Yeah, that would definitely help if it were efficient. In general the reason people don't use scalable/layered/incremental codecs in 1:1 video transmission is t

Yeah, that would definitely help if it were efficient. In general the reason people don't use scalable/layered/incremental codecs in 1:1 video transmission is that they're less efficient than just encoding a single stream. One of the challenges here is that it's hard to know how big a compressed frame will be until you compress it, and that takes time. Ideally an encoder would be able to produce a compressed frame that's the exact size that can be accommodated by the network path, right away. In practice that's not so easy. Salsify gets around this by having the encoder encode two candidate coded frames (one bigger, one smaller) and then giving the application the option of sending either one (after encoding is finished and it knows their exact length and quality) or no frame at all. If the encoder could just do the job perfectly and instantly the first time, you wouldn't need all that.