From 3cb2c612fb030278aaf5e4d49d42cf689bdc9cc0 Mon Sep 17 00:00:00 2001
From: Eskil Queseth <eskilq@kth.se>
Date: Sat, 12 Jun 2021 15:58:44 +0200
Subject: re-add noise gate

---
 mumd/src/audio/transformers.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 mumd/src/audio/transformers.rs

(limited to 'mumd/src/audio/transformers.rs')

diff --git a/mumd/src/audio/transformers.rs b/mumd/src/audio/transformers.rs
new file mode 100644
index 0000000..5c9681b
--- /dev/null
+++ b/mumd/src/audio/transformers.rs
@@ -0,0 +1,17 @@
+use dasp_ring_buffer::Bounded;
+
+
+pub fn create_noise_gate(chunks: usize, mute_percentage: f32) -> impl FnMut(&mut [f32]) -> Option<&mut [f32]> {
+    let mut peaks = Bounded::from_full(vec![0.0; chunks]);
+    let mut alltime_high: f32 = 0.0;
+    move |buf: &mut [f32]| {
+        let max = buf.iter().map(|e| e.abs()).max_by(|a, b| a.partial_cmp(b).unwrap()).unwrap();
+        peaks.push(max);
+        alltime_high = alltime_high.max(max);
+        if peaks.iter().any(|e| *e >= alltime_high * mute_percentage) {
+            Some(buf)
+        } else {
+            None
+        }
+    }
+}
-- 
cgit v1.2.1


From 5b2e2c4e266c61f35f7bcfbc603e02070b54e7d0 Mon Sep 17 00:00:00 2001
From: Eskil Queseth <eskilq@kth.se>
Date: Sat, 12 Jun 2021 16:47:36 +0200
Subject: FnMut -> Trait

---
 mumd/src/audio/transformers.rs | 46 +++++++++++++++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 10 deletions(-)

(limited to 'mumd/src/audio/transformers.rs')

diff --git a/mumd/src/audio/transformers.rs b/mumd/src/audio/transformers.rs
index 5c9681b..6994a40 100644
--- a/mumd/src/audio/transformers.rs
+++ b/mumd/src/audio/transformers.rs
@@ -1,17 +1,43 @@
-use dasp_ring_buffer::Bounded;
+pub trait Transformer {
+    fn transform<'a>(&mut self, buf: &'a mut [f32]) -> Option<&'a mut [f32]>;
+}
+
+pub struct NoiseGate {
+    alltime_high: f32,
+    open: usize,
+    deactivation_delay: usize,
+}
+
+impl NoiseGate {
+    pub fn new(deactivation_delay: usize) -> Self {
+        Self {
+            alltime_high: 0.0,
+            open: 0,
+            deactivation_delay,
+        }
+    }
+}
 
+impl Transformer for NoiseGate {
+    fn transform<'a>(&mut self, buf: &'a mut [f32]) -> Option<&'a mut [f32]> {
+        const MUTE_PERCENTAGE: f32 = 0.1;
 
-pub fn create_noise_gate(chunks: usize, mute_percentage: f32) -> impl FnMut(&mut [f32]) -> Option<&mut [f32]> {
-    let mut peaks = Bounded::from_full(vec![0.0; chunks]);
-    let mut alltime_high: f32 = 0.0;
-    move |buf: &mut [f32]| {
         let max = buf.iter().map(|e| e.abs()).max_by(|a, b| a.partial_cmp(b).unwrap()).unwrap();
-        peaks.push(max);
-        alltime_high = alltime_high.max(max);
-        if peaks.iter().any(|e| *e >= alltime_high * mute_percentage) {
-            Some(buf)
-        } else {
+
+        if max > self.alltime_high {
+            self.alltime_high = max;
+        }
+
+        if max > self.alltime_high * MUTE_PERCENTAGE {
+            self.open = self.deactivation_delay;
+        } else if self.open > 0 {
+            self.open -= 1;
+        }
+
+        if self.open == 0 {
             None
+        } else {
+            Some(buf)
         }
     }
 }
-- 
cgit v1.2.1


From c143931f9948a0249213bdaab2658a31d4dddaf2 Mon Sep 17 00:00:00 2001
From: Eskil Queseth <eskilq@kth.se>
Date: Sat, 12 Jun 2021 17:40:41 +0200
Subject: add documentation

---
 mumd/src/audio/transformers.rs | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'mumd/src/audio/transformers.rs')

diff --git a/mumd/src/audio/transformers.rs b/mumd/src/audio/transformers.rs
index 6994a40..25e28b8 100644
--- a/mumd/src/audio/transformers.rs
+++ b/mumd/src/audio/transformers.rs
@@ -1,7 +1,11 @@
+/// A trait that represents a transform of a audio buffer in some way.
 pub trait Transformer {
+    /// Do the transform. Returning `None` is interpreted as "the buffer is unwanted".
+    /// The implementor is free to modify the buffer however it wants to.
     fn transform<'a>(&mut self, buf: &'a mut [f32]) -> Option<&'a mut [f32]>;
 }
 
+/// A struct representing a noise gate transform.
 pub struct NoiseGate {
     alltime_high: f32,
     open: usize,
@@ -9,6 +13,8 @@ pub struct NoiseGate {
 }
 
 impl NoiseGate {
+    /// Create a new noise gate. `deactivation_delay` is defined in terms of
+    /// how many quiet frames it receives before closing the noise gate.
     pub fn new(deactivation_delay: usize) -> Self {
         Self {
             alltime_high: 0.0,
-- 
cgit v1.2.1