5.1 mix = Dolby Digital?
- Thread starter ronin99
- Start date
Zak Forsman
Major Contributor
5.1 only means there are six discrete channels of audio. nothing more. just like how calling something stereo only means that is has 2 channels of audio. has nothing to do with the format or compression scheme used.
Dolby Digital is compressed audio and often reserved for DVD, blu-ray and iTunes downloads. DTS is another popular format.
It used to be use din theaters but with the advent of DCPs (Digital Cinema Packages), those soundtracks are now uncompressed.
Dolby Digital is compressed audio and often reserved for DVD, blu-ray and iTunes downloads. DTS is another popular format.
It used to be use din theaters but with the advent of DCPs (Digital Cinema Packages), those soundtracks are now uncompressed.
Noiz2
Sound Ninja
Interesting about DCP's.
As Zak said "Dolby Digital" is a special format of a 5.1 mix. For 35mm films it required a mix in a Dolby certified stage and Dolby would send a guy out with a special recorder that would get patched in and they would record the 5.1 mix. That recording would get turned into a negative that would get printed with the film negative to produce what kind of looked like a bar code between frames, which was the digital audio track.
You also needed to pay for a license to use the DD track.
Then with DVD's the DD was (I believe) the same encoding but was of course a digital stream not optical.
For some time I tried to get out of Dolby what if any licensing one needed to sell DVD's with DD. What I eventually got was that as long as you didn't say it was DD they didn't care. If you wanted to slap a Dolby logo on your film you had to get a license. It was all kind of weird since Dolby licenses were not cheap so this "loop hole" actually made it better for straight to DVD filmmakers than it was for small budget films with a film release.
As Zak said "Dolby Digital" is a special format of a 5.1 mix. For 35mm films it required a mix in a Dolby certified stage and Dolby would send a guy out with a special recorder that would get patched in and they would record the 5.1 mix. That recording would get turned into a negative that would get printed with the film negative to produce what kind of looked like a bar code between frames, which was the digital audio track.
You also needed to pay for a license to use the DD track.
Then with DVD's the DD was (I believe) the same encoding but was of course a digital stream not optical.
For some time I tried to get out of Dolby what if any licensing one needed to sell DVD's with DD. What I eventually got was that as long as you didn't say it was DD they didn't care. If you wanted to slap a Dolby logo on your film you had to get a license. It was all kind of weird since Dolby licenses were not cheap so this "loop hole" actually made it better for straight to DVD filmmakers than it was for small budget films with a film release.
Rick R
Veteran
Multi-channel 5.1 audio doesn't necessarily mean 'Dolby' encoded, though Dolby's AC-3 encoder is often used for DVD and BD and can be stereo (2-track) as well. This licensed encoder is sometimes included with some NLE and authoring software. For instance, Sony's DVD Architect includes Dolby Digital AC-3 Pro. The Dolby AC-3 Studio version lacks the custom settings, such as normalization level, metadata, ect.
Last edited:
David W. Jones
Veteran
No.
GaryNattrass
Veteran
As others have said 5.1, 6.1, 7.1 and even 22.2 are just channel formats and how they are encoded to be included as part of a cinema release is all down to licencing and there are more formats than even Dolby Digital as Sony and even Lucas Films have their own formats.
The 22.2 is for super HD and to my knowledge NHK are the only ones mad enough to be covering events in 8k with 22.1.
To do a Dolby Digital encode for DVD or TV you used to just buy their hardware encoders and decoders for the mix stage but a lot of the features for AC3 are now available to purchase as part of a software licenced plug in for your audio edit software.
To do a full surround for cinema mix Dolby et all require that your set-up and mix room are authorised and usually you have to rent their encode/decode kit and it is installed and approved by their engineers.
That said some of the specs are quite silly IMO with SPL and JBL horn loaded PA type speaker systems required in huge dub stages that are supposed to resemble a cinema but in my experience the sound in most cinemas is pretty dreadful in the UK as they are built to make money from bums on seats and $10 popcorn and coke.
But it is their rules and if you are expecting to do it on the cheap you will find that it is a huge compromise although I have heard of some people miing at home and then just booking an hour or two to run the mix thru the Dolby kit to tick their boxes. The spec also used to include a film projector but I am sure things may have moved on but I would not bank on it.
There is another option though and it may be that Pro Logic 2 may give you enough of a surround experience and it can be done using reasonably costed plug ins such as this one: https://neyrinck.com/pdf/Mix 51 Users Guide.pdf
Note that the big mistake people think with 5.1 is that their speakers can be small boxes with just a sub bass for the low end. That is not what the Dolby spec is as the sub bass or LFE is designed to be used as and when required and not be fed all the time just to fill on the lower octaves.
The 22.2 is for super HD and to my knowledge NHK are the only ones mad enough to be covering events in 8k with 22.1.
To do a Dolby Digital encode for DVD or TV you used to just buy their hardware encoders and decoders for the mix stage but a lot of the features for AC3 are now available to purchase as part of a software licenced plug in for your audio edit software.
To do a full surround for cinema mix Dolby et all require that your set-up and mix room are authorised and usually you have to rent their encode/decode kit and it is installed and approved by their engineers.
That said some of the specs are quite silly IMO with SPL and JBL horn loaded PA type speaker systems required in huge dub stages that are supposed to resemble a cinema but in my experience the sound in most cinemas is pretty dreadful in the UK as they are built to make money from bums on seats and $10 popcorn and coke.
But it is their rules and if you are expecting to do it on the cheap you will find that it is a huge compromise although I have heard of some people miing at home and then just booking an hour or two to run the mix thru the Dolby kit to tick their boxes. The spec also used to include a film projector but I am sure things may have moved on but I would not bank on it.
There is another option though and it may be that Pro Logic 2 may give you enough of a surround experience and it can be done using reasonably costed plug ins such as this one: https://neyrinck.com/pdf/Mix 51 Users Guide.pdf
Note that the big mistake people think with 5.1 is that their speakers can be small boxes with just a sub bass for the low end. That is not what the Dolby spec is as the sub bass or LFE is designed to be used as and when required and not be fed all the time just to fill on the lower octaves.
Noiz2
Sound Ninja
As I think I mentioned if you don't have a license for Dolby you can't say the film was Dolby encoded, even if it is.
There are a number of surround formats and encodings but not all of them work on everything. Theatrical 35mm Dolby Digital has to be done through Dolby because they generate the negative with the digital codes.
Pro Logic is a 4.0, though ProLogic 2 I believe does 5.1. SRS is 5.1 or 7.1, but you would have to get an old box because they are not making it anymore. All of these are analog encoders so what you end up with is a "stereo" track that when played through the proper decoder expands to the surround format. The good part is that it will play back on systems with no decoder and sound fine. THe downside is it can be a pain to mix because you can get "steering issues" as in that sound yo paned left jumps to a surround every once in awhile. THe encoding is phase based so FX like phase shifters can drive the decoder crazy. Also most home "surround" systems will detect ProLogic and switch to surround.
While ProLogic is essentially the same as the theatrical Dolby 4.0 encoder, theatrical releases all use noise reduction on analog tracks and that is pretty much exclusively Dolby SR (though Dolby A was also popular once). The bottom line is that you really need to have your mix SR encoded if it is going to theatres, and you run the risk that some smart person decides your low budget masterpiece probably isn't SR encoded and switches it off and then you mix sounds AWFUL.
Since I doubt anybody here is distributing on 35mm film, I would not encode at all and go with desecrate tracks for the DCP. You really don't want to play a DVD on a large screen. For the DVD I would encode in Dolby Digital since almost everybody can play that and pretty much every DVD encoding software will give you that option.
There are a number of surround formats and encodings but not all of them work on everything. Theatrical 35mm Dolby Digital has to be done through Dolby because they generate the negative with the digital codes.
Pro Logic is a 4.0, though ProLogic 2 I believe does 5.1. SRS is 5.1 or 7.1, but you would have to get an old box because they are not making it anymore. All of these are analog encoders so what you end up with is a "stereo" track that when played through the proper decoder expands to the surround format. The good part is that it will play back on systems with no decoder and sound fine. THe downside is it can be a pain to mix because you can get "steering issues" as in that sound yo paned left jumps to a surround every once in awhile. THe encoding is phase based so FX like phase shifters can drive the decoder crazy. Also most home "surround" systems will detect ProLogic and switch to surround.
While ProLogic is essentially the same as the theatrical Dolby 4.0 encoder, theatrical releases all use noise reduction on analog tracks and that is pretty much exclusively Dolby SR (though Dolby A was also popular once). The bottom line is that you really need to have your mix SR encoded if it is going to theatres, and you run the risk that some smart person decides your low budget masterpiece probably isn't SR encoded and switches it off and then you mix sounds AWFUL.
Since I doubt anybody here is distributing on 35mm film, I would not encode at all and go with desecrate tracks for the DCP. You really don't want to play a DVD on a large screen. For the DVD I would encode in Dolby Digital since almost everybody can play that and pretty much every DVD encoding software will give you that option.