refactor: replace hand-written libopus FFI wrapper with the opus crate

Cargo.toml

@@ -12,6 +12,7 @@ homepage = "https://getstream.io/video/"
 documentation = "https://docs.rs/getstream"
 keywords = ["video", "webrtc", "sfu", "stream", "rtc"]
 categories = ["api-bindings", "multimedia::video", "network-programming"]
+
 # A published crate's own `.cargo/config.toml` is never read by Cargo (config is
 # discovered from the *consumer's* directory tree), so it is deliberately absent
 # from this list — see the note above `[dependencies]`.
@@ -44,15 +45,13 @@ rustdoc-args = ["--cfg", "docsrs", "--generate-link-to-definition"]
 # system dependency (libvpx) and the vendored-opus build tools.
 
 [dependencies]
-# Opus encode/decode for the audio media path. `opusic-sys` is a maintained
-# libopus binding (tracks libopus 1.6.1) that bundles + static-links a *vendored*
-# libopus, so the SDK build needs no system libopus at link or runtime. It
-# replaces the unmaintained `audiopus_sys` (RUSTSEC-2026-0150); see
-# `src/rtc/opus.rs` for the thin safe wrapper. The bundled CMake build needs
-# `cmake` and a C compiler on PATH and nothing else: its `CMakeLists.txt`
-# declares `cmake_minimum_required(VERSION 3.16)`, which satisfies CMake 4's
+# Opus encode/decode for the audio media path. A safe wrapper over `opusic-sys`,
+# which bundles + static-links a *vendored* libopus, so the SDK build needs no
+# system libopus at link or runtime. The bundled CMake build needs `cmake` and a
+# C compiler on PATH and nothing else: its `CMakeLists.txt` declares
+# `cmake_minimum_required(VERSION 3.16)`, which satisfies CMake 4's
 # minimum-policy floor without any build-time environment override.
-opusic-sys = "0.7.4"
+opus = "0.4"
 base64 = "0.23.1"
 bytes = "1.12.1"
 futures-util = "0.3.34"
@@ -86,9 +85,6 @@ flate2 = "1.1.9"
 openh264 = "=0.8.1"
 
 [dev-dependencies]
-# Example-only convenience for the two executable demos. OpenAI-specific bridge
-# orchestration stays in `examples/gpt_realtime_bot.rs`; `tokio` here adds the
-# runtime and signal features used only by the examples.
 anyhow = "1.0.86"
 criterion = "0.8.2"
 dotenvy = "0.15.7"

benches/media_baseline.rs

@@ -93,7 +93,8 @@ fn bench_resampling(criterion: &mut Criterion) {
 
 fn bench_opus(criterion: &mut Criterion) {
     let pcm = tone(48_000, 1, 20).samples;
-    let mut encoder = rtc::opus::Encoder::new_voip_mono().expect("create Opus encoder");
+    let mut encoder = opus::Encoder::new(48_000, opus::Channels::Mono, opus::Application::Voip)
+        .expect("create Opus encoder");
     let mut encoded = vec![0u8; 1_500];
 
     let mut group = criterion.benchmark_group("opus");
@@ -111,7 +112,8 @@ fn bench_opus(criterion: &mut Criterion) {
         .encode(&pcm, &mut encoded)
         .expect("encode Opus decode fixture");
     encoded.truncate(encoded_length);
-    let mut decoder = rtc::opus::Decoder::new_mono().expect("create Opus decoder");
+    let mut decoder =
+        opus::Decoder::new(48_000, opus::Channels::Mono).expect("create Opus decoder");
     let mut decoded = vec![0i16; 5_760];
     group.throughput(Throughput::Bytes(encoded.len() as u64));
     group.bench_function("decode_48k_mono_20ms", |bencher| {
@@ -274,8 +276,11 @@ fn bench_multitrack_load(criterion: &mut Criterion) {
     const VIDEO_H: u32 = 360;
 
     let pcm = tone(48_000, 1, 20).samples;
-    let mut audio_encoders: Vec<rtc::opus::Encoder> = (0..AUDIO_TRACKS)
-        .map(|_| rtc::opus::Encoder::new_voip_mono().expect("create multitrack Opus encoder"))
+    let mut audio_encoders: Vec<opus::Encoder> = (0..AUDIO_TRACKS)
+        .map(|_| {
+            opus::Encoder::new(48_000, opus::Channels::Mono, opus::Application::Voip)
+                .expect("create multitrack Opus encoder")
+        })
         .collect();
     let mut audio_scratch = vec![0u8; 1_500];
 

benches/support/rtc_sources.rs

@@ -12,8 +12,6 @@ pub(crate) mod error {
 
 #[path = "../../src/rtc/h264.rs"]
 pub(crate) mod h264;
-#[path = "../../src/rtc/opus.rs"]
-pub(crate) mod opus;
 #[path = "../../src/rtc/rtp_h264.rs"]
 pub(crate) mod rtp_h264;
 #[path = "../../src/rtc/rtp_vpx.rs"]

benches/timer_drift.rs

@@ -2,10 +2,6 @@
 
 use std::time::Duration;
 
-#[allow(dead_code)]
-#[path = "../src/rtc/opus.rs"]
-mod opus;
-
 const PERIOD: Duration = Duration::from_millis(20);
 const TICKS: usize = 500;
 
@@ -26,7 +22,9 @@ async fn measure_timer_drift() {
             (12_000.0 * (std::f64::consts::TAU * 440.0 * time).sin()) as i16
         })
         .collect();
-    let mut encoder = opus::Encoder::new_voip_mono().expect("create Opus encoder");
+    let mut encoder =
+        opus::Encoder::new(sample_rate, opus::Channels::Mono, opus::Application::Voip)
+            .expect("create Opus encoder");
     let mut encoded = vec![0u8; 1_500];
 
     let mut interval = tokio::time::interval(PERIOD);

deny.toml

@@ -6,9 +6,7 @@
 # from software licenses.
 
 [advisories]
-# Fail on all security advisories. There are no ignores: the previously
-# unmaintained Opus binding (`audiopus_sys`, RUSTSEC-2026-0150) was replaced by
-# the maintained `opusic-sys`, so no advisory needs suppressing.
+# Fail on all security advisories. There are no ignores.
 
 [licenses]
 # Dependency-license policy. If a new dependency introduces an unreviewed

src/rtc/local_track.rs

@@ -321,7 +321,7 @@ struct AudioInner {
     /// Resampled 48 kHz mono PCM awaiting the 20 ms pacer.
     pcm: StdMutex<VecDeque<i16>>,
     resampler: StdMutex<StreamResampler>,
-    encoder: StdMutex<super::opus::Encoder>,
+    encoder: StdMutex<opus::Encoder>,
     pacer: StdMutex<Option<JoinHandle<()>>>,
     pacer_started: AtomicBool,
     pcm_pacing: AtomicBool,
@@ -350,7 +350,12 @@ impl LocalAudioTrack {
         };
         let track_id = format!("audio-{}", uuid::Uuid::new_v4().simple());
         let core = TrackCore::new(codec, track_id, "stream-rust-audio".to_owned())?;
-        let encoder = super::opus::Encoder::new_voip_mono().map_err(RtcError::Media)?;
+        let encoder = opus::Encoder::new(
+            OPUS_SAMPLE_RATE,
+            opus::Channels::Mono,
+            opus::Application::Voip,
+        )
+        .map_err(|error| RtcError::Media(error.to_string()))?;
         Ok(Self {
             inner: Arc::new(AudioInner {
                 core,
@@ -601,12 +606,10 @@ fn push_bounded_pcm(queue: &mut VecDeque<i16>, samples: Vec<i16>) -> usize {
     overflow
 }
 
-fn encode_opus_into(
-    encoder: &mut super::opus::Encoder,
-    pcm: &[i16],
-    output: &mut [u8],
-) -> Result<usize> {
-    encoder.encode(pcm, output).map_err(RtcError::Media)
+fn encode_opus_into(encoder: &mut opus::Encoder, pcm: &[i16], output: &mut [u8]) -> Result<usize> {
+    encoder
+        .encode(pcm, output)
+        .map_err(|error| RtcError::Media(error.to_string()))
 }
 
 // Video
@@ -1915,6 +1918,42 @@ impl LocalTrack {
 mod tests {
     use super::*;
 
+    #[test]
+    fn encode_opus_into_produces_a_packet_for_a_20ms_mono_frame() {
+        let mut encoder = opus::Encoder::new(
+            OPUS_SAMPLE_RATE,
+            opus::Channels::Mono,
+            opus::Application::Voip,
+        )
+        .expect("encoder");
+        let pcm = vec![1_000i16; FRAME_SAMPLES_20MS];
+        let mut output = vec![0u8; 1_500];
+
+        let length = encode_opus_into(&mut encoder, &pcm, &mut output).expect("encode");
+
+        assert!(
+            length > 0 && length <= output.len(),
+            "packet length {length}"
+        );
+    }
+
+    #[test]
+    fn encode_opus_into_rejects_a_bogus_frame_size() {
+        let mut encoder = opus::Encoder::new(
+            OPUS_SAMPLE_RATE,
+            opus::Channels::Mono,
+            opus::Application::Voip,
+        )
+        .expect("encoder");
+        let mut output = vec![0u8; 1_500];
+
+        // 137 samples is not a valid 48 kHz Opus frame size.
+        let error = encode_opus_into(&mut encoder, &vec![0i16; 137], &mut output)
+            .expect_err("bogus frame size must be rejected");
+
+        assert!(matches!(error, RtcError::Media(_)), "error was: {error}");
+    }
+
     #[tokio::test]
     async fn opus_track_builds_and_writes_sample() {
         let track = LocalAudioTrack::opus().expect("opus track");

src/rtc/mod.rs

@@ -29,7 +29,6 @@ pub mod identity;
 pub mod join;
 mod layers;
 pub mod local_track;
-mod opus;
 pub mod pcm;
 pub mod peer;
 pub mod proto;