38. ytmp3.as [youtube] [downloader] [audio] [video]

/*
  base    : https://ytmp3.as
  update  : 27 agustus 2025
  by      : wolep
  node    : v24.5.0
  note    : buat download mp3, mp4 dari
            youtube biasa, youtube short
            dan youtube music
            support esm dan cjs
            skrep nya kadang ku cek ya
*/

const yt = {
    get baseHeaders() {
        return {
            'accept-encoding': 'gzip, deflate, br, zstd'
        }
    },

    get url() {
        return {
            origin: 'https://ytmp3.as'
        }
    },

    extractVideoId: function (fV) {
        let v
        if (fV.indexOf('youtu.be') > -1) {
            v = /\/([a-zA-Z0-9\-\_]{11})/.exec(fV);
        } else if (fV.indexOf('youtube.com') > -1) {
            if (fV.indexOf('/shorts/') > -1) {
                v = /\/([a-zA-Z0-9\-\_]{11})/.exec(fV);
            } else {
                v = /v\=([a-zA-Z0-9\-\_]{11})/.exec(fV);
            }
        }
        const result = v?.[1]
        if (!result) throw Error(`gagal extract video id`)
        return result
    },

    getInitUrl: async function () {
            "use strict"
        try {
            const r1 = await fetch(this.url.origin, { headers: this.baseHeaders })
            console.log('hit homepage')

            const html = await r1.text()
            const jsPath = html.match(/<script src="(.+?)"/)?.[1]
            const jsUrl = this.url.origin + jsPath

            const r2 = await fetch(jsUrl, { headers: this.baseHeaders })
            console.log('hit js')
            const js = await r2.text()

            // ayo main eval evalan

            // cari gB
            const gB_m = js.match(/gB=(.+?),gD/)?.[1]
            const gB = eval(gB_m)

            // cari gC
            const html_m = html.match(/<script>(.+?)<\/script>/)?.[1]
            const hiddenGc = eval(html_m + "gC")
            const gC = Object.fromEntries(Object.getOwnPropertyNames(hiddenGc).map(key => [key, hiddenGc[key]]))

            // fungsi
            const decodeBin = (d) => d.split(' ').map(v => parseInt(v, 2))
            const decodeHex = (d) => d.match(/0x[a-fA-F0-9]{2}/g).map(v => String.fromCharCode(v)).join("")
            function authorization() {
                var dec = decodeBin(gC.d(1)[0]);
                var k = '';
                for (var i = 0; i < dec.length; i++) k += (gC.d(2)[0] > 0) ? atob(gC.d(1)[1]).split('').reverse().join('')[(dec[i] - gC.d(2)[1])] : atob(gC.d(1)[1])[(dec[i] - gC.d(2)[1])];
                if (gC.d(2)[2] > 0) k = k.substring(0, gC.d(2)[2]);
                switch (gC.d(2)[3]) {
                    case 0:
                        return btoa(k + '_' + decodeHex(gC.d(3)[0]));
                    case 1:
                        return btoa(k.toLowerCase() + '_' + decodeHex(gC.d(3)[0]));
                    case 2:
                        return btoa(k.toUpperCase() + '_' + decodeHex(gC.d(3)[0]));
                }
            }

            const api_m = js.match(/t.open\("GET",(.+?),!/)?.[1]
            const apiUrl = eval(api_m)
            return apiUrl
        } catch (e) {
            throw new Error('fungsi getApiUrl gagal')
        }
    },

    download: async function (url, f = 'mp3') {
        // validation format
        if (!/^mp3|mp4$/.test(f)) throw Error(`format valid mp3 or mp4`)

        // extract video id
        const v = this.extractVideoId(url)

        const headers = {
            'referer': this.url.origin,
            ...this.baseHeaders
        }

        // get init url
        const initApi = await this.getInitUrl()

        // hit init
        const r1 = await fetch(initApi, { headers })
        console.log('hit init')

        const j1 = await r1.json()
        const { convertURL } = j1

        // hit convertURL
        const convertApi = convertURL + '&v=' + v + '&f=' + f + '&_=' + Math.random()
        const r2 = await fetch(convertApi, { headers })
        console.log('hit convert url')

        const j2 = await r2.json()
        if (j2.error) {
            throw Error(`ada error di value convert. nih\n${JSON.stringify(j2, null, 2)}`)
        }

        if (j2.redirectURL) {
            const r3 = await fetch(j2.redirectURL, { headers })
            console.log('hit redirect')
            const j3 = await r3.json()
            const result = {
                title: j3.title,
                downloadURL: j3.downloadURL,
                format: f
            }
            return result
        } else {
            // luping
            let j3b
            do {
                const r3b = await fetch(j2.progressURL, { headers })
                console.log('hit progress')
                j3b = await r3b.json()
                if (j3b.error) throw Error(`ada error pas cek progress. nih\n${JSON.stringify(j3b, null, 2)}`)
                if (j3b.progress == 3) {
                    const result = {
                        title: j3b.title,
                        downloadURL: j2.downloadURL,
                        format: f
                    }
                    return result
                }
                await new Promise(resolve => setTimeout(resolve, 3000))
            } while (j3b.error != 3)
        }
    }
}

// cara pakai
yt.download('https://www.youtube.com/watch?v=Fmf-G9fpwto', 'mp3')
    .then(console.log)
    .catch(console.log)


/* output
{
  title: 'Diamond Eyes - Stars | Dubstep | NCS - Copyright Free Music',
  downloadURL: 'https://ummn.ummn.nu/api/v1/download?sig=W%2B%2...........fVJHdP%2F%2BxcO%2FfA%3D%3D',
  format: 'mp3'
}


atauuuuu.....
yt.download('yt_url', 'mp4') -> untuk download mp4
yt.download('yt_url', 'mp3') -> untuk download mp3
yt.download('yt_url') -> empty param download mp3 juga
*/