tutorial.md

layout	title	questions	objectives	time_estimation	subtopic	key_points	contributors
tutorial_hands_on	Adding auto-generated video to your slides	How can we add auto-generated video? How does it work? What do I need to do to make it optimal for viewers?	Adding a video to a set of slides	20m	extras	Thanks to the GTN, videos are easy to add Be mindful of your captions. Short sentences are good!	hexylena

Video Lectures

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Based on the work by Delphine Larivière and James Taylor with their COVID-19 Lectures we have implemented a similar feature in the Galaxy Training Network.

Agenda

In this tutorial, we will:

1. TOC {:toc}

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How it Works

We wrote a short script which does the following:

Locally and in production:

• Extracts a 'script' from the slides. We extract every presenter comment in the slidedeck, and turn this into a text file.
• Every line of this text file is then narrated by Amazon Polly (if you have money) or MozillaTTS (free).
• The slide deck is converted to a PDF, and then each slide is extracted as a PNG.
• Captions are extracted from the audio components.
• The narration is stitched together into an mp3
• The images are stitched together into an mp4 file
• The video, audio, and captions are muxed together into a final mp4 file

In production

• We use Amazon Polly, paid for by the Galaxyproject
• The result is uploaded to an S3 bucket

Enabling Video

We have attempted to simplify this process as much as possible, but making good slides which work well is up to you.

Writing Good Captions

Every slide must have some narration in the presenter notes. It does not make sense for students to see a slide without commentary. For each slide, you'll need to write presenter notes in full, but short sentences.

Sentence Structure

Use short and uncomplex sentences whenever possible. Break up ideas into easy to digest bits. Students will be listening to this spoken and possibly reading the captions.

The captioning process is completely automated, but it means that for very long sentences, we do not currently break them up into multiple captions. So please keep your sentences under ~120 characters where possible.

Good

• Configuration management manages the configuration of machines.
• It specifies what software should be installed, and how it should be configured. {: .code-in}

Bad Configuration management manages the configuration of machines, it specifies what software should be installed, and how it should be configured {: .code-out} {: .code-2col}

Captions per Slide

Every slide must have some speaker notes in this system, NO exceptions.

Punctuation

Sentences should end with punctuation like . or ? or even ! if you're feeling excited.

Abbreviations

These are generally fine as-is. (e.g. e.g./i.e. is fine as-is, RNA is fine, etc.) Make sure abbreviations are all caps though.

Good This role deploys CVMFS. {: .code-in}

"Weird" Names

In the captions you will want to teach the GTN how to pronounce these words by editing bin/ari-map.yml to provide your definition.

E.g.

Word	Pronunciation
SQLAlchemy	SQL alchemy
FastQC	fast QC
nginx	engine X
gxadmin	GX admin
/etc	/ E T C

The same applies to the many terms we read differently from how they are written, e.g. 'src' vs 'source'. Most of us would pronounce it like the latter, even though it isn't spelt that way. Our speaking robot doesn't know what we mean, so we need to spell it out properly.

So we write the definition in the bin/ari-map.yml file.

Other Considerations

(Written 2020-12-16, things may have changed since.)

Be sure to check the pronunciation of the slides. There are known issues with heteronyms, words spelt the same but having different pronunciation and meaning. Consider "read" for a classic example, or "analyses" for one that comes up often in the GTN. "She analyses data" and "Multiple analyses" are pronounced quite differently based on their usage in sentences. See the wiktionary page for more information, or the list of English heteronyms you might want to be aware of.

This becomes an issue for AWS Polly and Mozilla's TTS which both don't have sufficient context sometimes to choose between the two pronunciations. You'll find that "many analyses" is pronounced correctly while "multiple analyses" isn't.

Oftentimes the services don't understand part of speech, so by adding adjectives to analyses, you confuse the engine in to thinking it should be the third person singular pronunciation. This is probably because it only has one or two words of context ahead of the word to be pronounced.

Enable the Video

Lastly, we need to tell the GTN framework we would like videos to be generated.

{% icon hands_on %} Hands-on: Enable video

1. Edit the slides.html for your tutorial
2. Add video: true to the top {: .hands_on}

That's it! With this, videos can be automatically generated.

Conclusion

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