PWAVFile Class Reference

#include <pwavfile.h>

Inheritance diagram for PWAVFile:
PFile PChannel PObject

List of all members.

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
PWAVFileFormatformatHandler
PBoolean autoConvert
PWAVFileConverterautoConverter
off_t lenHeader
off_t lenData
PBoolean header_needs_updating

Friends

class PWAVFileConverter

Construction



enum  WaveType {
  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 PWAVFileformat (const PString &format)
static PWAVFileformat (const PString &format, PFile::OpenMode mode, int opts=PFile::ModeDefault)

Detailed Description

A class representing a WAV audio file.


Member Enumeration Documentation

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

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.

void PWAVFile::Construct (  )  [protected]

Reimplemented from PChannel.

PBoolean PWAVFile::FileRead ( void *  buf,
PINDEX  len 
)
PBoolean PWAVFile::FileWrite ( const void *  buf,
PINDEX  len 
)
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.
static PWAVFile* PWAVFile::format ( const PString format  )  [static]
Parameters:
format Type of WAV File to create
PBoolean PWAVFile::GenerateHeader (  )  [protected]
virtual unsigned PWAVFile::GetBytesPerSecond (  )  const [virtual]

Find out how may bytes there are per second

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 off_t PWAVFile::GetDataLength (  )  [virtual]

Find out how many bytes of audio data there are.

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]
PString PWAVFile::GetFormatString (  )  const [inline]

Return a string that describes the WAV format

References formatHandler, and PWAVFileFormat::GetFormatString().

off_t PWAVFile::GetHeaderLength (  )  const

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

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 unsigned PWAVFile::GetSampleRate (  )  const [virtual]

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

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

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

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

References isValidWAV.

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::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 in the constructor 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.

PBoolean PWAVFile::ProcessHeader (  )  [protected]
off_t PWAVFile::RawGetDataLength (  ) 
off_t PWAVFile::RawGetPosition (  )  const
PBoolean PWAVFile::RawRead ( void *  buf,
PINDEX  len 
)
PBoolean PWAVFile::RawSetPosition ( off_t  pos,
FilePositionOrigin  origin 
)
PBoolean PWAVFile::RawWrite ( const void *  buf,
PINDEX  len 
)
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.

void PWAVFile::SelectFormat ( const PString format  )  [protected]
void PWAVFile::SelectFormat ( unsigned  fmt  )  [protected]
void PWAVFile::SetAutoconvert (  ) 

Enable autoconversion between PCM-16 and the native format.

virtual void PWAVFile::SetBytesPerSecond ( unsigned  v  )  [virtual]
virtual void PWAVFile::SetChannels ( unsigned  v  )  [virtual]
virtual PBoolean PWAVFile::SetFormat ( const PString format  )  [virtual]
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.

void PWAVFile::SetLastReadCount ( PINDEX  v  )  [inline]
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 void PWAVFile::SetSampleRate ( unsigned  v  )  [virtual]
virtual void PWAVFile::SetSampleSize ( unsigned  v  )  [virtual]
PBoolean PWAVFile::UpdateHeader (  )  [protected]
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.


Friends And Related Function Documentation

friend class PWAVFileConverter [friend]

Member Data Documentation

Referenced by GetFormatString().

Referenced by IsValid().

off_t PWAVFile::lenData [protected]
off_t PWAVFile::lenHeader [protected]
unsigned int PWAVFile::origFmt [protected]

The documentation for this class was generated from the following file:
Generated on Sun Jun 27 20:13:19 2010 for PTLib by  doxygen 1.6.3