btrtracks/src/common/download.js

import {spawn} from 'child_process'
import ffmpeg from 'fluent-ffmpeg'

import path from 'path'
import asn from './async'

function parseTitle (data) {
  let tt = data.title

  // Remove []'s from the beginning
  tt = tt.replace(/^\[\w+\]\s?/i, '')

  // Remove "Official Video/Audio" tag
  tt = tt.replace(/\s?(?:[\(\)\[\]])?Official\s?[\w]+(?:[\(\)\[\]])?/i, '')

  // Remove "Audio" tag
  tt = tt.replace(/\s?(?:[\(\)\[\]])Audio?(?:[\(\)\[\]])/i, '')

  // Remove "lyrics" tag
  tt = tt.replace(/\s?(?:[\(\)\[\]])?lyrics?\s?(?:[\w]+)?(?:[\(\)\[\]])?\s?/i, '')

  // Artist / Title split
  let at = tt.split(' - ', 2)
  let artist
  let title

  if (at.length > 1) {
    artist = at[0]
    title = tt.substring(artist.length + 3)
  } else {
    artist = data.artist
    title = tt
  }

  data.title = title
  data.artist = artist

  return data
}

function getVideoInfo (arg) {
  let yt = spawn('youtube-dl', ['--no-playlist', '-j', '-f', 'bestaudio/best', arg])

  let output = ''
  yt.stdout.on('data', function (chunk) {
    output += chunk.toString('utf8')
  })

  return new Promise((resolve, reject) => {
    yt.on('close', function () {
      let ftdata = output.trim().split('\n')
      if (ftdata.length > 1) {
        let composite = []
        for (let i in ftdata) {
          let dat
          try {
            dat = JSON.parse(ftdata[i])
          } catch (e) {
            console.error(e)
            continue
          }
          delete dat.formats
          composite.push(dat)
        }
        return resolve(composite)
      }

      let data = JSON.parse(output)
      delete data.formats
      resolve(data)
    })
  })
}

function fetchVideo (data) {
  return new Promise((resolve, reject) => {
    let tempName = path.join(process.cwd(), `/tmp.yt.${data.id}.mp3`)
    ffmpeg(data.url || data.file)
      .audioCodec('libmp3lame')
      .format('mp3')
      .on('error', reject)
      .on('end', function () {
        resolve({
          title: data.title,
          artist: data.uploader,
          url: data.webpage_url,
          art: data.thumbnail,
          source: tempName
        })
      })
      .output(tempName)
      .run()
  })
}

export default { parseTitle, getVideoInfo, fetchVideo }