBoolean PWAVFile::header_needs_updating [protected]

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

pwavfile.h

Generated on Mon Sep 15 01:21:39 2008 for PTLib by

1.5.1

PWAVFile Class Reference

Construction

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation