roc::audio Namespace Reference

Audio frames and audio processing. More...

Classes
class	BuiltinResampler
	Built-in resampler. More...
class	ChannelMapper
	Channel mapper. Converts between frames with specified channel masks. More...
class	ChannelMapperMatrix
	Contain conversation coefficients while mapping surround to surround. More...
class	ChannelMapperReader
	Channel mapper reader. Reads frames from nested reader and maps them to another channel mask. More...
struct	ChannelMapRule
	Defines multiplication coefficient for a pair of channels. More...
struct	ChannelMap
	Defines multiplication matrix for two channel masks. Instead of defining the whole matrix, it defines a list of pairs of output and input channel numbers and corresponding coefficients. Such representation allows more compact definition in the source code. The actual matrix is built by channel mapper at runtime. More...
struct	ChannelList
	Defines ordered list of channels. More...
class	ChannelMapperWriter
	Channel mapper writer. Reads frames from nested writer and maps them to another channel mask. More...
class	ChannelSet
	Channel set. Multi-word bitmask with bits corresponding to enabled channels. Meaning of each channel is defined by ChannelLayout. Order of serialized channels is defined by ChannelOrder. More...
class	channel_set_to_str
	Format ChannelSet to string. More...
class	DecimationResampler
	Decimating resampler. More...
class	Depacketizer
	Depacketizer. More...
class	Fanout
	Fanout. Duplicates audio stream to multiple output writers. More...
class	Frame
	Audio frame. More...
struct	FreqEstimatorConfig
	FreqEstimator tunable parameters. More...
class	FreqEstimator
	Evaluates sender's frequency to receivers's frequency ratio. More...
class	IFrameDecoder
	Audio frame decoder interface. More...
class	IFrameEncoder
	Audio frame encoder interface. More...
class	IFrameReader
	Frame reader interface. More...
class	IFrameWriter
	Frame writer interface. More...
class	IResampler
	Audio writer interface. More...
struct	LatencyMonitorConfig
	Parameters for latency monitor. More...
struct	LatencyMonitorMetrics
	Metrics of latency monitor. More...
class	LatencyMonitor
	Latency monitor. More...
class	Mixer
	Mixer. Mixes multiple input streams into one output stream. More...
class	NullWriter
	Null writer. More...
class	Packetizer
	Packetizer. More...
class	PcmDecoder
	PCM decoder. More...
class	PcmEncoder
	PCM encoder. More...
struct	PcmFormat
	PCM format description. More...
struct	PcmTraits
	PCM format meta-information. More...
class	PcmMapper
	PCM format mapper. Convert between PCM formats. More...
class	PoisonReader
	Poisons audio frames before reading them. More...
struct	ProfilerConfig
	Profiler Configuration Parameters. Controls profiling interval and duration of each circular buffer chunk. More...
class	Profiler
	Profiler The role of the profiler is to report the average processing speed (# of samples processed per time unit) during the last N seconds. We want to calculate the average processing speed efficiently (with O(1) complexity, without allocations, and as lightweight as possible). The problems with this are that we have variable-sized frames and SMA requires fixed-size chunks. To efficiently perform this calculation a ring buffer is employed. The idea behind the ring buffer is that each chunk of the buffer is the average speed of 10ms worth of samples. The ring buffer is initialized with fixed size (N * 1000)ms / (10ms) chunks. Within each chunk a weighted mean is used to calculate the average speed during those 10ms. Each frame will contribute a different number of samples to each chunk, the chunk speed is then weighted based on how many samples are contributed at what frame speed. As the chunks get populated the moving average is calculated. When the buffer is not entirely full the cumulative moving average algorithm is used and once the buffer is full the simple moving average algorithm is used. More...
class	ProfilingReader
	Profiling reader. More...
class	ProfilingWriter
	Profiling writer. More...
class	ResamplerMap
	Factory class for IResampler objects, according to the ResamplerBackend input. More...
class	ResamplerReader
	Resampler element for reading pipeline. More...
class	ResamplerWriter
	Resampler element for writing pipeline. More...
class	SampleSpec
	Sample specification. Describes sample rate and channels. More...
class	sample_spec_to_str
	Format SampleSpec to string. More...
class	SpeexResampler
	Speex resampler. More...
struct	WatchdogConfig
	Watchdog parameters. More...
class	Watchdog
	Watchdog. More...

Typedefs
typedef uint32_t	ChannelMask
	Channel mask. More...
typedef float	sample_t
	Audio sample. More...

Enumerations
enum	ChannelLayout { ChanLayout_None , ChanLayout_Surround , ChanLayout_Multitrack }
	Channel layout. Defines meaning of channels in ChannelSet. ChannelMapper uses channel layout to decide how to perform mapping. More...
enum	ChannelOrder { ChanOrder_None , ChanOrder_Smpte , ChanOrder_Alsa , ChanOrder_Max }
	Surround channel order. More...
enum	ChannelPosition {   ChanPos_FrontLeft , ChanPos_FrontCenter , ChanPos_FrontRight , ChanPos_SideLeft ,   ChanPos_SideRight , ChanPos_BackLeft , ChanPos_BackCenter , ChanPos_BackRight ,   ChanPos_TopFrontLeft , ChanPos_TopFrontRight , ChanPos_TopMidLeft , ChanPos_TopMidRight ,   ChanPos_TopBackLeft , ChanPos_TopBackRight , ChanPos_LowFrequency , ChanPos_Max }
	Surround channel position. More...
enum	FreqEstimatorProfile { FreqEstimatorProfile_Responsive , FreqEstimatorProfile_Gradual }
	FreqEstimator paremeter preset. More...
enum	PcmCode {   PcmCode_SInt8 , PcmCode_UInt8 , PcmCode_SInt16 , PcmCode_UInt16 ,   PcmCode_SInt18 , PcmCode_UInt18 , PcmCode_SInt18_3 , PcmCode_UInt18_3 ,   PcmCode_SInt18_4 , PcmCode_UInt18_4 , PcmCode_SInt20 , PcmCode_UInt20 ,   PcmCode_SInt20_3 , PcmCode_UInt20_3 , PcmCode_SInt20_4 , PcmCode_UInt20_4 ,   PcmCode_SInt24 , PcmCode_UInt24 , PcmCode_SInt24_4 , PcmCode_UInt24_4 ,   PcmCode_SInt32 , PcmCode_UInt32 , PcmCode_SInt64 , PcmCode_UInt64 ,   PcmCode_Float32 , PcmCode_Float64 , PcmCode_Max }
	PCM sample binary code. More...
enum	PcmEndian { PcmEndian_Native , PcmEndian_Big , PcmEndian_Little }
	PCM sample endianess. More...
enum	ResamplerBackend { ResamplerBackend_Default , ResamplerBackend_Builtin , ResamplerBackend_Speex , ResamplerBackend_SpeexDec }
	Resampler backends. More...
enum	ResamplerProfile { ResamplerProfile_Low , ResamplerProfile_Medium , ResamplerProfile_High }
	Resampler parameters presets. More...

Functions
const char *	channel_layout_to_str (ChannelLayout)
	Get string name of channel layout. More...
const char *	channel_order_to_str (ChannelOrder)
	Get string name of channel order. More...
const char *	channel_position_to_str (ChannelPosition)
	Get string name of channel position. More...
void	format_channel_set (const ChannelSet &ch_set, core::StringBuilder &bld)
	Format ChannelSet to string. More...
const char *	fe_profile_to_str (FreqEstimatorProfile profile)
	Get string name of FreqEstimator profile. More...
const char *	pcm_format_to_str (const PcmFormat &fmt)
	Get string name of PCM format. More...
ROC_ATTR_NODISCARD bool	pcm_format_parse (const char *str, PcmFormat &fmt)
	Parse PCM format from string name. More...
PcmTraits	pcm_format_traits (const PcmFormat &fmt)
	Get traits for PCM format. More...
const char *	resampler_backend_to_str (ResamplerBackend)
	Get string name of resampler backend. More...

Variables
const size_t	chan_map_count = 40
	Number of defined channel mappings. More...
const ChannelMap	chan_maps [chan_map_count]
	Defines list of mappings between all supported surround channel mask pairs. Channel mapper will search for appropriate mapping in this list, based on input and output channel masks. More...
const ChannelList	chan_orders [ChanOrder_Max]
	Defines mapping of channel order identifier to list of channel positions in corresponding order. More...
const double	fe_decim_h [fe_decim_len]
	Impulse response of decimation filter with factor of 10. More...
const double	fe_decim_h_gain
	Filters gain, sum(fe_decim_h). More...
const PcmFormat	SampleFormat
	Sample format description. More...
const sample_t	SampleMin
	Minimum possible value of a sample. More...
const sample_t	SampleMax
	Maximum possible value of a sample. More...

Detailed Description

Audio frames and audio processing.

Typedef Documentation

ChannelMask

typedef uint32_t roc::audio::ChannelMask

Channel mask.

Remarks

Used to construct short channel sets (up to 32 channels) for ChanLayout_Surround layout.

Definition at line 144 of file channel_defs.h.

sample_t

typedef float roc::audio::sample_t

Audio sample.

Definition at line 22 of file sample.h.

Enumeration Type Documentation

ChannelLayout

enum roc::audio::ChannelLayout

Channel layout. Defines meaning of channels in ChannelSet. ChannelMapper uses channel layout to decide how to perform mapping.

Enumerator
ChanLayout_None	Channel layout is not set. Remarks This is never valid and indicates that ChannelSet is not fully initialized.
ChanLayout_Surround	Multi-channel mono / stereo / surround sound. Remarks The meaning of channel index is defined by ChannelPosition enum. Channels are mapped according to their position in space, e.g. if top-left channel is missing, it can be mixed from front-left and side-left channels.
ChanLayout_Multitrack	Multi-channel multi-track sound. Remarks There is no special meaning of channels, they are considered to be independent tracks. Channels are mapped according to their numbers; channel N is mapped to channel N and nothing else.

Definition at line 23 of file channel_defs.h.

ChannelOrder

enum roc::audio::ChannelOrder

Surround channel order.

Remarks

Should be used with ChannelLayout_Surround. Defines order in which channels from ChannelSet are (de)serialized.

Enumerator
ChanOrder_None	Channel order is not set. Remarks For ChanLayout_Surround, this is never valid and indicates that ChannelSet is not fully initialized. For ChanLayout_Multitrack, in contrast, this is the only valid value.
ChanOrder_Smpte	ITU/SMPTE channel order. Order: FL, FR, FC, LFE, BL, BR, BC, SL, SR, TFL, TFR, TBL, TBR, TML, TMR. Remarks This order is actually a superset of what is defined by SMPTE, but when fileterd by actual masks like 5.1 or 7.1, it produces orderings equal to what is defined in the standard. When used with masks 2.x - 5.x (but not 6.x), it is also compatible with the channel order from AIFF-C, which is used by default in RTP/AVP, as defined in RFC 3551.
ChanOrder_Alsa	ALSA channel order. Order: FL, FR, BL, BR, FC, LFE, SL, SR, BC. Remarks This order is used by ALSA hardware devices. ALSA supports only 9 channels.
ChanOrder_Max	Maximum value of enum.

Definition at line 49 of file channel_defs.h.

ChannelPosition

enum roc::audio::ChannelPosition

Surround channel position.

Remarks

Should be used with ChannelLayout_Surround. Defines meaning of channel indicies for mono / stereo / surround sound.

Note

Despide mono, stereo, and 3.x technically are not surround layouts, in the code base they are considered a special case of surround.

Enumerator
ChanPos_FrontLeft	Front left (FL).
ChanPos_FrontCenter	Front center (FC).
ChanPos_FrontRight	Front right (FR).
ChanPos_SideLeft	Side left (SL).
ChanPos_SideRight	Side right (SR).
ChanPos_BackLeft	Back left (BL).
ChanPos_BackCenter	Back center (BC).
ChanPos_BackRight	Back right (BR).
ChanPos_TopFrontLeft	Top front left (TFL).
ChanPos_TopFrontRight	Top front right (TFR).
ChanPos_TopMidLeft	Top middle left (TML).
ChanPos_TopMidRight	Top middle right (TMR).
ChanPos_TopBackLeft	Top rear left (TBL).
ChanPos_TopBackRight	Top rear right (TBR).
ChanPos_LowFrequency	Low frequency speaker (LFE). Remarks Placed anywhere. Also known as "subwoofer" or "SW" speaker.
ChanPos_Max	Maximum value of enum.

Definition at line 86 of file channel_defs.h.

FreqEstimatorProfile

enum roc::audio::FreqEstimatorProfile

FreqEstimator paremeter preset.

Enumerator
FreqEstimatorProfile_Responsive	Fast and responsive tuning. Good for lower network latency and jitter.
FreqEstimatorProfile_Gradual	Slow and smooth tuning. Good for higher network latency and jitter.

Definition at line 24 of file freq_estimator.h.

PcmCode

enum roc::audio::PcmCode

PCM sample binary code.

Enumerator
PcmCode_SInt8	8-bit signed integer.
PcmCode_UInt8	8-bit unsigned integer.
PcmCode_SInt16	16-bit signed integer.
PcmCode_UInt16	16-bit unsigned integer.
PcmCode_SInt18	18-bit signed integer (2.25 bytes).
PcmCode_UInt18	18-bit unsigned integer (2.25 bytes).
PcmCode_SInt18_3	18-bit signed integer, in low bits of 3-byte container.
PcmCode_UInt18_3	18-bit unsigned integer, in low bits of 3-byte container.
PcmCode_SInt18_4	18-bit signed integer, in low bits of 4-byte container.
PcmCode_UInt18_4	18-bit unsigned integer, in low bits of 4-byte container.
PcmCode_SInt20	20-bit signed integer (2.5 bytes).
PcmCode_UInt20	20-bit unsigned integer (2.5 bytes).
PcmCode_SInt20_3	20-bit signed integer, in low bits of 3-byte container.
PcmCode_UInt20_3	20-bit unsigned integer, in low bits of 3-byte container.
PcmCode_SInt20_4	20-bit signed integer, in low bits of 4-byte container.
PcmCode_UInt20_4	20-bit unsigned integer, in low bits of 4-byte container.
PcmCode_SInt24	24-bit signed integer (3 bytes).
PcmCode_UInt24	24-bit unsigned integer (3 bytes).
PcmCode_SInt24_4	24-bit signed integer, in low bits of 4-byte container.
PcmCode_UInt24_4	24-bit unsigned integer, in low bits of 4-byte container.
PcmCode_SInt32	32-bit signed integer.
PcmCode_UInt32	32-bit unsigned integer.
PcmCode_SInt64	64-bit signed integer.
PcmCode_UInt64	64-bit unsigned integer.
PcmCode_Float32	32-bit IEEE-754 float in range [-1.0; +1.0].
PcmCode_Float64	64-bit IEEE-754 float in range [-1.0; +1.0].
PcmCode_Max	Maximum value.

Definition at line 22 of file pcm_format.h.

PcmEndian

enum roc::audio::PcmEndian

PCM sample endianess.

Enumerator
PcmEndian_Native	Endian native to current CPU.
PcmEndian_Big	Big endian.
PcmEndian_Little	Little endian.

Definition at line 54 of file pcm_format.h.

ResamplerBackend

enum roc::audio::ResamplerBackend

Resampler backends.

Enumerator
ResamplerBackend_Default	Default backend. Resolved to one of other backends, depending on what is enabled at build time.
ResamplerBackend_Builtin	Built-in resampler. High precision, high quality, slow.
ResamplerBackend_Speex	SpeexDSP resampler. Low precision, high quality, fast. May be disabled at build time.
ResamplerBackend_SpeexDec	Combined SpeexDSP + decimating resampler. Tolerable precision, tolerable quality, fast. May be disabled at build time.

Definition at line 19 of file resampler_backend.h.

ResamplerProfile

enum roc::audio::ResamplerProfile

Resampler parameters presets.

Enumerator
ResamplerProfile_Low	Low quality, fast speed.
ResamplerProfile_Medium	Medium quality, medium speed.
ResamplerProfile_High	Hight quality, low speed.

Definition at line 19 of file resampler_profile.h.

Function Documentation

channel_layout_to_str()

const char* roc::audio::channel_layout_to_str

(

ChannelLayout

)

Get string name of channel layout.

channel_order_to_str()

const char* roc::audio::channel_order_to_str

(

ChannelOrder

)

Get string name of channel order.

channel_position_to_str()

const char* roc::audio::channel_position_to_str

(

ChannelPosition

)

Get string name of channel position.

fe_profile_to_str()

const char* roc::audio::fe_profile_to_str

(

FreqEstimatorProfile

profile

)

Get string name of FreqEstimator profile.

format_channel_set()

void roc::audio::format_channel_set	(	const ChannelSet &	ch_set,
		core::StringBuilder &	bld
	)

Format ChannelSet to string.

pcm_format_parse()

ROC_ATTR_NODISCARD bool roc::audio::pcm_format_parse	(	const char *	str,
		PcmFormat &	fmt
	)

Parse PCM format from string name.

pcm_format_to_str()

const char* roc::audio::pcm_format_to_str

(

const PcmFormat &

fmt

)

Get string name of PCM format.

pcm_format_traits()

PcmTraits roc::audio::pcm_format_traits

(

const PcmFormat &

fmt

)

Get traits for PCM format.

resampler_backend_to_str()

const char* roc::audio::resampler_backend_to_str

(

ResamplerBackend

)

Get string name of resampler backend.

Variable Documentation

chan_map_count

const size_t roc::audio::chan_map_count = 40

Number of defined channel mappings.

Definition at line 50 of file channel_mapper_table.h.

chan_maps

const ChannelMap roc::audio::chan_maps[chan_map_count]

extern

Defines list of mappings between all supported surround channel mask pairs. Channel mapper will search for appropriate mapping in this list, based on input and output channel masks.

chan_orders

const ChannelList roc::audio::chan_orders[ChanOrder_Max]

extern

Defines mapping of channel order identifier to list of channel positions in corresponding order.

fe_decim_h

const double roc::audio::fe_decim_h[fe_decim_len]

extern

Impulse response of decimation filter with factor of 10.

fe_decim_h_gain

const double roc::audio::fe_decim_h_gain

extern

Filters gain, sum(fe_decim_h).

SampleFormat

const PcmFormat roc::audio::SampleFormat

extern

Sample format description.

SampleMax

const sample_t roc::audio::SampleMax

extern

Maximum possible value of a sample.

SampleMin

const sample_t roc::audio::SampleMin

extern

Minimum possible value of a sample.