ffmpeg.js VS ffmpeg.wasm

You likely want something like https://github.com/Kagami/ffmpeg.js/ for extracting slices

There are solutions to transcode to MP4 live in your browser, such as with [FFMPEG.js (https://github.com/Kagami/ffmpeg.js/). MP4 is actually just the containing file however! The codec that you record with still needs to be supported by MP4. So prepare for FFMPEG.js to do lots of work if you go this route!

Well, the heavy lifting is done by ffmpeg (https://github.com/Kagami/ffmpeg.js/)

I think you want ffmpeg.js

Recently, browser features such as SharedArrayBuffer and WebAssembly are increasing. Video and video converter ffmpeg also works in browsers.

ffmpeg.js uses a custom build of FFmpeg to keep its size low. I am trying to convert a .ts into a .mp4 which has always been an easy task on my desktop (especially since I believe they are even using the same codecs, aac and h.264), but on the custom build, I get the error sample1.ts: Invalid data found when processing input.

Maybe use something like that make conversions client side?

Super helpful, thanks so much! I wonder if you'd be able to use something like https://github.com/Kagami/ffmpeg.js to cut out the offline step. I'm working on something at the moment that I'd love to embed in a webpage for general use but getting an MP4 out of it from a browser has been a big stumbling block.

https://github.com/Kagami/ffmpeg.js/ to import most animation formats and export gifs/webm fully in browser (I don't want to pay real server costs to encode animation).

There's already ffmpeg wasm. I've used it in projects. Works great.

https://github.com/ffmpegwasm/ffmpeg.wasm

There's a low-hanging fruit that I think would make ffmpeg more helpful for regular people.

There's a million terrible websites that offer file conversion services. They're ad-ridden, with god-knows-what privacy/security postures. There's little reason for users to need to upload their files to a third-party when they can do it locally. But getting them to download fiddly technical software is tough - and they're right to mistrust it.

So, there's a WASM version of ffmpeg, already working and hosted at Netlify [1]. It downloads the WASM bundle to your browser and you can run conversions/transformations as you wish, in your browser. Sandboxed and pretty performant too!

If this tool a) was updated regularly b) had a nicer, non-CLI UI for everyday users and c) was available at an easily-Googlable domain name - it would solve all the problems I mentioned above.

[1]: https://ffmpegwasm.netlify.app/

As their github page says, based on https://ffmpegwasm.netlify.app ...

I'm guessing no one did GPU-optimizations? I saw a web app (not an ffmpeg transpilation) that went clever and used WebGL so it can access the GPU and use its parallel processing capabilities...

ffmpeg.wasm: The engine making all these happen. However, I’m a bit concerned about its current situation. The repo has not been updated for more than six months now, and that’s not a healthy sign for an open-source project. Clearly I was reading the commits wrong. The author mentioned “speed up x264 with SIMD intrinsics” in their roadmap (https://github.com/ffmpegwasm/ffmpeg.wasm/discussions/415), which, if landed, could make such on-device video editors much more competitive.

I use https://github.com/ffmpegwasm/ffmpeg.wasm and I want my FFMPEG commands to be hidden from others.

Possibly using this? https://github.com/ffmpegwasm/ffmpeg.wasm

You could try using something like ffmpeg wasm which is a way of using ffmpeg client side in browser. Unfortunately WebAssembly only supports files less than 2 gigabytes, which is a problem for videos. And I don't know if ffmpeg wasm contains ffprobe, so you might have to find another project or try to compile ffprobe to wasm yourself. This stuff is out of my wheelhouse so I can't offer much help.