Demos

One notebook per task, each short enough to read in a sitting and run before you lose interest. Open one in Colab, run it top to bottom, hear or see the result.

Each badge is that one notebook, executed cell by cell every Sunday against the release it pins — one workflow per notebook, since GitHub's badge cannot show a single job of a matrix. It is earned: nothing joins the table until it runs there, and unmaintained/ has no badge for the same reason.

What green means, and what it does not

Green says: on a clean Ubuntu runner, on CPU, with Python 3.12, every cell of every demo ran to the end without raising, last Sunday.

It does not say the output was right. Nothing here checks a transcript against a reference or listens to the audio; a model that quietly got worse would pass.

Most of what a demo depends on is not in this repository, and the run is green or red according to those too:

the pinned espnet release, from PyPI	the pin is exact, so this does not move
its dependency tree	not pinned — a new torch or numpy can break a demo with nothing changed here, and that is a real signal, not a false alarm
the checkpoints, from the Hugging Face Hub	a model that is renamed, made private or deleted turns the run red; most are in the espnet organization, and asr_streaming_demo uses one copied there for that reason
transformers and the LLM in sds_demo	outside ESPnet entirely
the sample audio, from the espnet repository	moved or renamed, the run goes red

So a red badge is a question — which of those changed? — rather than an accusation against the notebook. And the Sunday cadence means up to a week can pass before a break is noticed. workflow_dispatch is there for when you want the answer now.

Notebook		What it does
asr_demo.ipynb		Transcribe speech with OWSM-CTC, and let it work out the language
asr_streaming_demo.ipynb		Watch the words appear while the audio is still arriving
st_demo.ipynb		Translate English speech into German, French and Chinese — the same model
s2t_align_demo.ipynb		Line text up with the audio it was said in, and score how well they agree
s2t_pr_demo.ipynb		Hear the phones, and cross between phones and words with POWSM
tts_demo.ipynb		Type a sentence, hear it spoken — one English voice, then 128 of them
enh_demo.ipynb		Pull speech out of noise, and measure how much it helped
spk_demo.ipynb		Turn a voice into a vector, and score two recordings against each other
codec_demo.ipynb		Compress a waveform to a few integers a frame, rebuild it, count the bits
sds_demo.ipynb		Speech in, speech out, with a language model thinking in between

The naming rule

<task>_demo.ipynb or <task>_<variant>_demo.ipynb, flat in this directory, where <task> is the ESPnet task name the rest of the toolkit already uses:

<task>
asr	speech recognition
s2t	OWSM: recognition, translation and language ID in one model
tts	text-to-speech
enh	speech enhancement and separation
spk	speaker embedding, verification, diarization
st	speech translation
codec	neural audio codecs

These are the words espnet.load(model, task=...), espnet2/tasks/ and the model cards use, so a reader who knows one knows the others. Flat, because a directory per task held one or two files and made you click twice to find out there was nothing there.

A task may have a second angle worth its own page, and then the name carries it: asr_streaming_demo.ipynb beside asr_demo.ipynb. That is not a licence to multiply — this directory filled up once with notebooks nobody could tell apart. Every demo has to appear in the table above with a line saying what it does, and ../tools/check_layout.py fails if one does not, or if it has no workflow and badge of its own, so a second page cannot arrive without someone saying how it differs from the first.

What a demo owes the reader

• It runs, and goes on running. Every notebook here was executed end to end, on the release it pins, before it was committed — and again every Sunday by .github/workflows/run_notebooks.yml, which is what the badge at the top reports. A demo that does not run is worse than no demo: it costs the reader their afternoon and the project their credibility.
• It pins a release. espnet==<version>, never git+https://.... The notebook should do the same thing in April that it does today, and a break on master the night before someone opens it is not their problem. The install cell is also what CI installs — it is read rather than duplicated in the workflow, so what that cell may say is an interface: what --print-install supports.
• It ends by pointing onwards — the one-line terminal command, the Space if there is one, the course notebook for the long version.

unmaintained/

Everything that was here before, in one place. Most of it does not run: the oldest is from 2021 and installs packages that no longer resolve. They are kept because some of them are still the only written record of how a thing was done, and removed as they are replaced.

Nothing in there is checked. Do not send someone to one of those notebooks without opening it yourself first.