fix(ml): rubato 1.0.1 API upgrade and StreamChunk wrapping (#1858)

CHANGELOG.md

@@ -38,6 +38,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Fixed
 
+- fix(ml): rubato 1.0.1 API upgrade and StreamChunk wrapping for candle provider (#1858) — updated `candle_whisper.rs` resample function for rubato 1.0.1 (SincFixedIn removed, replaced with Async::new_sinc); wrapped ChatStream output in StreamChunk::Content pattern in candle_provider; added audioadapter-buffers dependency (gated on candle feature)
+
 ### Performance
 
 - perf(memory): add `expires_at` to `idx_response_cache_semantic` composite index (migration 038) — `get_semantic()` now filters expired rows within the index scan instead of post-filtering on the heap (#2030)

Cargo.toml

@@ -65,6 +65,7 @@ ratatui = "0.30"
 regex = "1.12"
 reqwest = { version = "0.13", default-features = false }
 rmcp = "1.2"
+audioadapter-buffers = "2.0"
 rubato = "1.0"
 schemars = "1.2"
 scrape-core = "0.2"

crates/zeph-llm/Cargo.toml

@@ -17,12 +17,13 @@ readme = "README.md"
 default = ["schema"]
 schema = ["dep:schemars"]
 stt = ["reqwest/multipart"]
-candle = ["dep:candle-core", "dep:candle-nn", "dep:candle-transformers", "dep:hf-hub", "dep:tokenizers", "dep:symphonia", "dep:rubato"]
+candle = ["dep:audioadapter-buffers", "dep:candle-core", "dep:candle-nn", "dep:candle-transformers", "dep:hf-hub", "dep:tokenizers", "dep:symphonia", "dep:rubato"]
 cuda = ["candle", "candle-core/cuda", "candle-nn/cuda", "candle-transformers/cuda"]
 metal = ["candle", "candle-core/metal", "candle-nn/metal", "candle-transformers/metal"]
 
 [dependencies]
 async-stream.workspace = true
+audioadapter-buffers = { workspace = true, optional = true }
 base64.workspace = true
 candle-core = { workspace = true, optional = true }
 candle-nn = { workspace = true, optional = true }

crates/zeph-llm/src/candle_provider/mod.rs

@@ -16,7 +16,7 @@ use self::embed::EmbedModel;
 use self::generate::{GenerationConfig, GenerationOutput, generate_tokens};
 use self::loader::{LoadedModel, ModelSource, load_chat_model};
 use self::template::ChatTemplate;
-use crate::provider::{ChatStream, LlmProvider, Message};
+use crate::provider::{ChatStream, LlmProvider, Message, StreamChunk};
 
 use candle_transformers::models::quantized_llama::ModelWeights;
 
@@ -146,7 +146,8 @@ impl LlmProvider for CandleProvider {
                     while !text.is_char_boundary(end) {
                         end -= 1;
                     }
-                    if tx.blocking_send(Ok(text[start..end].to_string())).is_err() {
+                    let chunk = StreamChunk::Content(text[start..end].to_string());
+                    if tx.blocking_send(Ok(chunk)).is_err() {
                         break;
                     }
                     start = end;

crates/zeph-llm/src/candle_whisper.rs

@@ -318,7 +318,8 @@ fn decode_audio(bytes: &[u8]) -> Result<Vec<f32>, LlmError> {
 
 fn resample(input: &[f32], from_rate: u32, to_rate: u32) -> Result<Vec<f32>, LlmError> {
     use rubato::{
-        Resampler, SincFixedIn, SincInterpolationParameters, SincInterpolationType, WindowFunction,
+        Async, FixedAsync, Resampler, SincInterpolationParameters, SincInterpolationType,
+        WindowFunction,
     };
 
     let params = SincInterpolationParameters {
@@ -330,14 +331,18 @@ fn resample(input: &[f32], from_rate: u32, to_rate: u32) -> Result<Vec<f32>, Llm
     };
 
     let ratio = f64::from(to_rate) / f64::from(from_rate);
-    let mut resampler = SincFixedIn::<f32>::new(ratio, 2.0, params, input.len(), 1)
-        .map_err(|e| LlmError::TranscriptionFailed(format!("resampler init: {e}")))?;
+    let mut resampler =
+        Async::<f32>::new_sinc(ratio, 2.0, &params, input.len(), 1, FixedAsync::Input)
+            .map_err(|e| LlmError::TranscriptionFailed(format!("resampler init: {e}")))?;
+
+    let input_adapter = audioadapter_buffers::direct::InterleavedSlice::new(input, 1, input.len())
+        .map_err(|e| LlmError::TranscriptionFailed(format!("input buffer: {e}")))?;
 
     let output = resampler
-        .process(&[input], None)
+        .process(&input_adapter, 0, None)
         .map_err(|e| LlmError::TranscriptionFailed(format!("resample: {e}")))?;
 
-    Ok(output.into_iter().next().unwrap_or_default())
+    Ok(output.take_data())
 }
 
 #[cfg(test)]