Add custom processing to Conversion API

dev/convert.html

@@ -56,6 +56,11 @@
 			output,
 			audio: (_, n) => ({
 				discard: n > 1,
+				/*
+				process: (sample) => {
+					return sample;
+				},
+				*/
 				//codec: 'pcm-s16',
 				//sampleRate: 16000,
 				//numberOfChannels: 1,
@@ -92,6 +97,24 @@
 			},
 			*/
 			video: () => ({
+				/*
+				process: (sample) => {
+					if (!ctx) {
+						// Create a canvas for image compositing
+						const canvas = new OffscreenCanvas(
+							sample.displayWidth,
+							sample.displayHeight,
+						);
+						ctx = canvas.getContext('2d');
+					}
+
+					ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+					sample.draw(ctx, 0, 0);
+					ctx.drawImage(watermark, 32, 32);
+
+					return ctx.canvas;
+				},
+				*/
 				width: 300,
 				//alpha: 'keep',
 				//width: 320,