Heya! Hope this is the right place for this question, if not I’m happy to move it.

I was trying to play around with speech-to-text using the OpenAI Whisper model in Livebook by kinda following along with Chris McCord’s YouTube video and this post from Dockyard: Audio Speech Recognition in Elixir with Whisper Bumblebee - DockYard. However, I’m getting the error:

** (KeyError) key :decoder_start_token_id not found in: [max_new_tokens: 100, defn_options: [compiler: EXLA]]. If you are using the dot syntax, such as map.field, make sure the left-hand side of the dot is a map
    (bumblebee 0.2.0) lib/bumblebee/text/generation.ex:135: Bumblebee.Text.Generation.build_generate/3
    (bumblebee 0.2.0) lib/bumblebee/audio/speech_to_text.ex:23: Bumblebee.Audio.SpeechToText.speech_to_text/5
    #cell:e4zqu3usyi6eu7maylexdftfnarnp432:6: (file)

Which, doing a little poking around, I think is related to specifying the language. I’ve got audio in en/US but not sure how to supply :decoder_start_token_id in this case (I’ve found some Python examples, but haven’t been able to get it to work in Elixir). I can’t find any examples of providing :decoder_start_token_id with Bumblebee.Audio.speech_to_text/4. Any help is greatly appreciated. For reference, here’s the .livebook source (in case I’m doing something stupid):

Mix.install([
  {:bumblebee, github: "elixir-nx/bumblebee"},
  {:exla, "~> 0.4"},
  {:nx, github: "elixir-nx/nx", sparse: "nx", override: true}
])

Section

Nx.default_backend(EXLA.Backend)

{:ok, whisper} = Bumblebee.load_model({:hf, "openai/whisper-tiny"})
{:ok, featurizer} = Bumblebee.load_featurizer({:hf, "openai/whisper-tiny"})
{:ok, tokenizer} = Bumblebee.load_tokenizer({:hf, "openai/whisper-tiny"})

serving =
  Bumblebee.Audio.speech_to_text(whisper, featurizer, tokenizer,
    max_new_tokens: 100,
    defn_options: [compiler: EXLA]
  )