motion-canvas VS Scrawl-canvas

Hey HN! We’re building Revideo (https://github.com/redotvideo/revideo), an open source toolkit that lets you programmatically create and export videos with the animation library Motion Canvas (https://github.com/motion-canvas/motion-canvas). This is useful whenever you want to build apps that automate certain video tasks, which is increasingly possible using AI tools - for instance, one of our first users is building an app that turns code documentation into video tutorials.

Revideo extends Motion Canvas with features that are essential for creating video, such as the ability to export audio tracks, a nodejs package for headless, parameterized & much faster rendering, and audio components that make audio editing and syncing easier. While Motion Canvas aims to be a standalone editor [1], we want to build a set of libraries that lets developers integrate video editing functionality into their apps. Our goal is to provide an open-source alternative to Remotion (https://github.com/remotion-dev/remotion).

At the start of this year, we explored a bunch of product ideas in the space of AI-based video creation. For example, we’ve built apps that automatically create educational short videos and have experimented with automatically A/B testing and personalizing video ads.

While building these products, we were frustrated with the video editing frameworks we used: Moviepy (https://github.com/Zulko/moviepy), which we relied on initially, doesn’t offer a way to preview your videos, so we’d often have to wait minutes for a video to render to test our code changes. Remotion (https://github.com/remotion-dev/remotion), which we switched to later, is really good, but we didn’t want to rely on it as it is not open source (source-available only). That’s why we decided to build Revideo.

We’d already been following Motion Canvas for some time and really liked using it, so we thought that extending it would get us to something useful much faster than building an animation library from scratch. Initially, we tried to build our features as Motion Canvas plugins, but this did not provide enough flexibility to achieve the desired functionality. Additionally, video-specific features (such as audio support) were generally considered out of scope by the Motion Canvas maintainers, which is why we ultimately ended up creating a fork. We’re unsure if this is the right way to go in the long term, and would prefer to find a way to build Revideo without diverging from Motion Canvas too much - if you have suggestions on how to solve this, we’d love your input.

Compared to Remotion, which builds on top of React, Motion Canvas uses the HTML Canvas API and makes you define animation flows with generator functions. Its API is more “procedural”, as it makes you define the things that happen in your animation as a sequence of yields, whereas Remotion gives you a frame number and lets you declare how your video should look like at that frame.

Our current focus is improving the open source project. In the long term, we want to make money by building a rendering service for developers building apps with Revideo. Such a service would offer a pretty similar deployment experience to Vercel, but instead of web apps, we let developers deploy Revideo projects and expose a rendering endpoint for them. Letting us manage the infrastructure will allow us to offer much faster rendering, as we can massively parallelize rendering jobs on our servers (e.g. spinning up 100 headless browsers that render 100 frames each to render a video with 10,000 frames).

We’d love to hear your feedback and suggestions! You can find our repo at https://github.com/redotvideo/revideo, We’ve also released an example video editing app at https://github.com/redotvideo/revideo-saas-template. Thank you!

[1] “Motion Canvas is not a normal npm package. It's a standalone tool that happens to be distributed via npm.” - https://github.com/orgs/motion-canvas/discussions/1015

I'm using https://motioncanvas.io/, but it's a little bit tough to learn

Coming to motion design, this rumour takes of due to the fact that there are programming libraries like Manim and Motion-Canvas which are actually used to generate animations from code. You can search 3Blue1Brown channel on youtube.

Personally I would look at codebased animation programs for something like this. Maybe possible with for example Motion Canvas - web github

You might also consider JavaScript to use ThreeJS or Motion Canvas.

Most of the credit goes to https://motioncanvas.io/ here 😉 But thanks anyway!

You can try to use motion Canvas its still new but amazing. Motion Canvas

> working with glyphs and iterating them in reverse for RTL is brain-breaking. And line wrapping gets really complicated. It's also the most obscure because nobody has written down everything you need to know in one place

I can confirm this. I've been working on a (much simpler!) text layout engine for my canvas library over the past couple of months and the amount of complexity associated with just stamping some glyphs onto a canvas has left me screaming at my laptop on an almost daily basis. Getting a decent underline was a proud moment!

Question: did you ever find out what algorithm the various browsers are using to calculate how many words can fit on a given line? I'm almost there, except words will occasionally jump between lines when I scale the text. Really annoying!

The PR's still a work in progress, but I've got all the functionality I want in there (shaping lines to fit in non-rectangular containers, styling text, text along a non-straight line, dynamic updates, etc). Just need to test and document it all now ... https://github.com/KaliedaRik/Scrawl-canvas/pull/75

I've got myself organised and prepared a List Of Things To Do[1] to make my 2D Javascript library even better than it already is. Given that I've been working on the library for over 10 years now, and have never before set out such a list, I call this Progress!

[1] https://github.com/KaliedaRik/Scrawl-canvas/discussions/cate...

'Kay, I don't know if this anywhere close to what the OP wants, but this sort of live browser tab manipulation is possible to do using a mix of a a canvas element and the browser's Screen Capture API[1] (plus my JS canvas library, once I merge and publish the changes into its next release[2]).

This solution[3] shows the modified browser tab in a separate browser tab. I've got no idea whether it's possible to do the same sort of trick in the same tab (but probably not). I also have no idea how secure the Screen Capture API is - I'd get very nervous about doing this sort of thing when looking at my bank's online portal!

[1] https://developer.mozilla.org/en-US/docs/Web/API/Screen_Capt...

[2] https://github.com/KaliedaRik/Scrawl-canvas/pull/57

[3] Youtube video of the effect: https://www.youtube.com/watch?v=hCi6LmKMAo0

My canvas library's README[1] has a video embedded in it. FWIW I'm not convinced it adds anything to the library's sales pitch.

[1] https://github.com/KaliedaRik/Scrawl-canvas

> And I’m just mentioning some of the unfixable problems with this approach

I agree that using a canvas instead of leveraging existing accessibility supplied by HTML/CSS/JS and the DOM is an accessibility nightmare.

However, I disagree that canvas accessibility issues are "unfixable". Difficult? Yes. But not unfixable. In my view, the element works best in partnership with its wider environment (HTML/CSS/JS and the DOM), not as a replacement for it. With that in mind, we can start to tackle the accessibility issues you raise - fonts, links, interactions, etc.[1][2]

I have an ambition to one day become intelligent enough to understand/code in Rust, and I'm really glad to see that people are thinking about accessibility as a fundamental part of UIs being developed in Rust.

[1] - Which is what my JS 2d canvas library tries to do: https://scrawl-v8.rikweb.org.uk/

[2] - My thoughts on accessibility, and how I try to fix them using my library: https://scrawl-v8.rikweb.org.uk/learn/eleventh-lesson/

If, however, your company is set on this course, I very strongly suggest you use a canvas library - if only for the MVP. Here's my canvas library (spam alert!) ... even if you don't use it in your product, the library might help give you some ideas on how to overcome some of the responsive, interactive and accessibility issues you'll be facing.

Scrawl-canvas - example and another example (links to code at bottom of each page)

My personal experience as a library developer, who has written my library in JS, not TS ...

TS is an excellent choice for a lib dev starting a new project today. I can see the advantages of using TS for the library code - in particular for a library that gets popular and welcomes contributions from other developers. However TS is a nightmare for someone like me who: 1. started writing the library 9 years ago; 2. has let the library get "quite" big; and 3. has only learned to use TS in the past year (for the day job) and is nowhere near to becoming a types expert.

I've had experience of people suggesting I rewrite the library in TS. Sometimes those suggestions have been quite 'evangelical' in their tone. As an (essentially) solo developer I just don't have the time, capacity or willingness to do that work - however much the end results might please others.

I also understand that having type definitions file for the library's interface is, nowadays, a critical factor if the lib dev wants others to use the library in their projects. But writing a .d.ts file for a large, mature repo to at least help those potential users can quickly turn into a World of Hurt. I know this because I've done that work[1] and I never want to do it again.

As much as I know that TS is a Force for Good in the JS coding world, there are days when I detest it!

[1] - link to the Scrawl-canvas .d.ts file on GitHub - https://github.com/KaliedaRik/Scrawl-canvas/blob/master/sour...