chore: 整理 AudioConfig

apps/hello/src/audio/codec.rs

@@ -1,4 +1,4 @@
-use crate::config::AudioConfig;
+use crate::config::{AudioConfig, AudioScene};
 use anyhow::{Context, Result};
 use opus::{Application, Bitrate, Channels, Decoder, Encoder};
 
@@ -9,14 +9,32 @@ pub struct OpusCodec {
 
 impl OpusCodec {
     pub fn new(config: &AudioConfig) -> Result<Self> {
-        let channels = if config.channels == 1 {
-            Channels::Mono
-        } else {
-            Channels::Stereo
+        let channels = match config.channels {
+            1 => Channels::Mono,
+            2 => Channels::Stereo,
+            _ => return Err(anyhow::anyhow!("Invalid channels: {}", config.channels)),
         };
-        let mut encoder = Encoder::new(config.sample_rate, channels, Application::Audio)
+        let mode = match config.audio_scene {
+            AudioScene::Music => Application::Audio,
+            AudioScene::Voice => Application::Voip,
+        };
+        let bitrate = match config.bitrate {
+            -1 => Bitrate::Max,
+            0 => Bitrate::Auto,
+            _ => Bitrate::Bits(config.bitrate),
+        };
+        
+        let mut encoder = Encoder::new(config.sample_rate, channels, mode)
             .context("Failed to create Opus encoder")?;
-        encoder.set_bitrate(Bitrate::Bits(config.bitrate))?;
+
+        encoder.set_bitrate(bitrate)?;
+        if config.vbr {
+            encoder.set_vbr(true)?;
+        }
+        if config.fec {
+            encoder.set_inband_fec(true)?; // 内联前向纠错
+            encoder.set_packet_loss_perc(20)?; // 预期丢包率20%
+        }
 
         let decoder =
             Decoder::new(config.sample_rate, channels).context("Failed to create Opus decoder")?;
@@ -36,7 +54,14 @@ impl OpusCodec {
             .context("Opus decoding failed")
     }
 
-    // Packet Loss Concealment
+    /// 前向纠错(FEC)
+    pub fn decode_fec(&mut self, opus: &[u8], out: &mut [i16]) -> Result<usize> {
+        self.decoder
+            .decode(opus, out, true)
+            .context("Opus FEC decoding failed")
+    }
+
+    /// 丢包补偿(PLC)
     pub fn decode_loss(&mut self, out: &mut [i16]) -> Result<usize> {
         self.decoder
             .decode(&[], out, false)