Show HN: Mac screen recorder that adds zoom animations from click data(screencharm.com)

3 pointsby snazarov92le mois dernier1 comments

Show HN: Mac screen recorder that adds zoom animations from click data

https://screencharm.com/

Hi HN, I started building my product around 2 years ago as a Chrome extension. After releasing it, I realized I would never reach the quality of desktop apps, so at the beginning of 2025 I pivoted to a macOS app. I spent 3 months rewriting the codebase for Electron. I’m still using Next.js under the hood because the chrome extension used it, but in the near future I want to switch to ViteJS since it’s lighter and I don’t need backend functionality for an Electron app.

Overall I spent about 2 years on the development. The more interesting part is tracking the cursor movements when user starts recording and transforming it into smooth cursor movements and click-driven zoom effects. I use Swift scripts for low-level cursor tracking, then run a post-processing pipeline: resampling to timeline FPS, outlier-jump clamping, stillness detection/snap-to-median, cursor-type flicker smoothing, and coordinate normalization for area vs full-screen recording. Clicks are converted into timed zoom segments with easing so playback feels intentional, not jumpy

For the video preview and export I use PixiJS. Before I used Remotion, which had the needed functionality, but the rendering was slower because it relied on a Chromium + FFmpeg pipeline. PixiJS uses WebGL so the 4k video rending is much faster. It took me about 3 weeks on switching from Remotion to PixiJS. The rendering speed improved by about 3-4x on the same projects and hardware. I was honestly relieved when it finally worked

I would never have built this product without AI assistants, since I had never built an Electron app before. Many things were not obvious to me, and my first users ran into lots of issues and edge cases I didn’t even know existed. I spent the last year fixing them.

I'm happy to answer on your questions

1 comments

photonairle mois dernier

Love the concept. Being able to click and then have video automatically zoom makes the tutorial looks more professional.