roc::audio Namespace Reference

Audio frames and audio processing. More...

Classes
class	BuiltinResampler
	Built-in resampler. More...
class	ChannelMapper
	Channel mapper. More...
class	ChannelMapperMatrix
	Channel mapping matrix. More...
class	ChannelMapperReader
	Channel mapper reader. Reads frames from nested reader and maps them to another channel mask. 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...
struct	ChannelPositionName
	Defines string name for channel position. More...
struct	ChannelMaskName
	Defines string name for pre-defined channel mask. More...
struct	ChannelMapRule
	Defines multiplication coefficient for a pair of channels. More...
struct	ChannelMapTable
	Defines multiplication matrix for two channel masks. More...
struct	ChannelOrderTable
	Defines ordered list of channels. More...
class	DecimationResampler
	Decimating resampler. More...
class	Depacketizer
	Depacketizer. More...
class	Fanout
	Fanout. Duplicates audio stream to multiple output writers. More...
struct	FeedbackConfig
	Feedback monitor configuration. More...
class	FeedbackMonitor
	Feedback monitor. More...
class	Frame
	Audio frame. More...
class	FrameFactory
	Frame factory. 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...
class	LatencyMonitor
	Latency monitor. More...
struct	LatencyConfig
	Latency settings. More...
struct	LatencyMetrics
	Latency-related metrics. More...
class	LatencyTuner
	Latency tuner. More...
class	Mixer
	Mixer. Mixes multiple input streams into one output stream. More...
class	NullWriter
	Null writer. More...
struct	PacketizerMetrics
	Metrics of packetizer. More...
class	Packetizer
	Packetizer. More...
class	PcmDecoder
	PCM decoder. More...
class	PcmEncoder
	PCM encoder. More...
struct	PcmTraits
	PCM format meta-information. More...
class	PcmMapper
	PCM format mapper. Convert between PCM formats. More...
class	PcmMapperReader
	Pcm mapper reader. Reads frames from nested reader and maps them to another pcm mask. More...
class	PcmMapperWriter
	Pcm mapper writer. Reads frames from nested writer and maps them to another pcm mask. 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...
struct	ResamplerConfig
	Resampler config. 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 void(*	PcmMapFn) (const uint8_t *in_data, size_t &in_bit_off, uint8_t *out_data, size_t &out_bit_off, size_t n_samples)
	PCM mapping function. More...
typedef float	sample_t
	Raw 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_FrontLeftOfCenter , ChanPos_FrontCenter , ChanPos_FrontRightOfCenter ,   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	LatencyTunerBackend { LatencyTunerBackend_Default , LatencyTunerBackend_Niq , LatencyTunerBackend_E2e }
	Latency tuner backend. Defines which latency we monitor and tune to achieve target. More...
enum	LatencyTunerProfile { LatencyTunerProfile_Default , LatencyTunerProfile_Intact , LatencyTunerProfile_Responsive , LatencyTunerProfile_Gradual }
	Latency tuner profile. Defines whether and how we tune latency on fly to compensate clock drift and jitter. More...
enum	PcmFormat {   PcmFormat_Invalid , PcmFormat_SInt8 , PcmFormat_SInt8_Be , PcmFormat_SInt8_Le ,   PcmFormat_UInt8 , PcmFormat_UInt8_Be , PcmFormat_UInt8_Le , PcmFormat_SInt16 ,   PcmFormat_SInt16_Be , PcmFormat_SInt16_Le , PcmFormat_UInt16 , PcmFormat_UInt16_Be ,   PcmFormat_UInt16_Le , PcmFormat_SInt18 , PcmFormat_SInt18_Be , PcmFormat_SInt18_Le ,   PcmFormat_UInt18 , PcmFormat_UInt18_Be , PcmFormat_UInt18_Le , PcmFormat_SInt18_3 ,   PcmFormat_SInt18_3_Be , PcmFormat_SInt18_3_Le , PcmFormat_UInt18_3 , PcmFormat_UInt18_3_Be ,   PcmFormat_UInt18_3_Le , PcmFormat_SInt18_4 , PcmFormat_SInt18_4_Be , PcmFormat_SInt18_4_Le ,   PcmFormat_UInt18_4 , PcmFormat_UInt18_4_Be , PcmFormat_UInt18_4_Le , PcmFormat_SInt20 ,   PcmFormat_SInt20_Be , PcmFormat_SInt20_Le , PcmFormat_UInt20 , PcmFormat_UInt20_Be ,   PcmFormat_UInt20_Le , PcmFormat_SInt20_3 , PcmFormat_SInt20_3_Be , PcmFormat_SInt20_3_Le ,   PcmFormat_UInt20_3 , PcmFormat_UInt20_3_Be , PcmFormat_UInt20_3_Le , PcmFormat_SInt20_4 ,   PcmFormat_SInt20_4_Be , PcmFormat_SInt20_4_Le , PcmFormat_UInt20_4 , PcmFormat_UInt20_4_Be ,   PcmFormat_UInt20_4_Le , PcmFormat_SInt24 , PcmFormat_SInt24_Be , PcmFormat_SInt24_Le ,   PcmFormat_UInt24 , PcmFormat_UInt24_Be , PcmFormat_UInt24_Le , PcmFormat_SInt24_4 ,   PcmFormat_SInt24_4_Be , PcmFormat_SInt24_4_Le , PcmFormat_UInt24_4 , PcmFormat_UInt24_4_Be ,   PcmFormat_UInt24_4_Le , PcmFormat_SInt32 , PcmFormat_SInt32_Be , PcmFormat_SInt32_Le ,   PcmFormat_UInt32 , PcmFormat_UInt32_Be , PcmFormat_UInt32_Le , PcmFormat_SInt64 ,   PcmFormat_SInt64_Be , PcmFormat_SInt64_Le , PcmFormat_UInt64 , PcmFormat_UInt64_Be ,   PcmFormat_UInt64_Le , PcmFormat_Float32 , PcmFormat_Float32_Be , PcmFormat_Float32_Le ,   PcmFormat_Float64 , PcmFormat_Float64_Be , PcmFormat_Float64_Le , PcmFormat_Max }
	PCM format. Defines PCM sample coding and endian. 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...
enum	SampleFormat { SampleFormat_Invalid , SampleFormat_Pcm }
	Sample format. Defines representation of samples in memory. Does not define sample rate and channel set. 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_pos_to_str (ChannelPosition)
	Get string name from channel position. More...
const char *	channel_mask_to_str (ChannelMask)
	Get string name from channel mask. More...
void	format_channel_set (const ChannelSet &ch_set, core::StringBuilder &bld)
	Format ChannelSet to string. More...
const char *	latency_tuner_backend_to_str (LatencyTunerBackend backend)
	Get string name of latency backend. More...
const char *	latency_tuner_profile_to_str (LatencyTunerProfile tuner)
	Get string name of latency tuner. More...
PcmMapFn	pcm_format_mapfn (PcmFormat in_format, PcmFormat out_format)
	Get mapping function for given PCM format pair. More...
PcmTraits	pcm_format_traits (PcmFormat format)
	Get format traits for given PCM format. More...
const char *	pcm_format_to_str (PcmFormat format)
	Get string name of PCM format. More...
PcmFormat	pcm_format_from_str (const char *str)
	Get PCM format from string name. More...
ROC_ATTR_NODISCARD bool	print_supported ()
	Print supported encodings. More...
const char *	resampler_backend_to_str (ResamplerBackend backend)
	Get string name of resampler backend. More...
const char *	resampler_profile_to_str (ResamplerProfile profile)
	Get string name of resampler profile. More...
const char *	sample_format_to_str (SampleFormat format)
	Get string name of sample format. More...
ROC_ATTR_NODISCARD bool	parse_sample_spec (const char *str, SampleSpec &result)
	Parse sample spec from string. More...
void	format_sample_spec (const SampleSpec &sample_spec, core::StringBuilder &bld)
	Format sample spec to string. More...

Variables
const ChannelPositionName	ChanPositionNames [ChanPos_Max]
	Defines mapping between channel position and its name. More...
const ChannelMaskName	ChanMaskNames [17]
	Defines mapping between channel mask and its name. More...
const ChannelOrderTable	ChanOrderTables [ChanOrder_Max]
	Defines mapping of channel order identifier to list of channel positions in corresponding order. More...
const ChannelMapTable	ChanMapTables [71]
	Defines list of mappings between all supported surround channel mask pairs. 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	Sample_RawFormat
	Format description for raw audio samples. More...
const sample_t	Sample_Min
	Minimum possible value of a raw sample. More...
const sample_t	Sample_Max
	Maximum possible value of a raw 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 148 of file channel_defs.h.

PcmMapFn

typedef void(* roc::audio::PcmMapFn) (const uint8_t *in_data, size_t &in_bit_off, uint8_t *out_data, size_t &out_bit_off, size_t n_samples)

PCM mapping function.

Definition at line 235 of file pcm_format.h.

sample_t

typedef float roc::audio::sample_t

Raw 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 filtered 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 indices for mono / stereo / surround sound.

Note

Despite 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_FrontLeftOfCenter	Front left of center (FLC).
ChanPos_FrontCenter	Front center (FC).
ChanPos_FrontRightOfCenter	Front right of center (FRC).
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.

LatencyTunerBackend

enum roc::audio::LatencyTunerBackend

Latency tuner backend. Defines which latency we monitor and tune to achieve target.

Enumerator
LatencyTunerBackend_Default	Deduce best default for given settings.
LatencyTunerBackend_Niq	Latency is Network Incoming Queue length. Calculated on receiver without use of any signaling protocol. Reported back to sender via RTCP XR.
LatencyTunerBackend_E2e	Latency is End-to-end delay. Can on receiver if RTCP XR is supported by both sides. Reported back to sender via RTCP XR.

Definition at line 29 of file latency_tuner.h.

LatencyTunerProfile

enum roc::audio::LatencyTunerProfile

Latency tuner profile. Defines whether and how we tune latency on fly to compensate clock drift and jitter.

Enumerator
LatencyTunerProfile_Default	Deduce best default for given settings.
LatencyTunerProfile_Intact	Do not tune latency.
LatencyTunerProfile_Responsive	Fast and responsive tuning. Good for lower network latency and jitter.
LatencyTunerProfile_Gradual	Slow and smooth tuning. Good for higher network latency and jitter.

Definition at line 47 of file latency_tuner.h.

PcmFormat

enum roc::audio::PcmFormat

PCM format. Defines PCM sample coding and endian.

Enumerator
PcmFormat_Invalid	Invalid format.
PcmFormat_SInt8	8-bit signed integer, native endian.
PcmFormat_SInt8_Be	8-bit signed integer, big endian.
PcmFormat_SInt8_Le	8-bit signed integer, little endian.
PcmFormat_UInt8	8-bit unsigned integer, native endian.
PcmFormat_UInt8_Be	8-bit unsigned integer, big endian.
PcmFormat_UInt8_Le	8-bit unsigned integer, little endian.
PcmFormat_SInt16	16-bit signed integer, native endian.
PcmFormat_SInt16_Be	16-bit signed integer, big endian.
PcmFormat_SInt16_Le	16-bit signed integer, little endian.
PcmFormat_UInt16	16-bit unsigned integer, native endian.
PcmFormat_UInt16_Be	16-bit unsigned integer, big endian.
PcmFormat_UInt16_Le	16-bit unsigned integer, little endian.
PcmFormat_SInt18	18-bit signed integer (2.25 bytes), native endian.
PcmFormat_SInt18_Be	18-bit signed integer (2.25 bytes), big endian.
PcmFormat_SInt18_Le	18-bit signed integer (2.25 bytes), little endian.
PcmFormat_UInt18	18-bit unsigned integer (2.25 bytes), native endian.
PcmFormat_UInt18_Be	18-bit unsigned integer (2.25 bytes), big endian.
PcmFormat_UInt18_Le	18-bit unsigned integer (2.25 bytes), little endian.
PcmFormat_SInt18_3	18-bit signed integer, in low bits of 3-byte container, native endian.
PcmFormat_SInt18_3_Be	18-bit signed integer, in low bits of 3-byte container, big endian.
PcmFormat_SInt18_3_Le	18-bit signed integer, in low bits of 3-byte container, little endian.
PcmFormat_UInt18_3	18-bit unsigned integer, in low bits of 3-byte container, native endian.
PcmFormat_UInt18_3_Be	18-bit unsigned integer, in low bits of 3-byte container, big endian.
PcmFormat_UInt18_3_Le	18-bit unsigned integer, in low bits of 3-byte container, little endian.
PcmFormat_SInt18_4	18-bit signed integer, in low bits of 4-byte container, native endian.
PcmFormat_SInt18_4_Be	18-bit signed integer, in low bits of 4-byte container, big endian.
PcmFormat_SInt18_4_Le	18-bit signed integer, in low bits of 4-byte container, little endian.
PcmFormat_UInt18_4	18-bit unsigned integer, in low bits of 4-byte container, native endian.
PcmFormat_UInt18_4_Be	18-bit unsigned integer, in low bits of 4-byte container, big endian.
PcmFormat_UInt18_4_Le	18-bit unsigned integer, in low bits of 4-byte container, little endian.
PcmFormat_SInt20	20-bit signed integer (2.5 bytes), native endian.
PcmFormat_SInt20_Be	20-bit signed integer (2.5 bytes), big endian.
PcmFormat_SInt20_Le	20-bit signed integer (2.5 bytes), little endian.
PcmFormat_UInt20	20-bit unsigned integer (2.5 bytes), native endian.
PcmFormat_UInt20_Be	20-bit unsigned integer (2.5 bytes), big endian.
PcmFormat_UInt20_Le	20-bit unsigned integer (2.5 bytes), little endian.
PcmFormat_SInt20_3	20-bit signed integer, in low bits of 3-byte container, native endian.
PcmFormat_SInt20_3_Be	20-bit signed integer, in low bits of 3-byte container, big endian.
PcmFormat_SInt20_3_Le	20-bit signed integer, in low bits of 3-byte container, little endian.
PcmFormat_UInt20_3	20-bit unsigned integer, in low bits of 3-byte container, native endian.
PcmFormat_UInt20_3_Be	20-bit unsigned integer, in low bits of 3-byte container, big endian.
PcmFormat_UInt20_3_Le	20-bit unsigned integer, in low bits of 3-byte container, little endian.
PcmFormat_SInt20_4	20-bit signed integer, in low bits of 4-byte container, native endian.
PcmFormat_SInt20_4_Be	20-bit signed integer, in low bits of 4-byte container, big endian.
PcmFormat_SInt20_4_Le	20-bit signed integer, in low bits of 4-byte container, little endian.
PcmFormat_UInt20_4	20-bit unsigned integer, in low bits of 4-byte container, native endian.
PcmFormat_UInt20_4_Be	20-bit unsigned integer, in low bits of 4-byte container, big endian.
PcmFormat_UInt20_4_Le	20-bit unsigned integer, in low bits of 4-byte container, little endian.
PcmFormat_SInt24	24-bit signed integer (3 bytes), native endian.
PcmFormat_SInt24_Be	24-bit signed integer (3 bytes), big endian.
PcmFormat_SInt24_Le	24-bit signed integer (3 bytes), little endian.
PcmFormat_UInt24	24-bit unsigned integer (3 bytes), native endian.
PcmFormat_UInt24_Be	24-bit unsigned integer (3 bytes), big endian.
PcmFormat_UInt24_Le	24-bit unsigned integer (3 bytes), little endian.
PcmFormat_SInt24_4	24-bit signed integer, in low bits of 4-byte container, native endian.
PcmFormat_SInt24_4_Be	24-bit signed integer, in low bits of 4-byte container, big endian.
PcmFormat_SInt24_4_Le	24-bit signed integer, in low bits of 4-byte container, little endian.
PcmFormat_UInt24_4	24-bit unsigned integer, in low bits of 4-byte container, native endian.
PcmFormat_UInt24_4_Be	24-bit unsigned integer, in low bits of 4-byte container, big endian.
PcmFormat_UInt24_4_Le	24-bit unsigned integer, in low bits of 4-byte container, little endian.
PcmFormat_SInt32	32-bit signed integer, native endian.
PcmFormat_SInt32_Be	32-bit signed integer, big endian.
PcmFormat_SInt32_Le	32-bit signed integer, little endian.
PcmFormat_UInt32	32-bit unsigned integer, native endian.
PcmFormat_UInt32_Be	32-bit unsigned integer, big endian.
PcmFormat_UInt32_Le	32-bit unsigned integer, little endian.
PcmFormat_SInt64	64-bit signed integer, native endian.
PcmFormat_SInt64_Be	64-bit signed integer, big endian.
PcmFormat_SInt64_Le	64-bit signed integer, little endian.
PcmFormat_UInt64	64-bit unsigned integer, native endian.
PcmFormat_UInt64_Be	64-bit unsigned integer, big endian.
PcmFormat_UInt64_Le	64-bit unsigned integer, little endian.
PcmFormat_Float32	32-bit IEEE-754 float in range [-1.0; +1.0], native endian.
PcmFormat_Float32_Be	32-bit IEEE-754 float in range [-1.0; +1.0], big endian.
PcmFormat_Float32_Le	32-bit IEEE-754 float in range [-1.0; +1.0], little endian.
PcmFormat_Float64	64-bit IEEE-754 float in range [-1.0; +1.0], native endian.
PcmFormat_Float64_Be	64-bit IEEE-754 float in range [-1.0; +1.0], big endian.
PcmFormat_Float64_Le	64-bit IEEE-754 float in range [-1.0; +1.0], little endian.
PcmFormat_Max	Maximum enum value.

Definition at line 22 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 21 of file resampler_config.h.

ResamplerProfile

enum roc::audio::ResamplerProfile

Resampler parameters presets.

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

Definition at line 43 of file resampler_config.h.

SampleFormat

enum roc::audio::SampleFormat

Sample format. Defines representation of samples in memory. Does not define sample rate and channel set.

Enumerator
SampleFormat_Invalid	Invalid format.
SampleFormat_Pcm	Interleaved PCM format. What specific PCM coding and endian is used is defined by PcmFormat enum.

Definition at line 23 of file sample_format.h.

Function Documentation

channel_layout_to_str()

const char* roc::audio::channel_layout_to_str

(

ChannelLayout

)

Get string name of channel layout.

channel_mask_to_str()

const char* roc::audio::channel_mask_to_str

(

ChannelMask

)

Get string name from channel mask.

channel_order_to_str()

const char* roc::audio::channel_order_to_str

(

ChannelOrder

)

Get string name of channel order.

channel_pos_to_str()

const char* roc::audio::channel_pos_to_str

(

ChannelPosition

)

Get string name from channel position.

format_channel_set()

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

Format ChannelSet to string.

format_sample_spec()

void roc::audio::format_sample_spec	(	const SampleSpec &	sample_spec,
		core::StringBuilder &	bld
	)

Format sample spec to string.

latency_tuner_backend_to_str()

const char* roc::audio::latency_tuner_backend_to_str

(

LatencyTunerBackend

backend

)

Get string name of latency backend.

latency_tuner_profile_to_str()

const char* roc::audio::latency_tuner_profile_to_str

(

LatencyTunerProfile

tuner

)

Get string name of latency tuner.

parse_sample_spec()

ROC_ATTR_NODISCARD bool roc::audio::parse_sample_spec	(	const char *	str,
		SampleSpec &	result
	)

Parse sample spec from string.

Remarks

The input string should have the form:

• "<format>/<rate>/<channels>"

Where:

• "<format>" is string name of sample format (e.g. "s16")
• "<rate>" is a positive integer
• "<channels>" can be: "<surround preset>", "<surround channel list>", "<multitrack mask>", "<multitrack channel list>"
• "<surround preset>" is a string name of predefined surround channel mask, e.g. "stereo", "surround4.1", etc.
• "<surround channel list>" is comma-separated list of surround channel names, e.g. "FL,FC,FR"
• "<multitrack mask>" is a 1024-bit hex mask defining which tracks are enabled, e.g. "0xAA00BB00"
• "<multitrack channel list>" is a comma-separated list of track numbers or ranges, e.g. "1,2,5-8"

Each of the three components ("<format>", "<rate>", "<channels>") may be set to "-", which means "keep unset".

All four forms of "<channels>" component are alternative ways to represent a bitmask of enabled channels or tracks. The order of channels does no matter.

Examples:

• "s16/44100/stereo"
• "s18_4le/48000/FL,FC,FR"
• "f32/96000/1,2,10-20,31"
• "f32/96000/0xA0000000FFFF0000000C"
• "-/44100/-"
• "-/-/-"

Returns

false if string can't be parsed.

pcm_format_from_str()

PcmFormat roc::audio::pcm_format_from_str

(

const char *

str

)

Get PCM format from string name.

pcm_format_mapfn()

PcmMapFn roc::audio::pcm_format_mapfn	(	PcmFormat	in_format,
		PcmFormat	out_format
	)

Get mapping function for given PCM format pair.

pcm_format_to_str()

const char* roc::audio::pcm_format_to_str

(

PcmFormat

format

)

Get string name of PCM format.

pcm_format_traits()

PcmTraits roc::audio::pcm_format_traits

(

PcmFormat

format

)

Get format traits for given PCM format.

print_supported()

ROC_ATTR_NODISCARD bool roc::audio::print_supported

(

)

Print supported encodings.

resampler_backend_to_str()

const char* roc::audio::resampler_backend_to_str

(

ResamplerBackend

backend

)

Get string name of resampler backend.

resampler_profile_to_str()

const char* roc::audio::resampler_profile_to_str

(

ResamplerProfile

profile

)

Get string name of resampler profile.

sample_format_to_str()

const char* roc::audio::sample_format_to_str

(

SampleFormat

format

)

Get string name of sample format.

Variable Documentation

ChanMapTables

const ChannelMapTable roc::audio::ChanMapTables[71]

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.

These tables define downmixing coefficients for mapping between different surround channel sets. They are used for both downmixing and upmixing.

Mappings should be ordered from smaller to larger masks, because channel mapper will use the very first pair that covers both output and input masks.

Only downmixing mappings are defined. Upmixing mappings are derived automatically from them.

Technically, some of the mappings are actually partially downmixing, and partially upmixing, for example mapping from 6.x to 5.1.x downmixes some channels and upmixes others. However, for convenience, we still call it "downmixing" because we consider 6.x to be a "larger" channel set than 5.x.

For groups of similar layouts, when possible, mappings are defined only for the most complete layout, and are automatically reused for the rest. For example, mappings for 5.1.2 may be automatically used for 5.1 and 5.0.

These tables were originally based on the following documents (and then extended to cover more combinations):

• ITU-R BS.775-1, ANNEX 4
• A/52, Digital Audio Compression (AC-3) (E-AC-3) Standard, sections 6.1.12 and 7.8

Useful links: https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.775-1-199407-S!!PDF-E.pdf https://prdatsc.wpenginepowered.com/wp-content/uploads/2021/04/A52-2018.pdf https://www.audiokinetic.com/en/library/edge/?source=Help&id=downmix_tables https://trac.ffmpeg.org/wiki/AudioChannelManipulation https://superuser.com/questions/852400

ChanMaskNames

const ChannelMaskName roc::audio::ChanMaskNames[17]

extern

Defines mapping between channel mask and its name.

ChanOrderTables

const ChannelOrderTable roc::audio::ChanOrderTables[ChanOrder_Max]

extern

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

When channel order is applied, the list of channels is filtered, and only channels present in channel mask are kept. The resulting filtered list defines how channels are placed in memory.

This allows us to define single list that for multiple channel masks. For example, ITU/SMPTE defines order for each channel mask (5.x, 7.x), but we define only one list ChanOrder_Smpte, and after filtering it becomes suitable for each of the masks.

The opposite is also true: if some channel is missing from the order's list, it is considered unsupported by the order and is zeroized.

Links: https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.2102-0-201701-I!!PDF-E.pdf

ChanPositionNames

const ChannelPositionName roc::audio::ChanPositionNames[ChanPos_Max]

extern

Defines mapping between channel position and its name.

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).

Sample_Max

const sample_t roc::audio::Sample_Max

extern

Maximum possible value of a raw sample.

Sample_Min

const sample_t roc::audio::Sample_Min

extern

Minimum possible value of a raw sample.

Sample_RawFormat

const PcmFormat roc::audio::Sample_RawFormat

extern

Format description for raw audio samples.