upstream-rocketchat/packages/mp3-encoder/src/lame/Presets.ts

import { ABRPresets } from './ABRPresets';
import type { LameGlobalFlags } from './LameGlobalFlags';
import type { Quality } from './Quality';
import { VBRPresets } from './VBRPresets';
import { VbrMode } from './VbrMode';

const enum Preset {
	V9 = 410,
	V8 = 420,
	V7 = 430,
	V6 = 440,
	V5 = 450,
	V4 = 460,
	V3 = 470,
	V2 = 480,
	V1 = 490,
	V0 = 500,
	R3MIX = 1000,
	STANDARD = 1001,
	EXTREME = 1002,
	INSANE = 1003,
	STANDARD_FAST = 1004,
	EXTREME_FAST = 1005,
	MEDIUM = 1006,
	MEDIUM_FAST = 1007,
}

export class Presets {
	private readonly vbrPresets = new VBRPresets();

	public readonly abrPresets = new ABRPresets();

	apply(gfp: LameGlobalFlags, preset: Preset) {
		switch (preset) {
			case Preset.R3MIX: {
				preset = Preset.V3;
				gfp.VBR = VbrMode.vbr_mtrh;
				break;
			}
			case Preset.MEDIUM: {
				preset = Preset.V4;
				gfp.VBR = VbrMode.vbr_rh;
				break;
			}
			case Preset.MEDIUM_FAST: {
				preset = Preset.V4;
				gfp.VBR = VbrMode.vbr_mtrh;
				break;
			}
			case Preset.STANDARD: {
				preset = Preset.V2;
				gfp.VBR = VbrMode.vbr_rh;
				break;
			}
			case Preset.STANDARD_FAST: {
				preset = Preset.V2;
				gfp.VBR = VbrMode.vbr_mtrh;
				break;
			}
			case Preset.EXTREME: {
				preset = Preset.V0;
				gfp.VBR = VbrMode.vbr_rh;
				break;
			}
			case Preset.EXTREME_FAST: {
				preset = Preset.V0;
				gfp.VBR = VbrMode.vbr_mtrh;
				break;
			}
			case Preset.INSANE: {
				gfp.preset = 320;
				gfp.VBR = VbrMode.vbr_off;
				this.abrPresets.apply(gfp, 320);
				return 320;
			}
		}

		gfp.preset = preset;

		switch (preset) {
			case Preset.V9:
				this.vbrPresets.apply(gfp, 9);
				return preset;
			case Preset.V8:
				this.vbrPresets.apply(gfp, 8);
				return preset;
			case Preset.V7:
				this.vbrPresets.apply(gfp, 7);
				return preset;
			case Preset.V6:
				this.vbrPresets.apply(gfp, 6);
				return preset;
			case Preset.V5:
				this.vbrPresets.apply(gfp, 5);
				return preset;
			case Preset.V4:
				this.vbrPresets.apply(gfp, 4);
				return preset;
			case Preset.V3:
				this.vbrPresets.apply(gfp, 3);
				return preset;
			case Preset.V2:
				this.vbrPresets.apply(gfp, 2);
				return preset;
			case Preset.V1:
				this.vbrPresets.apply(gfp, 1);
				return preset;
			case Preset.V0:
				this.vbrPresets.apply(gfp, 0);
				return preset;
			default:
				break;
		}

		if (preset >= 8 && preset <= 320) {
			return this.abrPresets.apply(gfp, preset);
		}

		gfp.preset = 0;
		return preset;
	}

	applyPresetFromQuality(gfp: LameGlobalFlags, quality: Quality) {
		return this.apply(gfp, 500 - 10 * quality);
	}
}