internal process dsp, skipping ladspa pipewire attempt, and reworked waveforms

README.md

@@ -24,7 +24,7 @@ Terminal DJ suite — Rust + Ratatui + PipeWire graph DSP.
 │  PipeWire Graph                                              │
 │                                                              │
 │  djdeck.deck.a ──► input.djdeck.chain.a                     │
-│                        [rubberband LADSPA]                   │
+│                        [pitch → lpL/lpR → reverb]            │
 │                    output.djdeck.chain.a ──► default sink    │
 │                                                              │
 │  (same for z, s, x)                                          │
@@ -32,29 +32,55 @@ Terminal DJ suite — Rust + Ratatui + PipeWire graph DSP.
 ```
 
 Each deck stream outputs raw decoded PCM. The PipeWire graph handles all DSP:
-- **Pitch shifting** and **time stretching** — rubberband LADSPA via `libpipewire-module-filter-chain`
+- **Pitch shifting** — rubberband `Semitones` port (requires `ladspa-rubberband`)
+- **Cutoff filter** — `lowpass_iir` + `highpass_iir` (swh-plugins), `Cutoff Frequency` port:
+  - Negative value → lowpass (kill highs), positive → highpass (kill lows), 0 → flat
+- **Reverb** — `plate` `Dry/wet mix` port (swh-plugins): 0=dry → 1=wet
 - **Volume (fader)** — `wpctl set-volume` on the stream node
-- **Pitch/Tempo params** — `pw-cli set-param <node-id> Props '{ params = [...] }'`
+- **Tempo** — varispeed in audio engine; rubberband compensates pitch automatically
 
 ## Dependencies
 
 ### System
 
+**Required:**
 ```bash
 # Arch
 pacman -S pipewire wireplumber pipewire-audio ladspa rubberband
 
 # Ubuntu / Debian
-apt install pipewire wireplumber pipewire-audio ladspa-sdk rubberband-ladspa
+apt install pipewire wireplumber ladspa-sdk rubberband-ladspa
 
 # Fedora
 dnf install pipewire wireplumber ladspa rubberband-ladspa
 ```
 
+**Required** (cutoff + reverb):
+```bash
+# Arch
+pacman -S swh-plugins
+
+# Ubuntu / Debian
+apt install swh-plugins
+
+# Fedora
+dnf install swh-plugins
+```
+
 Verify the rubberband LADSPA plugin is present:
 ```bash
-analyseplugin ladspa-rubberband.so
-# should list labels including: rubberband_pitchshifter_stereo
+python3 -c "
+import ctypes; lib = ctypes.CDLL('/usr/lib/ladspa/ladspa-rubberband.so')
+lib.ladspa_descriptor.restype = ctypes.c_void_p
+class D(ctypes.Structure):
+    _fields_ = [('uid',ctypes.c_ulong),('label',ctypes.c_char_p),('props',ctypes.c_int),('name',ctypes.c_char_p)]
+i=0
+while True:
+    d=lib.ladspa_descriptor(i)
+    if not d: break
+    print(ctypes.cast(d,ctypes.POINTER(D)).contents.label.decode()); i+=1
+"
+# should include: rubberband-pitchshifter-stereo
 ```
 
 ### Rust
@@ -77,10 +103,11 @@ cargo build --release
 Logs → `/tmp/djdeck.log`. Set `RUST_LOG=debug` for verbose output.
 
 On startup djdeck will:
-1. Load `libpipewire-module-filter-chain` for each deck (rubberband LADSPA)
-2. Start 4 PipeWire playback streams, each targeting its filter-chain sink
+1. Start 4 PipeWire playback streams, each targeting its filter-chain sink
+2. Load `libpipewire-module-filter-chain` for each deck via `pw-cli load-module` (pitch → lpL/lpR → reverb)
 3. Wait 800ms for PipeWire to settle, then resolve node IDs via `pw-dump`
-4. Start the TUI and OSC server
+4. Explicitly link each chain's output to the default sink via `pw-link -L`
+5. Start the TUI and OSC server
 
 Node IDs for each deck are shown in the deck panel title: `[pw:stream/filter]`.
 
@@ -96,8 +123,10 @@ Node IDs for each deck are shown in the deck panel title: `[pw:stream/filter]`.
 | `c` | Set cue point |
 | `v` | Jump to cue point |
 | `↑ / ↓` | Fader ±5% (via `wpctl set-volume`) |
-| `[ / ]` | Pitch ±0.5 semitones (via `pw-cli`, rubberband) |
-| `, / .` | Tempo ±1% (via `pw-cli`, rubberband) |
+| `[ / ]` | Pitch ±0.5 semitones (rubberband `Semitones` port) |
+| `, / .` | Tempo ±1% (varispeed; rubberband compensates pitch) |
+| `- / =` | Cutoff ±500 (negative=LP kills highs, positive=HP kills lows, 0=flat) |
+| `o / p` | Reverb wet ±5% (requires swh-plugins) |
 | `q` | Quit (unloads filter-chain modules) |
 
 **File selector:** type to filter, `↑/↓` navigate, `Enter` load, `Esc` cancel.