export working

src/lib/exporter/videoDecoder.ts

@@ -0,0 +1,91 @@
+export interface DecodedVideoInfo {
+  width: number;
+  height: number;
+  duration: number; // in seconds
+  frameRate: number;
+  codec: string;
+}
+
+/**
+ * Simple video decoder for WebM files using native VideoDecoder API.
+ * For export, we'll use a different approach - directly rendering from the HTML video element.
+ */
+export class VideoFileDecoder {
+  private decoder: VideoDecoder | null = null;
+  private info: DecodedVideoInfo | null = null;
+  private videoElement: HTMLVideoElement | null = null;
+
+  async loadVideo(videoUrl: string): Promise<DecodedVideoInfo> {
+    // Create a video element to get video info
+    this.videoElement = document.createElement('video');
+    this.videoElement.src = videoUrl;
+    this.videoElement.preload = 'metadata';
+
+    return new Promise((resolve, reject) => {
+      this.videoElement!.addEventListener('loadedmetadata', () => {
+        const video = this.videoElement!;
+        
+        this.info = {
+          width: video.videoWidth,
+          height: video.videoHeight,
+          duration: video.duration,
+          frameRate: 60, // 60fps for smooth playback
+          codec: 'avc1.640033', // H.264 High Profile Level 5.1
+        };
+
+        resolve(this.info);
+      });
+
+      this.videoElement!.addEventListener('error', (e) => {
+        reject(new Error(`Failed to load video: ${e}`));
+      });
+    });
+  }
+
+  /**
+   * Get video element for seeking
+   */
+  getVideoElement(): HTMLVideoElement | null {
+    return this.videoElement;
+  }
+
+  /**
+   * Seek to a specific time and wait for the frame to be ready
+   */
+  async seekToTime(timeInSeconds: number): Promise<void> {
+    if (!this.videoElement) {
+      throw new Error('Video not loaded');
+    }
+
+    return new Promise((resolve) => {
+      const video = this.videoElement!;
+      
+      const onSeeked = () => {
+        video.removeEventListener('seeked', onSeeked);
+        resolve();
+      };
+
+      video.addEventListener('seeked', onSeeked);
+      video.currentTime = timeInSeconds;
+    });
+  }
+
+  getInfo(): DecodedVideoInfo | null {
+    return this.info;
+  }
+
+  destroy(): void {
+    if (this.videoElement) {
+      this.videoElement.pause();
+      this.videoElement.src = '';
+      this.videoElement = null;
+    }
+    
+    if (this.decoder) {
+      if (this.decoder.state !== 'closed') {
+        this.decoder.close();
+      }
+      this.decoder = null;
+    }
+  }
+}