Compressing in browser preupload

google / brunsli

Practical JPEG Repacker

MIT License

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Compressing in browser preupload #67

Closed Charuru closed 4 years ago

Charuru commented 4 years ago

Can we have some instructions on how to setup wasm to do this please?

eustas commented 4 years ago

Hello. You could check https://brunsli.dev/test.html On this page ServiceWorker upgrades the HTTP request so that nginx plugin sends compressed file instead of original. When response arrives, ServiceWorker decodes it and passes as JPEG to browser.

Using up WASM is usually simple:

follow the Emscripten instructions
set CC and CXX environment variables to point to emcc and em++
freshly configure and build with CMake

Please refine the question, if I got it wrong.

Charuru commented 4 years ago

Thanks, the question was about how to upload a compressed file with image data from canvas instead of compressing on the server.

eustas commented 4 years ago

With current API it could be done in 2 steps:

canvas.toDataURL('image/jpeg', quality / 100.0);, then decode base64 payload to bytes
pass bytes to Brunsli, like here: https://github.com/google/brunsli/blob/master/docs/index.html#L231