transloadit/ruby-sdk

class AudioConcatTranscoder < MediaTranscoder
  require 'transloadit'
  require_relative 'media-transcoder'

  # in this example a file is encoded as an mp3, id3 tags are added, and it is stored in s3
  def transcode!(files)
    concat = transloadit_client.step('concat', '/audio/concat', {
      preset: 'mp3',
      use: {
        steps: files.map.each_with_index do |f, i|
          { name: ':original', as: "audio_#{i}", fields: "file_#{i}" }
        end
      },
      result: true
    })

    steps = [concat]

    begin
      store = transloadit_client.step('store', '/s3/store', {
        key: ENV.fetch('S3_ACCESS_KEY'),
        secret: ENV.fetch('S3_SECRET_KEY'),
        bucket: ENV.fetch('S3_BUCKET'),
        bucket_region: ENV.fetch('S3_REGION'),
        use: ['concat']
      })

      steps.push(store)
    rescue KeyError => e
      p 's3 config not set. Skipping s3 storage...'
    end

    assembly = transloadit_client.assembly(steps: steps)
    assembly.create! *open_files(files)
  end

  def open_files(files)
    files.map do |f|
      open(f)
    end
  end

  def mp3_metadata
    meta = { publisher: 'Transloadit', title: '${file.name}' }
    meta[:album] = 'Transloadit Compilation'
    meta[:artist] = 'Transloadit'
    meta[:track] = '1/1'
    meta
  end
end