docs(readme): document macOS support, Now Playing and loopback capture

Split the install instructions per platform, add the macOS microphone
permission and BlackHole/Multi-Output recipe for a synced spectrum,
describe the Now Playing integration and its limits, and note that config
and cache stay in the XDG locations. The in-app help text is now
platform-aware too, and the package metadata lists macOS.

README.md

@@ -3,13 +3,17 @@
 ![somafm-tui demo](assets/somafm-tui-demo.gif)
 
 A flashy terminal radio for **[SomaFM](https://somafm.com)** — a live spectrum
-analyser, song history, and full desktop media integration over MPRIS, drawn
+analyser, song history, and full desktop media integration, drawn with your
-with your terminal's own ANSI palette on the terminal's default background so
+terminal's own ANSI palette on the terminal's default background so it fits
-it fits any theme (including transparent terminals).
+any theme (including transparent terminals).
+
+It runs the same way on **Linux** (PulseAudio/PipeWire) and **macOS**
+(CoreAudio, iTerm2/Kitty/WezTerm): MPRIS on the desktop bus where that exists,
+macOS Now Playing (Control Center and the media keys) where it does not.
 
 No existing SomaFM client is used: the station list, playlists, song history,
-audio control, spectrum visualiser and MPRIS service are all implemented here from
+audio control, spectrum visualiser and media-session integration are all
-the public SomaFM endpoints and open protocols.
+implemented here from the public SomaFM endpoints and open protocols.
 
 ## Features
 
@@ -17,15 +21,17 @@ the public SomaFM endpoints and open protocols.
   gradient taken from your terminal's ANSI palette and a symmetric mirrored
   spectrum; or a full-height oscilloscope. Three modes (`v`).
 - **Synced spectrum, not a guess** — by default the analyser records your
-  actual PulseAudio/PipeWire output monitor with `parec`, so the bars follow
+  actual audio output, so the bars follow what you hear (`SYNC`): the
-  what you hear (`SYNC`). Without a monitor it falls back to a muted second
+  PulseAudio/PipeWire monitor via `parec` on Linux, an `ffmpeg`/avfoundation
-  `ffmpeg` decode of the stream (`FFT`, can drift), then to a synthesized
+  loopback input (BlackHole, Loopback, Soundflower, …) on macOS. Without an
-  display (`SIM`).
+  output capture it falls back to a muted second `ffmpeg` decode of the stream
-- **Real artwork where supported** — Kitty uses the kitty graphics protocol;
+  (`FFT`, can drift), then to a synthesized display (`SIM`).
-  iTerm2 and WezTerm use their native iTerm2 inline-image protocol. Images
+- **Real artwork on iTerm2, Kitty and WezTerm** — Kitty uses the kitty
-  occupy exactly the ON AIR art cell box and fall back to the procedural ANSI
+  graphics protocol; iTerm2 (including on macOS) and WezTerm use their native
-  mosaic for other terminals, failed loads, or blocked graphics passthrough.
+  iTerm2 inline-image protocol. Images occupy exactly the ON AIR art cell box
-  Images are cached in `~/.cache/somafm-tui/artwork`.
+  and fall back to the procedural ANSI mosaic for other terminals, failed
+  loads, or blocked graphics passthrough. Images are cached in
+  `~/.cache/somafm-tui/artwork`.
 - **Now playing** — artist, title, album, DJ, listeners, format/bitrate and
   "played N minutes ago", with procedural ANSI-shaded album art that changes
   per track. When the current track can be found on Bandcamp, a clickable
@@ -34,10 +40,13 @@ the public SomaFM endpoints and open protocols.
 - **Every station** — the whole `channels.json` roster (≈50 channels), live
   listener counts, genre search.
 - **Favourites** that float to the top, remembered between runs.
-- **MPRIS** — an `org.mpris.MediaPlayer2.somafmtui.instance<pid>` player exposes
+- **Desktop media integration** — on Linux an
+  `org.mpris.MediaPlayer2.somafmtui.instance<pid>` player exposes
   `PlaybackStatus`, `Metadata` (title/artist/album/artUrl), `Volume`, and
-  `Play`/`Pause`/`PlayPause`/`Stop`/`Next`/`Previous`. Desktop media widgets and
+  `Play`/`Pause`/`PlayPause`/`Stop`/`Next`/`Previous`, so GNOME/KDE widgets,
-  media keys pick it up automatically.
+  lock screens, `playerctl` and the media keys pick it up. On macOS the audio
+  engine (mpv) publishes to the system **Now Playing** session, so Control
+  Center, the menu bar and the keyboard media keys drive the app the same way.
 - **Theme-aware** — every accent is emitted as native ANSI (not RGB), and the
   background is the terminal default (`SGR 49`), so transparent terminals stay
   transparent and the TUI adopts your shell/terminal colour scheme.
@@ -48,17 +57,32 @@ the public SomaFM endpoints and open protocols.
 ## Requirements
 
 `somafm-tui` is a normal Python application: there is nothing to compile and
-no distro-specific packaging. It runs on any Linux distribution with Python
+no distro-specific packaging. It runs on any Linux distribution or macOS with
-**3.10+** and a few command-line audio tools on `$PATH`.
+Python **3.10+** and a few command-line audio tools on `$PATH`.
 
 | tool | why |
 | ---- | --- |
 | `python3` | runtime (3.10 or newer; no exact version pin) |
 | [`uv`](https://docs.astral.sh/uv/) | creates the venv and installs every Python dependency from `uv.lock` |
 | `mpv` | playback and JSON IPC control |
-| `ffmpeg` | muted stream decode for the fallback analyser |
+| `ffmpeg` | muted stream decode for the fallback analyser, and the macOS output capture |
-| `parec` / `pactl` | synced monitor capture for the spectrum (`pulseaudio-utils`; works with PipeWire) |
+| `parec` / `pactl` *(Linux)* | synced monitor capture for the spectrum (`pulseaudio-utils`; works with PipeWire) |
-| D-Bus session bus | MPRIS desktop media integration (`playerctl` is handy for testing) |
+| a loopback audio device *(macOS, optional)* | synced output capture for the spectrum: BlackHole, Loopback, Soundflower, … |
+| D-Bus session bus *(Linux)* | MPRIS desktop media integration (`playerctl` is handy for testing) |
+
+On macOS the media integration needs nothing extra: mpv is what the system's
+Now Playing session (Control Center, media keys) talks to.
+
+Install `uv` once (skip if it is already there):
+
+```bash
+curl -LsSf https://astral.sh/uv/install.sh | sh
+```
+
+`brew install uv`, `pipx install uv`, or a distro package also work. If your
+system Python is older than 3.10, let uv manage one: `uv python install 3.12`.
+
+### Linux
 
 Install these with your package manager. Names are usually:
 
@@ -80,14 +104,39 @@ For other distributions, install the equivalents. On a headless machine you
 can skip the audio/D-Bus tools and use `--no-audio` for a UI-only demo, though
 the synced spectrum needs `parec`/`pactl`.
 
-Install `uv` once with the official installer:
+### macOS
 
 ```bash
-curl -LsSf https://astral.sh/uv/install.sh | sh
+brew install mpv ffmpeg uv        # ffplay ships with ffmpeg
 ```
 
-`pipx install uv`, `brew install uv`, or a distro package also work. If your
+That is enough to run: playback, artwork in iTerm2/Kitty/WezTerm, the muted
-distro's Python is older than 3.10, let uv manage one: `uv python install 3.12`.
+`ffmpeg` spectrum tap and the macOS Now Playing integration all work out of the
+box. The first capture attempt makes macOS ask for **microphone** access for
+whatever terminal you use — that permission is what lets `ffmpeg` read the
+loopback device.
+
+For a *synced* spectrum (`SYNC` instead of `FFT`) macOS needs an output
+loopback, because CoreAudio does not let an ordinary process record the
+speakers directly:
+
+```bash
+brew install blackhole-2ch        # or Loopback / Soundflower
+```
+
+Then either
+
+1. create a **Multi-Output Device** in *Audio MIDI Setup* containing both your
+   speakers/headphones and *BlackHole 2ch*, and select it as the system output,
+   or
+2. set *BlackHole 2ch* as the output and monitor the audio elsewhere.
+
+The app auto-detects loopback-style inputs (BlackHole, Loopback, Soundflower,
+“Multi-Output”, “Aggregate”) and never grabs a plain microphone by accident.
+Pick one explicitly with `SOMAFM_SPECTRUM_DEVICE` (name or avfoundation index,
+see `ffmpeg -f avfoundation -list_devices true -i ""`). If the loopback turns
+out to be silent (nothing routed into it), the analyser notices after a few
+seconds and falls back to `FFT` instead of showing dead bars.
 
 Terminal image rendering uses [Pillow](https://python-pillow.org/) and is
 implemented directly (Kitty TGP + iTerm2 OSC 1337) — no terminal probing.
@@ -126,7 +175,7 @@ uv run somafm-tui --play                # start the last station immediately
 uv run somafm-tui --station defcon       # pick a station
 uv run somafm-tui --volume 55
 uv run somafm-tui --offline              # no network; cached/bundled stations
-uv run somafm-tui --no-mpris             # don't announce over D-Bus
+uv run somafm-tui --no-mpris             # no MPRIS / Now Playing, no media keys
 uv run somafm-tui --list                 # print station ids
 uv run somafm-tui --no-audio             # UI demo without mpv/ffmpeg
 uv run somafm-tui --spectrum-source monitor  # force synced output capture
@@ -158,9 +207,9 @@ The UI wants roughly **84×24**; it also works smaller, just less pretty.
 | `?`            | help                                          |
 | `q`            | quit                                          |
 
-## Desktop media widgets (MPRIS)
+## Desktop media widgets (MPRIS / Now Playing)
 
-While playing, the app exports
+**Linux** — while playing, the app exports
 `org.mpris.MediaPlayer2.somafmtui.instance<pid>` on the **session bus**. Check it:
 
 ```bash
@@ -173,6 +222,19 @@ playerctl play-pause
 channel logo. If there is no session bus (SSH without `dbus-run-session`,
 containers, …) MPRIS is skipped and the status bar shows `mpris off`.
 
+**macOS** — mpv owns the system Now Playing session, so Control Center, the
+menu-bar widget and the keyboard media keys (▶︎/⏸, ⏭, ⏮) all target this app
+while it is playing. mpv publishes the live stream title (the same
+“Artist - Title” that SomaFM sends with the audio), and the media keys are
+routed back into the TUI, so `⏭`/`⏮` really change station and the panel, the
+spectrum and the station list stay in sync. The status bar shows
+`nowplaying on`. There is no D-Bus and no extra dependency involved, and
+`--no-mpris` (also spelled `--no-media`) turns the media keys off again.
+
+> macOS shows one Now Playing app at a time. If Music/Safari/another mpv is
+> playing, the media keys go there instead — quit it or pause it to hand the
+> keys back.
+
 ## How it works
 
 - `somafm_tui/api.py` — async `httpx` client for:
@@ -183,14 +245,19 @@ containers, …) MPRIS is skipped and the status bar shows `mpris off`.
   offline.
 - `somafm_tui/player.py` — mpv over a Unix-socket JSON IPC channel. Observes
   `pause`/`volume`, handles mirror failover on `end-file`, auto-restarts a dead
-  engine, and uses `SIGSTOP`/`SIGCONT` when falling back to `ffplay`.
+  engine, and uses `SIGSTOP`/`SIGCONT` when falling back to `ffplay`. On macOS
+  it also asks mpv to publish Now Playing and maps the media keys onto
+  `script-message`s that come back over the same IPC socket.
 - `somafm_tui/spectrum.py` — 44.1 kHz mono s16le analyser. Prefers capturing
-  the real sink monitor with `parec` (SYNC); otherwise a muted low-latency
+  the real output: `parec` (PulseAudio/PipeWire monitor) on Linux, or
-  `ffmpeg` decode of the stream (FFT). Hann-windowed 2048-point FFT, log band
+  `ffmpeg -f avfoundation` on a loopback input on macOS (SYNC). Otherwise a
-  grouping, auto-gain, fast attack/decay smoothing, peak hold and waveform
+  muted low-latency `ffmpeg` decode of the stream (FFT). Hann-windowed
-  downsampling.
+  2048-point FFT, log band grouping, auto-gain, fast attack/decay smoothing,
+  peak hold and waveform downsampling.
+- `somafm_tui/mediasession.py` — picks the desktop media backend (MPRIS on
+  Linux, Now Playing on macOS) so the app has one platform-neutral interface.
 - `somafm_tui/mpris.py` — `dbus-next` MPRIS service in its own thread with a
-  thread-safe command queue back into the UI.
+  thread-safe command queue back into the UI (only loaded on D-Bus platforms).
 - `somafm_tui/bandcamp.py` — searches Bandcamp's public autocomplete API for
   the now-playing track (artist + track first, then artist + album, then the
   album page) and returns a track URL when there is a match.
@@ -208,14 +275,21 @@ containers, …) MPRIS is skipped and the status bar shows `mpris off`.
 ~/.cache/somafm-tui/artwork/<sha1>  cached album/channel artwork
 ```
 
+These stay in the XDG locations on every platform (macOS included), so the
+same dotfiles/config work everywhere; `XDG_CONFIG_HOME`, `XDG_CACHE_HOME` and
+`XDG_RUNTIME_DIR` are honoured when set.
+
 ## Notes / troubleshooting
 
 - **Artwork shows the mosaic?** Real images are auto-enabled for Kitty,
   iTerm2 and WezTerm. Force a protocol with `SOMAFM_IMAGES=tgp` (Kitty/TGP) or
   `SOMAFM_IMAGES=iterm2` (iTerm2/WezTerm); `SOMAFM_IMAGES=0` forces the ANSI
-  mosaic. Kitty inside tmux is attempted through tmux passthrough (enable
+  mosaic. iTerm2 on macOS is detected from `TERM_PROGRAM`/`LC_TERMINAL`, and
-  `set -g allow-passthrough on`); iTerm2/WezTerm inside tmux default to the
+  empty or `0` values in `TMUX`/`ZELLIJ`/`STY` (exported by some wrappers) are
-  mosaic. Images are cached under `~/.cache/somafm-tui/artwork`.
+  ignored so they cannot downgrade it. Kitty inside tmux is attempted through
+  tmux passthrough (enable `set -g allow-passthrough on`); iTerm2/WezTerm
+  inside tmux default to the mosaic. Images are cached under
+  `~/.cache/somafm-tui/artwork`.
 - **Clock shows UTC?** The clock and song history use the system zone from
   `/etc/localtime`; a non-UTC `TZ` overrides it. A container or dev shell can
   inherit a build-time `TZ=UTC`, which the app deliberately ignores; bind the
@@ -224,10 +298,11 @@ containers, …) MPRIS is skipped and the status bar shows `mpris off`.
 - **MPRIS says off/error?** No session bus. Run from your desktop session
   (the shell profile picks up `$XDG_RUNTIME_DIR/bus`). `dbus-run-session -- uv
   run somafm-tui` starts a private bus for testing, but desktop widgets won't
-  see it.
+  see it. macOS does not use MPRIS at all — see “Now Playing” above.
 - **No audio?** `somafm-tui` needs `mpv` (preferred) or `ffplay`. Without
   either, the UI still runs and tells you. Extra mpv args can be injected with
-  `SOMAFM_MPV_ARGS` (e.g. `SOMAFM_MPV_ARGS='--audio-device=...'`).
+  `SOMAFM_MPV_ARGS` (e.g. `SOMAFM_MPV_ARGS='--audio-device=...'`, which is the
+  macOS way to choose an output device).
 - **Spectrum says `FFT` instead of `SYNC`?** `parec`/`pactl` are unavailable,
   the monitor device failed, or you forced the stream tap. The bars are still
   real audio, but the second stream can drift relative to playback. Use
@@ -240,6 +315,20 @@ containers, …) MPRIS is skipped and the status bar shows `mpris off`.
 - **`SYNC` but the bars are flat?** mpv may be playing to a different sink (or
   directly to ALSA). Point `SOMAFM_SPECTRUM_DEVICE` at that sink's monitor, or
   use `--spectrum-source stream`.
+- **macOS: spectrum stays `FFT`?** Install a loopback (BlackHole/Loopback) and
+  route your speakers through a Multi-Output Device, then check
+  `ffmpeg -f avfoundation -list_devices true -i ""` lists it. The first capture
+  triggers a macOS microphone-permission prompt; grant it to your terminal
+  (System Settings → Privacy & Security → Microphone), otherwise ffmpeg cannot
+  open the device and the analyser stays on `FFT`.
+- **macOS: media keys do nothing?** Another app currently owns the Now Playing
+  session, or the app was started with `--no-mpris`, or the audio backend fell
+  back to `ffplay` (mpv is required for Now Playing). The status bar shows
+  `nowplaying on` when the integration is armed.
+- **macOS: Control Center shows only a title?** mpv publishes the stream's live
+  “Artist - Title” as the Now Playing title; artist/album fields and artwork are
+  not filled in by macOS for plain audio streams. The TUI itself always shows
+  the full metadata and album art.
 - **Bandwidth** is unchanged in SYNC mode (the monitor capture creates no
   second stream). The FFT fallback opens one extra stream; if you are on a
   metered link, use `--spectrum-source monitor` (or `--no-audio` for a UI-only

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "somafm-tui"
 version = "0.1.0"
-description = "A flashy terminal radio for SomaFM with a live spectrum analyser, MPRIS support and song history"
+description = "A flashy terminal radio for SomaFM with a live spectrum analyser, MPRIS / macOS Now Playing support and song history"
 readme = "README.md"
 license = "WTFPL"
 license-files = ["LICENSE"]
@@ -17,6 +17,9 @@ classifiers = [
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
   "Topic :: Multimedia :: Sound/Audio",
+  "Operating System :: POSIX :: Linux",
+  "Operating System :: MacOS",
+  "Environment :: MacOS X",
 ]
 dependencies = [
   "textual>=8.0,<9",

somafm_tui/widgets/help.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import sys
 import textwrap
 
 from rich.console import Group
@@ -31,11 +32,14 @@ HELP_ROWS: tuple[tuple[str, str], ...] = (
     ("q", "quit"),
 )
 
-ABOUT = (
+ABOUT_COMMON = (
     (
         "Stations and song history come from somafm.com "
         "(channels.json + songs/<station>.json)."
     ),
+)
+
+ABOUT_LINUX = (
     (
         "The spectrum captures your actual PulseAudio/PipeWire output with "
         "parec (SYNC); otherwise it falls back to a muted ffmpeg stream tap "
@@ -47,6 +51,21 @@ ABOUT = (
     ),
 )
 
+ABOUT_MACOS = (
+    (
+        "The spectrum follows your audio output (SYNC) when a loopback device "
+        "such as BlackHole is available for ffmpeg/avfoundation; otherwise it "
+        "falls back to a muted ffmpeg stream tap (FFT, can drift) or a "
+        "synthesized display (SIM)."
+    ),
+    (
+        "mpv publishes what is playing to the macOS Now Playing session, so "
+        "Control Center and the keyboard media keys control this app."
+    ),
+)
+
+ABOUT = ABOUT_COMMON + (ABOUT_MACOS if sys.platform == "darwin" else ABOUT_LINUX)
+
 
 class HelpScreen(ModalScreen[None]):
     def compose(self) -> ComposeResult: