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Advice needed: Transferring HDCAM SR tapes to HDD (REVISITED)...

Dave Draper

Dave Draper

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We have 240 minutes of footage shot on the D-20, captured to HDCAM SR tape, that we need transferred to hard-drive at its native resolution, bit-rate, color-depth, etc. We basically require an exact digital copy, from which we can edit and create our online, without having to touch the tapes again.

I cannot confirm, nor can the DP, the bit-rate we shot at, nor the colour-depth (though I believe it was 4:4:4), as this was almost ten years ago, and if anyone did write down the specs, they have long since been lost.

So firstly; what format would I be looking at having these tapes encoded?

Secondly; do we need to know the specs to have the tapes encoded correctly, or is there a way they can be found out beforehand? For example, in any embedded metadata on the tapes themselves, if they even have such a thing.

And lastly; is there anywhere anyone can recommend in the UK that we can have these tapes transferred to HDD, that isn't going to cost an arm and a leg?
 
ProRes 444 would be able to capture an HDCam-SR tape without any compromise. The bitrate is actually as good or better than the HDCam-SR tape. One trick will be to see what kind of shape the tapes are in -- if there's any dropouts or heat damage, the tape could be dicey.

I would also capture any color bars & tone on the tapes just to make sure it translates at the correct levels for Rec709. I would hope you could do this for maybe $200 an hour or maybe less, depending on the facility.
 
i've seen SR decks used to capture a DPX stream too... it was an optional data mode from distant memory... pretty rare tho

i think it was used on a Viper shoot.. but that was a long time ago

the SR deck will tell you what's on the tape in any case.... but anyone who owns an SR deck likely knows the answers to all your questions... that would be where i would point my questions.
 
David Mullen ASC said:
You'd think the HDCAM-SR deck playing the tape could tell you something about the recording format (422, 444, SQ, HQ, etc.) but there is a tapeless version of HDCAM-SR called the SStP SR codec that you can use:
http://www.shift-4.com/f5-and-f55-sstp-sr-codec-explained/
Click to expand...

Many thanks for the link, David. I like the idea of going with SSTP SR, as it just seems like a smart move -- being that it's the tapeless version of HDCAM-SR -- but am not yet sure if the Post House I'm using is able to render to that codec. I did suggest it to them, but they didn't comment, and said ProRes would be fine for this type of application.

Which brings me onto my next thought...

Say we shot in HQ 4:4:4 (880Mbs), which, OK, sounds a little mad, but could be possible; how's that going to compare to the likes of ProRes 4:4:4 (which is 264Mbs)? Or are we talking mathematical loss, and not a perceivable / visual loss in image quality?
 
From memory, there's a chance that it could be 4:4:4:4.....including an alpha. Putting the tape in the deck will tell you straight away as to the format.

https://en.wikipedia.org/wiki/HDCAM

As for capture, it'll probably need to be done via dual SDI into something like an AJA or Matrox card (don't use BM!). I'd go full uncompressed 10bit AVI. No need to get into a prores world.

As to where this can be done, Dubbs in Poland street...seems they are now called Premier;

http://www.premiercomms.com/content-services/tape-dubbing-and-servicing.php
 
The original recording format is irrelevant as its now on HDCAM SR. The SR deck will display all the details of the material recorded on the tape though. frame rate, resolution, bitrate, etc.
 
I think that you will not go wrong if you were to digitise the footage at Full resolution (1920x1080) from a deck, through an AJA or Deckling card by using the APPLE 10-bit Uncompressed codec. From those "masters" I would then create any lossy codec versions, like prores, AVID DNXHD etc.

The Apple 10 bit uncompressed codec is a larger file size, but actually allows for more real time because it eliminates the compression and decompression required by lossy codecs.
 
David Battistella said:
I think that you will not go wrong if you were to digitise the footage at Full resolution (1920x1080) from a deck, through an AJA or Deckling card by using the APPLE 10-bit Uncompressed codec. From those "masters" I would then create any lossy codec versions, like prores, AVID DNXHD etc.

The Apple 10 bit uncompressed codec is a larger file size, but actually allows for more real time because it eliminates the compression and decompression required by lossy codecs.
Click to expand...

and i would avoid at all costs that codec as it does not play nicely with others, and limits you to working inside the mac ecosystem, most highend gear is windoze or linux in 2015....

DPX takes the same space, and is universal, every piece of pro gear can read/write and it's color managment is rock solid... or better yet EXR or TIFF16bit

but yea, if someone shows up with any of the apple codec's, the first thing we do is transcode to something universall and based on stable color managment
 
We've been assured by the post house we're using that "Uncompressed ProRes" will preserve the original data as it is on the HDCAM-SR tapes...

Are there any specifics I should be asking them to make sure of during the encoding process?

Due to the cost of the transfers, I need everything to be correct right off the bat.
 
ProRes 4444 and ProRes 4444 XQ are lossy video compression formats.
ProRes 4444 has a target data rate of approximately 330 Mbit/s for 4:4:4 sources at 1920x1080 and 29.97 fps
ProRes 4444 XQ has a target data rate of approximately 500 Mbit/s for 4:4:4 sources at 1920x1080 and 29.97 fps, and requires OS X v10.8 (Mountain Lion) or later.

HDCAM SR record in 10 bits 4:2:2 or 4:4:4 RGB with a video bit rate of 440 Mbit/s, Some HDCAM SR VTRs can also use a 2× mode with an even higher video bit rate of 880 Mbit/s, allowing for a single 4:4:4 stream at a lower compression.

So if you do not want to double dip in compression you need to go to a uncompressed format. If I would do it I would capture in flame uncompressed and export 10bit DPX and a process LT or such for reference. Then you can easily edit the LT and online from the DPX files and you have then preserved all that was there without loss. Going for the proress4444 or 4444 XQ is possibly good enough but you are then adding compression onto compression and some would say that is totally fine but from reading your initial post that seams like something you don't want to do.
 
Björn Benckert said:
ProRes 4444 and ProRes 4444 XQ are lossy video compression formats.
ProRes 4444 has a target data rate of approximately 330 Mbit/s for 4:4:4 sources at 1920x1080 and 29.97 fps
ProRes 4444 XQ has a target data rate of approximately 500 Mbit/s for 4:4:4 sources at 1920x1080 and 29.97 fps, and requires OS X v10.8 (Mountain Lion) or later.

HDCAM SR record in 10 bits 4:2:2 or 4:4:4 RGB with a video bit rate of 440 Mbit/s, Some HDCAM SR VTRs can also use a 2× mode with an even higher video bit rate of 880 Mbit/s, allowing for a single 4:4:4 stream at a lower compression.

So if you do not want to double dip in compression you need to go to a uncompressed format. If I would do it I would capture in flame uncompressed and export 10bit DPX and a process LT or such for reference. Then you can easily edit the LT and online from the DPX files and you have then preserved all that was there without loss. Going for the proress4444 or 4444 XQ is possibly good enough but you are then adding compression onto compression and some would say that is totally fine but from reading your initial post that seams like something you don't want to do.
Click to expand...

DPX does seem like the way forward, as I literally want a like-for-like digitised copy. From that, I can render out my own lossy encodes, if I need.

Does "Uncompressed ProRes" even exist, or was I just fed a bunch of tosh?
 
Dave Draper said:
DPX does seem like the way forward, as I literally want a like-for-like digitised copy. From that, I can render out my own lossy encodes, if I need.

Does "Uncompressed ProRes" even exist, or was I just fed a bunch of tosh?
Click to expand...


Uncompressed ProRes, no there is no such thing. XQ is very good but it is still lossy.
 
Björn Benckert said:
Uncompressed ProRes, no there is no such thing. XQ is very good but it is still lossy.
Click to expand...

Figures. XQ would not be good enough, as it must be absolutely mathematically lossless. I hope this is the right terminology to describe a bit-by-bit identical copy of the original source material.

Alright, so in step by step formation; what exactly should I tell the post house to do with these tapes?

This way, I can just relay it to them, and hopefully no wires will get crossed.
 
DPX is a safe bet for most workflows.

Rock solid, easy to understand, simple to handle and fits into almost anything you want to throw it at.
 
Gunleik Groven said:
DPX is a safe bet for most workflows.

Rock solid, easy to understand, simple to handle and fits into almost anything you want to throw it at.
Click to expand...

We're pushing for DPX. The post house is going to get back to us early next week with regards to whether or not they'll be able to do this.

Please correct me if I'm wrong, but 240 minutes of HDCAM-SR tape captured at 880 Mbit/s should equate to around 1.51 terabytes of hard-drive space, right?

If so, what are we looking at in terms of terabytes if encoding / digitising directly from HDCAM-SR to DPX?

Also, while we're on the topic of hard-drives; what kind of hard-drive should we be looking at for storing / reading DPX / Uncompressed files? We'll need to go with spinners, and will be making copies, so SSDs will be far too expensive.
 
In terms of ingest, again, i strongly recommend you check they're not using a BlackMagic card to do the capture. This will ingest at Rec.709 and clamp all video levels. You want to ingest the full video signal, the full illegal signal. Then you've have an exact copy of the tape and can grade the full video range captured onto the tape.

Steer well clear of ProRes. DPX will do the job, but make sure they know what they're doing with color, bit depth etc on the ingest. Very easy for a novice to choose the wrong settings, especially as they appear to be a 'ProRes' house. I'd still recommend you go for 10bit uncompressed AVI. It's the most neutral full res format. Codec wise, 10bit uncompressed can come in many flavours. BM, AJA, Matrox, FCP, Premiere, Canopus all have their own. All will play back easily though, but you may need to install that codec pack on your edit machine.
 
Dave Draper said:
Figures. XQ would not be good enough, as it must be absolutely mathematically lossless. I hope this is the right terminology to describe a bit-by-bit identical copy of the original source material.
Click to expand...
Why do you believe it has to be "absolutely mathematically lossless"? I can tell you that many, many feature films and multi-million-dollar network have been shot or posted on HDCam-SR, and nobody cares about the 5:1 compression within the format. Look at it this way: many, many shooters routinely use Redcode compression at 5:1 without any visible artifacts.

There are realistic limits as to how far you can compress high-res material before the flaws are noticeable. But I don't think HDCam-SR and ProRes. ProRes 444 or 444 HQ is going to be fine. Do a test and look at it. Use test signals if you want to.

There's no problem there, in my opinion. Any problems that are there are embedded in the actual HDCam-SR compression algorithm (which I believe is more than 10 years old). I would worry more about potential glitches and hits in HDCam tape stock over time than I would any digital compression issues, since it is a mechanical format.
 
i know a cheap place near NYC that i work with that would cut you a steal on the job if you are willing to go outside UK? thx
 
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