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Author
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Topic: Converting betacam tapes to Uncompressed quicktime
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Leo Enticknap
Film God
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 04-10-2017 11:07 AM
I'm going to try to put this as sensitively as I can, and hopefully avoid being completely flamed.
When it comes to specific technical queries about operations or equipment functions or malfunctions, everyone on this board is more than willing to jump in whenever we can. Others here have saved my bacon more than once, and I would always do likewise if I can and I know the answer to a question being asked.
However, your query goes way beyond "How do I tell DCP-o-Matic to convert an audio file from 24 to 23.976?" (for an example of a technical query I posted recently): what you're basically asking for is free project management consultancy, which I would argue goes beyond what it is reasonable to ask for in a forum such as this one.
Furthermore (and writing as someone who does analog to digital media captures for archival preservation as a sideline), there are other questions you probably need to ask yourself, and your customer, first.
1 - What is the intended use of the transferred files? Short-term access, long term preservation, or both? Keep in mind that Quicktime is a proprietary format, and that can cause problems for the latter.
2 - Are the source tapes in good enough condition for playback? Sticky shed, mold growth and the mechanical condition of the cassette shells and mechanisms are all issues you'll need to look at, especially if these tapes have spent their lives in a tropical climate and not in a temperature and humidity controlled environment. For one thing, you can cause severe damage to a VTR by trying to play a tape that is affected by any one of these issues without taking remedial action first.
3 - Do you really mean Betacam, without the SP? This was a relatively short-lived format, that was rapidly superseded by Beta SP. Beta SP uses the same form factor of cassette as Betacam, but the way the signal is recorded on the tape is completely different. A Betacam SP cassette will not play on a Betacam (without the SP) VTR, and I'm not aware of any SP VTRs that will also play Betacam (without the SP) tapes. Furthermore, there were later formats that also use the same form factor of cassette: Digital Betacam, Beta SX, HDCAM, and HDCAM SR. You need to be sure which Beta format(s) you're dealing with.
4 - Even if you're not compressing the captured and digitized video, there are decisions you need to make in the transfer and encoding workflow. Do you deinterlace the signal on capture? Do you use a timebase corrector in the signal path (if the playback VTR doesn't have one built-in), etc. etc.?
5 - Keep in mind that even standard definition uncompressed video creates big files, and you'll need the media and infrastructure for dealing with these, especially if your customer expects you to keep backups for a given period after the job is done. As a guide, I've recently finished a job transferring 328 Hi-8 PAL tapes to uncompressed AVI with separate mono, 48kHz uncompressed audio. That generated around 90GB per hour of footage.
It seems to me that you need a professional video preservation consultant to work with you and your customer to resolve these issues and come up with a project workflow, before you think about what capture card and software to use, and what plugs in to what using what wires, and all that stuff, which is really putting the cart before the horse.
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Leo Enticknap
Film God
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 04-10-2017 06:36 PM
If he is dealing with SP tapes on which all four tracks have a signal, then either he'll need a capture card that can cope with four discrete tracks simultaneously, or will have to capture in multiple passes. That would double the capture time per tape, and introduce the problem of coming up with a way of being able to sync the audio to the pix later (if there is no sync plop on the tracks being captured in a separate pass from the video, it will be nontrivial to even get this roughly right).
And yet another issue I didn't think of earlier: does he have enough VTR head hours at his disposal to capture all the material needed to in the project? If he only has one VTR, which already has, say, 1,500 hours on the heads, and he's being asked to do a job transferring 5,000 hours of footage (effectively 10,000 if two passes are needed per tape), then good luck with that, without factoring in an equipment supplier and/or refurbisher, and the the cost of going there. This is why I'm suggesting that he needs to hire a professional consultant before committing to whatever project he's contemplating committing to.
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Leo Enticknap
Film God
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 04-10-2017 10:52 PM
We're getting outside my comfort zone here, but AFAIK, the Sony Beta SP VTRs (I assume we're talking about something like a UVW-1800) were only designed to be remote controllable via Sony's own edit controllers using the RS-223C (DB25) interface on the back of the VTR. I'm not aware of any computer-based NLE, or capture card, that supports the remote control function. That's not to say that it doesn't exist, but if it doesn't, it would be a significant science project to be able to do that.
A capture card that can capture four channels of audio from individual line level analog inputs would be the first line of attack that I'd try. I'm sure that Blackmagic, Aja, or a maker of broadcast hardware like them must make one. You'd pay a broadcast hardware price for it, though. But I've never been asked to do this, and so have never investigated what is available. But as a starting point, multiple capture passes per tape is something that I'd definitely want to avoid, given the extra cost in time and VTR head hours.
However, your mention of the timeline raises another issue. If the way this is to be done is to capture and then re-render the final digital asset that will be used for preservation and/or access, then rendering time has to be factored into the workflow as well. I used an old Matrox s-video capture card and VirtualDub to do the Hi-8 tapes mentioned above, which created uncompressed AVI files in the capture process without import into a NLE package and further rendering being necessary. My customer then took those files to a separate vendor who batch-processed H.264 versions from them for everyday viewing, and kept the uncompressed AVIs that I made as preservation masters. I simply don't have the processing power needed to do that much rendering in anything close to a timely manner, hence the two-vendor solution that the customer eventually went for.
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Mark Ogden
Jedi Master Film Handler
Posts: 943
From: Little Falls, N.J.
Registered: Jun 99
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posted 04-11-2017 05:07 AM
Again, I don't know what the specifics are here. He says he has an Ultrastudio 4K with Thunderbolt, which should be able to give him machine control via its RS422 port (goes to the remote connection on the back of the deck), and it also supports two-channel analog audio. Fundamentally, as I mentioned above, his issue is what is recorded on the tape. If the audio channels have isolated or pre-fade tracks, there should be no problem, but if they are all mix-down tracks, there's no way. As far as rendering goes, I assume he is running Resolve on his Mac, which renders in at least real time or better as long as he is not adding anything more that basic grades to the video track and takes only a little longer if you get into noise/grain manipulation or layer-based effects. Either way, it sounds like he has some pretty good firepower if he supports Thunderbolt, so I don't see render time as bring an issue here.
Difficult to give a comprehensive answer here without knowing which Beta format is being discussed.
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Leo Enticknap
Film God
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 04-11-2017 10:30 AM
quote: Mark Ogden
I assume he is running Resolve on his Mac, which renders in at least real time or better [...] so I don't see render time as bring an issue here.
Real time is not no time (unless you mean simultaneously during the capture pass). If we're talking about capturing to a NLE's timeline, then editing (if only minor), applying filters, etc., then rendering, then even with rendering in real time, you're doubling the time needed from taking the source tape out of its box to having the finished file. Put another way, you're processing 4-5 hours of footage in a typical working day and with one VTR/capture card/workstation setup, rather than 8-9. Again, it's something that has to be factored into the overall project workflow: and obviously, less of a problem if we're talking about one or two tapes rather than one or two thousand.
quote: Scott Norwood
What about using something like a DVW-A500 for playback and an SDI capture card? That should be able to capture all four tracks on the tape in one pass.
The digibeta player we have in one our booths (can't remember the model number; sorry) won't embed the audio into its SDI output; I had to make up a 4x XLR to DB25 patch cord to take the analog outs into our scaler, with the pix only going through SDI. Maybe there are players out there that will embed the audio, but if this is the way the original poster wants to extract his audio, he'll need to make sure that his player supports that.
Also, will the combined Beta SP/Digibeta players perform an analog to digital conversion on the signal from an analog tape and output the result through SDI, or will the SDI output only work when playing a digi? Our booth player doesn't have an "A" in the model number and therefore will only play digi tapes, so I haven't been able to experiment with this.
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Mark Ogden
Jedi Master Film Handler
Posts: 943
From: Little Falls, N.J.
Registered: Jun 99
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posted 04-11-2017 04:47 PM
quote:
Real time is not no time . . . then rendering, then even with rendering in real time, you're doubling the time needed from taking the source tape out of its box to having the finished file.
No, you're not at all. The Davinci Resolve, as well as all high end color correctors and NLEs, supports background rendering. What that means is the render process is continuous from the moment you make your very first grading adjustment. If you have your playhead parked in a scene, and you make an adjustment, the render for that scene happens at once, not at the end of the project. Typically, If I import and grade a thirty-minute clip, by the time I am done with grading the whole thing it is almost fully rendered. If I have graded multiple scenes with a lot of power windows, keyframes and secondary corrections, then it may take a few minutes to catch up, but basically I am ready to export a fully completed project within five minutes of the last scene grade.
But, yeah, even if you are doing just a straight import and transcode render with no grading at all, it takes time. Time to render, time to grade, time to export, and it cost head hours as well. So what? It takes what it takes to get the project done. That's no reason not to do it.
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Leo Enticknap
Film God
Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 04-12-2017 11:30 AM
Resolve is clearly a lot cleverer than Adobe Premiere and Lightworks, which are the only two NLEs I have significant experience with. They certainly can't render on the fly like that, unless possibly they're being used with cards and drivers that I don't have.
I'm not trying to suggest that rendering time or any of the other obstacles mentioned above are a reason not to do the project. But they are a reason to plan it properly, taking into account all the variables and gotchas that can be anticipated. From my admittedly limited experience of doing this sort of thing, you can easily end up losing a lot of money on a job like this if you don't understand thoroughly what you're getting in to, and make sure that your customer understands, too.
Example: a couple of years ago I made digital preservation and access files from a 12 acetate on glass transcription phonograph discs, that had been given to a local museum from someone whose grandfather had worked in radio in the '40s. I quoted a price based on an hour per side of my time, which turned out to be wildly optimistic. The records were absolutely filthy, some of the sides had acetate starting to part company with the substrate, etc. etc.
Any sort of wet cleaning is a complete no-go with these discs, so the job involved of a lot of gentle cleaning with a very fine horsehair brush, multiple attempts at capture passes to determine the right stylus and the optimal tracking/anti-skate tension to capture the strongest signal off them, followed by hours of manual click/pop removal and EQ (obviously these were pre-RIAA, so I had no idea what if any EQ curve was applied by the cutterhead preamp in the recording process, and therefore basically had to do everything by ear) and dynamic compression tweaking in Diamond Cut just to get to a point at which most of the words spoken on the recordings were intelligible. In the end, I reckon that I made $2-3 an hour on that.
If, rather than just agree to do it, I'd gone to this place, looked at the records and held a sensible discussion as to what we were getting in to, we'd have been in a much better place. The truth be told, I'd probably have taken it on anyways, because I enjoyed the challenge (plus, it's a nonprofit museum that is actually using the recordings in an exhibition, which is nice); but it's made me very wary of taking this sort of thing on without doing due diligence to establish precisely what I'm committing to, if I have the knowledge, the hardware and software, and, most importantly, the time, to do the job well, first.
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