Probe encoder support with sample (fixes #90), improve encoder error handling

dev/convert.html

@@ -18,15 +18,13 @@
 		const file = fileInput.files[0];
 
 		const source = new Mediabunny.BlobSource(file);
-		const target = new Mediabunny.NullTarget() ?? new Mediabunny.BufferTarget() ?? new Mediabunny.StreamTarget(new WritableStream({
+		const target = new Mediabunny.BufferTarget() ?? new Mediabunny.StreamTarget(new WritableStream({
 			write: console.log
 		}), {
 			chunked: true,
 			chunkSize: 2**20
 		});
-		const outputFormat = new Mediabunny.Mp4OutputFormat({
-			onMoov: console.log
-		});
+		const outputFormat = new Mediabunny.Mp4OutputFormat({});
 
 		const button = document.createElement('button');
 		button.textContent = 'Cancel';
@@ -76,7 +74,8 @@
 			},
 			*/
 			video: () => ({
-				//codec: 'avc',
+				forceTranscode: true,
+				codec: 'avc',
 				//fit: 'contain',
 				//frameRate: 27.123,
 				//width: 320,
@@ -98,8 +97,8 @@
 				//height: 100,
 			}),
 			trim: {
-				//start: 0,
-				//end: 20
+				start: 0,
+				end: 5
 			},
 		});
 		console.log(conversion);