- Dynamic adjustment of energy quantisation
- Psychacoustics
  * Error shaping within each band
  * Desisions on the rate
- Intensity stereo option (e.g. threshold)
- Dynamic (intra-frame) bit allocation 
- Joint encoding of stereo energy
- Disable intra-frame prediction for more than X pulses
- Remove contraction?
- Simplify search?
- Remove pulse spreading?

- Encode band shape (or just tilt)?
- Make energy encoding more robust to losses?