Fix encodability checks throwing due to unsupported config feature set; now counts as not supported (fixes #456)

src/encode.ts

@@ -1117,10 +1117,15 @@ export const canEncodeVideo = async (
 		}
 
 		for (const { config, quantizer } of candidates) {
+			try {
 				const support = await VideoEncoder.isConfigSupported(config);
 				if (!support.supported) {
 					continue;
 				}
+			} catch {
+				// Can type-error when unknown config features are used
+				continue;
+			}
 
 			if (!isFirefox()) {
 				return true;
@@ -1245,8 +1250,13 @@ export const canEncodeAudio = async (
 			return false;
 		}
 
+		try {
 			const support = await AudioEncoder.isConfigSupported(encoderConfig);
 			return support.supported === true;
+		} catch {
+			// Can type-error when unknown config features are used
+			return false;
+		}
 	})();
 	canEncodeAudioMemo.set(key, promise);
 

src/media-source.ts

@@ -705,11 +705,15 @@ class VideoEncoderWrapper {
 					);
 				}
 
+				try {
 					const support = await VideoEncoder.isConfigSupported(candidateConfig);
 					if (support.supported) {
 						selected = candidate;
 						break;
 					}
+				} catch {
+					// Not supported
+				}
 			}
 
 			if (!selected) {
@@ -2209,8 +2213,16 @@ class AudioEncoderWrapper {
 					throw new Error('AudioEncoder is not supported by this browser.');
 				}
 
+				let supported: boolean;
+
+				try {
 					const support = await AudioEncoder.isConfigSupported(encoderConfig);
-				if (!support.supported) {
+					supported = support.supported ?? false;
+				} catch {
+					supported = false;
+				}
+
+				if (!supported) {
 					throw new Error(
 						`This specific encoder configuration (${encoderConfig.codec}, ${encoderConfig.bitrate} bps,`
 						+ ` ${encoderConfig.numberOfChannels} channels, ${encoderConfig.sampleRate} Hz) is not`