Local SoundCloud Downloader (with cover->ID3)

Download SoundCloud without external service + embed cover art into MP3 ID3 metadata.

Este script no debería instalarse directamente. Es una biblioteca que utilizan otros scripts mediante la meta-directiva de inclusión // @require https://update.greasyfork.org/scripts/556576/1699828/Local%20SoundCloud%20Downloader%20%28with%20cover-%3EID3%29.js

Tendrás que instalar una extensión para tu navegador como Tampermonkey, Greasemonkey o Violentmonkey si quieres utilizar este script.

You will need to install an extension such as Tampermonkey to install this script.

Necesitarás instalar una extensión como Tampermonkey o Violentmonkey para instalar este script.

Necesitarás instalar una extensión como Tampermonkey o Userscripts para instalar este script.

Necesitará instalar una extensión como Tampermonkey para instalar este script.

Necesitarás instalar una extensión para administrar scripts de usuario si quieres instalar este script.

(Ya tengo un administrador de scripts de usuario, déjame instalarlo)

Necesitará instalar una extensión como Stylus para instalar este estilo.

Necesitará instalar una extensión como Stylus para instalar este estilo.

Necesitará instalar una extensión como Stylus para instalar este estilo.

Necesitará instalar una extensión del gestor de estilos de usuario para instalar este estilo.

Necesitará instalar una extensión del gestor de estilos de usuario para instalar este estilo.

Necesitará instalar una extensión del gestor de estilos de usuario para instalar este estilo.

(Ya tengo un administrador de estilos de usuario, déjame instalarlo)

// ==UserScript==
// @name         Local SoundCloud Downloader (with cover->ID3)
// @namespace    https://blog.maple3142.net/
// @version      0.2.1
// @description  Download SoundCloud without external service + embed cover art into MP3 ID3 metadata.
// @author       maple3142 + modified by ChatGPT
// @match        https://soundcloud.com/*
// @require      https://cdn.jsdelivr.net/npm/[email protected]/dist/ponyfill.min.js
// @require      https://cdn.jsdelivr.net/npm/[email protected]/StreamSaver.min.js
// @require      https://cdn.jsdelivr.net/npm/[email protected]/dist/browser-id3-writer.min.js
// @grant        none
// @license      MIT
// @icon         https://a-v2.sndcdn.com/assets/images/sc-icons/favicon-2cadd14bdb.ico
// @downloadURL  https://update.greasyfork.org/scripts/394837/Local%20SoundCloud%20Downloader.user.js
// @updateURL    https://update.greasyfork.org/scripts/394837/Local%20SoundCloud%20Downloader.meta.js
// ==/UserScript==

/* jshint esversion: 8 */

streamSaver.mitm = "https://maple3142.github.io/StreamSaver.js/mitm.html";

function hook(obj, name, callback, type) {
    const fn = obj[name];
    obj[name] = function (...args) {
        if (type === "before") callback.apply(this, args);
        fn.apply(this, args);
        if (type === "after") callback.apply(this, args);
    };
    return () => {
        // restore
        obj[name] = fn;
    };
}

function triggerDownload(url, name) {
    const a = document.createElement("a");
    document.body.appendChild(a);
    a.href = url;
    a.download = name;
    a.click();
    a.remove();
}

const btn = {
    init() {
        this.el = document.createElement("button");
        this.el.textContent = "Download";
        this.el.classList.add("sc-button");
        this.el.classList.add("sc-button-medium");
        this.el.classList.add("sc-button-icon");
        this.el.classList.add("sc-button-responsive");
        this.el.classList.add("sc-button-secondary");
        this.el.classList.add("sc-button-download");
    },
    cb() {
        const par = document.querySelector(".sc-button-toolbar .sc-button-group");
        if (par && this.el.parentElement !== par)
            par.insertAdjacentElement("beforeend", this.el);
    },
    attach() {
        this.detach();
        this.observer = new MutationObserver(this.cb.bind(this));
        this.observer.observe(document.body, { childList: true, subtree: true });
        this.cb();
    },
    detach() {
        if (this.observer) this.observer.disconnect();
    }
};

btn.init();

function getClientId() {
    return new Promise((resolve) => {
        const restore = hook(
            XMLHttpRequest.prototype,
            "open",
            function (method, url) {
                const u = new URL(url, document.baseURI);
                const clientId = u.searchParams.get("client_id");
                if (!clientId) return;
                console.log("got clientId", clientId);
                restore();
                resolve(clientId);
            },
            "after"
        );
    });
}

const clientIdPromise = getClientId();
let controller = null;

// helper: try to build best artwork url
function artworkBestUrl(track) {
    // track.artwork_url often contains e.g. -large.jpg ; try t500x500 or original; fallback to user avatar
    let art = track.artwork_url || (track.user && track.user.avatar_url) || null;
    if (
        !art &&
        track.publisher_metadata &&
        track.publisher_metadata.artwork &&
        track.publisher_metadata.artwork.url
    ) {
        art = track.publisher_metadata.artwork.url;
    }
    if (!art) return null;
    // replace size placeholders commonly used by SoundCloud
    return art.replace("-large", "-t500x500").replace("-crop", "-t500x500");
}

// fetch arrayBuffer with simple error handling
async function fetchArrayBuffer(url, signal) {
    const resp = await fetch(url, { signal });
    if (!resp.ok) throw new Error("Fetch failed: " + resp.status);
    return resp.arrayBuffer();
}

async function load(by) {
    btn.detach();
    console.log("load by", by, location.href);
    if (
        /^(\/(you|stations|discover|stream|upload|search|settings))/.test(
            location.pathname
        )
    )
        return;
    const clientId = await clientIdPromise;
    if (controller) {
        controller.abort();
        controller = null;
    }
    controller = new AbortController();
    const result = await fetch(
        `https://api-v2.soundcloud.com/resolve?url=${encodeURIComponent(
            location.href
        )}&client_id=${clientId}`,
        { signal: controller.signal }
    )
        .then((r) => r.json())
        .catch((e) => {
            console.warn("resolve failed", e);
            return {};
        });
    console.log("result", result);
    if (result.kind !== "track") return;
    btn.el.onclick = async () => {
        try {
            const progressive =
                result.media &&
                result.media.transcodings &&
                result.media.transcodings.find(
                    (t) => t.format && t.format.protocol === "progressive"
                );
            if (!progressive) {
                alert("Sorry, downloading this music is currently unsupported.");
                return;
            }
            // get the actual progressive audio URL
            const { url } = await fetch(
                progressive.url + `?client_id=${clientId}`
            ).then((r) => r.json());
            // fetch audio as ArrayBuffer (required to write ID3)
            const audioBuf = await fetchArrayBuffer(url);
            // try to fetch artwork
            let coverBuf = null;
            const artUrl = artworkBestUrl(result);
            if (artUrl) {
                try {
                    // SoundCloud sometimes returns SVG/other or redirects — let errors be caught
                    coverBuf = await fetchArrayBuffer(artUrl);
                } catch (e) {
                    console.warn("cover fetch failed", e);
                    coverBuf = null;
                }
            }

            // Use browser-id3-writer to set tags
            // ID3Writer is provided by browser-id3-writer (required at top)
            let filename = (result.title || "track") + ".mp3";
            // sanitize filename a bit
            filename = filename.replace(/[\/\\?%*:|"<>]/g, "_");

            let taggedBlob = null;
            try {
                const writer = new ID3Writer(audioBuf);
                // Basic tags
                if (result.title) writer.setFrame("TIT2", result.title);
                if (result.user && result.user.username)
                    writer.setFrame("TPE1", [result.user.username]);
                if (
                    result.publisher_metadata &&
                    result.publisher_metadata.album_title
                ) {
                    writer.setFrame("TALB", result.publisher_metadata.album_title);
                } else if (result.title) {
                    // optional: nothing
                }
                // add cover if available
                if (coverBuf) {
                    // attempt to detect mime from first bytes (jpeg/png)
                    let mime = "image/jpeg"; // default
                    const dv = new Uint8Array(coverBuf);
                    if (dv[0] === 0x89 && dv[1] === 0x50 && dv[2] === 0x4e)
                        mime = "image/png";
                    writer.setFrame("APIC", {
                        type: 3,
                        data: coverBuf,
                        description: "Cover",
                        mime: mime
                    });
                }
                writer.addTag();
                taggedBlob = writer.getBlob();
            } catch (e) {
                console.warn("ID3 tagging failed, falling back to raw file", e);
                // if tagging failed, fallback to raw audio
                taggedBlob = new Blob([audioBuf], { type: "audio/mpeg" });
            }

            // Attempt to save using StreamSaver (good for large files)
            // Note: StreamSaver supports streaming a blob stream to disk: taggedBlob.stream()
            try {
                const fileStream = streamSaver.createWriteStream(filename, {
                    size: taggedBlob.size
                });
                // Use readable stream from blob and pipe to streamSaver
                const readable = taggedBlob.stream();
                if (readable.pipeTo) {
                    await readable.pipeTo(fileStream);
                } else {
                    // fallback: manual pump
                    const reader = readable.getReader();
                    const writer = fileStream.getWriter();
                    const pump = () =>
                        reader
                            .read()
                            .then(({ done, value }) =>
                                done ? writer.close() : writer.write(value).then(pump)
                            );
                    await pump();
                }
            } catch (e) {
                // fallback to normal download via object URL
                console.warn("StreamSaver failed, fallback to anchor download", e);
                const urlObj = URL.createObjectURL(taggedBlob);
                triggerDownload(urlObj, filename);
                // release object URL after a while
                setTimeout(() => URL.revokeObjectURL(urlObj), 60 * 1000);
            }
        } catch (err) {
            console.error("Download failed", err);
            alert("Download error: " + (err.message || err));
        }
    };
    btn.attach();
    console.log("attached");
}

load("init");
hook(history, "pushState", () => load("pushState"), "after");
window.addEventListener("popstate", () => load("popstate"));