ost::AudioResample Class Reference

The AudioResample class is used to manage linear intropolation buffering for rate conversions. More...

#include <audio2.h>

Inheritance diagram for ost::AudioResample:

Public Member Functions
	AudioResample (Rate mul, Rate div)
	~AudioResample ()
size_t	process (Linear from, Linear to, size_t count)
size_t	estimate (size_t count)

Protected Attributes
unsigned	mfact
unsigned	dfact
unsigned	max
unsigned	gpos
unsigned	ppos
Sample	last
Linear	buffer

Additional Inherited Members
Public Types inherited from ost::Audio
enum	Rate {   rateUnknown , rate6khz = 6000 , rate8khz = 8000 , rate16khz = 16000 ,   rate32khz = 32000 , rate44khz = 44100 }
	Audio encoding rate, samples per second. More...
enum	Mode {   modeRead , modeReadAny , modeReadOne , modeWrite ,   modeCache , modeInfo , modeFeed , modeAppend ,   modeCreate }
	File processing mode, whether to skip missing files, etc. More...
enum	Encoding {   unknownEncoding = 0 , g721ADPCM , g722Audio , g722_7bit ,   g722_6bit , g723_2bit , g723_3bit , g723_5bit ,   gsmVoice , msgsmVoice , mulawAudio , alawAudio ,   mp1Audio , mp2Audio , mp3Audio , okiADPCM ,   voxADPCM , sx73Voice , sx96Voice , cdaStereo ,   cdaMono , pcm8Stereo , pcm8Mono , pcm16Stereo ,   pcm16Mono , pcm32Stereo , pcm32Mono , speexVoice ,   speexAudio , g729Audio , ilbcAudio , speexUltra ,   speexNarrow = speexVoice , speexWide = speexAudio , g723_4bit = g721ADPCM }
	Audio encoding formats. More...
enum	Format {   raw , snd , riff , mpeg ,   wave }
	Audio container file format. More...
enum	DeviceMode { PLAY , RECORD , PLAYREC }
	Audio device access mode. More...
enum	Error {   errSuccess = 0 , errReadLast , errNotOpened , errEndOfFile ,   errStartOfFile , errRateInvalid , errEncodingInvalid , errReadInterrupt ,   errWriteInterrupt , errReadFailure , errWriteFailure , errReadIncomplete ,   errWriteIncomplete , errRequestInvalid , errTOCFailed , errStatFailed ,   errInvalidTrack , errPlaybackFailed , errNotPlaying , errNoCodec }
	Audio error conditions. More...
typedef int16_t	snd16_t
typedef int32_t	snd32_t
typedef int16_t	Level
typedef int16_t	Sample
typedef int16_t *	Linear
typedef unsigned long	timeout_t
typedef unsigned char *	Encoded
typedef enum Rate	Rate
typedef enum Mode	Mode
typedef enum Encoding	Encoding
typedef enum Format	Format
typedef enum DeviceMode	DeviceMode
typedef enum Error	Error
Static Public Member Functions inherited from ost::Audio
static Level	tolevel (float dbm)
	Convert dbm power level to integer value (0-32768).
static float	todbm (Level power)
	Convert integer power levels to dbm.
static bool	hasDevice (unsigned device=0)
	Test for the presense of a specified (indexed) audio device.
static AudioDevice *	getDevice (unsigned device=0, DeviceMode mode=PLAY)
	Get a audio device object that can be used to play or record audio.
static const char *	getCodecPath (void)
	Get pathname to where loadable codec modules are stored.
static const char *	getMIME (Info &info)
	Get the mime descriptive type for a given Audio encoding description, usually retrieved from a newly opened audio file.
static const char *	getName (Encoding encoding)
	Get the short ascii description used for the given audio encoding type.
static const char *	getExtension (Encoding encoding)
	Get the preferred file extension name to use for a given audio encoding type.
static Encoding	getEncoding (const char *name)
	Get the audio encoding format that is specified by a short ascii name.
static Encoding	getStereo (Encoding encoding)
	Get the stereo encoding format associated with the given format.
static Encoding	getMono (Encoding encoding)
	Get the mono encoding format associated with the given format.
static bool	isLinear (Encoding encoding)
	Test if the audio encoding format is a linear one.
static bool	isBuffered (Encoding encoding)
	Test if the audio encoding format must be packetized (that is, has irregular sized frames) and must be processed only through buffered codecs.
static bool	isMono (Encoding encoding)
	Test if the audio encoding format is a mono format.
static bool	isStereo (Encoding encoding)
	Test if the audio encoding format is a stereo format.
static Rate	getRate (Encoding encoding)
	Return default sample rate associated with the specified audio encoding format.
static Rate	getRate (Encoding e, Rate request)
	Return optional rate setting effect.
static timeout_t	getFraming (Encoding encoding, timeout_t timeout=0)
	Return frame timing for an audio encoding format.
static timeout_t	getFraming (Info &info, timeout_t timeout=0)
	Return frame time for an audio source description.
static bool	isEndian (Encoding encoding)
	Test if the endian byte order of the encoding format is different from the machine's native byte order.
static bool	isEndian (Info &info)
	Test if the endian byte order of the audio source description is different from the machine's native byte order.
static bool	swapEndian (Encoding encoding, void *buffer, unsigned number)
	Optionally swap endian of audio data if the encoding format endian byte order is different from the machine's native endian.
static void	swapEncoded (Info &info, Encoded data, size_t bytes)
	Optionally swap endian of encoded audio data based on the audio encoding type, and relationship to native byte order.
static bool	swapEndian (Info &info, void *buffer, unsigned number)
	Optionally swap endian of audio data if the audio source description byte order is different from the machine's native endian byte order.
static Level	getImpulse (Encoding encoding, void *buffer, unsigned number)
	Get the energey impulse level of a frame of audio data.
static Level	getImpulse (Info &info, void *buffer, unsigned number=0)
	Get the energey impulse level of a frame of audio data.
static Level	getPeak (Encoding encoding, void *buffer, unsigned number)
	Get the peak (highest energy) level found in a frame of audio data.
static Level	getPeak (Info &info, void *buffer, unsigned number=0)
	Get the peak (highest energy) level found in a frame of audio data.
static void	toTimestamp (timeout_t duration, char *address, size_t size)
	Provide ascii timestamp representation of a timeout value.
static timeout_t	toTimeout (const char *timestamp)
	Convert ascii timestamp representation to a timeout number.
static int	getFrame (Encoding encoding, int samples=0)
	Returns the number of bytes in a sample frame for the given encoding type, rounded up to the nearest integer.
static int	getCount (Encoding encoding)
	Returns the number of samples in all channels for a frame in the given encoding.
static unsigned long	toSamples (Encoding encoding, size_t bytes)
	Compute byte counts of audio data into number of samples based on the audio encoding format used.
static unsigned long	toSamples (Info &info, size_t bytes)
	Compute byte counts of audio data into number of samples based on the audio source description used.
static size_t	toBytes (Info &info, unsigned long number)
	Compute the number of bytes a given number of samples in a given audio encoding will occupy.
static size_t	toBytes (Encoding encoding, unsigned long number)
	Compute the number of bytes a given number of samples in a given audio encoding will occupy.
static void	fill (unsigned char *address, int number, Encoding encoding)
	Fill an audio buffer with "empty" (silent) audio data, based on the audio encoding format.
static bool	loadPlugin (const char *path)
	Load a dso plugin (codec plugin), used internally...
static size_t	maxFramesize (Info &info)
	Maximum framesize for a given coding that may be needed to store a result.
Static Public Attributes inherited from ost::Audio
static const unsigned	ndata

Detailed Description

The AudioResample class is used to manage linear intropolation buffering for rate conversions.

Author

David Sugar dyfet.nosp@m.@ost.nosp@m.el.co.nosp@m.m

linear intropolation and rate conversion.

Constructor & Destructor Documentation

AudioResample()

ost::AudioResample::AudioResample	(	Rate	mul,
		Rate	div )

~AudioResample()

ost::AudioResample::~AudioResample

(

)

Member Function Documentation

estimate()

size_t ost::AudioResample::estimate

(

size_t

count

)

process()

size_t ost::AudioResample::process	(	Linear	from,
		Linear	to,
		size_t	count )

Member Data Documentation

buffer

Linear ost::AudioResample::buffer

protected

dfact

unsigned ost::AudioResample::dfact

protected

gpos

unsigned ost::AudioResample::gpos

protected

last

Sample ost::AudioResample::last

protected

max

unsigned ost::AudioResample::max

protected

mfact

unsigned ost::AudioResample::mfact

protected

ppos

unsigned ost::AudioResample::ppos

protected

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

• audio2.h