From c9846394ac6cddd82442baadcabad653a28fed66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gustav=20S=C3=B6rn=C3=A4s?= <gustav@sornas.net>
Date: Wed, 21 Oct 2020 03:37:22 +0200
Subject: refactor audio into input.rs and output.rs

---
 mumd/src/audio/input.rs | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 mumd/src/audio/input.rs

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

diff --git a/mumd/src/audio/input.rs b/mumd/src/audio/input.rs
new file mode 100644
index 0000000..4e95360
--- /dev/null
+++ b/mumd/src/audio/input.rs
@@ -0,0 +1,52 @@
+use bytes::Bytes;
+use cpal::{InputCallbackInfo, Sample};
+use mumble_protocol::voice::VoicePacketPayload;
+use std::collections::VecDeque;
+use std::sync::{Arc, Mutex};
+use tokio::sync::{mpsc, watch};
+
+pub fn callback<T: Sample>(
+    mut opus_encoder: opus::Encoder,
+    mut input_sender: mpsc::Sender<VoicePacketPayload>,
+    sample_rate: u32,
+    input_volume_receiver: watch::Receiver<f32>,
+    opus_frame_size_blocks: u32, // blocks of 2.5ms
+) -> impl FnMut(&[T], &InputCallbackInfo) + Send + 'static {
+    if !(opus_frame_size_blocks == 1
+        || opus_frame_size_blocks == 2
+        || opus_frame_size_blocks == 4
+        || opus_frame_size_blocks == 8)
+    {
+        panic!(
+            "Unsupported amount of opus frame blocks {}",
+            opus_frame_size_blocks
+        );
+    }
+    let opus_frame_size = opus_frame_size_blocks * sample_rate / 400;
+
+    let buf = Arc::new(Mutex::new(VecDeque::new()));
+    move |data: &[T], _info: &InputCallbackInfo| {
+        let mut buf = buf.lock().unwrap();
+        let input_volume = *input_volume_receiver.borrow();
+        let out: Vec<f32> = data.iter().map(|e| e.to_f32())
+                                       .map(|e| e * input_volume)
+                                       .collect();
+        buf.extend(out);
+        while buf.len() >= opus_frame_size as usize {
+            let tail = buf.split_off(opus_frame_size as usize);
+            let mut opus_buf: Vec<u8> = vec![0; opus_frame_size as usize];
+            let result = opus_encoder
+                .encode_float(&Vec::from(buf.clone()), &mut opus_buf)
+                .unwrap();
+            opus_buf.truncate(result);
+            let bytes = Bytes::copy_from_slice(&opus_buf);
+            match input_sender.try_send(VoicePacketPayload::Opus(bytes, false)) {
+                Ok(_) => {}
+                Err(_e) => {
+                    //warn!("Error sending audio packet: {:?}", e);
+                }
+            }
+            *buf = tail;
+        }
+    }
+}
-- 
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