Is it possible to do .FLV to .MP4 conversion on client side by ffmpeg-asm.js? The main issue lot's of mobile video players didn't support flash, but .FLV still popular at the internet ;(
Have no idea how to avoid server-side conversion and storing...
Yes, it is possible to convert in browser to an MSE compatible format. But I would still recommend a server side conversion. Its is extreme cheap to switch containers from flv to mp4.