Streaming callbacks

Cargo.toml

@@ -72,6 +72,11 @@ name = "simple_stream"
 path = "examples/transcription/websocket/simple_stream.rs"
 required-features = ["listen"]
 
+[[example]]
+name = "callback_stream"
+path = "examples/transcription/websocket/callback_stream.rs"
+required-features = ["listen"]
+
 [[example]]
 name = "microphone_stream"
 path = "examples/transcription/websocket/microphone_stream.rs"

examples/transcription/websocket/callback_stream.rs

@@ -0,0 +1,53 @@
+use std::env;
+use std::time::Duration;
+
+use futures::stream::StreamExt;
+
+use deepgram::{
+    common::options::{Encoding, Endpointing, Language, Options},
+    Deepgram, DeepgramError,
+};
+
+static PATH_TO_FILE: &str = "examples/audio/bueller.wav";
+static AUDIO_CHUNK_SIZE: usize = 3174;
+static FRAME_DELAY: Duration = Duration::from_millis(16);
+
+#[tokio::main]
+async fn main() -> Result<(), DeepgramError> {
+    let deepgram_api_key =
+        env::var("DEEPGRAM_API_KEY").expect("DEEPGRAM_API_KEY environmental variable");
+
+    let dg_client = Deepgram::new(&deepgram_api_key)?;
+
+    let options = Options::builder()
+        .smart_format(true)
+        .language(Language::en_US)
+        .build();
+
+    let callback_url = env::var("DEEPGRAM_CALLBACK_URL")
+        .expect("DEEPGRAM_CALLBACK_URL environmental variable")
+        .parse()
+        .expect("DEEPGRAM_CALLBACK_URL not a valid URL");
+
+    let mut results = dg_client
+        .transcription()
+        .stream_request_with_options(options)
+        .keep_alive()
+        .encoding(Encoding::Linear16)
+        .sample_rate(44100)
+        .channels(2)
+        .endpointing(Endpointing::CustomDurationMs(300))
+        .interim_results(true)
+        .utterance_end_ms(1000)
+        .vad_events(true)
+        .no_delay(true)
+        .callback(callback_url)
+        .file(PATH_TO_FILE, AUDIO_CHUNK_SIZE, FRAME_DELAY)
+        .await?;
+
+    while let Some(result) = results.next().await {
+        println!("got: {:?}", result);
+    }
+
+    Ok(())
+}

src/common/options.rs

@@ -1887,7 +1887,12 @@ impl OptionsBuilder {
     ///
     /// See the [Deepgram Callback Method feature docs][docs] for more info.
     ///
+    /// Note that modifying the callback method is only available for pre-recorded audio.
+    /// See the [Deepgram Callback feature docs for streaming][streaming-docs] for details
+    /// on streaming callbacks.
+    ///
     /// [docs]: https://developers.deepgram.com/docs/callback#pre-recorded-audio
+    /// [streaming-docs]: https://developers.deepgram.com/docs/callback#streaming-audio
     ///
     /// # Examples
     ///

src/listen/websocket.rs

@@ -62,6 +62,7 @@ pub struct WebsocketBuilder<'a> {
     vad_events: Option<bool>,
     stream_url: Url,
     keep_alive: Option<bool>,
+    callback: Option<Url>,
 }
 
 impl Transcription<'_> {
@@ -143,6 +144,7 @@ impl Transcription<'_> {
             vad_events: None,
             stream_url: self.listen_stream_url(),
             keep_alive: None,
+            callback: None,
         }
     }
 
@@ -214,6 +216,7 @@ impl<'a> WebsocketBuilder<'a> {
             no_delay,
             vad_events,
             stream_url,
+            callback,
         } = self;
 
         let mut url = stream_url.clone();
@@ -257,6 +260,9 @@ impl<'a> WebsocketBuilder<'a> {
             if let Some(vad_events) = vad_events {
                 pairs.append_pair("vad_events", &vad_events.to_string());
             }
+            if let Some(callback) = callback {
+                pairs.append_pair("callback", callback.as_ref());
+            }
         }
 
         Ok(url)
@@ -315,6 +321,12 @@ impl<'a> WebsocketBuilder<'a> {
 
         self
     }
+
+    pub fn callback(mut self, callback: Url) -> Self {
+        self.callback = Some(callback);
+
+        self
+    }
 }
 
 impl<'a> WebsocketBuilder<'a> {