Merge remote and fix color space

daw-backend/src/audio/engine.rs

@@ -71,6 +71,16 @@ pub struct Engine {
     // Disk reader for streaming playback of compressed files
     disk_reader: Option<crate::audio::disk_reader::DiskReader>,
 
+    // Input monitoring and metering
+    input_monitoring: bool,
+    input_gain: f32,
+    input_level_peak: f32,
+    input_level_counter: usize,
+    output_level_peak_l: f32,
+    output_level_peak_r: f32,
+    output_level_counter: usize,
+    track_level_counter: usize,
+
     // Callback timing diagnostics (enabled by DAW_AUDIO_DEBUG=1)
     debug_audio: bool,
     callback_count: u64,
@@ -138,6 +148,14 @@ impl Engine {
             metronome: Metronome::new(sample_rate),
             recording_sample_buffer: Vec::with_capacity(4096),
             disk_reader: Some(disk_reader),
+            input_monitoring: false,
+            input_gain: 1.0,
+            input_level_peak: 0.0,
+            input_level_counter: 0,
+            output_level_peak_l: 0.0,
+            output_level_peak_r: 0.0,
+            output_level_counter: 0,
+            track_level_counter: 0,
             debug_audio: std::env::var("DAW_AUDIO_DEBUG").map_or(false, |v| v == "1"),
             callback_count: 0,
             timing_worst_total_us: 0,
@@ -380,27 +398,72 @@ impl Engine {
             self.process_live_midi(output);
         }
 
-        // Process recording if active (independent of playback state)
+        // Compute stereo output peaks for master VU meter (independent of playback state)
-        if let Some(recording) = &mut self.recording_state {
+        {
+            let channels = self.channels as usize;
+            for frame in output.chunks(channels) {
+                if channels >= 2 {
+                    self.output_level_peak_l = self.output_level_peak_l.max(frame[0].abs());
+                    self.output_level_peak_r = self.output_level_peak_r.max(frame[1].abs());
+                } else {
+                    let v = frame[0].abs();
+                    self.output_level_peak_l = self.output_level_peak_l.max(v);
+                    self.output_level_peak_r = self.output_level_peak_r.max(v);
+                }
+            }
+            self.output_level_counter += output.len();
+            let meter_interval = self.sample_rate as usize / 20; // ~50ms
+            if self.output_level_counter >= meter_interval {
+                let _ = self.event_tx.push(AudioEvent::OutputLevel(self.output_level_peak_l, self.output_level_peak_r));
+                self.output_level_peak_l = 0.0;
+                self.output_level_peak_r = 0.0;
+                self.output_level_counter = 0;
+            }
+
+            // Send per-track peak levels periodically
+            self.track_level_counter += output.len();
+            if self.track_level_counter >= meter_interval {
+                let levels = self.project.collect_track_peaks();
+                let _ = self.event_tx.push(AudioEvent::TrackLevels(levels));
+                self.track_level_counter = 0;
+            }
+        }
+
+        // Process input monitoring and/or recording (independent of playback state)
+        let is_recording = self.recording_state.is_some();
+        if is_recording || self.input_monitoring {
             if let Some(input_rx) = &mut self.input_rx {
-                // Phase 1: Discard stale samples by popping without storing
+                // Phase 1: Discard stale samples during recording skip phase
-                // (fast — no Vec push, no add_samples overhead)
+                if let Some(recording) = &mut self.recording_state {
                     while recording.samples_to_skip > 0 {
                         match input_rx.pop() {
                             Ok(_) => recording.samples_to_skip -= 1,
                             Err(_) => break,
                         }
                     }
-
-                // Phase 2: Pull fresh samples for actual recording
-                self.recording_sample_buffer.clear();
-                while let Ok(sample) = input_rx.pop() {
-                    self.recording_sample_buffer.push(sample);
                 }
 
-                // Add samples to recording
+                // Phase 2: Pull fresh samples
+                self.recording_sample_buffer.clear();
+                while let Ok(sample) = input_rx.pop() {
+                    // Apply input gain
+                    self.recording_sample_buffer.push(sample * self.input_gain);
+                }
+
                 if !self.recording_sample_buffer.is_empty() {
-                    // Calculate how many samples will be skipped (stale buffer data)
+                    // Compute input peak for VU metering
+                    let input_peak = self.recording_sample_buffer.iter().map(|s| s.abs()).fold(0.0f32, f32::max);
+                    self.input_level_peak = self.input_level_peak.max(input_peak);
+                    self.input_level_counter += self.recording_sample_buffer.len();
+                    let meter_interval = self.sample_rate as usize / 20; // ~50ms
+                    if self.input_level_counter >= meter_interval {
+                        let _ = self.event_tx.push(AudioEvent::InputLevel(self.input_level_peak));
+                        self.input_level_peak = 0.0;
+                        self.input_level_counter = 0;
+                    }
+
+                    // Feed samples to recording if active
+                    if let Some(recording) = &mut self.recording_state {
                         let skip = if recording.paused {
                             self.recording_sample_buffer.len()
                         } else {
@@ -426,7 +489,6 @@ impl Engine {
                                 // Update clip duration in project as recording progresses
                                 if let Some(crate::audio::track::TrackNode::Audio(track)) = self.project.get_track_mut(track_id) {
                                     if let Some(clip) = track.clips.iter_mut().find(|c| c.id == clip_id) {
-                                    // Update both internal_end and external_duration as recording progresses
                                         clip.internal_end = clip.internal_start + duration;
                                         clip.external_duration = duration;
                                     }
@@ -440,17 +502,16 @@ impl Engine {
                                 }
                             }
                             Err(e) => {
-                            // Recording error occurred
                                 let _ = self.event_tx.push(AudioEvent::RecordingError(
                                     format!("Recording write error: {}", e)
                                 ));
-                            // Stop recording on error
                                 self.recording_state = None;
                             }
                         }
                     }
                 }
             }
+        }
 
         // Timing diagnostics (DAW_AUDIO_DEBUG=1)
         if let (true, Some(t_start), Some(t_commands)) = (self.debug_audio, t_start, t_commands) {
@@ -1136,6 +1197,14 @@ impl Engine {
                 self.metronome.set_enabled(enabled);
             }
 
+            Command::SetInputMonitoring(enabled) => {
+                self.input_monitoring = enabled;
+            }
+
+            Command::SetInputGain(gain) => {
+                self.input_gain = gain;
+            }
+
             Command::SetTempo(bpm, time_sig) => {
                 self.metronome.update_timing(bpm, time_sig);
                 self.project.set_tempo(bpm, time_sig.0);
@@ -2851,6 +2920,16 @@ impl EngineController {
         let _ = self.command_tx.push(Command::SetTrackSolo(track_id, solo));
     }
 
+    /// Enable or disable input monitoring (mic level metering)
+    pub fn set_input_monitoring(&mut self, enabled: bool) {
+        let _ = self.command_tx.push(Command::SetInputMonitoring(enabled));
+    }
+
+    /// Set the input gain multiplier (applied before recording)
+    pub fn set_input_gain(&mut self, gain: f32) {
+        let _ = self.command_tx.push(Command::SetInputGain(gain));
+    }
+
     /// Move a clip to a new timeline position (changes external_start)
     pub fn move_clip(&mut self, track_id: TrackId, clip_id: ClipId, new_start_time: f64) {
         let _ = self.command_tx.push(Command::MoveClip(track_id, clip_id, new_start_time));

daw-backend/src/audio/project.rs

@@ -441,13 +441,34 @@ impl Project {
         // Handle audio track vs MIDI track vs group track
         match self.tracks.get_mut(&track_id) {
             Some(TrackNode::Audio(track)) => {
-                // Render audio track directly into output
+                // Render audio track into a temp buffer for peak measurement
-                track.render(output, audio_pool, ctx.playhead_seconds, ctx.sample_rate, ctx.channels);
+                let mut track_buffer = buffer_pool.acquire();
+                track_buffer.resize(output.len(), 0.0);
+                track_buffer.fill(0.0);
+                track.render(&mut track_buffer, audio_pool, ctx.playhead_seconds, ctx.sample_rate, ctx.channels);
+                // Accumulate peak level for VU metering (max over meter interval)
+                let buffer_peak = track_buffer.iter().map(|s| s.abs()).fold(0.0f32, f32::max);
+                track.peak_level = track.peak_level.max(buffer_peak);
+                // Mix into output
+                for (out, src) in output.iter_mut().zip(track_buffer.iter()) {
+                    *out += src;
+                }
+                buffer_pool.release(track_buffer);
             }
             Some(TrackNode::Midi(track)) => {
-                // Render MIDI track directly into output
+                // Render MIDI track into a temp buffer for peak measurement
-                // Access midi_clip_pool from self - safe because we only need immutable access
+                let mut track_buffer = buffer_pool.acquire();
-                track.render(output, &self.midi_clip_pool, ctx.playhead_seconds, ctx.sample_rate, ctx.channels);
+                track_buffer.resize(output.len(), 0.0);
+                track_buffer.fill(0.0);
+                track.render(&mut track_buffer, &self.midi_clip_pool, ctx.playhead_seconds, ctx.sample_rate, ctx.channels);
+                // Accumulate peak level for VU metering (max over meter interval)
+                let buffer_peak = track_buffer.iter().map(|s| s.abs()).fold(0.0f32, f32::max);
+                track.peak_level = track.peak_level.max(buffer_peak);
+                // Mix into output
+                for (out, src) in output.iter_mut().zip(track_buffer.iter()) {
+                    *out += src;
+                }
+                buffer_pool.release(track_buffer);
             }
             Some(TrackNode::Group(group)) => {
                 // Skip rendering if playhead is outside the metatrack's trim window
@@ -534,6 +555,25 @@ impl Project {
         }
     }
 
+    /// Collect per-track peak levels for VU metering and reset accumulators
+    pub fn collect_track_peaks(&mut self) -> Vec<(TrackId, f32)> {
+        let mut levels = Vec::new();
+        for (id, track) in &mut self.tracks {
+            match track {
+                TrackNode::Audio(t) => {
+                    levels.push((*id, t.peak_level));
+                    t.peak_level = 0.0;
+                }
+                TrackNode::Midi(t) => {
+                    levels.push((*id, t.peak_level));
+                    t.peak_level = 0.0;
+                }
+                TrackNode::Group(_) => {}
+            }
+        }
+        levels
+    }
+
     /// Stop all notes on all MIDI tracks
     pub fn stop_all_notes(&mut self) {
         for track in self.tracks.values_mut() {

daw-backend/src/audio/track.rs

@@ -435,6 +435,10 @@ pub struct MidiTrack {
     /// Used to detect when the playhead exits a clip, so we can send all-notes-off.
     #[serde(skip)]
     prev_active_instances: HashSet<MidiClipInstanceId>,
+
+    /// Peak level of last render() call (for VU metering)
+    #[serde(skip, default)]
+    pub peak_level: f32,
 }
 
 impl Clone for MidiTrack {
@@ -452,6 +456,7 @@ impl Clone for MidiTrack {
             next_automation_id: self.next_automation_id,
             live_midi_queue: Vec::new(), // Don't clone live MIDI queue
             prev_active_instances: HashSet::new(),
+            peak_level: 0.0,
         }
     }
 }
@@ -479,6 +484,7 @@ impl MidiTrack {
             next_automation_id: 0,
             live_midi_queue: Vec::new(),
             prev_active_instances: HashSet::new(),
+            peak_level: 0.0,
         }
     }
 
@@ -705,6 +711,10 @@ pub struct AudioTrack {
     /// Pre-allocated buffer for clip rendering (avoids heap allocation per callback)
     #[serde(skip, default)]
     clip_render_buffer: Vec<f32>,
+
+    /// Peak level of last render() call (for VU metering)
+    #[serde(skip, default)]
+    pub peak_level: f32,
 }
 
 impl Clone for AudioTrack {
@@ -721,6 +731,7 @@ impl Clone for AudioTrack {
             effects_graph_preset: self.effects_graph_preset.clone(),
             effects_graph: default_audio_graph(), // Create fresh graph, not cloned
             clip_render_buffer: Vec::new(),
+            peak_level: 0.0,
         }
     }
 }
@@ -764,6 +775,7 @@ impl AudioTrack {
             effects_graph_preset: None,
             effects_graph,
             clip_render_buffer: Vec::new(),
+            peak_level: 0.0,
         }
     }
 
@@ -987,7 +999,7 @@ impl AudioTrack {
         }
 
         // Calculate combined gain
-        let combined_gain = clip.gain * self.volume;
+        let combined_gain = clip.gain;
 
         let mut total_rendered = 0;
 

daw-backend/src/command/types.rs

@@ -226,6 +226,12 @@ pub enum Command {
         priority: u8, // 0=Low, 1=Medium, 2=High
     },
 
+    // Input monitoring/gain commands
+    /// Enable or disable input monitoring (mic level metering)
+    SetInputMonitoring(bool),
+    /// Set the input gain multiplier (applied before recording)
+    SetInputGain(f32),
+
     // Async audio import
     /// Import an audio file asynchronously. The engine probes the file format
     /// and either memory-maps it (WAV/AIFF) or sets up stream decode
@@ -333,6 +339,13 @@ pub enum AudioEvent {
         channels: u32,
     },
 
+    /// Peak amplitude of mic input (for input monitoring meter)
+    InputLevel(f32),
+    /// Peak amplitude of mix output (for master meter), stereo (left, right)
+    OutputLevel(f32, f32),
+    /// Per-track playback peak levels
+    TrackLevels(Vec<(TrackId, f32)>),
+
     /// Background waveform decode progress/completion for a compressed audio file.
     /// Internal event — consumed by the engine to update the pool, not forwarded to UI.
     /// `decoded_frames` < `total_frames` means partial; equal means complete.

lightningbeam-ui/lightningbeam-core/src/actions/mod.rs

@@ -32,6 +32,7 @@ pub mod region_split;
 pub mod toggle_group_expansion;
 pub mod group_layers;
 pub mod raster_stroke;
+pub mod move_layer;
 
 pub use add_clip_instance::AddClipInstanceAction;
 pub use add_effect::AddEffectAction;
@@ -62,3 +63,4 @@ pub use region_split::RegionSplitAction;
 pub use toggle_group_expansion::ToggleGroupExpansionAction;
 pub use group_layers::GroupLayersAction;
 pub use raster_stroke::RasterStrokeAction;
+pub use move_layer::MoveLayerAction;

lightningbeam-ui/lightningbeam-core/src/actions/move_layer.rs

@@ -0,0 +1,137 @@
+use crate::action::Action;
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use uuid::Uuid;
+
+/// Action that moves one or more layers to a new position, possibly changing their parent group.
+/// All layers are inserted contiguously into the same target parent.
+/// Handles batch moves atomically: removes all, then inserts all, so indices stay consistent.
+pub struct MoveLayerAction {
+    /// (layer_id, old_parent_id) for each layer to move, in visual order (top to bottom)
+    layers: Vec<(Uuid, Option<Uuid>)>,
+    new_parent_id: Option<Uuid>,
+    /// Insertion index in the new parent's children vec AFTER all dragged layers have been removed
+    new_base_index: usize,
+    /// Stored during execute for rollback: (layer, old_parent_id, old_index_in_parent)
+    removed: Vec<(AnyLayer, Option<Uuid>, usize)>,
+}
+
+impl MoveLayerAction {
+    pub fn new(
+        layers: Vec<(Uuid, Option<Uuid>)>,
+        new_parent_id: Option<Uuid>,
+        new_base_index: usize,
+    ) -> Self {
+        Self {
+            layers,
+            new_parent_id,
+            new_base_index,
+            removed: Vec::new(),
+        }
+    }
+}
+
+fn get_parent_children(
+    document: &mut Document,
+    parent_id: Option<Uuid>,
+) -> Result<&mut Vec<AnyLayer>, String> {
+    match parent_id {
+        None => Ok(&mut document.root.children),
+        Some(id) => {
+            let layer = document
+                .root
+                .get_child_mut(&id)
+                .ok_or_else(|| format!("Parent group {} not found", id))?;
+            match layer {
+                AnyLayer::Group(g) => Ok(&mut g.children),
+                _ => Err(format!("Layer {} is not a group", id)),
+            }
+        }
+    }
+}
+
+impl Action for MoveLayerAction {
+    fn execute(&mut self, document: &mut Document) -> Result<(), String> {
+        self.removed.clear();
+
+        // Phase 1: Remove all layers from their old parents.
+        // Group removals by parent, then remove back-to-front within each parent.
+        // Collect (layer_id, old_parent_id) with their current index.
+        let mut removals: Vec<(Uuid, Option<Uuid>, usize)> = Vec::new();
+        for (layer_id, old_parent_id) in &self.layers {
+            let children = get_parent_children(document, *old_parent_id)?;
+            let idx = children.iter().position(|l| l.id() == *layer_id)
+                .ok_or_else(|| format!("Layer {} not found in parent", layer_id))?;
+            removals.push((*layer_id, *old_parent_id, idx));
+        }
+
+        // Sort by (parent, index) descending so we remove back-to-front
+        removals.sort_by(|a, b| {
+            a.1.cmp(&b.1).then(b.2.cmp(&a.2))
+        });
+
+        let mut removed_layers: Vec<(Uuid, AnyLayer, Option<Uuid>, usize)> = Vec::new();
+        for (layer_id, old_parent_id, idx) in &removals {
+            let children = get_parent_children(document, *old_parent_id)?;
+            let layer = children.remove(*idx);
+            removed_layers.push((*layer_id, layer, *old_parent_id, *idx));
+        }
+
+        // Phase 2: Insert all at new parent, in visual order (self.layers order).
+        // self.new_base_index is the index in the post-removal children vec.
+        let new_children = get_parent_children(document, self.new_parent_id)?;
+        let base = self.new_base_index.min(new_children.len());
+
+        // Insert in forward visual order, all at `base`. Each insert pushes the previous
+        // one to a higher children index. Since the timeline displays children in reverse,
+        // a higher children index = visually higher. So the first visual layer (layers[0])
+        // ends up at the highest children index = visually topmost. Correct.
+        for (layer_id, _) in self.layers.iter() {
+            // Find this layer in removed_layers
+            let pos = removed_layers.iter().position(|(id, _, _, _)| id == layer_id)
+                .ok_or_else(|| format!("Layer {} missing from removed set", layer_id))?;
+            let (_, layer, old_parent_id, old_idx) = removed_layers.remove(pos);
+            self.removed.push((layer.clone(), old_parent_id, old_idx));
+
+            let new_children = get_parent_children(document, self.new_parent_id)?;
+            let insert_at = base.min(new_children.len());
+            new_children.insert(insert_at, layer);
+        }
+
+        Ok(())
+    }
+
+    fn rollback(&mut self, document: &mut Document) -> Result<(), String> {
+        if self.removed.is_empty() {
+            return Err("Cannot rollback: action was not executed".to_string());
+        }
+
+        // Phase 1: Remove all layers from new parent (back-to-front by insertion order).
+        for (layer_id, _) in self.layers.iter().rev() {
+            let new_children = get_parent_children(document, self.new_parent_id)?;
+            let pos = new_children.iter().position(|l| l.id() == *layer_id)
+                .ok_or_else(|| format!("Layer {} not found in new parent for rollback", layer_id))?;
+            new_children.remove(pos);
+        }
+
+        // Phase 2: Re-insert at old positions, sorted by (parent, index) ascending.
+        let mut restore: Vec<(AnyLayer, Option<Uuid>, usize)> = self.removed.drain(..).collect();
+        restore.sort_by(|a, b| a.1.cmp(&b.1).then(a.2.cmp(&b.2)));
+
+        for (layer, old_parent_id, old_idx) in restore {
+            let children = get_parent_children(document, old_parent_id)?;
+            let idx = old_idx.min(children.len());
+            children.insert(idx, layer);
+        }
+
+        Ok(())
+    }
+
+    fn description(&self) -> String {
+        if self.layers.len() == 1 {
+            "Move layer".to_string()
+        } else {
+            format!("Move {} layers", self.layers.len())
+        }
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/set_layer_properties.rs

@@ -12,6 +12,7 @@ use uuid::Uuid;
 #[derive(Clone, Debug)]
 pub enum LayerProperty {
     Volume(f64),
+    InputGain(f64),
     Muted(bool),
     Soloed(bool),
     Locked(bool),
@@ -25,6 +26,7 @@ pub enum LayerProperty {
 #[derive(Clone, Debug)]
 enum OldValue {
     Volume(f64),
+    InputGain(f64),
     Muted(bool),
     Soloed(bool),
     Locked(bool),
@@ -85,6 +87,7 @@ impl Action for SetLayerPropertiesAction {
                 if self.old_values[i].is_none() {
                     self.old_values[i] = Some(match &self.property {
                         LayerProperty::Volume(_) => OldValue::Volume(layer.volume()),
+                        LayerProperty::InputGain(_) => OldValue::InputGain(layer.layer().input_gain),
                         LayerProperty::Muted(_) => OldValue::Muted(layer.muted()),
                         LayerProperty::Soloed(_) => OldValue::Soloed(layer.soloed()),
                         LayerProperty::Locked(_) => OldValue::Locked(layer.locked()),
@@ -104,6 +107,7 @@ impl Action for SetLayerPropertiesAction {
                 // Set new value
                 match &self.property {
                     LayerProperty::Volume(v) => layer.set_volume(*v),
+                    LayerProperty::InputGain(g) => layer.layer_mut().input_gain = *g,
                     LayerProperty::Muted(m) => layer.set_muted(*m),
                     LayerProperty::Soloed(s) => layer.set_soloed(*s),
                     LayerProperty::Locked(l) => layer.set_locked(*l),
@@ -128,6 +132,7 @@ impl Action for SetLayerPropertiesAction {
                 if let Some(old_value) = &self.old_values[i] {
                     match old_value {
                         OldValue::Volume(v) => layer.set_volume(*v),
+                        OldValue::InputGain(g) => layer.layer_mut().input_gain = *g,
                         OldValue::Muted(m) => layer.set_muted(*m),
                         OldValue::Soloed(s) => layer.set_soloed(*s),
                         OldValue::Locked(l) => layer.set_locked(*l),
@@ -159,6 +164,7 @@ impl Action for SetLayerPropertiesAction {
             if let Some(&track_id) = backend.layer_to_track_map.get(&layer_id) {
                 match &self.property {
                     LayerProperty::Volume(v) => controller.set_track_volume(track_id, *v as f32),
+                    LayerProperty::InputGain(g) => controller.set_input_gain(*g as f32),
                     LayerProperty::Muted(m) => controller.set_track_mute(track_id, *m),
                     LayerProperty::Soloed(s) => controller.set_track_solo(track_id, *s),
                     _ => {} // Locked/Opacity/Visible/CameraEnabled are UI-only
@@ -183,6 +189,7 @@ impl Action for SetLayerPropertiesAction {
                 if let Some(old_value) = &self.old_values[i] {
                     match old_value {
                         OldValue::Volume(v) => controller.set_track_volume(track_id, *v as f32),
+                        OldValue::InputGain(g) => controller.set_input_gain(*g as f32),
                         OldValue::Muted(m) => controller.set_track_mute(track_id, *m),
                         OldValue::Soloed(s) => controller.set_track_solo(track_id, *s),
                         _ => {} // Locked/Opacity/Visible are UI-only
@@ -196,6 +203,7 @@ impl Action for SetLayerPropertiesAction {
     fn description(&self) -> String {
         let property_name = match &self.property {
             LayerProperty::Volume(_) => "volume",
+            LayerProperty::InputGain(_) => "input gain",
             LayerProperty::Muted(_) => "mute",
             LayerProperty::Soloed(_) => "solo",
             LayerProperty::Locked(_) => "lock",

lightningbeam-ui/lightningbeam-core/src/layer.rs

@@ -63,6 +63,8 @@ pub trait LayerTrait {
     fn set_locked(&mut self, locked: bool);
 }
 
+fn default_input_gain() -> f64 { 1.0 }
+
 /// Base layer structure
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Layer {
@@ -87,6 +89,10 @@ pub struct Layer {
     /// Audio volume (1.0 = 100%, affects nested audio layers/clips)
     pub volume: f64,
 
+    /// Input gain for recording (1.0 = unity, range 0.0–4.0)
+    #[serde(default = "default_input_gain")]
+    pub input_gain: f64,
+
     /// Audio mute state
     pub muted: bool,
 
@@ -111,6 +117,7 @@ impl Layer {
             visible: true,
             opacity: 1.0,
             volume: 1.0,             // 100% volume
+            input_gain: 1.0,
             muted: false,
             soloed: false,
             locked: false,
@@ -128,6 +135,7 @@ impl Layer {
             visible: true,
             opacity: 1.0,
             volume: 1.0,
+            input_gain: 1.0,
             muted: false,
             soloed: false,
             locked: false,

lightningbeam-ui/lightningbeam-core/src/webcam.rs

@@ -359,12 +359,19 @@ fn capture_thread_main(
     let mut decoded_frame = ffmpeg::frame::Video::empty();
     let mut rgba_frame = ffmpeg::frame::Video::empty();
 
+    // Helper closure: decode current packet, scale, send preview frame, and
+    // optionally encode into the active recorder.  Returns updated frame_count.
+    let row_bytes = (width * 4) as usize;
+
+    let mut stop_result_tx: Option<std::sync::mpsc::Sender<Result<RecordingResult, String>>> = None;
+
     'outer: for (stream_ref, packet) in input.packets() {
         if stream_ref.index() != stream_index {
             continue;
         }
 
-        // Check for commands (non-blocking).
+        // Check for commands BEFORE decoding so that StartRecording takes effect
+        // on the current packet (no lost frame at the start).
         while let Ok(cmd) = cmd_rx.try_recv() {
             match cmd {
                 CaptureCommand::StartRecording {
@@ -384,20 +391,19 @@ fn capture_thread_main(
                     }
                 }
                 CaptureCommand::StopRecording { result_tx } => {
-                    if let Some(rec) = recorder.take() {
+                    eprintln!("[WEBCAM stop] StopRecording command received on capture thread");
-                        let _ = result_tx.send(rec.finish());
+                    // Defer stop until AFTER we decode this packet, so the
-                    } else {
+                    // current frame is captured before we finalize.
-                        let _ = result_tx.send(Err("Not recording".into()));
+                    stop_result_tx = Some(result_tx);
-                    }
                 }
                 CaptureCommand::Shutdown => break 'outer,
             }
         }
 
+        // Decode current packet and process frames.
         decoder.send_packet(&packet).ok();
 
         while decoder.receive_frame(&mut decoded_frame).is_ok() {
-            // Skip initial corrupt frames from v4l2
             if frame_count < SKIP_INITIAL_FRAMES {
                 frame_count += 1;
                 continue;
@@ -407,10 +413,8 @@ fn capture_thread_main(
 
             let timestamp = start_time.elapsed().as_secs_f64();
 
-            // Build tightly-packed RGBA data (remove stride padding).
             let data = rgba_frame.data(0);
             let stride = rgba_frame.stride(0);
-            let row_bytes = (width * 4) as usize;
 
             let rgba_data = if stride == row_bytes {
                 data[..row_bytes * height as usize].to_vec()
@@ -433,13 +437,52 @@ fn capture_thread_main(
             let _ = frame_tx.try_send(frame);
 
             if let Some(ref mut rec) = recorder {
-                if let Err(e) = rec.encode_rgba(&rgba_arc, width, height, frame_count) {
+                if let Err(e) = rec.encode_rgba(&rgba_arc, width, height, timestamp) {
                     eprintln!("[webcam] recording encode error: {e}");
                 }
             }
 
             frame_count += 1;
         }
+
+        // Now handle deferred StopRecording (after the current packet is decoded).
+        if let Some(result_tx) = stop_result_tx.take() {
+            if let Some(mut rec) = recorder.take() {
+                // Flush any frames still buffered in the decoder.
+                let pre_drain_count = frame_count;
+                decoder.send_eof().ok();
+                while decoder.receive_frame(&mut decoded_frame).is_ok() {
+                    if frame_count < SKIP_INITIAL_FRAMES {
+                        frame_count += 1;
+                        continue;
+                    }
+                    scaler.run(&decoded_frame, &mut rgba_frame).ok();
+                    let timestamp = start_time.elapsed().as_secs_f64();
+                    let data = rgba_frame.data(0);
+                    let stride = rgba_frame.stride(0);
+                    let rgba_data = if stride == row_bytes {
+                        data[..row_bytes * height as usize].to_vec()
+                    } else {
+                        let mut buf = Vec::with_capacity(row_bytes * height as usize);
+                        for y in 0..height as usize {
+                            buf.extend_from_slice(&data[y * stride..y * stride + row_bytes]);
+                        }
+                        buf
+                    };
+                    let _ = rec.encode_rgba(&rgba_data, width, height, timestamp);
+                    frame_count += 1;
+                }
+                eprintln!(
+                    "[WEBCAM stop] drained {} extra frames from decoder (total frames={})",
+                    frame_count - pre_drain_count, frame_count
+                );
+                // Reset the decoder so it can accept new packets for preview.
+                decoder.flush();
+                let _ = result_tx.send(rec.finish());
+            } else {
+                let _ = result_tx.send(Err("Not recording".into()));
+            }
+        }
     }
 
     // Clean up: if still recording when shutting down, finalize.
@@ -463,6 +506,10 @@ struct FrameRecorder {
     path: PathBuf,
     frame_count: u64,
     fps: f64,
+    /// Timestamp of the first recorded frame (for offsetting PTS to start at 0)
+    first_timestamp: Option<f64>,
+    /// Timestamp of the most recent frame (for computing actual duration)
+    last_timestamp: f64,
 }
 
 impl FrameRecorder {
@@ -510,7 +557,10 @@ impl FrameRecorder {
         encoder.set_width(aligned_width);
         encoder.set_height(aligned_height);
         encoder.set_format(pixel_format);
-        encoder.set_time_base(ffmpeg::Rational(1, fps as i32));
+        // Use microsecond time base for precise timestamp-based PTS.
+        // This avoids speedup artifacts when the camera delivers frames
+        // at irregular intervals (common under CPU load or with USB cameras).
+        encoder.set_time_base(ffmpeg::Rational(1, 1_000_000));
         encoder.set_frame_rate(Some(ffmpeg::Rational(fps as i32, 1)));
 
         if codec_id == ffmpeg::codec::Id::H264 {
@@ -549,6 +599,8 @@ impl FrameRecorder {
             path: path.clone(),
             frame_count: 0,
             fps,
+            first_timestamp: None,
+            last_timestamp: 0.0,
         })
     }
 
@@ -557,7 +609,7 @@ impl FrameRecorder {
         rgba_data: &[u8],
         width: u32,
         height: u32,
-        _global_frame: u64,
+        timestamp: f64,
     ) -> Result<(), String> {
         let mut src_frame =
             ffmpeg::frame::Video::new(ffmpeg::format::Pixel::RGBA, width, height);
@@ -576,8 +628,15 @@ impl FrameRecorder {
             .run(&src_frame, &mut dst_frame)
             .map_err(|e| format!("Scale: {e}"))?;
 
-        dst_frame.set_pts(Some(self.frame_count as i64));
+        // PTS in microseconds from actual capture timestamps.
+        // Time base is 1/1000000, so PTS = elapsed_seconds * 1000000.
+        // This ensures correct playback timing even when the camera delivers
+        // frames at irregular intervals (e.g. under CPU load).
+        let first_ts = *self.first_timestamp.get_or_insert(timestamp);
+        let elapsed_us = ((timestamp - first_ts).max(0.0) * 1_000_000.0) as i64;
+        dst_frame.set_pts(Some(elapsed_us));
         self.frame_count += 1;
+        self.last_timestamp = timestamp;
 
         self.encoder
             .send_frame(&dst_frame)
@@ -616,7 +675,14 @@ impl FrameRecorder {
             .write_trailer()
             .map_err(|e| format!("Write trailer: {e}"))?;
 
-        let duration = self.frame_count as f64 / self.fps;
+        let duration = match self.first_timestamp {
+            Some(first_ts) => self.last_timestamp - first_ts,
+            None => self.frame_count as f64 / self.fps,
+        };
+        eprintln!(
+            "[WEBCAM finish] frames={}, first_ts={:?}, last_ts={:.4}, duration={:.4}s, fps={}",
+            self.frame_count, self.first_timestamp, self.last_timestamp, duration, self.fps,
+        );
         Ok(RecordingResult {
             file_path: self.path,
             duration,

lightningbeam-ui/lightningbeam-editor/src/main.rs

@@ -786,8 +786,6 @@ struct EditorApp {
     webcam_frame: Option<lightningbeam_core::webcam::CaptureFrame>,
     /// Pending webcam recording command (set by timeline, processed in update)
     webcam_record_command: Option<panes::WebcamRecordCommand>,
-    /// Layer being recorded to via webcam
-    webcam_recording_layer_id: Option<Uuid>,
     // Track ID mapping (Document layer UUIDs <-> daw-backend TrackIds)
     layer_to_track_map: HashMap<Uuid, daw_backend::TrackId>,
     track_to_layer_map: HashMap<daw_backend::TrackId, Uuid>,
@@ -808,7 +806,7 @@ struct EditorApp {
     is_recording: bool,                   // Whether recording is currently active
     recording_clips: HashMap<Uuid, u32>,  // layer_id -> backend clip_id during recording
     recording_start_time: f64,            // Playback time when recording started
-    recording_layer_id: Option<Uuid>,     // Layer being recorded to (for creating clips)
+    recording_layer_ids: Vec<Uuid>,       // Layers being recorded to (for creating clips)
     // Asset drag-and-drop state
     dragging_asset: Option<panes::DraggingAsset>, // Asset being dragged from Asset Library
     // Clipboard
@@ -831,6 +829,11 @@ struct EditorApp {
     region_selection: Option<lightningbeam_core::selection::RegionSelection>,
     region_select_mode: lightningbeam_core::tool::RegionSelectMode,
 
+    // VU meter levels
+    input_level: f32,
+    output_level: (f32, f32),
+    track_levels: HashMap<daw_backend::TrackId, f32>,
+
     /// Cache for MIDI event data (keyed by backend midi_clip_id)
     /// Prevents repeated backend queries for the same MIDI clip
     /// Format: (timestamp, note_number, velocity, is_note_on)
@@ -1051,7 +1054,6 @@ impl EditorApp {
             webcam: None,
             webcam_frame: None,
             webcam_record_command: None,
-            webcam_recording_layer_id: None,
             layer_to_track_map: HashMap::new(),
             track_to_layer_map: HashMap::new(),
             clip_to_metatrack_map: HashMap::new(),
@@ -1064,7 +1066,7 @@ impl EditorApp {
             is_recording: false,              // Not recording initially
             recording_clips: HashMap::new(),  // No active recording clips
             recording_start_time: 0.0,        // Will be set when recording starts
-            recording_layer_id: None,         // Will be set when recording starts
+            recording_layer_ids: Vec::new(),  // Will be populated when recording starts
             dragging_asset: None, // No asset being dragged initially
             clipboard_manager: lightningbeam_core::clipboard::ClipboardManager::new(),
             effect_to_load: None,
@@ -1079,6 +1081,9 @@ impl EditorApp {
             polygon_sides: 5,                // Default to pentagon
             region_selection: None,
             region_select_mode: lightningbeam_core::tool::RegionSelectMode::default(),
+            input_level: 0.0,
+            output_level: (0.0, 0.0),
+            track_levels: HashMap::new(),
             midi_event_cache: HashMap::new(), // Initialize empty MIDI event cache
             audio_duration_cache: HashMap::new(), // Initialize empty audio duration cache
             audio_pools_with_new_waveforms: HashSet::new(), // Track pool indices with new raw audio
@@ -4099,12 +4104,8 @@ impl eframe::App for EditorApp {
 
         // Webcam management: open/close based on camera_enabled layers, poll frames
         {
-            let any_camera_enabled = self.action_executor.document().root.children.iter().any(|layer| {
+            let any_camera_enabled = self.action_executor.document().all_layers().iter().any(|layer| {
-                if let lightningbeam_core::layer::AnyLayer::Video(v) = layer {
+                matches!(layer, lightningbeam_core::layer::AnyLayer::Video(v) if v.camera_enabled)
-                    v.camera_enabled
-                } else {
-                    false
-                }
             });
 
             if any_camera_enabled && self.webcam.is_none() {
@@ -4388,8 +4389,9 @@ impl eframe::App for EditorApp {
                         AudioEvent::RecordingStarted(track_id, backend_clip_id, rec_sample_rate, rec_channels) => {
                             println!("🎤 Recording started on track {:?}, backend_clip_id={}", track_id, backend_clip_id);
 
-                            // Create clip in document and add instance to layer
+                            // Create clip in document and add instance to the layer for this track
-                            if let Some(layer_id) = self.recording_layer_id {
+                            if let Some(&layer_id) = self.track_to_layer_map.get(&track_id) {
+                                if self.recording_layer_ids.contains(&layer_id) {
                                     use lightningbeam_core::clip::{AudioClip, ClipInstance};
 
                                     // Create a recording-in-progress clip (no pool index yet)
@@ -4411,17 +4413,22 @@ impl eframe::App for EditorApp {
                                     // Store mapping for later updates
                                     self.recording_clips.insert(layer_id, backend_clip_id);
                                 }
+                            }
 
                             // Initialize live waveform cache for recording
                             self.raw_audio_cache.insert(usize::MAX, (Arc::new(Vec::new()), rec_sample_rate, rec_channels));
 
                             ctx.request_repaint();
                         }
-                        AudioEvent::RecordingProgress(_clip_id, duration) => {
+                        AudioEvent::RecordingProgress(_backend_clip_id, duration) => {
                             // Update clip duration as recording progresses
-                            if let Some(layer_id) = self.recording_layer_id {
+                            // Find which layer this backend clip belongs to via recording_clips
-                                // First, find the clip_id from the layer (read-only borrow)
+                            let layer_id = self.recording_clips.iter()
-                                let clip_id = {
+                                .find(|(_, &cid)| cid == _backend_clip_id)
+                                .map(|(&lid, _)| lid);
+                            if let Some(layer_id) = layer_id {
+                                // First, find the doc clip_id from the layer (read-only borrow)
+                                let doc_clip_id = {
                                     let document = self.action_executor.document();
                                     document.get_layer(&layer_id)
                                         .and_then(|layer| {
@@ -4434,8 +4441,8 @@ impl eframe::App for EditorApp {
                                 };
 
                                 // Then update the clip duration (mutable borrow)
-                                if let Some(clip_id) = clip_id {
+                                if let Some(doc_clip_id) = doc_clip_id {
-                                    if let Some(clip) = self.action_executor.document_mut().audio_clips.get_mut(&clip_id) {
+                                    if let Some(clip) = self.action_executor.document_mut().audio_clips.get_mut(&doc_clip_id) {
                                         if clip.is_recording() {
                                             clip.duration = duration;
                                         }
@@ -4445,7 +4452,7 @@ impl eframe::App for EditorApp {
                             ctx.request_repaint();
                         }
                         AudioEvent::RecordingStopped(_backend_clip_id, pool_index, _waveform) => {
-                            println!("🎤 Recording stopped: pool_index={}", pool_index);
+                            eprintln!("[STOP] AudioEvent::RecordingStopped received (pool_index={})", pool_index);
 
                             // Clean up live recording waveform cache
                             self.raw_audio_cache.remove(&usize::MAX);
@@ -4469,7 +4476,7 @@ impl eframe::App for EditorApp {
                                 let mut controller = controller_arc.lock().unwrap();
                                 match controller.get_pool_file_info(pool_index) {
                                     Ok((dur, _, _)) => {
-                                        println!("✅ Got duration from backend: {:.2}s", dur);
+                                        eprintln!("[AUDIO] Got duration from backend: {:.4}s", dur);
                                         self.audio_duration_cache.insert(pool_index, dur);
                                         dur
                                     }
@@ -4484,7 +4491,11 @@ impl eframe::App for EditorApp {
 
                             // Finalize the recording clip with real pool_index and duration
                             // and sync to backend for playback
-                            if let Some(layer_id) = self.recording_layer_id {
+                            // Find which layer this recording belongs to via recording_clips
+                            let recording_layer = self.recording_clips.iter()
+                                .find(|(_, &cid)| cid == _backend_clip_id)
+                                .map(|(&lid, _)| lid);
+                            if let Some(layer_id) = recording_layer {
                                 // First, find the clip instance and clip id
                                 let (clip_id, instance_id, timeline_start, trim_start) = {
                                     let document = self.action_executor.document();
@@ -4506,7 +4517,7 @@ impl eframe::App for EditorApp {
                                     if let Some(clip) = self.action_executor.document_mut().audio_clips.get_mut(&clip_id) {
                                         if clip.finalize_recording(pool_index, duration) {
                                             clip.name = format!("Recording {}", pool_index);
-                                            println!("✅ Finalized recording clip: pool={}, duration={:.2}s", pool_index, duration);
+                                            eprintln!("[AUDIO] Finalized recording clip: pool={}, duration={:.4}s", pool_index, duration);
                                         }
                                     }
 
@@ -4548,22 +4559,32 @@ impl eframe::App for EditorApp {
                                 }
                             }
 
-                            // Clear recording state
+                            // Remove this layer from active recordings
+                            if let Some(layer_id) = recording_layer {
+                                self.recording_layer_ids.retain(|id| *id != layer_id);
+                                self.recording_clips.remove(&layer_id);
+                            }
+                            // Clear global recording state only when all recordings are done
+                            if self.recording_layer_ids.is_empty() {
                                 self.is_recording = false;
                                 self.recording_clips.clear();
-                            self.recording_layer_id = None;
+                            }
                             ctx.request_repaint();
                         }
                         AudioEvent::RecordingError(message) => {
                             eprintln!("❌ Recording error: {}", message);
                             self.is_recording = false;
                             self.recording_clips.clear();
-                            self.recording_layer_id = None;
+                            self.recording_layer_ids.clear();
                             ctx.request_repaint();
                         }
                         AudioEvent::MidiRecordingProgress(_track_id, clip_id, duration, notes) => {
                             // Update clip duration in document (so timeline bar grows)
-                            if let Some(layer_id) = self.recording_layer_id {
+                            // Find layer for this track via track_to_layer_map
+                            let midi_layer_id = self.track_to_layer_map.get(&_track_id)
+                                .filter(|lid| self.recording_layer_ids.contains(lid))
+                                .copied();
+                            if let Some(layer_id) = midi_layer_id {
                                 let doc_clip_id = {
                                     let document = self.action_executor.document();
                                     document.get_layer(&layer_id)
@@ -4622,7 +4643,10 @@ impl eframe::App for EditorApp {
                                         self.midi_event_cache.insert(clip_id, cache_events);
 
                                         // Update document clip with final duration and name
-                                        if let Some(layer_id) = self.recording_layer_id {
+                                        let midi_layer_id = self.track_to_layer_map.get(&track_id)
+                                            .filter(|lid| self.recording_layer_ids.contains(lid))
+                                            .copied();
+                                        if let Some(layer_id) = midi_layer_id {
                                             let doc_clip_id = {
                                                 let document = self.action_executor.document();
                                                 document.get_layer(&layer_id)
@@ -4656,10 +4680,15 @@ impl eframe::App for EditorApp {
                             // The backend created the instance in create_midi_clip(), but doesn't
                             // report the instance_id back. Needed for move/trim operations later.
 
-                            // Clear recording state
+                            // Remove this MIDI layer from active recordings
+                            if let Some(&layer_id) = self.track_to_layer_map.get(&track_id) {
+                                self.recording_layer_ids.retain(|id| *id != layer_id);
+                                self.recording_clips.remove(&layer_id);
+                            }
+                            if self.recording_layer_ids.is_empty() {
                                 self.is_recording = false;
                                 self.recording_clips.clear();
-                            self.recording_layer_id = None;
+                            }
                             ctx.request_repaint();
                         }
                         AudioEvent::AudioFileReady { pool_index, path, channels, sample_rate, duration, format } => {
@@ -4706,6 +4735,19 @@ impl eframe::App for EditorApp {
                             );
                             ctx.request_repaint();
                         }
+                        AudioEvent::InputLevel(peak) => {
+                            self.input_level = self.input_level.max(peak);
+                        }
+                        AudioEvent::OutputLevel(peak_l, peak_r) => {
+                            self.output_level.0 = self.output_level.0.max(peak_l);
+                            self.output_level.1 = self.output_level.1.max(peak_r);
+                        }
+                        AudioEvent::TrackLevels(levels) => {
+                            for (track_id, peak) in levels {
+                                let entry = self.track_levels.entry(track_id).or_insert(0.0);
+                                *entry = entry.max(peak);
+                            }
+                        }
                         _ => {} // Ignore other events for now
                     }
                 }
@@ -4720,6 +4762,39 @@ impl eframe::App for EditorApp {
             }
         }
 
+        // Update input monitoring based on active layer
+        if let Some(controller) = &self.audio_controller {
+            let should_monitor = self.active_layer_id.map_or(false, |layer_id| {
+                let doc = self.action_executor.document();
+                if let Some(layer) = doc.get_layer(&layer_id) {
+                    matches!(layer, lightningbeam_core::layer::AnyLayer::Audio(a) if a.audio_layer_type == lightningbeam_core::layer::AudioLayerType::Sampled)
+                } else {
+                    false
+                }
+            });
+            if let Ok(mut ctrl) = controller.try_lock() {
+                ctrl.set_input_monitoring(should_monitor);
+            }
+        }
+
+        // Decay VU meter levels (~1.5s full fall at 60fps)
+        {
+            let decay = 0.97f32;
+            self.input_level *= decay;
+            self.output_level.0 *= decay;
+            self.output_level.1 *= decay;
+            for level in self.track_levels.values_mut() {
+                *level *= decay;
+            }
+            // Request repaint while any level is visible
+            let any_active = self.input_level > 0.001
+                || self.output_level.0 > 0.001 || self.output_level.1 > 0.001
+                || self.track_levels.values().any(|&v| v > 0.001);
+            if any_active {
+                ctx.request_repaint();
+            }
+        }
+
         let _post_events_ms = _frame_start.elapsed().as_secs_f64() * 1000.0;
 
         // Request continuous repaints when playing to update time display
@@ -5090,7 +5165,7 @@ impl eframe::App for EditorApp {
                     is_recording: &mut self.is_recording,
                     recording_clips: &mut self.recording_clips,
                     recording_start_time: &mut self.recording_start_time,
-                    recording_layer_id: &mut self.recording_layer_id,
+                    recording_layer_ids: &mut self.recording_layer_ids,
                     dragging_asset: &mut self.dragging_asset,
                     stroke_width: &mut self.stroke_width,
                     fill_enabled: &mut self.fill_enabled,
@@ -5113,6 +5188,10 @@ impl eframe::App for EditorApp {
                     target_format: self.target_format,
                     pending_menu_actions: &mut pending_menu_actions,
                     clipboard_manager: &mut self.clipboard_manager,
+                    input_level: self.input_level,
+                    output_level: self.output_level,
+                    track_levels: &self.track_levels,
+                    track_to_layer_map: &self.track_to_layer_map,
                     waveform_stereo: self.config.waveform_stereo,
                     project_generation: &mut self.project_generation,
                     script_to_edit: &mut self.script_to_edit,
@@ -5216,7 +5295,7 @@ impl eframe::App for EditorApp {
             // Process webcam recording commands from timeline
             if let Some(cmd) = self.webcam_record_command.take() {
                 match cmd {
-                    panes::WebcamRecordCommand::Start { layer_id } => {
+                    panes::WebcamRecordCommand::Start { .. } => {
                         // Ensure webcam is open
                         if self.webcam.is_none() {
                             if let Some(device) = lightningbeam_core::webcam::default_camera() {
@@ -5250,7 +5329,6 @@ impl eframe::App for EditorApp {
                             let recording_path = recording_dir.join(format!("webcam_recording_{}.{}", timestamp, ext));
                             match webcam.start_recording(recording_path, codec) {
                                 Ok(()) => {
-                                    self.webcam_recording_layer_id = Some(layer_id);
                                     eprintln!("[WEBCAM] Recording started");
                                 }
                                 Err(e) => {
@@ -5260,13 +5338,25 @@ impl eframe::App for EditorApp {
                         }
                     }
                     panes::WebcamRecordCommand::Stop => {
+                        eprintln!("[STOP] Webcam stop command processed (main.rs handler)");
+                        // Find the webcam recording layer before stopping (need it for cleanup)
+                        let webcam_layer_id = {
+                            let document = self.action_executor.document();
+                            self.recording_layer_ids.iter().copied().find(|lid| {
+                                document.get_layer(lid).map_or(false, |l| {
+                                    matches!(l, lightningbeam_core::layer::AnyLayer::Video(v) if v.camera_enabled)
+                                })
+                            })
+                        };
                         if let Some(webcam) = &mut self.webcam {
+                            let stop_t = std::time::Instant::now();
                             match webcam.stop_recording() {
                                 Ok(result) => {
+                                    eprintln!("[STOP] webcam.stop_recording() returned in {:.1}ms", stop_t.elapsed().as_secs_f64() * 1000.0);
                                     let file_path_str = result.file_path.to_string_lossy().to_string();
-                                    eprintln!("[WEBCAM] Recording saved to: {}", file_path_str);
+                                    eprintln!("[WEBCAM] Recording saved to: {} (recorder duration={:.4}s)", file_path_str, result.duration);
                                     // Create VideoClip + ClipInstance from recorded file
-                                    if let Some(layer_id) = self.webcam_recording_layer_id.take() {
+                                    if let Some(layer_id) = webcam_layer_id {
                                         match lightningbeam_core::video::probe_video(&file_path_str) {
                                             Ok(info) => {
                                                 use lightningbeam_core::clip::{VideoClip, ClipInstance};
@@ -5344,7 +5434,10 @@ impl eframe::App for EditorApp {
                                                     }
                                                 });
 
-                                                eprintln!("[WEBCAM] Created video clip: {:.1}s @ {:.1}fps", duration, info.fps);
+                                                eprintln!(
+                                                    "[WEBCAM] probe_video: duration={:.4}s, fps={:.1}, {}x{}. Using probe duration for clip.",
+                                                    info.duration, info.fps, info.width, info.height,
+                                                );
                                             }
                                             Err(e) => {
                                                 eprintln!("[WEBCAM] Failed to probe recorded video: {}", e);
@@ -5354,12 +5447,18 @@ impl eframe::App for EditorApp {
                                 }
                                 Err(e) => {
                                     eprintln!("[WEBCAM] Failed to stop recording: {}", e);
-                                    self.webcam_recording_layer_id = None;
+                                    // webcam layer cleanup handled by recording_layer_ids.clear() below
                                 }
                             }
                         }
+                        // Remove webcam layer from active recordings
+                        if let Some(wid) = webcam_layer_id {
+                            self.recording_layer_ids.retain(|id| *id != wid);
+                        }
+                        if self.recording_layer_ids.is_empty() {
                             self.is_recording = false;
-                        self.recording_layer_id = None;
+                            self.recording_clips.clear();
+                        }
                     }
                 }
             }

lightningbeam-ui/lightningbeam-editor/src/panes/mod.rs

@@ -57,8 +57,10 @@ pub struct DraggingAsset {
 
 /// Command for webcam recording (issued by timeline, processed by main)
 #[derive(Debug)]
+#[allow(dead_code)]
 pub enum WebcamRecordCommand {
     /// Start recording on the given video layer
+    // TODO: remove layer_id — recording_layer_ids now tracks which layers are recording
     Start { layer_id: uuid::Uuid },
     /// Stop current webcam recording
     Stop,
@@ -203,7 +205,7 @@ pub struct SharedPaneState<'a> {
     pub is_recording: &'a mut bool,  // Whether recording is currently active
     pub recording_clips: &'a mut std::collections::HashMap<uuid::Uuid, u32>, // layer_id -> clip_id
     pub recording_start_time: &'a mut f64,  // Playback time when recording started
-    pub recording_layer_id: &'a mut Option<uuid::Uuid>,  // Layer being recorded to
+    pub recording_layer_ids: &'a mut Vec<uuid::Uuid>,  // Layers being recorded to
     /// Asset being dragged from Asset Library (for cross-pane drag-and-drop)
     pub dragging_asset: &'a mut Option<DraggingAsset>,
     // Tool-specific options for infopanel
@@ -247,6 +249,12 @@ pub struct SharedPaneState<'a> {
     pub pending_menu_actions: &'a mut Vec<crate::menu::MenuAction>,
     /// Clipboard manager for cut/copy/paste operations
     pub clipboard_manager: &'a mut lightningbeam_core::clipboard::ClipboardManager,
+    // VU meter levels
+    pub input_level: f32,
+    pub output_level: (f32, f32),
+    pub track_levels: &'a std::collections::HashMap<daw_backend::TrackId, f32>,
+    #[allow(dead_code)] // Available for panes that need reverse track->layer lookup
+    pub track_to_layer_map: &'a std::collections::HashMap<daw_backend::TrackId, Uuid>,
     /// Whether to show waveforms as stacked stereo (true) or combined mono (false)
     pub waveform_stereo: bool,
     /// Generation counter - incremented on project load to force reloads

lightningbeam-ui/lightningbeam-editor/src/panes/shaders/canvas_blit.wgsl

@@ -67,17 +67,21 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
     }
 
     // The canvas stores premultiplied linear RGBA.
-    // The srgb_to_linear converter downstream applies the sRGB gamma formula
+    // The downstream pipeline (srgb_to_linear → compositor) expects the sRGB
-    // channel-by-channel without alpha awareness.  To make the round-trip
+    // buffer to contain straight-alpha sRGB, i.e. the same format Vello outputs:
-    // transparent we pre-encode with linear_to_srgb here:
+    //   sRGB buffer: srgb(r_straight), srgb(g_straight), srgb(b_straight), a
-    //   canvas (linear premul) → sRGB buffer → srgb_to_linear → linear premul ✓
+    //   srgb_to_linear: r_straight, g_straight, b_straight, a   (linear straight)
-    // Without this, srgb_to_linear darkens small premultiplied values
+    //   compositor:  r_straight * a * opacity  (premultiplied, correct)
-    // (e.g. white at 10% opacity: 0.1 → 0.01), producing a grey halo.
+    //
+    // Without unpremultiplying, the compositor would double-premultiply:
+    //   src = (premul_r, premul_g, premul_b, a)  → output = premul_r * a = r * a²
+    // which produces a dark halo over transparent regions.
     let c = textureSample(canvas_tex, canvas_sampler, canvas_uv);
+    let inv_a = select(0.0, 1.0 / c.a, c.a > 1e-6);
     return vec4<f32>(
-        linear_to_srgb(c.r),
+        linear_to_srgb(c.r * inv_a),
-        linear_to_srgb(c.g),
+        linear_to_srgb(c.g * inv_a),
-        linear_to_srgb(c.b),
+        linear_to_srgb(c.b * inv_a),
         c.a,
     );
 }