quality preset

sam-tool-tauri/src-tauri/src/settings.rs

@@ -24,6 +24,11 @@ pub struct Settings {
     /// bulk extract (take every Nth frame in range). 1 = no decimation.
     #[serde(default = "default_frame_skip")]
     pub frame_skip: u64,
+    /// Maximum height (in pixels) of the canvas backing store during preview.
+    /// 0 = no cap beyond native resolution. Common presets: 2160 (4K),
+    /// 1440 (2K), 1080, 720, 480. Smaller → less draw cost.
+    #[serde(default)]
+    pub preview_max_height: u32,
 }
 
 fn default_sam_url() -> String {
@@ -58,6 +63,7 @@ impl Default for Settings {
             cache_capacity: default_cache_capacity(),
             hwaccel: String::new(),
             frame_skip: default_frame_skip(),
+            preview_max_height: 0,
         }
     }
 }