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Suround sound on HDcam
Well I will admit that I am amateur compared to you guys but if you could lend me any advice I would really appreciate it.
Ok so I’m a film student in my final year, I’m doing audio design for a short film and the director and myself want to have surround 5.1. We are still in pre-production and are looking at the feasibility of it. I have never done surround mixing before but I can at least get help with that. What my problem is is the output. I know blue-ray is the highest quality for pro-consumer, bit we want to export both vision and sound to tape (HDcam) We have a Deck that should be sufficient but none of the universities staff or any one else have a clue how to do it.
Just to let you know i am in the sound field but I have a pretty competent general knowledge of all other areas – and if I don’t someone else in the crew will. I’m glad I’m addressing this problem now rather than when I have spent days in the studio mixing so I know there is a lot to do between now and then but any help would be great.
Thanks
Shaun O’Brien -
10 Replies
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Hi Shaun,
Welcome to the fun fun world of pro audio interfacing! You need to do a Dolby-E layback to get your 5.1 to HDCam. That will encode your 5.1 as 2 channels. Those two channels can not be listened to directly, as they now transport data, not sound. You need a Dolby-E decoder to get your full sound back. The normal procedure (with the place I send stuff to at least) is to lay back the Dolby-E to channels 3 and 4, with your stereo mix on channels 1 and 2.
If you’re a student, Dolby-E may be out of your reach, as many pro post houses don’t even have it. Another solution would be to lay down your Lt/Rt mix on two tracks of the HDCam. The Lt/Rt can be converted back to LCRS (not 5.1) by a ProLogic audio decoder. If you go down this road, still include a true stereo mix (Lo/Ro) on the other two tracks of the HDCam. I hate going the Lt/Rt road because the decoded signal is so flat and narrow compared to the full Dolby Digital. The best solution would be to lay back to HDCam-SR, if at all possible.
If you’re now interested in the necessary tools, https://www.neyrinck.com is a good place to start. I personally do both Dolby-E and Lt/Rt with a combination of Neyrinck, Waves 360 bundle and a hardware Dolby DMU.
IHTH,
JC Boulay
Technical Director
Audio Z
Montreal, Canada
http://www.audioz.com -
Hello Shaun and welcome to the Cow Audio Forum.
First you need a post production rig that’s at least capable of 5.1. That’s software and monitors.
You’ll also need a Dolby Digital encoder.
Regards,
Ty Ford
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Watch Ty play guitar -
Yeah Got protools HD sute full of gear. Not sure of the dolby didgital though. is it software or hardware?
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Have a look at the Holophone mic some of them have an inbuilt encoder…
I have used one of the discreet o/p versions and WAS astounded with the results.
https://holophone.com/products/h4-supermini
https://holophone.com/products/portamic-15
https://holophone.com/products/porta-mic-proThe difference between Knowledge and Wisdom is… Knowledge is the knowing of facts…. Wisdom is the sensible application of good quality knowledge…
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Nahh i will record it all with monomicrophones and mix it in post, i just need to figure out what to do after post
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[Shaun O'Brien] “i just need to figure out what to do after post”
My favorite quote of the week…
I will echo most of what the folks here have said and maybe fill in some gaps for you. HDCAM and HDCAM-SR are two different tape formats. HDCAM-SR supports up to 12 channels of audio, while HDCAM supports up to 4 channels. If you are laying off to HDCAM, and mixing in 5.1, you see the issue: not enough channels on tape for your full discrete mix. Therefore, you have several choices. One is to take your 5.1 mix and encode it into a digital bitstream of Dolby E. This will preserve your discrete surround mix and take the 6 channels down to two, so you can fit it on HDCAM. For this to work, you will need to use a Dolby E encoder, and probably want to have a Dolby E decoder on hand to make sure you can hear your mix once it’s on tape. If Dolby E isn’t an option for you, then you may be able to make a Pro Logic encoding. This encodes the 5.1 mix into two channels that are stereo-compatible and when decoded can come back to L, C, R, and mono Surround. Not discrete like what you put in, but it is not a bitstream either, so it can be played back with or without a decoder. You’ll need a Pro Logic encoder for this. If neither of these are options, then you can lay it off in two passes. One pass will have L, R, C, LFe; the other pass will have Ls, Rs, and maybe Lt/Rt. That way you won’t be able to play the full mix at once, but you can put them back together at some future point.
My advice would be to lay off to tape however you can, but also make a Blu-Ray with AC3 encoding for screenings.
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Thanks for filling my gaps, Mark.
Wait… that didn’t come out right…
JC Boulay
Technical Director
Audio Z
Montreal, Canada
http://www.audioz.com -
Hey Guys,
You’re all absolutely right and have the workflow down. I work for Minnetonka Audio Software and we have a solution for Dolby E as well as Dolby Pro Logic II as well. Our SurCode for Dolby E is the perfect solution for laying your 5.1 and stereo mixes to a stereo Dolby E stream for your HDCAM. SurCode for Dolby Pro Logic II is also a somewhat common fold down procedure as well, but Dolby E allows a more discrete delivery.
Our SurCode Dolby E encoder comes as an AudioSuite Plugin for Pro-Tools as well as a VST encoder as well, with an export feature within Final Cut Pro soon to follow. Our SurCode for Dolby E Decoder is available as RTAS for Pro-Tools, and VST. The decoder also works within our Audio Tools AWE application, so you can batch process one or multiple files.
For further information feel free to contact me on here, or offline via email or phone.
Andrew Neumiller
https://www.minnetonkaaudio.com
andrew at minnetonkaaudio dot com -
Hello Andrew and welcome to the Cow Audio Forum.
Thanks for dropping by with the good news. What are your solutions for 5.1 monitoring for FCP especially, and for the other softwares as well? I guess you need some sort of I/O box that would allow you to hear the mix in surround, plus the monitors and amps.
Regards,
Ty Ford
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
Watch Ty play guitar -
Thumbs up for Minnetonka’s SurCode plugins. I am a Pro Tools engineer as well and can vouch for the quality and reliability of both the Pro Logic and Dolby E encoders/decoders. SurCode for Dolby E allowed me to save the day on delivering a short film to the Tribeca Film Festival recently. The film was transferred on an HDCAM tape at 24p, and I was supplied with a Dolby E mix at 29.97. I was able to decode the mix into its discrete 5.1 + Lt/Rt (8 channels) and then change frame rates in Pro Tools and re-encode the mix to Dolby E and lay it off to tape frame-accurately in time for that day’s screening. The operations manual for the decoder is written very well and my crash course in understanding how to pull the stream apart and put it back together was very straightforward. An added plus is that I can lay off a Dolby E stream that I created with SurCode from both Pro Tools and FCP (using KONA LH). Just about the only thing it won’t do is real-time live encoding/decoding (wishlist). But the offline operations are faster than 1:1, so the added time is never a dealbreaker.
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