download audio from youtube channels

yc2audio.js

const axios = require('axios')
const fs = require('fs')

const req = async (url) => {
    return await axios.get(url, { headers: { 'X-YouTube-Client-Name': 1, 'X-YouTube-Client-Version': '2.20200514.05.00', 'X-YouTube-Page-CL': 311468061 } })
}

const getAudio = async (url) => {
    const resp = await req('https://youtube.com' + url + '&pbj=1')
    if (resp.status == 200 && resp.data[2]?.player) {
        let data = JSON.parse(resp.data[2].player.args.player_response)
        let rawFormats = data.streamingData.adaptiveFormats.filter(o => o.audioQuality?.indexOf('AUDIO_QUALITY') == 0)
        let rawFormat = rawFormats[0]
        rawFormats.forEach(r => {
            if (r.contentLength < rawFormat.contentLength && r.url)
            rawFormat = r
        });
        // console.log(r)
        let audioUrl = rawFormat.url
        let title = data.videoDetails.title
        if (!audioUrl) {
            console.log('  [-] missing url to ' + title + ' ' + url)
            return
        }
        // let lastModified = new Date(Number(rawFormat.lastModified.substr(0,13)))
        // let quality = rawFormat.audioQuality
        let publishDate = data.microformat.playerMicroformatRenderer.publishDate
        console.log('  [*] Downloading ' + (rawFormat.contentLength/(1024*1024)).toFixed(2) + 'MB from ' + title)
        let audio = await axios.get(audioUrl, {responseType: 'arraybuffer'})
        let fileName = publishDate + ' ' + title
        fileName = fileName.replace(/\//g,'')
        fs.writeFileSync(fileName, audio.data)
    } else {
        console.error(resp.status)
        console.error(resp.data)
    }
}




(async () => {

    const channelId = 'UCwSxSJqGpSRpEsq5-YUbM8g'
    let loadAllUrls = false
    let resp = await req('https://youtube.com/channel/' + channelId + '/videos?pbj=1')
    let data = resp.data[1]?.response?.contents?.twoColumnBrowseResultsRenderer?.tabs[1]?.tabRenderer?.content?.sectionListRenderer?.contents[0]?.itemSectionRenderer?.contents[0]?.gridRenderer
    
    let countVideos = 0
    while (!loadAllUrls) {
        let videos = data?.items
        videos.forEach(v => {
            countVideos += 1
            let title = v.gridVideoRenderer.title.simpleText
            let info = v.gridVideoRenderer.publishedTimeText.simpleText
            let url = v.gridVideoRenderer.navigationEndpoint.commandMetadata.webCommandMetadata.url

            console.log('[' + countVideos + '] ' + title + ' ' + info + ' ' + url)
            getAudio(url)
        });
        if (resp.status != 200 || !data) {
            console.error(resp.status)
            console.error(resp.data)
            return
        }
        
        let continuation = data.continuations?.[0].nextContinuationData?.continuation
        if (videos.length < 30 || !continuation) {
            loadAllUrls = true
        } else {
            resp = await req('https://www.youtube.com/browse_ajax?continuation=' + continuation)
            data = resp.data[1]?.response?.continuationContents?.gridContinuation
        }
    }
    
})()