feat: enhance HLS stream URL generation with remuxing options for Jellyfin

k-tv-backend/infra/src/jellyfin.rs

@@ -158,18 +158,20 @@ impl IMediaProvider for JellyfinMediaProvider {
 
     /// Build an HLS stream URL for a Jellyfin item.
     ///
-    /// Returns a `master.m3u8` playlist URL. Jellyfin transcodes to H.264/AAC
-    /// segments on the fly. HLS is preferred over a single MP4 stream because
-    /// `StartTimeTicks` works reliably with HLS — each segment is independent,
-    /// so Jellyfin can begin the playlist at the correct broadcast offset
-    /// without needing to byte-range seek into an in-progress transcode.
+    /// Returns a `master.m3u8` playlist URL. HLS is preferred over a single
+    /// MP4 stream because hls.js `startPosition` can seek to the broadcast
+    /// offset before the first segment fetch, without byte-range seeking into
+    /// an in-progress transcode.
+    ///
+    /// `allowVideoStreamCopy=true` and `allowAudioStreamCopy=true` tell
+    /// Jellyfin to remux (not re-encode) content that is already H.264/AAC,
+    /// avoiding transcode cache file buildup. Content in other codecs will
+    /// still be transcoded to H.264/AAC for browser compatibility.
     ///
     /// The API key is embedded so the player needs no separate auth header.
-    /// The caller (stream proxy route) appends `StartTimeTicks` when there is
-    /// a non-zero broadcast offset.
     async fn get_stream_url(&self, item_id: &MediaItemId) -> DomainResult<String> {
         Ok(format!(
-            "{}/Videos/{}/master.m3u8?videoCodec=h264&audioCodec=aac&VideoBitRate=40000000&mediaSourceId={}&api_key={}",
+            "{}/Videos/{}/master.m3u8?videoCodec=h264&audioCodec=aac&allowVideoStreamCopy=true&allowAudioStreamCopy=true&mediaSourceId={}&api_key={}",
             self.config.base_url,
             item_id.as_ref(),
             item_id.as_ref(),