better visualizer

This commit is contained in:
2026-02-06 11:08:41 -05:00
parent 8d6b19582c
commit e1dc242b1d
11 changed files with 908 additions and 19 deletions

View File

@@ -7,7 +7,7 @@
import { ensureConfigDir, getConfigFilePath } from "./config-dir"
import { backupConfigFile } from "./config-backup"
import type { AppState, AppSettings, UserPreferences, ThemeColors } from "../types/settings"
import type { AppState, AppSettings, UserPreferences, ThemeColors, VisualizerSettings } from "../types/settings"
import { DEFAULT_THEME } from "../constants/themes"
const APP_STATE_FILE = "app-state.json"
@@ -18,11 +18,20 @@ const LEGACY_PROGRESS_KEY = "podtui_progress"
// --- Defaults ---
const defaultVisualizerSettings: VisualizerSettings = {
bars: 32,
sensitivity: 1,
noiseReduction: 0.77,
lowCutOff: 50,
highCutOff: 10000,
}
const defaultSettings: AppSettings = {
theme: "system",
fontSize: 14,
playbackSpeed: 1,
downloadPath: "",
visualizer: defaultVisualizerSettings,
}
const defaultPreferences: UserPreferences = {

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@@ -0,0 +1,191 @@
/**
* Real-time audio stream reader for visualization.
*
* Spawns a separate ffmpeg process that decodes the same audio URL
* the player is using and outputs raw PCM data (signed 16-bit LE, mono,
* 44100 Hz) to a pipe. The reader accumulates samples in a ring buffer
* and provides them to the caller on demand.
*
* This is independent from the actual playback backend — it's a
* read-only "tap" on the audio for FFT analysis purposes.
*/
/** PCM output format constants */
const SAMPLE_RATE = 44100
const CHANNELS = 1
const BYTES_PER_SAMPLE = 2 // s16le
/** How many samples to buffer (≈1 second) */
const RING_BUFFER_SAMPLES = SAMPLE_RATE
export interface AudioStreamReaderOptions {
/** Audio URL or file path to decode */
url: string
/** Start position in seconds (for seeking sync) */
startPosition?: number
/** Sample rate (default: 44100) */
sampleRate?: number
}
export class AudioStreamReader {
private proc: ReturnType<typeof Bun.spawn> | null = null
private ringBuffer: Float64Array
private writePos = 0
private totalSamplesWritten = 0
private _running = false
private readPromise: Promise<void> | null = null
private url: string
private sampleRate: number
constructor(options: AudioStreamReaderOptions) {
this.url = options.url
this.sampleRate = options.sampleRate ?? SAMPLE_RATE
this.ringBuffer = new Float64Array(RING_BUFFER_SAMPLES)
}
/** Whether the reader is actively reading samples. */
get running(): boolean {
return this._running
}
/** Total number of samples written since start(). */
get samplesWritten(): number {
return this.totalSamplesWritten
}
/**
* Start the ffmpeg decode process and begin reading PCM data.
* @param startPosition Seek position in seconds (default: 0).
*/
start(startPosition = 0): void {
if (this._running) return
if (!Bun.which("ffmpeg")) {
throw new Error("ffmpeg not found — required for audio visualization")
}
const args = [
"ffmpeg",
"-loglevel", "quiet",
]
// Seek before input for network efficiency
if (startPosition > 0) {
args.push("-ss", String(startPosition))
}
args.push(
"-i", this.url,
"-ac", String(CHANNELS),
"-ar", String(this.sampleRate),
"-f", "s16le", // raw signed 16-bit little-endian PCM
"-acodec", "pcm_s16le",
"-", // output to stdout
)
this.proc = Bun.spawn(args, {
stdout: "pipe",
stderr: "ignore",
stdin: "ignore",
})
this._running = true
this.writePos = 0
this.totalSamplesWritten = 0
// Start async reading loop
this.readPromise = this.readLoop()
// Detect process exit
this.proc.exited.then(() => {
this._running = false
}).catch(() => {
this._running = false
})
}
/**
* Read available samples into the provided buffer.
* Returns the number of samples actually copied.
*
* @param out - Float64Array to fill with samples (scaled ~±32768 for cavacore).
* @returns Number of samples written to `out`.
*/
read(out: Float64Array): number {
const available = Math.min(out.length, this.totalSamplesWritten, this.ringBuffer.length)
if (available <= 0) return 0
// Read the most recent `available` samples from the ring buffer
const readStart = (this.writePos - available + this.ringBuffer.length) % this.ringBuffer.length
if (readStart + available <= this.ringBuffer.length) {
// Contiguous read
out.set(this.ringBuffer.subarray(readStart, readStart + available))
} else {
// Wraps around
const firstChunk = this.ringBuffer.length - readStart
out.set(this.ringBuffer.subarray(readStart, this.ringBuffer.length))
out.set(this.ringBuffer.subarray(0, available - firstChunk), firstChunk)
}
return available
}
/**
* Stop the ffmpeg process and clean up.
* Safe to call multiple times.
*/
stop(): void {
this._running = false
if (this.proc) {
try { this.proc.kill() } catch { /* ignore */ }
this.proc = null
}
this.writePos = 0
this.totalSamplesWritten = 0
}
/**
* Restart the reader at a new position (e.g. after a seek).
*/
restart(startPosition = 0): void {
this.stop()
this.start(startPosition)
}
/** Internal: continuously reads stdout from ffmpeg and fills the ring buffer. */
private async readLoop(): Promise<void> {
const stdout = this.proc?.stdout
if (!stdout || typeof stdout === "number") return
const reader = (stdout as ReadableStream<Uint8Array>).getReader()
try {
while (this._running) {
const { done, value } = await reader.read()
if (done || !this._running) break
if (!value || value.byteLength === 0) continue
// Convert raw s16le bytes → Float64Array scaled for cavacore
// Ensure we have an even number of bytes (each sample = 2 bytes)
const sampleCount = Math.floor(value.byteLength / BYTES_PER_SAMPLE)
if (sampleCount === 0) continue
const int16View = new Int16Array(
value.buffer,
value.byteOffset,
sampleCount,
)
// Write samples into ring buffer (as doubles, preserving int16 scale)
for (let i = 0; i < sampleCount; i++) {
this.ringBuffer[this.writePos] = int16View[i] // ±32768 range
this.writePos = (this.writePos + 1) % this.ringBuffer.length
this.totalSamplesWritten++
}
}
} catch {
// Stream ended or process killed — expected during stop()
} finally {
try { reader.releaseLock() } catch { /* ignore */ }
}
}
}

230
src/utils/cavacore.ts Normal file
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@@ -0,0 +1,230 @@
/**
* TypeScript FFI bindings for libcavacore.
*
* Wraps cava's frequency-analysis engine (cavacore) via Bun's dlopen.
* The precompiled shared library ships in src/native/ (dev) and dist/ (prod)
* with fftw3 statically linked — zero native dependencies for end users.
*
* Usage:
* ```ts
* const cava = loadCavaCore()
* if (cava) {
* cava.init({ bars: 32, sampleRate: 44100 })
* const freqs = cava.execute(pcmSamples)
* cava.destroy()
* }
* ```
*/
import { dlopen, FFIType, ptr } from "bun:ffi"
import { existsSync } from "fs"
import { join, dirname } from "path"
// ── Types ────────────────────────────────────────────────────────────
export interface CavaCoreConfig {
/** Number of frequency bars (default: 32) */
bars?: number
/** Audio sample rate in Hz (default: 44100) */
sampleRate?: number
/** Number of audio channels (default: 1 = mono) */
channels?: number
/** Automatic sensitivity: 1 = enabled, 0 = disabled (default: 1) */
autosens?: number
/** Noise reduction factor 0.01.0 (default: 0.77) */
noiseReduction?: number
/** Low frequency cutoff in Hz (default: 50) */
lowCutOff?: number
/** High frequency cutoff in Hz (default: 10000) */
highCutOff?: number
}
const DEFAULTS: Required<CavaCoreConfig> = {
bars: 32,
sampleRate: 44100,
channels: 1,
autosens: 1,
noiseReduction: 0.77,
lowCutOff: 50,
highCutOff: 10000,
}
// eslint-disable-next-line @typescript-eslint/no-explicit-any
type CavaLib = { symbols: Record<string, (...args: any[]) => any>; close(): void }
// ── Library resolution ───────────────────────────────────────────────
function findLibrary(): string | null {
const platform = process.platform
const libName = platform === "darwin"
? "libcavacore.dylib"
: platform === "win32"
? "cavacore.dll"
: "libcavacore.so"
// Candidate paths, in priority order:
// 1. src/native/ (development)
// 2. Same directory as the running executable (dist bundle)
// 3. dist/ relative to cwd
const candidates = [
join(import.meta.dir, "..", "native", libName),
join(dirname(process.execPath), libName),
join(process.cwd(), "dist", libName),
]
for (const candidate of candidates) {
if (existsSync(candidate)) return candidate
}
return null
}
// ── CavaCore class ───────────────────────────────────────────────────
export class CavaCore {
private lib: CavaLib
private plan: ReturnType<CavaLib["symbols"]["cava_init"]> | null = null
private inputBuffer: Float64Array | null = null
private outputBuffer: Float64Array | null = null
private _bars = 0
private _channels = 1
private _destroyed = false
/** Use loadCavaCore() instead of constructing directly. */
constructor(lib: CavaLib) {
this.lib = lib
}
/** Number of frequency bars configured. */
get bars(): number {
return this._bars
}
/** Whether this instance has been initialized (and not yet destroyed). */
get isReady(): boolean {
return this.plan !== null && !this._destroyed
}
/**
* Initialize the cavacore engine with the given configuration.
* Must be called before execute(). Can be called again after destroy()
* to reinitialize with different parameters.
*/
init(config: CavaCoreConfig = {}): void {
if (this.plan) {
this.destroy()
}
const cfg = { ...DEFAULTS, ...config }
this._bars = cfg.bars
this._channels = cfg.channels
this.plan = this.lib.symbols.cava_init(
cfg.bars,
cfg.sampleRate,
cfg.channels,
cfg.autosens,
cfg.noiseReduction,
cfg.lowCutOff,
cfg.highCutOff,
)
if (!this.plan) {
throw new Error("cava_init returned null — initialization failed")
}
// Pre-allocate output buffer (bars * channels)
this.outputBuffer = new Float64Array(cfg.bars * cfg.channels)
this._destroyed = false
}
/**
* Feed PCM samples into cavacore and get frequency bar values back.
*
* @param samples - Float64Array of PCM samples (scaled ~±32768).
* The array length determines the number of samples processed.
* @returns Float64Array of bar values (0.01.0 range, length = bars * channels).
* Returns the same buffer reference each call (overwritten in place).
*/
execute(samples: Float64Array): Float64Array {
if (!this.plan || !this.outputBuffer) {
throw new Error("CavaCore not initialized — call init() first")
}
// Reuse input buffer if same size, otherwise allocate new
if (!this.inputBuffer || this.inputBuffer.length !== samples.length) {
this.inputBuffer = new Float64Array(samples.length)
}
this.inputBuffer.set(samples)
this.lib.symbols.cava_execute(
ptr(this.inputBuffer),
samples.length,
ptr(this.outputBuffer),
this.plan,
)
return this.outputBuffer
}
/**
* Release all native resources. Safe to call multiple times.
* After calling destroy(), init() can be called again to reuse the instance.
*/
destroy(): void {
if (this.plan && !this._destroyed) {
this.lib.symbols.cava_destroy(this.plan)
this.plan = null
this._destroyed = true
}
this.inputBuffer = null
this.outputBuffer = null
}
}
// ── Factory ──────────────────────────────────────────────────────────
/**
* Attempt to load the cavacore shared library and return a CavaCore instance.
* Returns null if the library cannot be found — callers should fall back
* to the static waveform display.
*/
export function loadCavaCore(): CavaCore | null {
try {
const libPath = findLibrary()
if (!libPath) return null
const lib = dlopen(libPath, {
cava_init: {
args: [
FFIType.i32, // bars
FFIType.u32, // rate
FFIType.i32, // channels
FFIType.i32, // autosens
FFIType.double, // noise_reduction
FFIType.i32, // low_cut_off
FFIType.i32, // high_cut_off
],
returns: FFIType.ptr,
},
cava_execute: {
args: [
FFIType.ptr, // cava_in (double*)
FFIType.i32, // samples
FFIType.ptr, // cava_out (double*)
FFIType.ptr, // plan
],
returns: FFIType.void,
},
cava_destroy: {
args: [FFIType.ptr], // plan
returns: FFIType.void,
},
})
return new CavaCore(lib as CavaLib)
} catch {
// Library load failed — missing dylib, wrong arch, etc.
return null
}
}