[ldjb]

I interpret that as meaning the difference between using stream copy and re-encoding videos when converting between different formats.

For instance, the user might upload an H.264 video as an MP4 file. Streaming services generally won't serve the MP4 file itself, but will create an HTTP Live Streaming (HLS) version where the video is split into multiple .ts chunks along with a .m3u8 playlist.

However, such services (including YouTube) will generally re-encode the video when doing so, and the end result will have poorer quality than the original uploaded file.

This is actually unnecessary because .ts files support the H.264 codec, so the video does not need to be re-encoded. Instead the streams can be copied to retain their original quality.

If additional compression is necessary, I suppose it would be possible to apply HTTP compression using algorithms such as gzip or deflate.

Of course, this is purely speculation. It would be nice if Cloudflare clarified what they meant. But it would certainly be great if they used stream copying where possible instead of re-encoding.