WAVHeader Class Reference

Parser for Wav header data for details see https://de.wikipedia.org/wiki/RIFF_WAVE. More...

#include <CodecWAV.h>

Public Member Functions
	WAVHeader ()=default
WAVAudioInfo &	audioInfo ()
	provides the info from the header
size_t	available ()
	number of bytes available in the header buffer
void	clear ()
	Reset internal stored header information and buffer.
void	dumpHeader ()
	Debug helper: dumps header bytes as printable characters.
int	getDataPos ()
	Determines the data start position using the data tag.
bool	isDataComplete ()
	Returns true if the header is complete (containd data tag).
bool	isOverflow ()
bool	parse ()
	Call when header data write is complete to parse the data.
void	setAudioInfo (WAVAudioInfo info)
	Sets the info in the header.
int	write (uint8_t *data, size_t data_len)
bool	writeHeader (Print *out)
	Just write a wav header to the indicated outputbu.
bool	writeHeader (Print *out, const WAVAudioInfo &info)
	Just write a wav header with explicit info to the indicated output.

Static Public Member Functions
static int	extraHeaderBytes (const WAVAudioInfo &info)

Protected Member Functions
bool	eof ()
int	getChar ()
uint32_t	getChar32 ()
int	indexOf (const char *str)
void	logInfo ()
uint16_t	read_int16 ()
uint32_t	read_int32 ()
uint32_t	read_tag ()
void	seek (long int offset, int origin)
bool	setPos (const char *id)
void	skip (int n)
size_t	tell ()
void	write16 (BaseBuffer< uint8_t > &buffer, uint16_t value)
void	write32 (BaseBuffer< uint8_t > &buffer, uint64_t value)
void	writeDataHeader (BaseBuffer< uint8_t > &buffer, const WAVAudioInfo &info)
void	writeFactChunk (BaseBuffer< uint8_t > &buffer, const WAVAudioInfo &info)
void	writeFMT (BaseBuffer< uint8_t > &buffer, const WAVAudioInfo &info)
void	writeRiffHeader (BaseBuffer< uint8_t > &buffer, const WAVAudioInfo &info)

Static Protected Member Functions
static uint16_t	samplesPerBlock (const WAVAudioInfo &info)

Protected Attributes
SingleBuffer< uint8_t >	buffer { 200 }
size_t	data_pos = 0
WAVAudioInfo	headerInfo

Detailed Description

Parser for Wav header data for details see https://de.wikipedia.org/wiki/RIFF_WAVE.

Logic notes for WAVAudioInfo size fields:

• file_size stores the full RIFF file size in bytes. In the RIFF header this is written/read as chunk_size = file_size - 8.
• data_length stores the WAV payload size (data chunk length).
• is_streamed indicates unknown/unbounded payload length.

Parsing behavior:

• RIFF chunk_size is normalized to full file_size by adding 8.
• If parsed data_length is 0 or very large (>= 0x7fff0000), the stream is treated as streamed (is_streamed=true) and data_length is normalized to ~0.

Writing behavior:

• RIFF writes file_size - 8 into the chunk-size field.
• If data_length==0 in non-streamed mode, it is derived from file_size - 36 (standard WAV relationship).
• In streamed mode, data_length is written as max (~0) when not set.

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

WAVHeader()

WAVHeader ( )

default

Member Function Documentation

audioInfo()

WAVAudioInfo & audioInfo ( )

inline

provides the info from the header

available()

size_t available ( )

inline

number of bytes available in the header buffer

clear()

void clear ( )

inline

Reset internal stored header information and buffer.

dumpHeader()

void dumpHeader ( )

inline

Debug helper: dumps header bytes as printable characters.

eof()

bool eof ( )

inlineprotected

extraHeaderBytes()

int extraHeaderBytes ( const WAVAudioInfo & info )

inlinestatic

Number of header bytes preceeding the 'data' chunk's payload, beyond the 36 bytes of a standard PCM header (12 byte RIFF + 24 byte fmt + 8 byte data tag/size = 36 + sizeof('fmt ' extension) + sizeof('fact' chunk)). Only non-zero for ADPCM formats when ext_adpcm_header is enabled.

getChar()

int getChar ( )

inlineprotected

getChar32()

uint32_t getChar32 ( )

inlineprotected

getDataPos()

int getDataPos ( )

inline

Determines the data start position using the data tag.

indexOf()

int indexOf ( const char * str )

inlineprotected

isDataComplete()

bool isDataComplete ( )

inline

Returns true if the header is complete (containd data tag).

isOverflow()

bool isOverflow ( )

inline

True if the header buffer has grown to its maximum allowed size (MAX_WAV_HEADER_LEN_LIMIT) without finding the 'data' chunk - indicates a malformed or unusually large header that will never complete.

logInfo()

void logInfo ( )

inlineprotected

parse()

bool parse ( )

inline

Call when header data write is complete to parse the data.

read_int16()

uint16_t read_int16 ( )

inlineprotected

read_int32()

uint32_t read_int32 ( )

inlineprotected

read_tag()

uint32_t read_tag ( )

inlineprotected

samplesPerBlock()

uint16_t samplesPerBlock ( const WAVAudioInfo & info )

inlinestaticprotected

Number of samples encoded in a single block, for ADPCM formats (assumes 4 bits per sample as used by MS/IMA ADPCM).

seek()

void seek ( long int offset, int origin )

inlineprotected

setAudioInfo()

void setAudioInfo ( WAVAudioInfo info )

inline

Sets the info in the header.

setPos()

bool setPos ( const char * id )

inlineprotected

skip()

void skip ( int n )

inlineprotected

tell()

size_t tell ( )

inlineprotected

write()

int write ( uint8_t * data, size_t data_len )

inline

Adds data to the wav header data buffer and make it available for parsing. The buffer grows automatically (up to MAX_WAV_HEADER_LEN_LIMIT) if the header does not fit into the initial MAX_WAV_HEADER_LEN bytes - e.g. because of LIST/bext/other metadata chunks before 'data'.

write16()

void write16 ( BaseBuffer< uint8_t > & buffer, uint16_t value )

inlineprotected

write32()

void write32 ( BaseBuffer< uint8_t > & buffer, uint64_t value )

inlineprotected

writeDataHeader()

void writeDataHeader ( BaseBuffer< uint8_t > & buffer, const WAVAudioInfo & info )

inlineprotected

writeFactChunk()

void writeFactChunk ( BaseBuffer< uint8_t > & buffer, const WAVAudioInfo & info )

inlineprotected

'fact' chunk: required for compressed (e.g. ADPCM) formats, holds the total number of samples (per channel) in the data chunk.

writeFMT()

void writeFMT ( BaseBuffer< uint8_t > & buffer, const WAVAudioInfo & info )

inlineprotected

writeHeader() [1/2]

bool writeHeader ( Print * out )

inline

Just write a wav header to the indicated outputbu.

writeHeader() [2/2]

bool writeHeader ( Print * out, const WAVAudioInfo & info )

inline

Just write a wav header with explicit info to the indicated output.

writeRiffHeader()

void writeRiffHeader ( BaseBuffer< uint8_t > & buffer, const WAVAudioInfo & info )

inlineprotected

Member Data Documentation

buffer

SingleBuffer<uint8_t> buffer { 200 }

protected

data_pos

size_t data_pos = 0

protected

headerInfo

WAVAudioInfo headerInfo

protected

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

• src/AudioTools/AudioCodecs/CodecWAV.h