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Author
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Topic: Using DVD/LaserDisc Audio for Super 8 Stereo
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Mike Spice
Master Film Handler
Posts: 421
From: none of your business
Registered: Jun 2017
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posted November 11, 2017 03:31 PM
If I understand your post, you want to record from a dvd or laser disc or blu ray, to then put on super 8 stripe?
Given the narrow tape on super 8 I don't think you will hear a difference in the source once it is on mag stripe, and of course, you will have to record to super 8 mag using analogue unbalanced connection, so either way, just go for the easiest, but make the best possible recording using good control of the levels being recorded. .
Personally I would record in to audacity, do any top and tailing and normalising required, and from there to super 8 mag stripe.
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Bill Brandenstein
Phenomenal Film Handler
Posts: 1632
From: California
Registered: Aug 2007
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posted November 17, 2017 12:23 AM
Another great question, Osi, and you already have some great answers. Let me add a little bit to this.
Which format is easier is entirely up to the gear and workflow you want to try. Any video format is useful. You already know that you can record through analog cables to your Super 8 gear; better is to try to extract/create digital data in a computer or recording device, then transferring. The latter gives the most control of course (hence Mike's advice), but makes the workflow much, much more complex. The benefit, however, is precise results and the possibility of exact synchronization.
So you have several considerations:
What gear you have, including computer audio and software
If you have any sort of synchronization control to regulate the film re-recording speed, or if it's guesswork
Whether or not the audio is adequately usable directly from the video device
Etc
So, for your encouragement, I can tell you that I've re-recorded faulty Super 8 soundtracks from Laserdisc, DVD, and even VHS. You'd never be able to tell now by just listening to the film sound which is which.
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Brad Miller
Administrator
Posts: 525
From: Dallas, TX, USA
Registered: Jun 2003
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posted November 17, 2017 03:36 PM
Most blurays have remastered audio for tiny tv speakers and "home theater in a box" type of systems. In my opinion, and many others, this destroys the original audio mix.
This silly remixing practice wasn't happening with DVDs. The DVD, even though it has AC3 compression, is much lower compression than theatrical SRD Dolby Digital soundtracks and will be a better source than a bluray.
VHS HI-FI tends to have issues with buzzing during modulation so that would definitely be my last recommendation.
LaserDisc is going to have really good quality audio, but back in the day of VHS and LaserDisc I found reel changes on the video sometimes had extra frames missing that were in the Derann prints, and also sometimes had extra frames that were not in the Derann prints. Basically every reel A and reel B is a potential point for sync to suddenly be off by a frame or more PLUS the side flip point of the LaserDiscs. This just means more unnecessary work. I found this wasn't near as big of an issue using a DVD as a source.
So the straightforward answer is, get a DVD and choose the 2 channel stream. Try to avoid the 5.1 mix. By choosing the 2 channel stream, you are getting the exact mix that was Lt, Rt from the 35mm optical release prints designed for decoding with a Dolby matrix circuit (aka: Pro Logic).
For the Pro Logic to TRULY work properly though, the output of your print playback must be not only balanced level-wise, but frequency response-wise. To do this I would play a CD with pink noise through an EQ and record onto the track of the print to be re-recorded. Usually a minute or two (or make a loop out of the leader). Then I would rewind and play it back and look at the signal on a real time analyzer to see how flat it was. If I saw a dip at some frequencies, I would boost those frequencies on the EQ pre-recording and try it again. After a few passes you can fine-tune things so the final output is shockingly similar between the two channels of audio coming out of your projector. This means the Pro-Logic circuit in your receiver will do a far more impressive and discrete job.
Finally to top it all off, I encoded my prints with dbx Type II nose reduction. This gives dangerously close results to CD quality from Super 8 mag tracks, and no that is not an exaggeration. Used encoder/decoder boxes are all over ebay for under $50, but you need to do the equalizer/RTA step above before considering dbx encoding.
During the re-recording, project the 8mm image on the wall beside your tv at approximately the same size. Leave a foot or so of space in between the two images. Then watch that empty wall during the re-recording, NOT either of the images! All you are doing is watching for the camera cuts to flash exactly in sync with each other out of your peripheral vision. If you see one start to flash even a half frame before the other, by looking at the wall between the two images you will know exactly when to tap the speed control on the projector just a nudge to force them back into sync. By recording with this setup, you will never be more than 1 frame out of sync on the entire movie.
And of course, bonus points to those who change the potentiometer out on their projector that regulates speed control so they can turn the knob MORE to achieve LESS of a speed difference. That permits you to really make super fine adjustments to the speed during recording, even if one entire knob's rotation only ends up being 22.5 frames per second to 25.5 frames per second.
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Bill Brandenstein
Phenomenal Film Handler
Posts: 1632
From: California
Registered: Aug 2007
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posted November 18, 2017 12:00 PM
Always great to benefit from Brad's extensive knowledge, so let me add my thanks as well.
I want to add a few technical details from my own workflow, which for those who are technically adventurous gives the best results. My home and work computers are Windows desktops and therefore both have multiple audio outs available right from the motherboard sound connectors. I also have used Adobe Audition personally and professionally for years, and if you happen to have Audition 3.0 you can do everything you'd ever want to do for Super 8 sound sync.
So with audio software that will play 2 wave files to 2 separate outputs on your computer's audio hardware, you can drive a wave file with a pulse to your projector from one output, and the soundtrack of your movie with the other. At 48KHz, that's 2002 samples between each pulse at 23.976 fps.
When I've replaced bad or mono Super 8 tracks, I've added a third track: I record the existing film sound in as a guide. Locked to the 23.976 pulse, this guide track makes a perfect re-do much easier for obvious reasons. If you happen to video the image during transfer (with sound up, please!!!), you can also scrutize any sync errors in the original transfer, but I find that usually this is done very well on Super 8 prints and no corrections are necessary.
The trick and advantage of this now comes into play. If you transfer your replacement audio into your computer digitally, you merely trim or edit your replacement sound source to match your film audio. Simple enough, right? Well, no. There are too many sources.
Analog sources like VHS or old Laserdiscs have to also be digitized to match the 23.976 frame rate. I happen to have access to old Tascam 8-channel DTRS machines, which are now available inexpensively on eBay. Why this is important is because a DA-88 with the SY88 card, or later DA-78s or 98s (make sure it has analog in/out!), have the ability to accept an incoming NTSC video signal (standard def) as a clock source. Well, there you go. You can hook your VHS or Laserdisc video up and digitize the analog audio at precisely the correct sampling rate. So set it up at 48KHz and go! You don't even record to a tape if you're using a DA-78 or DA-98, you simply route the audio pair to a SPDIF output and capture the SPDIF with your computer sound card. OK, so there's another workflow requirement: you need SPDIF in and out. But once that transfer is done, you can edit the audio to minimize the hum and buzz from VHS Hi-Fi tracks, or even reduce noise on analog video tracks.
Later Laserdiscs have uncompressed PCM stereo tracks identical in quality to Compact Disc, which is lovely. Obviously you can also record a 44.1KHz digital track from a laserdisc if your player has a SPDIF output, which for most Hollywood movies sound great in Pro Logic as Brad mentioned. In that case your Sync work has to either be set up for 44.1 KHz, or you need to do a conversion to 48Khz (recommended).
You can also rip a DVD, and I understand Blu-ray can be as well, and convert the audio tracks to Wave files. Your mileage will vary depending on which audio tracks you rip, how many channels are present, and whether your software reads a Dolby Digital 5.1 track as 6 channels or as bass-less, dynamically limited stereo downmix. You can also rip ac3 or DTS data directly (I've never tried the latter) and work it up as a SPDIF-wave for 5.1 playback from your computer.
Let's talk about "SPDIF-Waves" a moment. When your DVD player sends a 5.1 stream to a receiver, it's dropping compressed data through a 48Khz, 2-channel, 16-bit container. If you capture or create that information as a 48K/x2/16bit file undecoded, you have a SPDIF wave. The trick is that in no instance may a single bit of that information be altered or dithered. The slightest corruption ruins the 5.1 playback.
One of the other advantages of Audition 3.0 is you can drop into your playback track a Dolby Digital SPDIF stream as converted to such a 48Khz, 16-bit stereo wave file (this consists of a series of very loud bursts of noise if played back as PCM). Audition 3.x, and this one only, does NOT touch the data if your gains are unity and all other processing is off (panning, EQ, etc). Pretty much all other audio DAWs add dither, so they won't work. Hook a SPDIF connection from your computer output of that track to any basic home theater receiver, and your SPDIF-Wave will be heard by your receiver as if it's playing from a DVD. There, you now have the ability to do 5.1 with Super 8, locked with no drift. Unfortunately "Fantasia 2000" is the only feature I have with this capability, but some other shorts or trailers sound great this way too.
As a result, I have a small library of Super 8 sync folders on my computer with the ability to add digital stereo or surround to my presentations. Some were silent prints to begin with, so just added mono sound, some had bad transfers now made good, one has a faulty sound stripe, and most had stereo or 5.1 tracks existing in the video world but the Super 8 track was mono.
Anyone still with me? Was that helpful at all?
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