Add codec-specific encoder configs

src/codec.ts

@@ -181,6 +181,42 @@ export const buildAudioCodecString = (codec: AudioCodec, numberOfChannels: numbe
 	throw new TypeError(`Unhandled codec '${codec}'.`);
 };
 
+export const getVideoEncoderConfigExtension = (codec: VideoCodec) => {
+	if (codec === 'avc') {
+		return {
+			avc: {
+				format: 'avc' as const // Ensure the format is not Annex B
+			}
+		};
+	} else if (codec === 'hevc') {
+		return {
+			hevc: {
+				format: 'hevc' as const // Ensure the format is not Annex B
+			}
+		};
+	}
+
+	return {};
+};
+
+export const getAudioEncoderConfigExtension = (codec: AudioCodec) => {
+	if (codec === 'aac') {
+		return {
+			aac: {
+				format: 'aac' as const // Ensure the format is not ADTS
+			}
+		};
+	} else if (codec === 'opus') {
+		return {
+			opus: {
+				format: 'opus' as const
+			}
+		};
+	}
+
+	return {};
+};
+
 export const validateVideoChunkMetadata = (metadata: EncodedVideoChunkMetadata | undefined) => {
 	if (!metadata) {
 		throw new TypeError("Video chunk metadata must be provided.");
@@ -236,12 +272,9 @@ export const validateVideoChunkMetadata = (metadata: EncodedVideoChunkMetadata |
 	}
 
 	if ((metadata.decoderConfig.codec.startsWith('avc1') || metadata.decoderConfig.codec.startsWith('avc3')) && !metadata.decoderConfig.description) {
-		// TODO Technically not correct, they can also lack a description in which case the chunks are annexb. Generally,
-		// go through all the codec registrations and catch these edge cases.
 		throw new TypeError("Video chunk metadata decoder configuration for AVC must include a description, which is expected to be an AVCDecoderConfigurationRecord as specified in ISO 14496-15.");
 	}
 	if ((metadata.decoderConfig.codec.startsWith('hev1') || metadata.decoderConfig.codec.startsWith('hvc1')) && !metadata.decoderConfig.description) {
-		// TODO Same as above
 		throw new TypeError("Video chunk metadata decoder configuration for HEVC must include a description, which is expected to be an HEVCDecoderConfigurationRecord as specified in ISO 14496-15.");
 	}
 	if ((metadata.decoderConfig.codec === 'vp8' || metadata.decoderConfig.codec.startsWith('vp09')) && metadata.decoderConfig.colorSpace === undefined) {
@@ -278,6 +311,9 @@ export const validateAudioChunkMetadata = (metadata: EncodedAudioChunkMetadata |
 		}
 	}
 
+	if (metadata.decoderConfig.codec.startsWith('mp4a') && !metadata.decoderConfig.description) {
+		throw new TypeError("Audio chunk metadata decoder configuration for AAC must include a description, which is expected to be an AudioSpecificConfig as specified in ISO 14496-3.");
+	}
 	if (metadata.decoderConfig.codec === 'opus' && metadata.decoderConfig.description && metadata.decoderConfig.description.byteLength < 18) {
 		throw new TypeError('Invalid decoder description provided for Opus; must be at least 18 bytes long.');
 	}

src/isobmff/isobmff-boxes.ts

@@ -696,7 +696,7 @@ export const dOps = (trackData: IsobmffAudioTrackData) => {
 	// https://www.rfc-editor.org/rfc/rfc7845#section-5
 	const description = trackData.info.decoderConfig?.description;
 	if (description) {
-		assert(description.byteLength < 18); // Is validated in an earlier step
+		assert(description.byteLength >= 18); // Is validated in an earlier step
 
 		const view = ArrayBuffer.isView(description)
 			? new DataView(description.buffer, description.byteOffset, description.byteLength)

src/source.ts

@@ -1,4 +1,4 @@
-import { buildAudioCodecString, buildVideoCodecString } from "./codec";
+import { buildAudioCodecString, buildVideoCodecString, getAudioEncoderConfigExtension, getVideoEncoderConfigExtension } from "./codec";
 import { assert } from "./misc";
 import { Muxer } from "./muxer";
 import { OutputAudioTrack, OutputSubtitleTrack, OutputTrack, OutputVideoTrack } from "./output";
@@ -194,6 +194,7 @@ class VideoEncoderWrapper {
 			bitrate: this.codecConfig.bitrate,
 			framerate: this.source._connectedTrack?.metadata.frameRate,
 			latencyMode: this.codecConfig.latencyMode,
+			...getVideoEncoderConfigExtension(this.codecConfig.codec)
 		});
 
 		assert(this.source._connectedTrack);
@@ -438,6 +439,7 @@ class AudioEncoderWrapper {
 			numberOfChannels: audioData.numberOfChannels,
 			sampleRate: audioData.sampleRate,
 			bitrate: this.codecConfig.bitrate,
+			...getAudioEncoderConfigExtension(this.codecConfig.codec)
 		});
 
 		assert(this.source._connectedTrack);