Files
beefcarver e30ca09627 refactor!: rename somafm-tui to beefy-player
The app is now a general internet-radio player rather than a SomaFM client, so the package, console script, MPRIS identity, mpv namespaces, macOS tap names, XDG directories and docs all move to beefy-player.

Environment variables are now BEEFY_* (the old SOMAFM_* spellings are still honoured) and an existing ~/.config/somafm-tui/config.json is migrated on first run, so favourites and volume survive the rename.

The visible interface is untouched: same layout, same logo, same keys.
2026-11-03 16:10:25 -05:00

880 lines
33 KiB
Python

"""Spectrum analyser.
The audio you hear is played by mpv. The *synced* mode captures the real
output of the sound card mpv is playing to, so the bars follow exactly what
leaves the speakers (status ``SYNC``).
That capture is platform specific:
* **Linux** — ``parec`` records the PulseAudio/PipeWire monitor of the default
sink (or ``BEEFY_SPECTRUM_DEVICE``).
* **macOS** — a native Core Audio *process tap* records the default output
device (see :mod:`beefy_player.macos_tap`). Nothing to install: no virtual
loopback, no Multi-Output Device, no helper binary. macOS asks for
**System Audio Recording** permission the first time; while it is missing
the tap delivers silence, which is treated as a failed capture.
If no output capture is available we fall back to a muted second ffmpeg decode
of the stream (status ``FFT``; it can drift relative to playback), and finally
to a synthesized show (``SIM``) so the UI stays alive.
"""
from __future__ import annotations
import contextlib
import math
import os
import select
import shutil
import subprocess
import sys
import threading
import time
from dataclasses import dataclass
import numpy as np
from . import macos_tap
from .config import USER_AGENT, env_var
SAMPLE_RATE = 44100
FFT_SIZE = 2048
READ_BYTES = 4096 # 2048 mono s16le samples
BAND_COUNT = 72
WAVE_POINTS = 192
MIN_FREQ = 35.0
MAX_FREQ = 16000.0
SOURCE_MODES = ("auto", "monitor", "stream", "sim")
#: ~46 ms of all-zero audio per block; give an output capture ~6 s to prove
#: itself before falling back to the stream tap. This only applies before the
#: capture has ever delivered real audio. Once a capture has worked, silence
#: means the output really is silent (or mpv is rebuffering), so SYNC is kept
#: and the bars simply fall instead of switching to the drifting stream tap.
SILENT_MONITOR_BLOCKS = 130
#: How long a monitor may deliver no data at all before the stream tap takes
#: over. Kept longer than a normal station change.
MONITOR_IDLE_SECONDS = 10.0
#: How often a quiet monitor pipe is polled so stop/URL changes stay responsive.
MONITOR_POLL_SECONDS = 0.5
#: Frames per analysis block for the macOS tap (float32, ~43 ms at 48 kHz).
TAP_BLOCK_FRAMES = 2048
#: Give up (for now) on the tap when the output renders nothing for this long.
#: macOS only drives a tap while the output device is playing, so this is also
#: the window playback gets to start before the stream tap takes over.
TAP_IDLE_SECONDS = 10.0
#: How long the stream tap covers for us before an output capture is retried.
TAP_RETRY_SECONDS = 60.0
@dataclass(frozen=True)
class Frame:
bands: tuple[float, ...]
peaks: tuple[float, ...]
wave: tuple[float, ...]
level: float
status: str # "monitor" | "live" | "sim" | "idle" | "off"
@property
def is_live(self) -> bool:
return self.status in ("monitor", "live")
@property
def label(self) -> str:
return {
"monitor": "SYNC",
"live": "FFT",
"sim": "SIM",
"idle": "IDLE",
"off": "OFF",
}.get(self.status, self.status.upper())
class SpectrumEngine:
def __init__(
self,
bands: int = BAND_COUNT,
sample_rate: int = SAMPLE_RATE,
fft_size: int = FFT_SIZE,
wave_points: int = WAVE_POINTS,
ffmpeg_path: str | None = None,
source_mode: str = "auto",
) -> None:
self.band_count = bands
self.sample_rate = sample_rate
self.fft_size = fft_size
self.wave_points = wave_points
self.source_mode = source_mode if source_mode in SOURCE_MODES else "auto"
self._ffmpeg = ffmpeg_path if ffmpeg_path is not None else shutil.which("ffmpeg")
self._parec = shutil.which("parec")
self._pactl = shutil.which("pactl")
self._darwin = sys.platform == "darwin"
self._window = np.hanning(fft_size).astype(np.float32)
self._groups = self._make_groups()
self._history = np.zeros(fft_size, dtype=np.float32)
self._levels = np.zeros(bands, dtype=np.float32)
self._peaks = np.zeros(bands, dtype=np.float32)
self._wave = np.zeros(wave_points, dtype=np.float32)
self._level = 0.0
self._gain = -24.0
self._status = "idle"
self._url: str | None = None
self._proc: subprocess.Popen[bytes] | None = None
self._capture_kind: str | None = None
#: Incremented whenever the source changes; captures from an older
#: generation must not affect the new one (or latch a failure).
self._generation = 0
self._reset_pending = False
#: True once any output capture has ever delivered real audio. A later
#: silent capture is then a gap, not a misconfigured device.
self._monitor_worked = False
self._monitor_failed = False
#: Next time an output capture may be tried (shared by parec and tap).
self._tap_retry_at = 0.0
#: Why ``_capture`` last returned ("eof", "idle", "silent", ...).
self._capture_reason = "eof"
self._monitor_device_cache: str | None = None
self._notice: str | None = None
self._lock = threading.Lock()
self._stop = threading.Event()
self._thread: threading.Thread | None = None
self._rng = np.random.default_rng()
self._sim_phase = 0.0
# ------------------------------------------------------------------ #
# public API
# ------------------------------------------------------------------ #
@property
def ffmpeg_available(self) -> bool:
return bool(self._ffmpeg)
@property
def monitor_available(self) -> bool:
return not self._monitor_failed and self._monitor_kind() is not None
def start(self) -> None:
if self._thread is not None:
return
self._thread = threading.Thread(
target=self._run, name="beefy-player-spectrum", daemon=True
)
self._thread.start()
def set_source(self, url: str | None) -> None:
"""Start analysing playback, or idle when ``url`` is ``None``.
A station change is a clean slate: any capture belonging to the old
station is retired, a previous monitor failure is forgotten, and the
analyser's display state is reset. That way every tune gets a fresh
chance to lock onto the real output (SYNC) instead of inheriting the
drifting stream tap (FFT) or the synthesized fallback (SIM).
"""
url = url or None
with self._lock:
changed = url != self._url
self._url = url
if changed:
self._request_reset()
if url is None:
self._status = "idle"
if changed:
# Unblock a stream read and retire a subprocess monitor. A tap has
# no process; its generation check makes it stop and restart.
self._kill_proc()
def reset(self) -> None:
"""Give the output capture a clean slate (called when tuning).
Forgets a previous monitor failure - including a hard one that set
``_monitor_failed`` - and clears the displayed state, so the next
capture may use the real output (SYNC) again. Unlike :meth:`set_source`
this does not change the source, so re-tuning the same station works.
"""
with self._lock:
self._request_reset()
self._kill_proc()
def snapshot(self) -> Frame:
with self._lock:
return Frame(
bands=tuple(float(v) for v in self._levels),
peaks=tuple(float(v) for v in self._peaks),
wave=tuple(float(v) for v in self._wave),
level=float(self._level),
status=self._status,
)
def take_notice(self) -> str | None:
"""One-shot message for the UI (e.g. macOS audio-capture permission)."""
with self._lock:
notice, self._notice = self._notice, None
return notice
def stop(self) -> None:
self._stop.set()
self._kill_proc()
thread = self._thread
if thread is not None and thread.is_alive():
thread.join(timeout=2.0)
self._thread = None
with self._lock:
self._status = "off"
# ------------------------------------------------------------------ #
# internals
# ------------------------------------------------------------------ #
def _make_groups(self) -> list[tuple[int, int]]:
freqs = np.fft.rfftfreq(self.fft_size, 1.0 / self.sample_rate)
top = min(MAX_FREQ, self.sample_rate / 2 - 100)
edges = np.geomspace(MIN_FREQ, top, self.band_count + 1)
groups: list[tuple[int, int]] = []
last = len(freqs) - 1
for index in range(self.band_count):
lo = int(np.searchsorted(freqs, edges[index], side="left"))
hi = int(np.searchsorted(freqs, edges[index + 1], side="left"))
lo = min(max(lo, 0), last)
hi = min(max(hi, lo + 1), len(freqs))
groups.append((lo, hi))
return groups
def _read_url(self) -> str | None:
with self._lock:
return self._url
def _request_reset(self) -> None:
"""Arm a clean restart; the caller must hold ``self._lock``."""
self._generation += 1
self._reset_pending = True
self._monitor_failed = False
self._tap_retry_at = 0.0
self._capture_reason = "eof"
# The default sink may have changed along with the stream; resolve it
# again for the next monitor capture.
self._monitor_device_cache = None
def _read_generation(self) -> int:
with self._lock:
return self._generation
def _take_reset(self) -> bool:
with self._lock:
pending, self._reset_pending = self._reset_pending, False
return pending
def _reset_analysis(self) -> None:
"""Drop the previous station's samples and display state.
Only called from the analyser thread (or before it starts), so the
history buffer needs no lock; the values read by ``snapshot`` do.
"""
self._history[:] = 0.0
self._sim_phase = 0.0
with self._lock:
self._levels[:] = 0.0
self._peaks[:] = 0.0
self._wave[:] = 0.0
self._level = 0.0
self._gain = -24.0
def _kill_proc(self) -> None:
with self._lock:
proc = self._proc
self._proc = None
self._capture_kind = None
if proc is not None:
with contextlib.suppress(OSError):
proc.kill()
with contextlib.suppress(Exception):
proc.wait(timeout=1)
def _use_monitor(self) -> bool:
if self._monitor_failed or self.source_mode in ("sim", "stream"):
return False
if self._monitor_kind() is None:
return False
# A capture that had nothing to give us (a station change leaves the
# sink quiet while mpv buffers, a tap is idle before playback starts)
# is retried later instead of being written off for the session.
return time.monotonic() >= self._tap_retry_at
def _monitor_kind(self) -> str | None:
"""Name of the output-capture backend available here, if any."""
if self._parec:
return "parec"
if self._darwin and macos_tap.available():
return "tap"
return None
def _monitor_device(self) -> str:
override = env_var("SPECTRUM_DEVICE")
if override:
return override
if self._monitor_device_cache is not None:
return self._monitor_device_cache
if self._pactl:
try:
result = subprocess.run(
[self._pactl, "get-default-sink"],
stdin=subprocess.DEVNULL,
stdout=subprocess.PIPE,
stderr=subprocess.DEVNULL,
text=True,
timeout=1.0,
check=False,
)
sink = result.stdout.strip()
if result.returncode == 0 and sink:
self._monitor_device_cache = f"{sink}.monitor"
return self._monitor_device_cache
except (OSError, subprocess.SubprocessError):
pass
self._monitor_device_cache = "@DEFAULT_MONITOR@"
return self._monitor_device_cache
def _monitor_command(self) -> list[str] | None:
if self._monitor_kind() != "parec":
return None
return [
self._parec or "parec",
f"--device={self._monitor_device()}",
"--format=s16le",
"--rate=44100",
"--channels=1",
"--raw",
"--latency-msec=30",
"--client-name=beefy-player",
]
def _spawn(
self, command: list[str], kind: str
) -> subprocess.Popen[bytes] | None:
try:
proc = subprocess.Popen(
command,
stdin=subprocess.DEVNULL,
stdout=subprocess.PIPE,
stderr=subprocess.DEVNULL,
bufsize=0,
start_new_session=True,
)
except (OSError, ValueError):
return None
with self._lock:
self._proc = proc
self._capture_kind = kind
self._status = "monitor" if kind == "monitor" else "live"
return proc
def _stop_proc(self, proc: subprocess.Popen[bytes]) -> None:
with self._lock:
if self._proc is proc:
self._proc = None
self._capture_kind = None
with contextlib.suppress(OSError):
proc.kill()
with contextlib.suppress(Exception):
proc.wait(timeout=1)
def _run(self) -> None:
while not self._stop.is_set():
if self._take_reset():
self._reset_analysis()
url = self._read_url()
if not url:
self._idle_frame()
self._stop.wait(0.05)
continue
if self.source_mode == "sim":
self._simulate_for(url, 0.05)
continue
if self._use_monitor():
generation = self._read_generation()
outcome = self._capture_monitor(url)
if generation != self._read_generation():
# The station changed while this capture was running; its
# result belongs to the old source. Start over cleanly.
continue
if outcome == "done":
continue
if outcome == "retry":
# Nothing was rendered (yet), or the sink went quiet while
# the station changed: try the output capture again later.
self._tap_retry_at = time.monotonic() + TAP_RETRY_SECONDS
else:
# Hard failure (the capture never produced audio): do not
# retry until the source changes (which resets this).
self._monitor_failed = True
if self._stop.is_set():
break
if self._read_url() is None:
continue
if not self._ffmpeg:
# Keep re-checking: a pending output-capture retry may become
# due while we are showing the synthesized fallback.
self._simulate_for(url, 0.05, duration=5.0)
continue
generation = self._read_generation()
proc = self._spawn(self._command(url), "stream")
if proc is None:
with self._lock:
self._status = "sim"
self._simulate_for(url, 0.06, duration=5.0)
continue
self._capture(
proc,
url,
stop_on_url_change=True,
status="live",
generation=generation,
)
self._stop_proc(proc)
if self._stop.is_set():
break
if generation != self._read_generation():
continue
# The stream tap only covers periods where no output capture is
# available. Once the retry deadline has passed, go back around
# and try the real thing instead of simulating on top of the tap.
if self._use_monitor():
continue
if self._read_url() == url:
with self._lock:
self._status = "sim"
self._simulate_for(url, 0.06, duration=12.0)
def _command(self, url: str) -> list[str]:
return [
self._ffmpeg or "ffmpeg",
"-hide_banner",
"-loglevel",
"error",
"-nostdin",
"-reconnect",
"1",
"-reconnect_streamed",
"1",
"-reconnect_at_eof",
"1",
"-reconnect_delay_max",
"5",
"-fflags",
"nobuffer",
"-flags",
"low_delay",
"-probesize",
"32768",
"-analyzeduration",
"0",
"-user_agent",
USER_AGENT,
"-i",
url,
"-map",
"0:a:0",
"-vn",
"-ac",
"1",
"-ar",
str(self.sample_rate),
"-f",
"s16le",
"-acodec",
"pcm_s16le",
"-",
]
def _capture_monitor(self, url: str) -> str:
"""Capture the real audio output.
Returns ``"done"`` when playback stopped, ``"failed"`` when the
capture never produced audio (the device is gone or the sink is not
routed into it), and ``"retry"`` when it is temporarily unavailable.
"""
generation = self._read_generation()
if self._monitor_kind() == "tap":
outcome = self._capture_tap()
if generation != self._read_generation():
return "done"
return outcome
command = self._monitor_command()
proc = self._spawn(command, "monitor") if command else None
if proc is None:
return "failed"
try:
self._capture(
proc,
url,
stop_on_url_change=False,
status="monitor",
generation=generation,
)
finally:
self._stop_proc(proc)
if generation != self._read_generation():
# Deliberately stopped/restarted between stations; not a failure.
return "done"
if self._stop.is_set() or self._read_url() is None:
return "done"
# A sink that is quiet for a moment (mpv rebuffers a new station, a
# device is briefly suspended) is not broken: let the stream tap cover
# us until the next retry instead of permanently writing SYNC off.
if self._capture_reason == "idle":
return "retry"
return "failed"
def _capture_tap(self) -> str:
"""Capture the native macOS output tap."""
generation = self._read_generation()
tap = macos_tap.SystemAudioTap()
try:
tap.start()
except macos_tap.TapError as exc:
self._notify(f"macOS audio capture failed ({exc}) — using FFT")
return "failed"
with self._lock:
self._capture_kind = "monitor"
self._status = "monitor"
try:
self._retune(tap.sample_rate)
return self._pump_tap(tap, generation)
finally:
tap.stop()
with self._lock:
if self._capture_kind == "monitor":
self._capture_kind = None
def _pump_tap(
self, tap: macos_tap.SystemAudioTap, generation: int | None = None
) -> str:
"""Feed tap audio to the analyser until playback stops or it fails."""
if generation is None:
generation = self._read_generation()
channels = max(1, tap.channels)
block_bytes = TAP_BLOCK_FRAMES * max(4, tap.bytes_per_frame)
buffer = bytearray()
silent_blocks = 0
ever_worked = self._monitor_worked
last_audio = time.monotonic()
while not self._stop.is_set():
if self._read_generation() != generation:
return "done"
if self._read_url() is None:
return "done"
chunk = tap.read(0.5)
now = time.monotonic()
if chunk is None:
# A tap only ticks while the output device renders something;
# give playback a moment to start before giving up on it.
if now - last_audio >= TAP_IDLE_SECONDS:
self._notify(
"nothing is playing on the default output device — "
"using the stream tap (FFT)"
)
return "retry"
continue
last_audio = now
buffer.extend(chunk)
# Fixed-size blocks keep attack/decay smoothing tied to time.
while len(buffer) >= block_bytes:
block = bytes(buffer[:block_bytes])
del buffer[:block_bytes]
if not block.strip(b"\x00"):
silent_blocks += 1
# A tap that was never granted permission is created
# happily but only ever hands out digital silence; detect
# that here. Silence after real audio, however, is just a
# station change or an actually silent output, so keep
# monitoring (the bars fall by themselves).
if not ever_worked and silent_blocks >= SILENT_MONITOR_BLOCKS:
self._notify(
"macOS is not letting the app record audio — allow "
"'System Audio Recording' for your terminal in "
"System Settings, then restart (using FFT)"
)
return "failed"
else:
silent_blocks = 0
ever_worked = True
self._monitor_worked = True
self.feed_audio(block, channels, "monitor")
return "done"
def _capture(
self,
proc: subprocess.Popen[bytes],
url: str,
*,
stop_on_url_change: bool,
status: str,
generation: int | None = None,
) -> bool:
"""Read PCM until playback stops, the source changes, or the process dies.
``self._capture_reason`` records why the loop ended so the caller can
tell a capture that has gone for good (``"eof"``/``"dead"``) from one
that is merely quiet while a station is being tuned (``"idle"`` /
``"restart"``).
"""
stdout = proc.stdout
if stdout is None:
self._capture_reason = "eof"
return False
if generation is None:
generation = self._read_generation()
fd = stdout.fileno()
got_data = False
buffer = bytearray()
silent_blocks = 0
ever_worked = self._monitor_worked
last_data = time.monotonic()
reason = "stop"
while not self._stop.is_set():
if self._read_generation() != generation:
reason = "restart"
break
current = self._read_url()
if current is None:
reason = "idle"
break
if stop_on_url_change and current != url:
reason = "url"
break
# The stream tap yields once an output capture is due for a retry,
# so a monitor with a momentary lapse does not keep us on the
# (drifting) stream tap for the rest of the session.
if status == "live" and self._use_monitor():
reason = "monitor"
break
# A monitor can go quiet while mpv rebuffers a newly tuned station,
# or when the device disappears. Don't block the analyser thread
# forever, but give silence a fair chance to turn back into audio.
# os.read returns whatever is available (instead of waiting for a
# full 4 KiB), which keeps latency low.
if status == "monitor" and os.name == "posix":
try:
ready, _, _ = select.select(
[fd], [], [], MONITOR_POLL_SECONDS
)
except (OSError, ValueError):
ready = [fd]
if not ready:
if proc.poll() is not None:
reason = "eof"
break
if time.monotonic() - last_data >= MONITOR_IDLE_SECONDS:
reason = "idle"
break
continue
try:
data = os.read(fd, READ_BYTES)
except OSError:
reason = "eof"
break
if not data:
reason = "eof"
break
now = time.monotonic()
last_data = now
buffer.extend(data)
# Process fixed-size blocks so attack/decay smoothing is tied to
# time (~46 ms per block), regardless of how the pipe fragments.
while len(buffer) >= READ_BYTES:
block = bytes(buffer[:READ_BYTES])
del buffer[:READ_BYTES]
if status == "monitor":
if block.count(0) == len(block):
silent_blocks += 1
else:
silent_blocks = 0
ever_worked = True
self._monitor_worked = True
# A capture that was never granted permission (macOS) or
# that nobody routes into (PulseAudio) delivers endless
# digital silence. SYNC bars that never move are worse
# than the (slightly drifting) stream tap, so give up on a
# backend that has never worked. Once it has worked,
# silence is real (or mpv rebuffering): keep SYNC and let
# the bars fall.
if not ever_worked and silent_blocks >= SILENT_MONITOR_BLOCKS:
self._capture_reason = "dead"
return False
got_data = True
self.feed_pcm(block, status)
self._capture_reason = reason
return got_data
# ------------------------------------------------------------------ #
# signal processing
# ------------------------------------------------------------------ #
def feed_pcm(self, data: bytes, status: str = "live") -> None:
"""Feed raw little-endian mono s16 PCM (also used by the tests)."""
if not data or len(data) < 2:
return
usable = len(data) - (len(data) % 2)
try:
samples = np.frombuffer(data[:usable], dtype="<i2")
except ValueError:
return
if samples.size == 0:
return
self._process(samples.astype(np.float32) / 32768.0, status)
def feed_audio(self, data: bytes, channels: int = 1, status: str = "monitor") -> None:
"""Feed interleaved little-endian ``float32`` PCM (the macOS tap)."""
usable = len(data) - (len(data) % 4)
if usable <= 0:
return
try:
samples = np.frombuffer(data[:usable], dtype="<f4")
except ValueError:
return
if samples.size == 0:
return
channels = max(1, int(channels))
if channels > 1:
frames = samples.size - (samples.size % channels)
samples = samples[:frames].reshape(-1, channels).mean(axis=1)
self._process(np.ascontiguousarray(samples, dtype=np.float32), status)
def _retune(self, sample_rate: int) -> None:
"""Rebuild the FFT window and band edges for a different capture rate."""
rate = int(sample_rate) or self.sample_rate
if rate == self.sample_rate:
return
self.sample_rate = rate
self._window = np.hanning(self.fft_size).astype(np.float32)
self._groups = self._make_groups()
def _notify(self, message: str) -> None:
with self._lock:
self._notice = message
def _process(self, samples: np.ndarray, status: str = "live") -> None:
size = self.fft_size
if samples.size >= size:
self._history[:] = samples[-size:]
else:
count = samples.size
self._history[:-count] = self._history[count:]
self._history[-count:] = samples
chunk = self._history
spectrum = np.abs(np.fft.rfft(chunk * self._window))
spectrum /= size * 0.5
db = 20.0 * np.log10(spectrum + 1e-9)
values = np.array(
[db[lo:hi].max() for lo, hi in self._groups], dtype=np.float32
)
peak_db = float(values.max())
self._gain = max(peak_db, self._gain - 0.35)
floor = self._gain - 42.0
norm = np.clip((values - floor) / 42.0, 0.0, 1.0) ** 1.4
rms = float(np.sqrt(np.mean(np.square(chunk)) + 1e-12))
level = float(np.clip((20.0 * math.log10(rms + 1e-9) + 55.0) / 45.0, 0.0, 1.0))
wave = self._downsample(chunk)
self._apply(norm.astype(np.float32), wave, level, status)
def _downsample(self, samples: np.ndarray) -> np.ndarray:
target = self.wave_points
if samples.size < target:
padded = np.zeros(target, dtype=np.float32)
padded[-samples.size :] = samples
samples = padded
step = max(1, samples.size // target)
trimmed = samples[samples.size - step * target :]
try:
folded = trimmed.reshape(target, step).mean(axis=1)
except ValueError:
return np.zeros(target, dtype=np.float32)
peak = float(np.max(np.abs(folded)))
if peak > 1e-4:
folded = folded / peak
return np.clip(folded, -1.0, 1.0).astype(np.float32)
def _apply(
self, values: np.ndarray, wave: np.ndarray, level: float, status: str
) -> None:
with self._lock:
self._levels = np.maximum(values, self._levels * 0.65).astype(np.float32)
self._peaks = np.maximum(values, self._peaks - 0.04).astype(np.float32)
self._wave = (self._wave * 0.55 + wave * 0.45).astype(np.float32)
self._level = float(self._level * 0.5 + level * 0.5)
self._status = status
def _idle_frame(self) -> None:
with self._lock:
self._levels = (self._levels * 0.86).astype(np.float32)
self._peaks = np.maximum(self._peaks - 0.02, 0.0).astype(np.float32)
self._wave = (self._wave * 0.8).astype(np.float32)
self._level *= 0.9
self._status = "idle"
# ------------------------------------------------------------------ #
# simulation
# ------------------------------------------------------------------ #
def _simulate_for(
self, url: str, delay: float, duration: float | None = None
) -> None:
deadline = None if duration is None else time.monotonic() + duration
while not self._stop.is_set():
if self._read_url() != url:
return
# Stop pretending as soon as a real output capture is available
# again (e.g. the retry deadline expired during the fallback).
if self._use_monitor():
return
self._simulate_step()
if self._stop.wait(delay):
return
if deadline is not None and time.monotonic() >= deadline:
return
def _simulate_step(self) -> None:
self._sim_phase += 0.16
t = self._sim_phase
index = np.linspace(0.0, 1.0, self.band_count, dtype=np.float32)
humps = np.exp(-((index - 0.16) ** 2) / 0.020) * 0.58
humps += np.exp(-((index - 0.46) ** 2) / 0.055) * 0.34
humps += np.exp(-((index - 0.80) ** 2) / 0.130) * 0.20
motion = 0.55 + 0.45 * np.sin(t * 1.9 + index * 11.0)
noise = self._rng.random(self.band_count, dtype=np.float32) * 0.22
beat_phase = (t * 0.55) % 1.0
beat = math.exp(-(beat_phase / 0.16)) * 0.28 * np.exp(-(index**2) / 0.03)
values = np.clip((humps * motion + noise + beat), 0.02, 1.0)
values = np.clip(values * (1.15 - 0.25 * index), 0.0, 1.0).astype(np.float32)
points = np.linspace(0.0, 2.0 * math.pi * 7.0, self.wave_points)
wave = 0.42 * np.sin(points + t * 3.0) * (0.6 + 0.4 * math.sin(t * 0.7))
wave += 0.20 * np.sin(points * 1.9 + t * 4.3)
wave += self._rng.normal(0.0, 0.05, self.wave_points)
wave = np.clip(wave, -1.0, 1.0).astype(np.float32)
level = float(
min(1.0, 0.32 + 0.14 * math.sin(t * 1.7) + 0.25 * math.exp(-(beat_phase / 0.2)))
)
self._apply(values, wave, level, "sim")