polly.rb

##
# Synthesizes audio for the given text.
#
# @param text [String] The text to synthesize audio for.
# @param output [String|IO] (optional) Path to file to write or IO object to stream to.
# @return [SynthesizeSpeechOutput] A struct containing `audio_stream` (IO) and `content_type` (String).
def say(text, language: nil, output: nil, ssml: false)
  client.synthesize_speech(
    response_target: output,
    output_format: "ogg_vorbis",
    sample_rate: "22050",
    voice_id: language_voice_id(language),
    text: text,
    text_type: ssml ? 'ssml' : 'text'
  )
end

##
# Polly client. Configured through the environment variables
# AWS_REGION, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY
def client
  @client ||= Aws::Polly::Client.new
end

def language_voice_id(lang)
  case lang
  when "de"
    "Hans"
  when "ru"
    "Maxim"
  when "en"
    "Brian"
  else
    "Brian"
  end
end