Buffering a several second chunk allows the transmitter to include forward error correction (FEC). This allows operators to trade off latency for stream integr

Buffering a several second chunk allows the transmitter to include forward error correction (FEC). This allows operators to trade off latency for stream integrity which is important when it's going to be transmitted over a lossy medium such as terrestrial broadcast. This differs from the size problem because the amount of FEC (if any) is a parameter that can be configured between encoder and decoder. A size header would be a built in part of the protocol: hence my assertion that it would force a frame of latency. i.e. FEC is an operational concern whereas the size header is a protocol design concern.