Bayonne2 / Common C++ 2 Framework
Public Types | Public Member Functions | Static Public Member Functions | Static Public Attributes | Protected Member Functions | Protected Attributes | Private Attributes | Static Private Attributes
ost::StreamingBuffer Class Reference

Streaming buffer for audio, to be used in bgm audio sources. More...

#include <bayonne.h>

Inheritance diagram for ost::StreamingBuffer:
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Public Types

enum   Rate {
  rateUnknown, rate6khz = 6000, rate8khz = 8000, rate16khz = 16000,
  rate32khz = 32000, rate44khz = 44100
}
  Audio encoding rate, samples per second. More...
 
typedef enum Rate  Rate
 
  File processing mode, whether to skip missing files, etc. More...
 
typedef enum Mode  Mode
 
  Audio encoding formats. More...
 
typedef enum Encoding  Encoding
 
enum   Format {
  raw, snd, riff, mpeg,
  wave
}
  Audio container file format. More...
 
typedef enum Format  Format
 
enum   DeviceMode { PLAY, RECORD, PLAYREC }
  Audio device access mode. More...
 
typedef enum DeviceMode  DeviceMode
 
  Audio error conditions. More...
 
typedef enum Error  Error
 
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
 

Public Member Functions

virtual bool  isActive (void)
  Check if streaming source is active. More...
 
virtual unsigned long  getPosition (timeout_t framing)
  Get position marker we use in audio consumer. More...
 
virtual Linear  getBuffer (unsigned long *mark, timeout_t duration)
  Used by consumer to get a linear buffer of audio data. More...
 

Static Public Member Functions

static StreamingBufferget (const char *id, Rate rate)
  Find a streaming feed by identifier. More...
 
static Level  tolevel (float dbm)
  Convert dbm power level to integer value (0-32768). More...
 
static float  todbm (Level power)
  Convert integer power levels to dbm. More...
 
static bool  hasDevice (unsigned device=0)
  Test for the presense of a specified (indexed) audio device. More...
 
static AudioDevicegetDevice (unsigned device=0, DeviceMode mode=PLAY)
  Get a audio device object that can be used to play or record audio. More...
 
static const char *  getCodecPath (void)
  Get pathname to where loadable codec modules are stored. More...
 
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. More...
 
static const char *  getName (Encoding encoding)
  Get the short ascii description used for the given audio encoding type. More...
 
static const char *  getExtension (Encoding encoding)
  Get the preferred file extension name to use for a given audio encoding type. More...
 
static Encoding  getEncoding (const char *name)
  Get the audio encoding format that is specified by a short ascii name. More...
 
static Encoding  getStereo (Encoding encoding)
  Get the stereo encoding format associated with the given format. More...
 
static Encoding  getMono (Encoding encoding)
  Get the mono encoding format associated with the given format. More...
 
static bool  isLinear (Encoding encoding)
  Test if the audio encoding format is a linear one. More...
 
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. More...
 
static bool  isMono (Encoding encoding)
  Test if the audio encoding format is a mono format. More...
 
static bool  isStereo (Encoding encoding)
  Test if the audio encoding format is a stereo format. More...
 
static Rate  getRate (Encoding encoding)
  Return default sample rate associated with the specified audio encoding format. More...
 
static Rate  getRate (Encoding e, Rate request)
  Return optional rate setting effect. More...
 
static timeout_t  getFraming (Encoding encoding, timeout_t timeout=0)
  Return frame timing for an audio encoding format. More...
 
static timeout_t  getFraming (Info &info, timeout_t timeout=0)
  Return frame time for an audio source description. More...
 
static bool  isEndian (Encoding encoding)
  Test if the endian byte order of the encoding format is different from the machine's native byte order. More...
 
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. More...
 
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. More...
 
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. More...
 
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. More...
 
static Level  getImpulse (Encoding encoding, void *buffer, unsigned number)
  Get the energey impulse level of a frame of audio data. More...
 
static Level  getImpulse (Info &info, void *buffer, unsigned number=0)
  Get the energey impulse level of a frame of audio data. More...
 
static Level  getPeak (Encoding encoding, void *buffer, unsigned number)
  Get the peak (highest energy) level found in a frame of audio data. More...
 
static Level  getPeak (Info &info, void *buffer, unsigned number=0)
  Get the peak (highest energy) level found in a frame of audio data. More...
 
static void  toTimestamp (timeout_t duration, char *address, size_t size)
  Provide ascii timestamp representation of a timeout value. More...
 
static timeout_t  toTimeout (const char *timestamp)
  Convert ascii timestamp representation to a timeout number. More...
 
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. More...
 
static int  getCount (Encoding encoding)
  Returns the number of samples in all channels for a frame in the given encoding. More...
 
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. More...
 
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. More...
 
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. More...
 
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. More...
 
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. More...
 
static bool  loadPlugin (const char *path)
  Load a dso plugin (codec plugin), used internally... More...
 
static size_t  maxFramesize (Info &info)
  Maximum framesize for a given coding that may be needed to store a result. More...
 

Static Public Attributes

static const unsigned  ndata
 

Protected Member Functions

void  cleanup ()
 
  StreamingBuffer (const char *id, timeout_t size=600, Rate rate=rate8khz)
 
virtual  ~StreamingBuffer ()
 
virtual Linear  putBuffer (timeout_t duration)
 
virtual void  clearBuffer (timeout_t duration)
 

Protected Attributes

unsigned long  position
 
unsigned long  count
 
 

Private Attributes

 
const char *  id
 
 

Static Private Attributes

static StreamingBufferfirst
 

Detailed Description

Streaming buffer for audio, to be used in bgm audio sources.

Author
David Sugar dyfet.nosp@m.@gnu.nosp@m.telep.nosp@m.hony.nosp@m..org audio buffering

Definition at line 96 of file bayonne.h.

Member Typedef Documentation

inherited

Definition at line 247 of file audio2.h.

typedef unsigned char* ost::Audio::Encoded
inherited

Definition at line 143 of file audio2.h.

inherited

Definition at line 225 of file audio2.h.

typedef enum Error ost::Audio::Error
inherited

Definition at line 274 of file audio2.h.

typedef enum Format ost::Audio::Format
inherited

Definition at line 237 of file audio2.h.

typedef int16_t ost::Audio::Level
inherited

Definition at line 101 of file audio2.h.

typedef int16_t* ost::Audio::Linear
inherited

Definition at line 103 of file audio2.h.

typedef enum Mode ost::Audio::Mode
inherited

Definition at line 175 of file audio2.h.

typedef enum Rate ost::Audio::Rate
inherited

Definition at line 157 of file audio2.h.

typedef int16_t ost::Audio::Sample
inherited

Definition at line 102 of file audio2.h.

typedef int16_t ost::Audio::snd16_t
inherited

Definition at line 99 of file audio2.h.

typedef int32_t ost::Audio::snd32_t
inherited

Definition at line 100 of file audio2.h.

typedef unsigned long ost::Audio::timeout_t
inherited

Definition at line 104 of file audio2.h.

Member Enumeration Documentation

inherited

Audio device access mode.

Enumerator
PLAY 
RECORD 
PLAYREC 

Definition at line 242 of file audio2.h.

inherited

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 

Definition at line 180 of file audio2.h.

inherited

Audio error conditions.

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

Definition at line 252 of file audio2.h.

inherited

Audio container file format.

Enumerator
raw 
snd 
riff 
mpeg 
wave 

Definition at line 230 of file audio2.h.

inherited

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

Enumerator
modeRead 
modeReadAny 
modeReadOne 
modeWrite 
modeCache 
modeInfo 
modeFeed 
modeAppend 
modeCreate 

Definition at line 162 of file audio2.h.

inherited

Audio encoding rate, samples per second.

Enumerator
rateUnknown 
rate6khz 
rate8khz 
rate16khz 
rate32khz 
rate44khz 

Definition at line 148 of file audio2.h.

Constructor & Destructor Documentation

ost::StreamingBuffer::StreamingBuffer ( const char *  id,
timeout_t  size = 600,
Rate  rate = rate8khz  
)
protected
virtual ost::StreamingBuffer::~StreamingBuffer ( )
protectedvirtual

Member Function Documentation

void ost::StreamingBuffer::cleanup ( )
protected
virtual void ost::StreamingBuffer::clearBuffer ( timeout_t  duration )
protectedvirtual
static void ost::Audio::fill ( unsigned char *  address,
int  number,
Encoding  encoding 
)
staticinherited

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 StreamingBuffer* ost::StreamingBuffer::get ( const char *  id,
Rate  rate 
)
static

Find a streaming feed by identifier.

Returns
pointer to feed or NULL.
Parameters
identifer to search for.
sample rate to use.
virtual Linear ost::StreamingBuffer::getBuffer ( unsigned long *  mark,
timeout_t  duration 
)
virtual

Used by consumer to get a linear buffer of audio data.

Returns
data buffer of samples.
Parameters
consumer position.
timeout of frame for updating position.
static const char* ost::Audio::getCodecPath ( void  )
staticinherited

Get pathname to where loadable codec modules are stored.

Returns
file path to loadable codecs.
static int ost::Audio::getCount ( Encoding  encoding )
staticinherited

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

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 Encoding ost::Audio::getEncoding ( const char *  name )
staticinherited

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 const char* ost::Audio::getExtension ( Encoding  encoding )
staticinherited

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

Parameters
encoding format.
Returns
ascii file extension to use.
static int ost::Audio::getFrame ( Encoding  encoding,
int  samples = 0 
)
staticinherited

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 timeout_t ost::Audio::getFraming ( Encoding  encoding,
timeout_t  timeout = 0 
)
staticinherited

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 ( Infoinfo,
timeout_t  timeout = 0 
)
staticinherited

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 Level ost::Audio::getImpulse ( Encoding  encoding,
void *  buffer,
unsigned  number 
)
staticinherited

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 ( Infoinfo,
void *  buffer,
unsigned  number = 0 
)
staticinherited

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 const char* ost::Audio::getMIME ( Infoinfo )
staticinherited

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 Encoding ost::Audio::getMono ( Encoding  encoding )
staticinherited

Get the mono encoding format associated with the given format.

Parameters
encoding format.
Returns
associated mono audio encoding format.
static const char* ost::Audio::getName ( Encoding  encoding )
staticinherited

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

Parameters
encoding format.
Returns
ascii name of encoding format.
static Level ost::Audio::getPeak ( Encoding  encoding,
void *  buffer,
unsigned  number 
)
staticinherited

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 ( Infoinfo,
void *  buffer,
unsigned  number = 0 
)
staticinherited

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.
virtual unsigned long ost::StreamingBuffer::getPosition ( timeout_t  framing )
virtual

Get position marker we use in audio consumer.

Parameters
framing size we will use.
Returns
consumer position.
static Rate ost::Audio::getRate ( Encoding  encoding )
staticinherited

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 
)
staticinherited

Return optional rate setting effect.

Many codecs are fixed rate.

Returns
result rate for audio date.
Parameters
encoding format.
requested rate.
static Encoding ost::Audio::getStereo ( Encoding  encoding )
staticinherited

Get the stereo encoding format associated with the given format.

Parameters
encoding format being tested for stereo.
Returns
associated stereo audio encoding format.
static bool ost::Audio::hasDevice ( unsigned  device = 0 )
staticinherited

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.
virtual bool ost::StreamingBuffer::isActive ( void  )
virtual

Check if streaming source is active.

Returns
true if active.
static bool ost::Audio::isBuffered ( Encoding  encoding )
staticinherited

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::isEndian ( Encoding  encoding )
staticinherited

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 ( Infoinfo )
staticinherited

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::isLinear ( Encoding  encoding )
staticinherited

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::isMono ( Encoding  encoding )
staticinherited

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 )
staticinherited

Test if the audio encoding format is a stereo format.

Returns
true if encoding format is stereo audio data.
Parameters
encoding format.
static bool ost::Audio::loadPlugin ( const char *  path )
staticinherited

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

Returns
true if loaded.
Parameters
path to codec.
static size_t ost::Audio::maxFramesize ( Infoinfo )
staticinherited

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.
virtual Linear ost::StreamingBuffer::putBuffer ( timeout_t  duration )
protectedvirtual
static void ost::Audio::swapEncoded ( Infoinfo,
Encoded  data,
size_t  bytes 
)
staticinherited

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 ( Encoding  encoding,
void *  buffer,
unsigned  number 
)
staticinherited

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 bool ost::Audio::swapEndian ( Infoinfo,
void *  buffer,
unsigned  number 
)
staticinherited

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 size_t ost::Audio::toBytes ( Infoinfo,
unsigned long  number 
)
staticinherited

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 
)
staticinherited

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 float ost::Audio::todbm ( Level  power )
staticinherited

Convert integer power levels to dbm.

Parameters
power level.
Returns
dbm power level.
static Level ost::Audio::tolevel ( float  dbm )
staticinherited

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

Parameters
dbm power level
Returns
integer value.
static unsigned long ost::Audio::toSamples ( Encoding  encoding,
size_t  bytes 
)
staticinherited

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 ( Infoinfo,
size_t  bytes 
)
staticinherited

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 timeout_t ost::Audio::toTimeout ( const char *  timestamp )
staticinherited

Convert ascii timestamp representation to a timeout number.

Parameters
timestamp ascii data.
Returns
timeout_t duration from data.
static void ost::Audio::toTimestamp ( timeout_t  duration,
char *  address,
size_t  size 
)
staticinherited

Provide ascii timestamp representation of a timeout value.

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

Field Documentation

unsigned long ost::StreamingBuffer::count
protected

Definition at line 105 of file bayonne.h.

Linear ost::StreamingBuffer::data
protected

Definition at line 106 of file bayonne.h.

StreamingBuffer* ost::StreamingBuffer::first
staticprivate

Definition at line 99 of file bayonne.h.

const char* ost::StreamingBuffer::id
private

Definition at line 101 of file bayonne.h.

const unsigned ost::Audio::ndata
staticinherited

Definition at line 107 of file audio2.h.

StreamingBuffer* ost::StreamingBuffer::next
private

Definition at line 100 of file bayonne.h.

unsigned long ost::StreamingBuffer::position
protected

Definition at line 105 of file bayonne.h.

Rate ost::StreamingBuffer::rate
private

Definition at line 102 of file bayonne.h.


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

Generated on Dec 21, 2017 for commoncpp2-1.8.1, ccrtp-1.7.2, libzrtpcpp-2.3.4, ccscript3-1.1.7, ccaudio2-1.0.0 and bayonne2-2.3.2 (after installation in /usr/local/) by   doxygen 1.8.6

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