feat: rms + peak meters

dsp408-protocol.md

@@ -1868,7 +1868,7 @@ Sine Wave:
 |---|---|---|---|
 | `Byte 1-36` | 12 meter channels | 3 bytes × 12 | [Enc §8.1 Meter Level](#81-meter-level) |
 | `Byte 37` | Input clip indicator | 1 byte bitmask | Same OR bitmask pattern as [Enc §4.1](#41-matrix-input-mask) |
-| `Byte 38` | Output clip indicator | 1 byte bitmask | Same OR bitmask pattern as [Enc §4.1](#41-matrix-input-mask) |
+| `Byte 38` | Output limit indicator | 1 byte bitmask | Same OR bitmask pattern as [Enc §4.1](#41-matrix-input-mask) |
 
 **Example — Query**
 

src/dsp408/mapper/response.rs

@@ -1,10 +1,7 @@
 use crate::{
     common::errors::ProtocolError,
     dsp408::{
-        protocol::{
-            constants::{METERS_HIGH_STEP, METERS_LOW_STEP, METERS_SPLIT, METERS_SPLIT_LEVEL_DB},
-            frame::Frame,
-        },
+        protocol::frame::Frame,
         types::{
             Acknowledgement, AuthenticationResult, ConfigChunk, CurrentPreset, DeviceFlags,
             DeviceInfo, DeviceResponseType, HandshakeAck, Meter, Meters, ModifiedPreset,
@@ -166,43 +163,35 @@ pub fn map_response(frame: &Frame) -> Result<DeviceResponseType, ProtocolError>
 
     // Command `0x40` (Get Level Meters)
     if cmd == 0x40 {
+        fn float_to_db(v: f32) -> f32 {
+            40.0 * v.abs().max(1e-12).log10()
+        }
+
         if payload.len() != 38 {
             return Err(ProtocolError::new("Not enough bytes for meter levels"));
         }
 
-        // Bytes 0..36 = 12 × 3-byte meter levels
-        let levels: Vec<f32> = (0..36)
+        let channels: Vec<Meter> = (0..36)
             .step_by(3)
-            .map(|i| decode_float16(payload[i], payload[i + 1]).unwrap_or_default())
-            .map(|f| {
-                if f < METERS_SPLIT {
-                    METERS_SPLIT_LEVEL_DB + (f - METERS_SPLIT) / METERS_LOW_STEP
-                } else {
-                    METERS_SPLIT_LEVEL_DB + (f - METERS_SPLIT) / METERS_HIGH_STEP
-                }
-            })
-            .collect();
-
-        // Byte 36 = input clip bitmask
-        let input_clip_mask = payload[36];
-
-        // Byte 37 = output clip bitmask
-        let output_clip_mask = payload[37];
-
-        let channels = levels
-            .into_iter()
             .enumerate()
-            .map(|(index, level)| {
+            .map(|(index, i)| {
+                let rms = decode_float16(payload[i], payload[i + 1]).unwrap_or_default();
+                let peak = decode_float16(payload[i + 2], payload[i + 1]).unwrap_or_default();
+
+                let rms_db = float_to_db(rms);
+                let peak_db = float_to_db(peak);
+
                 let clip = if index < 4 {
-                    // InA..InD
-                    input_clip_mask & (1 << index) != 0
+                    payload[36] & (1 << index) != 0
                 } else {
-                    // Out1..Out8
-                    let output_index = index - 4;
-                    output_clip_mask & (1 << output_index) != 0
+                    payload[37] & (1 << (index - 4)) != 0
                 };
 
-                Meter { level, clip }
+                Meter {
+                    rms: rms_db,
+                    peak: peak_db,
+                    clip,
+                }
             })
             .collect();
 
@@ -438,7 +427,7 @@ mod tests {
                 assert_eq!(m.channels.len(), 12);
 
                 for channel in m.channels {
-                    assert!(channel.level.is_finite());
+                    assert!(channel.rms.is_finite());
                 }
             }
             other => panic!("unexpected {:?}", other),

src/dsp408/protocol/constants.rs

@@ -77,8 +77,3 @@ pub fn output_link_mask(channel: u8) -> Option<u8> {
         _ => None,
     }
 }
-
-pub const METERS_SPLIT: f32 = 1.0;
-pub const METERS_SPLIT_LEVEL_DB: f32 = -18.0;
-pub const METERS_LOW_STEP: f32 = 0.0104;
-pub const METERS_HIGH_STEP: f32 = 0.0208;

src/dsp408/types.rs

@@ -221,7 +221,8 @@ pub struct AuthenticationResult {
 #[cfg_attr(feature = "serialization", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct Meter {
-    pub level: f32,
+    pub rms: f32,
+    pub peak: f32,
     pub clip: bool,
 }
 

src/main.rs

@@ -32,3 +32,5 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     Ok(())
 }
+
+// 10020100 27 40 263df7 263dfd 263dfd 263dfd 063d8d 063d63 263dcf 263dfd 263df6 263dcf 263dcf 263dcf 0300 10038b