airing 5.1 spots

[hef]

okay i know there have been a bunch of threads recently regarding Lt/Rt and Lo/Ro and what the networks are doing with this and i'm still confused.

i just mixed an HD spot and did a stereo mix and a 5.1 mix for it. the specs from the traffic house say they want the discreet 6 channels, and either an Lt/Rt on 7 and 8 or the Lo/Ro. since we don't have the surround encoding plugins the Lo/Ro seems like the way to go until we get them. what i want to know, is what happens with this Lo/Ro mix? is this what is played on people's HDTV who don't have surround sound? or are the networks making fold downs from the discreet 5.1 channels? i've seen some network specs that don't want the discreet channels and only the Lt/Rt. i guess these networks will only be playing my stereo mix? as the mixer i'm not sure what networks are getting these spots, probably many- and all with different specs. so i'm just providing it to the traffic house's specs.

i looked at CBS, ESPN, and Fox and all have different specs
is there any standard here? and when will there be one?

below is a link to those specs.

http://dswiki.wikispaces.com/WikiSub_DeliverySpecs

[hef]

nobody?

[CCH]

Hi,

I mixed 3 Superbowl spots this year and we provided two sets of masters for the event. One set was a standard-def Digibeta with a stereo mix on channels 1 and 2. The other set was a Hi-Def D5 with a six channel 5.1 mix. Channels 7-8 were left MOS. I was concerned about this because I wondered what would happen if someone could not decode the AC3 stream that accompanies a HighDef signal; would they then hear nothing? How would they hear an LtRt? I got a hold of the engineer in charge of the broadcast and this is what he told me.

First of all, they ran two control rooms during the event. One broadcast in standard-def, and the other simulcast in high-def. In answer to my concern about how the six channel 5.1 mix got folded down, he replied that the local affiliates sent the discrete six channels through a Dolby DP563 which on the fly encodes the six channels into a Dolby ProLogicII LtRt.

http://www.dolby.com/professional/pr.../dp563_01.html

This is then broadcast with the High Def Picture, and AC3 stream. Its been a while since I had that conversation, and I don't have my notes with me, but that is how I remember it. You can imagine how worried I was when they didn't want me to include an LtRt with the discrete 5.1 Mix. Perhaps someone here can fill in the blanks if there are any.

In your case, I bet a network will use the LoRo on channels 7-8 if they need them. Perhaps, if an affiliate doesn't use the DP563 method, then they have a stereo mix available to broadcast. That channel layout with the 5.1 on channels 1-6, and the LtRt or LoRo on 7-8, seems to be the most versatile to accommodate all of the networks.

Well, I hope that helps. It would be great if all of the networks agreed on their standards, but I doubt that will ever happen. My situation might only apply to the Superbowl and CBS, but it makes sense to me that a DP563 would be used to create these LtRt mixes at the local affiliates.

Thank goodness for resourceful producers, or I might have never gotten a hold of that broadcast engineer.


-CCH

[hef]

thank you, that is very helpful.

i don't understand why ESPN and most likely some others won't take the discreet channels. i guess its easier for them, but its not giving their advertisers what they're paying for. they're paying for a 5.1 mix not an Lt Rt.