feat: representative frame - auto-detect thumbnail + JSON endpoint

src/api/media_api.rs

@@ -690,7 +690,7 @@ async fn stream_video(
 
 #[derive(Debug, serde::Deserialize)]
 struct ThumbQuery {
-    frame: i64,
+    frame: Option<i64>,
     x: Option<i32>,
     y: Option<i32>,
     w: Option<i32>,
@@ -703,6 +703,20 @@ async fn face_thumbnail(
     Query(q): Query<ThumbQuery>,
 ) -> Result<impl IntoResponse, StatusCode> {
     let videos_table = schema::table_name("videos");
+
+    let frame = match q.frame {
+        Some(f) => f,
+        None => {
+            let result = crate::core::processor::tkg::query_auto_representative_frame(
+                state.db.pool(),
+                &file_uuid,
+            )
+            .await
+            .map_err(|_| StatusCode::NOT_FOUND)?;
+            result.frame_number
+        }
+    };
+
     let row: Option<(String,)> = sqlx::query_as(&format!(
         "SELECT file_path FROM {} WHERE file_uuid = $1",
         videos_table
@@ -713,7 +727,7 @@ async fn face_thumbnail(
     .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
     let (file_path,) = row.ok_or(StatusCode::NOT_FOUND)?;
 
-    let select = format!("select=eq(n\\,{})", q.frame);
+    let select = format!("select=eq(n\\,{})", frame);
     let vf = if let (Some(x), Some(y), Some(w), Some(h)) = (q.x, q.y, q.w, q.h) {
         format!("{},crop={}:{}:{}:{}", select, w, h, x, y)
     } else {