feature: OpusFormatDecoder — Ogg-page-aligned segmenting, sidecar parser, accurate index-based seek (Phase 18.4)

DeepDrftPublic/Interop/audio/index.ts

@@ -3,6 +3,7 @@
  */
 
 import { AudioPlayer, AudioResult, StreamingResult, AudioState } from './AudioPlayer.js';
+import { canDecodeOggOpus } from './OpusCapability.js';
 
 // Player instances by ID
 const audioPlayers = new Map<string, AudioPlayer>();
@@ -37,6 +38,20 @@ const DeepDrftAudio = {
         return player.initializeStreaming(totalStreamLength, contentType);
     },
 
+    // Opus injection seam (wave 18.4). Wave 18.5 fetches the per-track sidecar (setup header +
+    // seek index) over HTTP and hands the raw bytes here BEFORE initializeStreaming on an Opus
+    // stream. This module never fetches the sidecar — it only parses + stores it on the player.
+    setOpusSidecar: (playerId: string, sidecarBytes: Uint8Array): AudioResult => {
+        const player = audioPlayers.get(playerId);
+        if (!player) return { success: false, error: 'Player not found' };
+        return player.setOpusSidecar(sidecarBytes);
+    },
+
+    // Capability seam (wave 18.4). Resolves whether this browser can decode Ogg Opus via
+    // decodeAudioData (Safari < 18.4 cannot). Wave 18.5 / 18.6 consume this to choose lossless
+    // when unsupported; this module only reports the capability.
+    canDecodeOggOpus: (): Promise<boolean> => canDecodeOggOpus(),
+
     processStreamingChunk: async (playerId: string, chunk: Uint8Array): Promise<StreamingResult> => {
         const player = audioPlayers.get(playerId);
         if (!player) return { success: false, error: 'Player not found' };