Documentation
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Index ¶
Constants ¶
const ChunkBytes = WindowSize * 2 * 2
ChunkBytes is the number of raw bytes per FFT frame (stereo, 16-bit). 2048 samples × 2 channels × 2 bytes = 8192.
const NumBands = 64
NumBands is the number of frequency bands in FFT output.
const WindowSize = 2048
WindowSize is the number of mono samples per FFT frame. 2048 at 44100 Hz = ~46 ms, a good latency/resolution tradeoff.
Variables ¶
var DefaultFormat = PCMFormat{SampleRate: 44100, Channels: 2, BitDepth: 16}
DefaultFormat is librespot's default output: 44100 Hz, stereo, 16-bit signed LE.
Functions ¶
func DecodeFrame ¶
func DecodeFrame(r io.Reader, fd *FrequencyData) error
DecodeFrame reads a fixed-size binary frame from r into fd.
func EncodeFrame ¶
func EncodeFrame(w io.Writer, fd *FrequencyData) error
EncodeFrame writes a FrequencyData as a fixed-size binary frame to w.
Types ¶
type Analyzer ¶
type Analyzer struct {
// contains filtered or unexported fields
}
Analyzer performs FFT analysis on PCM audio chunks and produces FrequencyData.
func NewAnalyzer ¶
NewAnalyzer creates an Analyzer with a precomputed Hann window of the given size.
func (*Analyzer) Analyze ¶
func (a *Analyzer) Analyze(samples []int16) FrequencyData
Analyze takes interleaved stereo int16 PCM samples and returns FrequencyData. The samples slice must contain at least WindowSize*2 values (stereo pairs).
type FrequencyData ¶
type FrequencyData struct {
Bands [NumBands]float32 // log-spaced frequency bands, normalized 0.0–1.0
Peak float32 // overall peak amplitude this frame
Bass float32 // average of bands 0–7
Mid float32 // average of bands 8–31
High float32 // average of bands 32–63
ProgressMs int32 // playback progress derived from PCM sample count
}
FrequencyData holds FFT output mapped to visualization-friendly bands.
func (*FrequencyData) ComputeConvenienceFields ¶
func (fd *FrequencyData) ComputeConvenienceFields()
ComputeConvenienceFields fills Bass, Mid, and High from Bands.
type Receiver ¶
type Receiver struct {
// contains filtered or unexported fields
}
Receiver listens on a unix socket for FrequencyData from the audio worker.
func NewReceiver ¶
func NewReceiver() *Receiver
NewReceiver creates a Receiver with an auto-generated socket path.
func (*Receiver) Latest ¶
func (r *Receiver) Latest() *FrequencyData
Latest returns the most recent FrequencyData, or nil if no fresh data. Returns nil if the last frame is older than 150ms (e.g., paused). Thread-safe; called from the Bubble Tea goroutine.
func (*Receiver) SocketPath ¶
SocketPath returns the path for the audio worker to connect to.
Source Files