Notes

Emacs

General

• Find face at point C-u C-x =

Macro

• Kmacro-keymap default binding C-x C-k
• kmacro-set-counter is C-x C-k C-c

H264 encoding

QP parameter

It regulates how much of spatial data is kept

• Small: a lot of data is kept so it's good quality
• High: data is discarded, which implies lower quality (but lower bitrate)

VBR vs CBR

• VBR means variable bit rate. It is open loop bitrate encoding. Given raw video and QP parameter: yields a video of fairly constant quality, but bitrate may change a lot
• CBR means constant bit rate. It's a closed loop bitrate encoding. We target a given bitrate and adapt the encoder parameters (QP?) accordingly during the encoding like any system in control theory