John Shutt wrote: > This is going to come as quite a shock to our four Tandberg encoders that are > using VBR to statistically multiplex four streams into one ATSC transmission. > > I'm not sure how to break the news to them... > > John > ----- Original Message ----- > From: Mike Tsinberg > To: opendtv@xxxxxxxxxxxxx > > The broadcasting such as ATSC can only be done in CBR. > They may technically be VBR but I'd wager they still have some fairly stringent peak bit rate limits that restrict the efficiency of the encoding for the total program, sort of a compromise between optimizing the average bit rate over a two hour movie and individually optimizing each second or so. That is, you can't save up bits displaying a still scene or talking heads and then apply the bits to a explosion scene 10 minutes later like you could on a BD. Basically, low latency = reduced encoding efficiency. Even Internet streaming has an advantage if you allow a bit of tricky buffering. Though I'll grant averaging over four different streams does help. It would help a lot more if ATSC had been designed to allow a low latency low resolution quick channel change stream stat muxed with a high delay high rez enhancement layer that would appear some extra seconds after channel change. - Tom ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.