ost::Audio Class Reference

Generic audio class to hold master data types and various useful class encapsulated friend functions as per GNU Common C++ 2 coding standard.Master audio class. More...

#include <audio2.h>

Inheritance diagram for ost::Audio:

ost::AudioBase ost::AudioCodec ost::AudioResample ost::AudioTone ost::DTMFDetect ost::AudioBuffer ost::AudioDevice ost::AudioFile ost::DTMFTones ost::MFTones ost::TelTone ost::AudioStream List of all members.

Public Types

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

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 AudioDevicegetDevice (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

static const unsigned ndata

Classes

struct  dtmf_detect_state_t
struct  goertzel_state_t
class  Info
 Audio source description. More...
struct  mpeg_audio
struct  mpeg_tagv1
struct  tone_detection_descriptor_t

Detailed Description

Generic audio class to hold master data types and various useful class encapsulated friend functions as per GNU Common C++ 2 coding standard.Master audio class.

Author:
David Sugar <dyfet@ostel.com>


Member Typedef Documentation

typedef int16_t ost::Audio::snd16_t

typedef int32_t ost::Audio::snd32_t

typedef int16_t ost::Audio::Level

typedef int16_t ost::Audio::Sample

typedef int16_t* ost::Audio::Linear

typedef unsigned long ost::Audio::timeout_t

typedef unsigned char* ost::Audio::Encoded

typedef enum Rate ost::Audio::Rate

typedef enum Mode ost::Audio::Mode

typedef enum Encoding ost::Audio::Encoding

typedef enum Format ost::Audio::Format

typedef enum DeviceMode ost::Audio::DeviceMode

typedef enum Error ost::Audio::Error


Member Enumeration Documentation

enum ost::Audio::Rate

Audio encoding rate, samples per second.

Enumerator:
rateUnknown 
rate6khz 
rate8khz 
rate16khz 
rate32khz 
rate44khz 

enum ost::Audio::Mode

File processing mode, whether to skip missing files, etc.

Enumerator:
modeRead 
modeReadAny 
modeReadOne 
modeWrite 
modeCache 
modeInfo 
modeFeed 
modeAppend 
modeCreate 

enum ost::Audio::Encoding

Audio encoding formats.

Enumerator:
unknownEncoding 
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 
speexWide 
g723_4bit 

enum ost::Audio::Format

Audio container file format.

Enumerator:
raw 
snd 
riff 
mpeg 
wave 

enum ost::Audio::DeviceMode

Audio device access mode.

Enumerator:
PLAY 
RECORD 
PLAYREC 

enum ost::Audio::Error

Audio error conditions.

Enumerator:
errSuccess 
errReadLast 
errNotOpened 
errEndOfFile 
errStartOfFile 
errRateInvalid 
errEncodingInvalid 
errReadInterrupt 
errWriteInterrupt 
errReadFailure 
errWriteFailure 
errReadIncomplete 
errWriteIncomplete 
errRequestInvalid 
errTOCFailed 
errStatFailed 
errInvalidTrack 
errPlaybackFailed 
errNotPlaying 
errNoCodec 


Member Function Documentation

static Level ost::Audio::tolevel ( float  dbm  )  [static]

Convert dbm power level to integer value (0-32768).

Parameters:
dbm power level
Returns:
integer value.

static float ost::Audio::todbm ( Level  power  )  [static]

Convert integer power levels to dbm.

Parameters:
power level.
Returns:
dbm power level.

static bool ost::Audio::hasDevice ( unsigned  device = 0  )  [static]

Test for the presense of a specified (indexed) audio device.

This is normally used to test for local soundcard access.

Parameters:
device index or 0 for default audio device.
Returns:
true if device exists.

static AudioDevice* ost::Audio::getDevice ( unsigned  device = 0,
DeviceMode  mode = PLAY 
) [static]

Get a audio device object that can be used to play or record audio.

This is normally a local soundcard, though an abstract base class is returned, so the underlying device may be different.

Parameters:
device index or 0 for default audio device.
mode of device; play, record, or full duplex.
Returns:
pointer to abstract audio device object interface class.

static const char* ost::Audio::getCodecPath ( void   )  [static]

Get pathname to where loadable codec modules are stored.

Returns:
file path to loadable codecs.

static const char* ost::Audio::getMIME ( Info info  )  [static]

Get the mime descriptive type for a given Audio encoding description, usually retrieved from a newly opened audio file.

Parameters:
info source description object
Returns:
text of mime type to use for this audio source.

static const char* ost::Audio::getName ( Encoding  encoding  )  [static]

Get the short ascii description used for the given audio encoding type.

Parameters:
encoding format.
Returns:
ascii name of encoding format.

static const char* ost::Audio::getExtension ( Encoding  encoding  )  [static]

Get the preferred file extension name to use for a given audio encoding type.

Parameters:
encoding format.
Returns:
ascii file extension to use.

static Encoding ost::Audio::getEncoding ( const char *  name  )  [static]

Get the audio encoding format that is specified by a short ascii name.

This will either accept names like those returned from getName(), or .xxx file extensions, and return the audio encoding type associated with the name or extension.

Parameters:
name of encoding or file extension.
Returns:
audio encoding format.
See also:
getName

static Encoding ost::Audio::getStereo ( Encoding  encoding  )  [static]

Get the stereo encoding format associated with the given format.

Parameters:
encoding format being tested for stereo.
Returns:
associated stereo audio encoding format.

static Encoding ost::Audio::getMono ( Encoding  encoding  )  [static]

Get the mono encoding format associated with the given format.

Parameters:
encoding format.
Returns:
associated mono audio encoding format.

static bool ost::Audio::isLinear ( Encoding  encoding  )  [static]

Test if the audio encoding format is a linear one.

Returns:
true if encoding format is linear audio data.
Parameters:
encoding format.

static bool ost::Audio::isBuffered ( Encoding  encoding  )  [static]

Test if the audio encoding format must be packetized (that is, has irregular sized frames) and must be processed only through buffered codecs.

Returns:
true if packetized audio.
Parameters:
encoding format.

static bool ost::Audio::isMono ( Encoding  encoding  )  [static]

Test if the audio encoding format is a mono format.

Returns:
true if encoding format is mono audio data.
Parameters:
encoding format.

static bool ost::Audio::isStereo ( Encoding  encoding  )  [static]

Test if the audio encoding format is a stereo format.

Returns:
true if encoding format is stereo audio data.
Parameters:
encoding format.

static Rate ost::Audio::getRate ( Encoding  encoding  )  [static]

Return default sample rate associated with the specified audio encoding format.

Returns:
sample rate for audio data.
Parameters:
encoding format.

static Rate ost::Audio::getRate ( Encoding  e,
Rate  request 
) [static]

Return optional rate setting effect.

Many codecs are fixed rate.

Returns:
result rate for audio date.
Parameters:
encoding format.
requested rate.

static timeout_t ost::Audio::getFraming ( Encoding  encoding,
timeout_t  timeout = 0 
) [static]

Return frame timing for an audio encoding format.

Returns:
frame time to use in milliseconds.
Parameters:
encoding of frame to get timing segment for.
timeout of frame time segment to request.

static timeout_t ost::Audio::getFraming ( Info info,
timeout_t  timeout = 0 
) [static]

Return frame time for an audio source description.

Returns:
frame time to use in milliseconds.
Parameters:
info descriptor of frame encoding to get timing segment for.
timeout of frame time segment to request.

static bool ost::Audio::isEndian ( Encoding  encoding  )  [static]

Test if the endian byte order of the encoding format is different from the machine's native byte order.

Returns:
true if endian format is different.
Parameters:
encoding format.

static bool ost::Audio::isEndian ( Info info  )  [static]

Test if the endian byte order of the audio source description is different from the machine's native byte order.

Returns:
true if endian format is different.
Parameters:
info source description object.

static bool ost::Audio::swapEndian ( Encoding  encoding,
void *  buffer,
unsigned  number 
) [static]

Optionally swap endian of audio data if the encoding format endian byte order is different from the machine's native endian.

Returns:
true if endian format was different.
Parameters:
encoding format of data.
buffer of audio data.
number of audio samples.

static void ost::Audio::swapEncoded ( Info info,
Encoded  data,
size_t  bytes 
) [static]

Optionally swap endian of encoded audio data based on the audio encoding type, and relationship to native byte order.

Parameters:
info source description of object.
buffer of audio data.
number of bytes of audio data.

static bool ost::Audio::swapEndian ( Info info,
void *  buffer,
unsigned  number 
) [static]

Optionally swap endian of audio data if the audio source description byte order is different from the machine's native endian byte order.

Returns:
true if endian format was different.
Parameters:
info source description object of data.
buffer of audio data.
number of audio samples.

static Level ost::Audio::getImpulse ( Encoding  encoding,
void *  buffer,
unsigned  number 
) [static]

Get the energey impulse level of a frame of audio data.

Returns:
impulse energy level of audio data.
Parameters:
encoding format of data to examine.
buffer of audio data to examine.
number of audio samples to examine.

static Level ost::Audio::getImpulse ( Info info,
void *  buffer,
unsigned  number = 0 
) [static]

Get the energey impulse level of a frame of audio data.

Returns:
impulse energy level of audio data.
Parameters:
info encoding source description object.
buffer of audio data to examine.
number of audio samples to examine.

static Level ost::Audio::getPeak ( Encoding  encoding,
void *  buffer,
unsigned  number 
) [static]

Get the peak (highest energy) level found in a frame of audio data.

Returns:
peak energy level found in data.
Parameters:
encoding format of data.
buffer of audio data.
number of samples to examine.

static Level ost::Audio::getPeak ( Info info,
void *  buffer,
unsigned  number = 0 
) [static]

Get the peak (highest energy) level found in a frame of audio data.

Returns:
peak energy level found in data.
Parameters:
info description object of audio data.
buffer of audio data.
number of samples to examine.

static void ost::Audio::toTimestamp ( timeout_t  duration,
char *  address,
size_t  size 
) [static]

Provide ascii timestamp representation of a timeout value.

Parameters:
duration timeout value
address for ascii data.
size of ascii data.

static timeout_t ost::Audio::toTimeout ( const char *  timestamp  )  [static]

Convert ascii timestamp representation to a timeout number.

Parameters:
timestamp ascii data.
Returns:
timeout_t duration from data.

static int ost::Audio::getFrame ( Encoding  encoding,
int  samples = 0 
) [static]

Returns the number of bytes in a sample frame for the given encoding type, rounded up to the nearest integer.

A frame is defined as the minimum number of bytes necessary to create a point or points in the output waveform for all output channels. For example, 16-bit mono PCM has a frame size of two (because those two bytes constitute a point in the output waveform). GSM has it's own definition of a frame which involves decompressing a sequence of bytes to determine the final points on the output waveform. The minimum number of bytes you can feed to the decompression engine is 32.5 (260 bits), so this function will return 33 (because we round up) given an encoding type of GSM. Other compressed encodings will return similar results. Be prepared to deal with nonintuitive return values for rare encodings.

Parameters:
encoding The encoding type to get the frame size for.
samples Reserved. Use zero.
Returns:
The number of bytes in a frame for the given encoding.

static int ost::Audio::getCount ( Encoding  encoding  )  [static]

Returns the number of samples in all channels for a frame in the given encoding.

For example, pcm32Stereo has a frame size of 8 bytes: Note that different codecs have different definitions of a frame - for example, compressed encodings have a rather large frame size relative to the sample size due to the way bytes are fed to the decompression engine.

Parameters:
encoding The encoding to calculate the frame sample count for.
Returns:
samples The number of samples in a frame of the given encoding.

static unsigned long ost::Audio::toSamples ( Encoding  encoding,
size_t  bytes 
) [static]

Compute byte counts of audio data into number of samples based on the audio encoding format used.

Returns:
number of audio samples in specified data.
Parameters:
encoding format.
bytes of data.

static unsigned long ost::Audio::toSamples ( Info info,
size_t  bytes 
) [static]

Compute byte counts of audio data into number of samples based on the audio source description used.

Returns:
number of audio samples in specified data.
Parameters:
info encoding source description.
bytes of data.

static size_t ost::Audio::toBytes ( Info info,
unsigned long  number 
) [static]

Compute the number of bytes a given number of samples in a given audio encoding will occupy.

Returns:
number of bytes samples will occupy.
Parameters:
info encoding source description.
number of samples.

static size_t ost::Audio::toBytes ( Encoding  encoding,
unsigned long  number 
) [static]

Compute the number of bytes a given number of samples in a given audio encoding will occupy.

Returns:
number of bytes samples will occupy.
Parameters:
encoding format.
number of samples.

static void ost::Audio::fill ( unsigned char *  address,
int  number,
Encoding  encoding 
) [static]

Fill an audio buffer with "empty" (silent) audio data, based on the audio encoding format.

Parameters:
address of data to fill.
number of samples to fill.
encoding format of data.

static bool ost::Audio::loadPlugin ( const char *  path  )  [static]

Load a dso plugin (codec plugin), used internally.

..

Returns:
true if loaded.
Parameters:
path to codec.

static size_t ost::Audio::maxFramesize ( Info info  )  [static]

Maximum framesize for a given coding that may be needed to store a result.

Parameters:
info source description object.
Returns:
maximum possible frame size to allocate for encoded data.


Member Data Documentation

const unsigned ost::Audio::ndata [static]


The documentation for this class was generated from the following file:
Generated on Thu Dec 7 08:35:26 2006 for ccAudio by  doxygen 1.5.1