Method createCodecContext

src/audio_encoder.ts:117–150

(config: AudioEncoderConfig)

	}

	private static createCodecContext(config: AudioEncoderConfig) {
		const inferred = inferCodecFromCodecString(config.codec);
		if (!inferred) {
			return null;
		}

		const codec = Codec.findEncoder(inferred);
		if (!codec) {
			return null;
		}

		let sampleFormat = AV_SAMPLE_FMT_FLTP;
		if (codec.sampleFormats && !codec.sampleFormats.includes(AV_SAMPLE_FMT_FLTP)) {
			sampleFormat = codec.sampleFormats[0];
		}

		const codecContext = new CodecContext();
		codecContext.allocContext3(codec);

		codecContext.sampleRate = config.sampleRate;
		codecContext.channelLayout = getChannelLayout(config.numberOfChannels);
		codecContext.codecType = AVMEDIA_TYPE_AUDIO;
		codecContext.codecId = inferred;
		codecContext.sampleFormat = sampleFormat;
		codecContext.timeBase = new Rational(1, 1e6);
		codecContext.bitRate = BigInt(config.bitrate ?? getDecentAudioBitrate(inferred));

		if (config.bitrateMode === 'constant') {
			codecContext.rcMinRate = codecContext.bitRate;
			codecContext.rcMaxRate = codecContext.bitRate;
		}

		return { codecContext, sampleFormat };
	}

	/**
	 * Checks if the encoder can support the given configuration.