Introducing a Templating Engine, Styling Language, and Modern Library Integration for MoviePy

[JoelOnyedika]

Discussed in #2241

^{Originally posted by JoelOnyedika November 19, 2024}

Proposal: Introducing a Templating Engine, Styling Language, and Modern Library Integration for MoviePy

Summary
MoviePy is an amazing library for programmatic video editing, but it faces limitations in flexibility, performance, and modern developer workflows. This proposal suggests introducing:

1. A templating engine (similar to Jinja2/Django templates) to simplify video creation.
2. A CSS-like styling language to decouple design and logic for video elements.
3. Integration with modern libraries like Numba, SciPy, or TensorFlow for performance optimization.

---

Challenges with Current MoviePy
As a developer working on a SaaS application a platform that createa headless videos with text-to-speech—I’ve faced significant challenges using MoviePy:

1. Rigid Syntax: Every part of the video has to be manually coded, making the process tedious and error-prone, especially for dynamic content like tweets.
2. Styling Limitations: Customizing text, animations, and transitions for different clients is time-consuming and often requires creative hacks.
3. Performance Bottlenecks: Processing a single video with heavy assets or effects can take too long, especially without GPU acceleration. And dont get me started on the speed. Its even impractical to run on a serverless architecture because it if a 30 secs video takes 4 mins to generate imagine a 30 mins video. It will break you
4. Dynamic Updates: There’s no easy way to dynamically update properties (like replacing text or changing styles) without regenerating the entire video. Which is so frustrating

All these limitations and a whole full month of headaches, i forced me to leave moviepy and go for node js remotion which so far is beyond amazing. But I believe the following enhancements could make MoviePy a truly modern and competitive tool for video generation.

Proposed Features

1. Templating Engine

Introduce a declarative syntax for video creation, similar to how HTML works for web development. Example:

<video width="1920" height="1080">
  <text content="Hello, MoviePy!" position="center" style="my-style-class" />
  <image src="background.png" />
</video>

This template could be rendered into MoviePy scripts, allowing non-Python developers to create videos easily. For apps like TweetFlow, this would simplify workflows and open doors for non-technical users to define video templates.

Thhis can be achieved using jinja2 which is already being used in Django and flask as the primary templating engine

---

2. CSS-Like Styling Language

Develop a lightweight styling language to define the appearance and animations of video elements. This would decouple design from logic, similar to CSS in web development. Example:

.my-style-class {
  font-size: 48px;
  color: #FFFFFF;
  animation: fadeIn 2s;
}

This would be game-changing for dynamic SaaS apps where video content varies for every user, as the style definitions could be reused and easily updated.

---

3. Modern Library Integration

To improve performance, MoviePy could leverage:

• Numba: For GPU-accelerated video processing.
• SciPy: For advanced mathematical operations and effects.
• TensorFlow: For AI-based effects like object tracking or intelligent cropping.
• Cython: To optimize critical paths and speed up rendering.

For TweetFlow, integrating these tools would reduce processing times and enable smoother scaling for real-time video generation.

---

4. Dynamic Updates

Add functionality to dynamically update element properties during runtime. Example:

video.update_text(content="Dynamic Text", time=10)  # Changes text at 10 seconds

This would enable reactive video creation where content adapts based on data (e.g., timestamps, API responses). For example, in TweetFlow, user-generated tweets and their associated replies could be rendered into videos dynamically without rerunning the entire pipeline.

---

Benefits

• Accessibility: Easier for developers with different skill sets (not just Python) to use MoviePy.
• Improved Workflow: Separation of logic (Python) and design (styling templates).
• Performance: Faster rendering with GPU acceleration and modern libraries.
• Flexibility: Dynamically update elements during video generation.

---

Personal Motivation and Vision
As a developer who has faced challenges in scaling video generation for a SaaS platform, I believe this is an opportunity for MoviePy to evolve into a leading tool in the video editing ecosystem. By introducing modern features like templating, styling, and dynamic updates, we can create a tool that empowers developers to build creative, scalable, and performant video solutions.

MoviePy has immense potential, and this proposal is a step toward unlocking it.

---

Next Steps

1. Build a proof of concept for the templating engine.
2. Design a minimal syntax for the CSS-like styling language.
3. Identify specific areas in MoviePy’s codebase for integration with Numba/SciPy.
4. Collect feedback from the community.

---

Call to Action
I’d love to hear your thoughts! Do you think these features could make MoviePy more powerful and accessible? Would anyone like to collaborate on a proof of concept? Let’s build something amazing together!

---

[Zulko]

Thanks! Mostly agree, the problem to get all this realized will be bandwidth. Some remarks:

• (1) and (2), i.e. a "HTML/CSS-like definition of videos", would be indeed useful. I believe some people have made a JSON-> moviepy video specification, and to me the ideal flow would be "high level language, HTML like -> JSON -> MoviePy". Note that this doesn't need to be owned by the moviepy repo, it could be an external library/framework built on top of moviepy.
• For 3 I believe the bottlenecks are (1) maybe use GPU-accelerated FFMPEG to speed up rendering (haven't looked into it) and (2) speed up operations like resizing etc. via GPU (these are typical bottlenecks). Not sure about other needed operations, I believe a lot of the heavy work is done with numpy so Cython won't speed things up much.
• For (4) this is an interesting concept. An alternative naming I'd suggest:

new_text_clip = text_clip.with_updated_parameters_in_time(text="new text", after_t=10)

It might be a good idea, I am not sure how generalizable it is, or how confusing it might be if people used this a lot. For now people can write this which I agree is longer and more effort to read, but also more explicit.

other_clip = Text(...)
new_clip = concatenate_videoclips([clip.set_duration(10), other_clip]) 

[OsaAjani]

I do have something that does some json to moviepy magic, I would need it dig it up and share it, but that will be something for early 2025 on my side.

[Implosiv3]

Hi. I'm very interested in this project. I'm currently working on a huge project that involves moviepy so I'm getting used to its behavior, bugs and stuff. I work on video automation and involving web is one of the steps I planned for the future. You mention 'remotion' and its seems to be nice, but the posibilities with moviepy are completely awesome. I'm doing things pretty cool with this library. I take a seat here.