multi-downloader-nx_mirror/modules/module.transform-mpd.ts

import { parse as mpdParse } from 'mpd-parser';
import { LanguageItem, findLang, languages } from './module.langsData';
import { console } from './log';

type Segment = {
	uri: string;
	timeline: number;
	duration: number;
	map: {
		uri: string;
		byterange?: {
			length: number;
			offset: number;
		};
	};
	byterange?: {
		length: number;
		offset: number;
	};
	number?: number;
	presentationTime?: number;
};

export type PlaylistItem = {
	pssh_wvd?: string;
	pssh_prd?: string;
	bandwidth: number;
	segments: Segment[];
};

type AudioPlayList = {
	language: LanguageItem;
	default: boolean;
} & PlaylistItem;

type VideoPlayList = {
	quality: {
		width: number;
		height: number;
	};
} & PlaylistItem;

export type MPDParsed = {
	[server: string]: {
		audio: AudioPlayList[];
		video: VideoPlayList[];
	};
};

function extractPSSH(manifest: string, schemeIdUri: string, psshTagNames: string[]): string | null {
	const regex = new RegExp(`<ContentProtection[^>]*schemeIdUri=["']${schemeIdUri}["'][^>]*>([\\s\\S]*?)</ContentProtection>`, 'i');
	const match = regex.exec(manifest);
	if (match && match[1]) {
		const innerContent = match[1];
		for (const tagName of psshTagNames) {
			const psshRegex = new RegExp(`<${tagName}[^>]*>([\\s\\S]*?)</${tagName}>`, 'i');
			const psshMatch = psshRegex.exec(innerContent);
			if (psshMatch && psshMatch[1]) {
				return psshMatch[1].trim();
			}
		}
	}
	return null;
}

export async function parse(manifest: string, language?: LanguageItem, url?: string) {
	if (!manifest.includes('BaseURL') && url) {
		manifest = manifest.replace(/(<MPD*\b[^>]*>)/gm, `$1<BaseURL>${url}</BaseURL>`);
	}
	const parsed = mpdParse(manifest);
	const ret: MPDParsed = {};

	// Audio Loop
	for (const item of Object.values(parsed.mediaGroups.AUDIO.audio)) {
		for (const playlist of item.playlists) {
			const host = new URL(playlist.resolvedUri).hostname;
			if (!Object.prototype.hasOwnProperty.call(ret, host)) ret[host] = { audio: [], video: [] };

			if (playlist.sidx && playlist.segments.length == 0) {
				const options: RequestInit = {
					method: 'head'
				};
				const item = await fetch(playlist.sidx.uri, options);
				if (!item.ok)
					console.warn(`${item.status}: ${item.statusText}, Unable to fetch byteLength for audio stream ${Math.round(playlist.attributes.BANDWIDTH / 1024)}KiB/s`);
				const byteLength = parseInt(item.headers.get('content-length') as string);
				let currentByte = playlist.sidx.map.byterange.length;
				while (currentByte <= byteLength) {
					playlist.segments.push({
						duration: 0,
						map: {
							uri: playlist.resolvedUri,
							resolvedUri: playlist.resolvedUri,
							byterange: playlist.sidx.map.byterange
						},
						uri: playlist.resolvedUri,
						resolvedUri: playlist.resolvedUri,
						byterange: {
							length: 500000,
							offset: currentByte
						},
						timeline: 0,
						number: 0,
						presentationTime: 0
					});
					currentByte = currentByte + 500000;
				}
			}

			//Find and add audio language if it is found in the MPD
			let audiolang: LanguageItem;
			const foundlanguage = findLang(languages.find((a) => a.code === item.language)?.cr_locale ?? 'unknown');
			if (item.language) {
				audiolang = foundlanguage;
			} else {
				audiolang = language ? language : foundlanguage;
			}
			const pItem: AudioPlayList = {
				bandwidth: playlist.attributes.BANDWIDTH,
				language: audiolang,
				default: item.default,
				segments: playlist.segments.map((segment): Segment => {
					const uri = segment.resolvedUri;
					const map_uri = segment.map.resolvedUri;
					return {
						duration: segment.duration,
						map: { uri: map_uri, byterange: segment.map.byterange },
						number: segment.number,
						presentationTime: segment.presentationTime,
						timeline: segment.timeline,
						byterange: segment.byterange,
						uri
					};
				})
			};

			const playreadyPssh = extractPSSH(manifest, 'urn:uuid:9A04F079-9840-4286-AB92-E65BE0885F95', ['cenc:pssh', 'mspr:pro']);

			const widevinePssh = extractPSSH(manifest, 'urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed', ['cenc:pssh']);

			if (widevinePssh) {
				pItem.pssh_wvd = widevinePssh;
			}

			if (playreadyPssh) {
				pItem.pssh_prd = playreadyPssh;
			}

			ret[host].audio.push(pItem);
		}
	}

	// Video Loop
	for (const playlist of parsed.playlists) {
		const host = new URL(playlist.resolvedUri).hostname;
		if (!Object.prototype.hasOwnProperty.call(ret, host)) ret[host] = { audio: [], video: [] };

		if (playlist.sidx && playlist.segments.length == 0) {
			const options: RequestInit = {
				method: 'head'
			};
			const item = await fetch(playlist.sidx.uri, options);
			if (!item.ok)
				console.warn(
					`${item.status}: ${item.statusText}, Unable to fetch byteLength for video stream ${playlist.attributes.RESOLUTION?.height}x${playlist.attributes.RESOLUTION?.width}@${Math.round(playlist.attributes.BANDWIDTH / 1024)}KiB/s`
				);
			const byteLength = parseInt(item.headers.get('content-length') as string);
			let currentByte = playlist.sidx.map.byterange.length;
			while (currentByte <= byteLength) {
				playlist.segments.push({
					duration: 0,
					map: {
						uri: playlist.resolvedUri,
						resolvedUri: playlist.resolvedUri,
						byterange: playlist.sidx.map.byterange
					},
					uri: playlist.resolvedUri,
					resolvedUri: playlist.resolvedUri,
					byterange: {
						length: 2000000,
						offset: currentByte
					},
					timeline: 0,
					number: 0,
					presentationTime: 0
				});
				currentByte = currentByte + 2000000;
			}
		}

		const pItem: VideoPlayList = {
			bandwidth: playlist.attributes.BANDWIDTH,
			quality: playlist.attributes.RESOLUTION!,
			segments: playlist.segments.map((segment): Segment => {
				const uri = segment.resolvedUri;
				const map_uri = segment.map.resolvedUri;
				return {
					duration: segment.duration,
					map: { uri: map_uri, byterange: segment.map.byterange },
					number: segment.number,
					presentationTime: segment.presentationTime,
					timeline: segment.timeline,
					byterange: segment.byterange,
					uri
				};
			})
		};

		const playreadyPssh = extractPSSH(manifest, 'urn:uuid:9A04F079-9840-4286-AB92-E65BE0885F95', ['cenc:pssh', 'mspr:pro']);

		const widevinePssh = extractPSSH(manifest, 'urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed', ['cenc:pssh']);

		if (widevinePssh) {
			pItem.pssh_wvd = widevinePssh;
		}

		if (playreadyPssh) {
			pItem.pssh_prd = playreadyPssh;
		}

		ret[host].video.push(pItem);
	}

	return ret;
}

function arrayBufferToBase64(buffer: Uint8Array): string {
	return Buffer.from(buffer).toString('base64');
}