audio

Documentation

Index

• func AdjustChannels(iChs, oChs int, audioFrames []float32) []float32
• func AdjustVolume(volume float32, aBuffer []float32)
• type DefaultRouter
  • func NewDefaultRouter() (*DefaultRouter, error)
  • func (r *DefaultRouter) AddSink(name string, s Sink, enabled bool) error
  • func (r *DefaultRouter) Close()
  • func (r *DefaultRouter) EnableSink(name string, enabled bool) error
  • func (r *DefaultRouter) Flush()
  • func (r *DefaultRouter) RemoveSink(name string) error
  • func (r *DefaultRouter) Sink(name string) (Sink, bool, error)
  • func (r *DefaultRouter) Write(msg Msg) SinkErrors
• type DefaultSelector
  • func NewDefaultSelector() (*DefaultSelector, error)
  • func (s *DefaultSelector) AddSource(name string, src Source)
  • func (s *DefaultSelector) Close()
  • func (s *DefaultSelector) RemoveSource(name string) error
  • func (s *DefaultSelector) SetOnDataCb(cb OnDataCb)
  • func (s *DefaultSelector) SetSource(name string) error
• type Msg
• type Node
• type OnDataCb
• type Router
• type Selector
• type Sink
• type SinkError
• type SinkErrors
• type Source
• type Token

Functions

func AdjustChannels

func AdjustChannels(iChs, oChs int, audioFrames []float32) []float32

AdjustChannels is a helper function which will either add or remove a channel (e.g. converting from Mono to Stereo or vice versa).

func AdjustVolume

func AdjustVolume(volume float32, aBuffer []float32)

AdjustVolume adjusts the volume in all the audio frames within an audio buffer

Types

type DefaultRouter

type DefaultRouter struct {
	sync.RWMutex // for map & variables
	// contains filtered or unexported fields
}

DefaultRouter is the standard manager for audio sinks.

func NewDefaultRouter

func NewDefaultRouter() (*DefaultRouter, error)

NewDefaultRouter returns an initialized default router for audio sinks.

func (*DefaultRouter) AddSink

func (r *DefaultRouter) AddSink(name string, s Sink, enabled bool) error

AddSink adds an audio device which satisfies the Sink interface. When marked as enabled, incoming audio Msgs will be written to this device.

func (*DefaultRouter) Close

func (r *DefaultRouter) Close()

Close disables and closes all the Sinks of the router.

func (*DefaultRouter) EnableSink

func (r *DefaultRouter) EnableSink(name string, enabled bool) error

EnableSink will mark the audio Sink as enabled, so that incoming audio Msgs will be written to it.

func (*DefaultRouter) Flush

func (r *DefaultRouter) Flush()

Flush flushes the buffers of all enabled sinks.

func (*DefaultRouter) RemoveSink

func (r *DefaultRouter) RemoveSink(name string) error

RemoveSink removes an audio sink from the router.

func (*DefaultRouter) Sink

func (r *DefaultRouter) Sink(name string) (Sink, bool, error)

Sink returns the audio sink object. The boolean return value indicates if the sink is currently enabled. If no sink is found under the specified name, an error will be returned.

func (*DefaultRouter) Write

func (r *DefaultRouter) Write(msg Msg) SinkErrors

Write will write the Msg to all enabled audio sinks.

type DefaultSelector

type DefaultSelector struct {
	sync.Mutex
	// contains filtered or unexported fields
}

DefaultSelector is the default implementation of an audio Selector.

func NewDefaultSelector

func NewDefaultSelector() (*DefaultSelector, error)

NewDefaultSelector returns an initialized, but empty DefaultSelector.

func (*DefaultSelector) AddSource

func (s *DefaultSelector) AddSource(name string, src Source)

AddSource adds an audio device which implements the audio.Source interface to the Selector.

func (*DefaultSelector) Close

func (s *DefaultSelector) Close()

Close disables and closes all the Sources of the selector.

func (*DefaultSelector) RemoveSource

func (s *DefaultSelector) RemoveSource(name string) error

RemoveSource removes an audio Source from the Selector.

func (*DefaultSelector) SetOnDataCb

func (s *DefaultSelector) SetOnDataCb(cb OnDataCb)

SetOnDataCb sets the callback function will will be executed when new audio msgs are available from the selected source.

func (*DefaultSelector) SetSource

func (s *DefaultSelector) SetSource(name string) error

SetSource selects the audio source from which data data will be provided (through the OnDataCb callback).

type Msg

type Msg struct {
	Data       []float32              // audio data, float32 interleaved (if stereo)
	Samplerate float64                // samplerate, e.g. 48000Hz
	Channels   int                    // most of the time either 1 (mono) or 2 (stereo)
	Frames     int                    // Number of Frames in the buffer
	EOF        bool                   // End of File
	Metadata   map[string]interface{} // storage for passing any kind of data along the audio Msg
}

Msg contains an audio buffer with it's metadata. Msgs are internally used to pass the data from the source, through the audio nodes to the audio sink(s).

type Node

type Node interface {
	Write(Msg) error // Write data into the Node
	SetCb(OnDataCb)  // Set the callback which will be executed when processing has finished.
}

Node is the interface for an audio node. Nodes are typically located in an audio Chain between the Source and the Sink and perform custom processing on (Audio)Msgs.

type OnDataCb

type OnDataCb func(Msg)

OnDataCb is a callback function which will be called by an audio source when new data is available

type Router

type Router interface {
	AddSink(string, Sink, bool) error
	RemoveSink(string) error
	Sink(string) (Sink, bool, error)
	EnableSink(string, bool) error
	Write(Msg) SinkErrors
	Close()
	Flush()
}

Router manages several audio sinks. It allows to write incoming audio Messages to serveral sinks (e.g. speakers, files, network..etc).

type Selector

type Selector interface {
	AddSource(string, Source)
	RemoveSource(string) error
	SetSource(string) error
	SetOnDataCb(OnDataCb)
	Close()
}

Selector manages several audio sources. Whenever the selected source (network, microphone..etc) has new data available the provided OnDataCb Callback will be executed.

type Sink

type Sink interface {
	Start() error
	Stop() error
	Close() error
	SetVolume(float32)
	Volume() float32
	Write(Msg) error
	Flush()
}

Sink is the interface which is implemented by an audio sink. This could be an Audio player or a file for recording.

type SinkError

type SinkError struct {
	Sink  Sink
	Error error
}

SinkError is an Error which is used when data could not be written to a particular audio Sink.

type SinkErrors

type SinkErrors []*SinkError

SinkErrors is a convenience type which represents a slice of SinkError.

type Source

type Source interface {
	Start() error
	Stop() error
	Close() error
	SetCb(OnDataCb)
}

Source is the interface which is implemented by an audio source. This could be streaming data received from a network connection, a local audio source (e.g. microphone) or a local file.

type Token

type Token struct {
	*sync.WaitGroup
}

Token contains a sync.Waitgroup and is used with an audio sink. The token will indicate the application to wait until further audio buffers can be enqueued into the sink.