Distribution formats

[Noiz2]

The other thread that has been closed, was drifting in a direction that I think would be of some use.

There was a post close to the end that was actually incorrect about 5.1 and I don't want that just sitting there.

5.1 is a discrete system with one exception. Some flavors of ProLogic use a complicated martixing system for sticking 5.1 (and even 7.1) into a two track stream.

The 5.1 on DVD's and used for theatrical distribution however has six discrete channels.

The more standard ProLogic like "Dolby Surround" is a matrixed 4.0 system that folds four channels into a two channel stream.

As far as I know the current sound formats for distribution of film and video are.

SDDS wich is 7.1. Five across the front (L,LC,C,RC,R) two surround and a LFE
Dolby Digital 5.1 Three across the front (LCR) two surround and a LFE
Dolby Surround 4.0 Three across the front Mono surround and the LFE is filtered from the L&R. (there are also a number of compatible systems like SDS)

Stereo (2.0) Just L & R
Mono

There are some old formats that are not used much if at all these days like the discrete six track tapes that were used with 72mm prints.

Video has the above plus.

ProLogic is basically Dolby surround
ProLogic II (5.0) adds a second surround speaker.
ProLogic IIx (6,1 & 7.1) adds Rear speaker(s)
ProLogic IIz (7.1 & 9.1) adds hight speakers to the format.

On the specialty theatrical release formats you have

An IMAX version that I believe is pretty much the 5.1 with one or two overhead speakers

There is a "3D" format that has some other speakers that I believe are overhead and in the rear.

There was an argument about 3.0 as a distribution format.
While there probably are live theatre spaces that are set up as LCR, and one might get a three channel file to play across the LCR there is no 3.0 distribution format for film or video that I have ever heard of.

You could of course mix to 3.0 and put that in a larger format and just not use the surrounds. A lot of films basically do that because of the problematic nature of surround playback in the real world. But it's still a 4.0 or 5.1 distribution format.

This list is I think pretty curent but feel free to add to it because formats keep getting added.

I do hope we get a digital film "standard" that is accessible by low budget filmmakers. At the moment you are pretty limited by the media theaters can play back and weird licensing restrictions.

Right now I don't think anything but stereo is really "safe" for low budget films heading to festivals and such. But this could change in a heartbeat and I expect it will change pretty soon. I just read that 88% of all screens in the US are using digital projectors. Once you can author your film to a drive they can read the current format limits should open up a lot.

 

[Richard Crowley]

Thank you for resurrecting this topic, Scott. I wanted to clarify that I didn't mean that the (live) theatrical L-C-R scheme is the same as the front 3 channels of 5.1 I was only trying to suggest a possible method of distributing "3.0" via an established format.

Interesting to hear that digital exhibition has achieved such penetration into theaters. I would suppose that more modern projection comes along with at least the theatrical equivalent of 5.1 audio channels and likely more.

 

[ryanjf]

Thanks Scott. I haven't seen SDDS 7.1 in a while, but it is now more of Dolby 7.1, L R C LFE Lss Rss Lsr Rsr

I've also thought of the ProLogic stuff to be decoding/"magic" upmixing mechanisms or even more of "feed it stereo and out comes surround".

 

[ryanjf]

Oh! You can't forget about Dolby Atmos!

 

[Rick R]

I am surprised at how many theaters I'm been to where the sound is mono, the films (major releases) certainly weren't mixed that way.. and these theaters ain't small-town either.. Manhattan. Who knows what they have at film festivals.. I would'nt send a surround mix if I did'nt know the system and what type.. just asking for trouble. I agree a stereo mix is safer and would even down-mix to mono if phase issues were kept in check.

 

[ryanjf]

I am surprised at how many theaters I'm been to where the sound is mono, the films (major releases) certainly weren't mixed that way.. and these theaters ain't small-town either.. Manhattan. Who knows what they have at film festivals.. I would'nt send a surround mix if I did'nt know the system and what type.. just asking for trouble. I agree a stereo mix is safer and would even down-mix to mono if phase issues were kept in check.

I agree with you. One thing that has saved my ass is delivering a stereo downmix (even better a LtRt) BUT working with in a 5.1/7.1 session setup. That way, it is easier to go back to the 5.1 or 7.1 mix architecture for any surround sound deliverables.

So I would setup a [insert DAW here] session that would have 5.1 or 7.1 stems/buses from the start of the project. All the editing would be done in this surround sound environment.

However, what I would be listening to is a downmix of the 5.1 or 7.1 stems/buses the entire time.

The panning of sounds would still have a surround panning pot but the panning would be done and auditioned in the downmixed stereo field.

When mixing and if the client only wants a stereo mix at that point in time, I just simply print the stereo downmix that I was listening to.

If the client returns a few months later and says, "Hey, can you give me a 5.1 mix?" ... I can just simply take out the downmix bus array/downmix plugin, and since the panning automation, outputs, etc. have already been in a surround sound session format, I can just fine tweak panning/levels from there. Of course, it won't be perfect but it'll save time rebuilding the entire stereo-centric session into a surround-based session.

Nonetheless, it gives people practice setting up and mixing in a surround sound session, which can be complex at times.

Regarding Mono, some consoles/controllers (like the PreSonus Monitor Station ($300)) have a "mono" button that can quickly fold stereo to mono, so there's no need to have a mono downmix array in my session.

 

[Rick R]

I always check mixes in mono (and verify it with a scope) it is mono compatible.. should that occur..
and as 'ryanjf' stated render stems too.

 

[Noiz2]

...
I've also thought of the ProLogic stuff to be decoding/"magic" upmixing mechanisms or even more of "feed it stereo and out comes surround".

The "magic" is when you plop that stereo music track in and it starts popping into the surrounds randomly ;~)

If you mix for a matrixed master it's actually trickier than going 5.1, because you have to encode and monitor the decode to make sure things are where you want them to be. You really don't want to play a stereo mix through the decoder because phase differences in recordings and especially some effects will send the sounds spinning all over the place. You have to sometimes almost pull the music down to mono to keep it from heading into the surrounds.

I think this is part of why so many sound libraries that were build a lot before 5.1 are almost all mono except for ambiences. If you use, say, a doppler by in stereo the phase shift in the sound is going to move the sound around as it goes by.

With discrete 5.1 you put the sound someplace and it stays there. well until you go to a theatre where the system is funky and you only have a L surround or it's all in mono.

Hearing a film you worked on played in a commercial theatre is often a very depressing experience.