From 2e9bba8a1f3773266d1c61d26e348a146ef1545d Mon Sep 17 00:00:00 2001
From: will wade <willwade@gmail.com>
Date: Wed, 9 Sep 2026 07:26:52 +0100
Subject: [PATCH] =?UTF-8?q?feat:=20SSML=E2=86=92SpeechMarkdown=20gains=20a?=
 =?UTF-8?q?mazon:effect=20whisper=20+=20mstts:express-as;=20v3=20style=20p?=
 =?UTF-8?q?assthrough?=
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to_smd now translates <amazon:effect name="whispered"> to the whisper
modifier and <mstts:express-as style=…> to the generic style modifier;
the ElevenLabs v3 dialect passes style values through as audio tags
(v3 tags are open-ended natural language). Together these unblock
tts_speak_ssml on ElevenLabs: W3C/Alexa/Azure SSML can round-trip into
the model-matched dialect instead of being stripped — pinned by a
round-trip test (break → pause tier, prosody → tempo tag, whisper).
---
 src/formatters/elevenlabs_v3.rs | 10 +++++
 src/ssml_to_smd.rs              | 75 +++++++++++++++++++++++++++------
 2 files changed, 73 insertions(+), 12 deletions(-)

diff --git a/src/formatters/elevenlabs_v3.rs b/src/formatters/elevenlabs_v3.rs
index 800965c..cef9143 100644
--- a/src/formatters/elevenlabs_v3.rs
+++ b/src/formatters/elevenlabs_v3.rs
@@ -100,6 +100,16 @@ impl ElevenLabsV3Formatter {
                 "reduced" => Some("[understated]".to_string()),
                 _ => None,
             },
+            // Generic style modifier (e.g. translated from Azure's
+            // mstts:express-as): v3 tags are open-ended natural language,
+            // so the style value passes through as the tag.
+            "style" => {
+                if value.is_empty() {
+                    None
+                } else {
+                    Some(format!("[{value}]"))
+                }
+            }
             _ => None,
         }
     }
diff --git a/src/ssml_to_smd.rs b/src/ssml_to_smd.rs
index 82c3e64..4352b7f 100644
--- a/src/ssml_to_smd.rs
+++ b/src/ssml_to_smd.rs
@@ -135,12 +135,7 @@ fn handle_self_closing(name: &str, attrs: &[(String, String)], result: &mut Stri
     }
 }
 
-fn handle_closing(
-    name: &str,
-    attrs: &[(String, String)],
-    text_start: usize,
-    result: &mut String,
-) {
+fn handle_closing(name: &str, attrs: &[(String, String)], text_start: usize, result: &mut String) {
     match name {
         "emphasis" => {
             if let Some(level) = get_attr(attrs, "level") {
@@ -206,6 +201,28 @@ fn handle_closing(
                 result.push_str(&format!("({})/{}", inner, ph));
             }
         }
+        // Amazon's whispered effect (the local name quick-xml reports for
+        // <amazon:effect>). Round-trips into the ElevenLabs dialects via
+        // the whisper modifier.
+        "effect" => {
+            if get_attr(attrs, "name").is_some_and(|name| name.eq_ignore_ascii_case("whispered")) {
+                let inner = extract_inner(text_start, result);
+                if !inner.is_empty() {
+                    result.push_str(&format!("({})[whisper]", inner));
+                }
+            }
+        }
+        // Azure's express-as (<mstts:express-as style="…">) → the generic
+        // style modifier, which the ElevenLabs v3 dialect renders as an
+        // audio tag and other platforms drop.
+        "express-as" => {
+            if let Some(style) = get_attr(attrs, "style") {
+                let inner = extract_inner(text_start, result);
+                if !inner.is_empty() {
+                    result.push_str(&format!("({})[style:\"{}\"]", inner, style));
+                }
+            }
+        }
         "sub" => {
             if let Some(alias) = get_attr(attrs, "alias") {
                 let inner = extract_inner(text_start, result);
@@ -274,10 +291,7 @@ fn extract_inner(text_start: usize, result: &mut String) -> String {
 }
 
 fn get_attr(attrs: &[(String, String)], key: &str) -> Option<String> {
-    attrs
-        .iter()
-        .find(|(k, _)| k == key)
-        .map(|(_, v)| v.clone())
+    attrs.iter().find(|(k, _)| k == key).map(|(_, v)| v.clone())
 }
 
 #[cfg(test)]
@@ -406,8 +420,7 @@ mod tests {
 
     #[test]
     fn test_say_as_date_with_format() {
-        let ssml =
-            r#"<speak><say-as interpret-as="date" format="mdy">01/02/2024</say-as></speak>"#;
+        let ssml = r#"<speak><say-as interpret-as="date" format="mdy">01/02/2024</say-as></speak>"#;
         let result = ssml_to_smd(ssml).unwrap();
         assert_eq!(result, r#"(01/02/2024)[date:"mdy"]"#);
     }
@@ -431,4 +444,42 @@ mod tests {
         let result = ssml_to_smd(ssml).unwrap();
         assert_eq!(result, "A & B < C > D");
     }
+
+    #[test]
+    fn test_amazon_whispered_effect() {
+        let ssml =
+            r#"<speak><amazon:effect name="whispered">it's a secret</amazon:effect></speak>"#;
+        let result = ssml_to_smd(ssml).unwrap();
+        assert_eq!(result, "(it's a secret)[whisper]");
+    }
+
+    #[test]
+    fn test_amazon_other_effect_dropped() {
+        let ssml = r#"<speak><amazon:effect name="damped">plain</amazon:effect></speak>"#;
+        let result = ssml_to_smd(ssml).unwrap();
+        assert_eq!(result, "plain");
+    }
+
+    #[test]
+    fn test_mstts_express_as_style() {
+        let ssml =
+            r#"<speak><mstts:express-as style="cheerful">hello there</mstts:express-as></speak>"#;
+        let result = ssml_to_smd(ssml).unwrap();
+        assert_eq!(result, r#"(hello there)[style:"cheerful"]"#);
+    }
+
+    #[test]
+    fn elevenlabs_round_trip_ssml_to_v3_dialect() {
+        // The chain tts_speak_ssml uses: W3C SSML → SpeechMarkdown →
+        // v3 audio-tag dialect.
+        use crate::formatters::base::Platform;
+        use crate::parser::SpeechMarkdownParser;
+        let ssml = r#"<speak>Hello <break time="2s"/> <prosody rate="slow">world</prosody> <amazon:effect name="whispered">quietly</amazon:effect></speak>"#;
+        let smd = ssml_to_smd(ssml).unwrap();
+        let dialect = SpeechMarkdownParser::to_ssml(&smd, Platform::ElevenLabsV3).unwrap();
+        assert_eq!(
+            dialect,
+            "Hello [long pause] [drawn out] world [whispers] quietly"
+        );
+    }
 }