VHS & 3/4" Archiving

[mark23]

Hello,

I have a project to mass convert 150+ tapes to a file based format. These tapes were given to me when a cable station was trying to reclaim space and disposed of their tapes that were not converted. As I didn't want to see them thrown out, I took it on myself to preserve them but have been overwhelmed by the choices. I have tested DVD (backing up .vobs), DV, MP4, ProRes & uncompressed. I have good decks and TBCs and analog converters (ADVC-300). I have both PC & MAC and set top DVD recorders. I would like to preserve the quality with the least amount of digital artifacts, but also be able to do simple edits and clean up down the road. With the number of tapes I have to do, uncompressed and other huge codecs are not an option for me. I could afford to put aside a few hard drives for this project, but as I am not a TV station I don't have a huge budget. I have seen TV stations archive to MP4 format however, I have read a lot of discouraging views about MP4 for archiving. Is there one safe file to archive to? I would like to convert to one common format and be able dispose of the tapes after. Final display would mostly be private, some online sharing (ex. YouTube) and ability to share with the cable station upon request.


Thanks
Mark

[LMotlow]

I would like to preserve the quality with the least amount of digital artifacts, but also be able to do simple edits and clean up down the road. With the number of tapes I have to do, uncompressed and other huge codecs are not an option for me.

If uncompressed or losslessly compressed options are out, and you want to do some clean up, you can forget about "the least amount of digital artifacts". Second best from lossless would be DV, from which you'll see artifacts from analog tapes that can't be avoided. Simple DV cut-and-join edits are OK, but if you clean-up or modify the image you'll lose quality thru re-encoding. Lossless and DV video are PC-only playback; there is no external or web playback support for those formats. If you don't want lossless or DV, expect plenty of digital artifacts and further damage by using lossy codecs not designed for editing or further modfication without losss.

You can work simple edits on a Mac using your choice of two types of Mac-available software: cheapo or budget NLE's, or pricey stuff like FCP prosumer apps. Windows offers many more choices, tons of which are free.

[mark23]

hmmm. What I was afraid of. What would be a good losslessly compressed format? I did a 10 min or so test last night with uncompress and prores. Uncompressed was about 15GB, ProRes went from 4GB (ProRes 422) to 2GB (ProRes 422 LT). Any chance of getting smaller with another comparable losslessly compressed?

Thanks

[smrpix]

ProRes, DNxHD (increasingly DNxHR), are real-life codecs that broadcasters use. To a decreasing extent XDCam and P2, even lesser Cinemform and Edius. They will all have comparable rates for comparable quality. If you're thinking about DV, which isn't bad, you may as well just jump up to XDCam at an additional 10/mbs.

mp4 is fine for on-hand low resolution screeners.

[mark23]

At the moment, the cable station uses Avid Media Composer on PC. Would a flavour of DnXHD be better for highest compatibilty over ProRes or is ProRes better?

I just tested ProRes 422 LT and that seems to be very comparable to NTSC DV and h264 at 20Mb/s. An online video calculator says an hour of ProRes 422 LT is about 12GB (http://www.digitalrebellion.com/webapps/videocalc?format=prores_422_lt_ntsc&frame_rate...gth_type=hours). Is ProRes 422 LT still a good format too, if the calculated file size is to be believed.


Thanks
Mark

[jagabo]

MP4 is a container. It's like saying you archive video tapes in a wooden box. The box has no direct bearing on the quality of what's inside. It might make a difference in how easy it is to access the contents now, 10 years from now, or 100 years from now.

What does make a difference in quality is the capture device, how the video is handled, and the codecs and settings you use. Lossless codecs can be literally lossless but don't give you much compression. Visually lossless codecs give a little more compression. DV gives more compression but will result in some DCT and mild blocking artifacts. MJPEG lets you control how big a file you get, from small and low quality, to large and high quality, slightly better quality (and bigger) than DV at the high end, total junk at the low end. Inter frame codecs like MPEG 2, MEPG 4 part 2 (Xvid, Divx), and MPEG 4 part 10 (h.264, AVC) also let you select the quality/size tradeoff. At the high quality end they don't have much advantage over MJPEG or DV because the noise in analog tape pretty much guarantees there will be no redundancy between frames.

If you're looking at long term storage you need to stick with mainstream codecs. Who knows if you'll be able to find a Lagarith or UT decoder 100 years from now. But an MPEG 2 decoder will probably still be available.

Then there's the issue of what you store your videos on. DVD? Hard drives? Tape? Each has advantages and disadvantages.

[themaster1]

You could record in mpeg2 4.2.2 with a high bitrate (+10kbps, so non dvd compliant) or H264 to gain some space and have some degree of liberty as far as re-encoding/editing after. Sound track in Dolby stereo (with a high bitrate ~ 384 kbps) should save some space

NTSC DV is a no-no to me (4.1.1 color subsampling unlike pal 4.2.0)

[jagabo]

NTSC DV's 4:1:1 chroma subsampling isn't a problem for VHS with its ~40 lines of chroma resolution. It can be a problem with higher quality sources.

[mark23]

I think I have decided to ditch DVD completely. Other than ease of use, it seems to be the lowest quality, even though it probably is good enough. As much as I would like to have the option to do some editing with the files I archive to they will probably sit unedited for awhile. Main goal is just to get back the limited space I have.

I think my choice is between:
MP4 - H.264 (20mb/s) as I have a Blackmagic H.264 Pro Recorder
DV - Canopus ADVC-300
AVID DV50 - mentioned by some to be comparable to ProRes 422 LT for SD
Apple ProRes 422 LT - NTSC SD

I also have a video switcher that can stream to computer via USB3, but I would need to use an analog to SDI converter. This would let me record to AVID DV50 or the Apple ProRes, unless I purchased a better capture device that was not limited to DV or MP4 such as a BlackMagic Decklink or Intensity Pro.

[smrpix]

I've never seen any visible difference between DV25 and Avid DV50. Avid 2:1 or even 3:1 would be better -- however, DV50, Avid 3:1 and Avid 2:1, while they will be supported by Avid and available as free downloads well into the future, are all basically obsolete.

As much as I hate to say it, ProRes 4:2:2 HQ (no need to be stingy with LT in SD frame sizes) is probably your better option. You are at the mercy of Apple, but there's to big a user base for them to pull the plug too quickly.

[mark23]

I think I have it down to ProRes now. I do have a couple of macs I can use for this. I thought of using the h.264 pro recorder, however it looks like the only SD that it does is 480 Progressive and no interlaced option for SD. Also the aspect ratio is slightly different (unless they changed it in later updates). I was going to try to use an Avid codec as that is what the cable channel uses at the moment so would be best compatibility for them at them. Mind you I doubt they will ever want the footage. It's been at least 20 years since most of the tapes had been looked at and they were destined for the dumpster before I got them.

The only question is now, this is the equipment path i had thought of, unless I should just scrap it and get something else.

(JVC-9911U VCR0 - S-video in (canopus advc-300) - S-video out - (analog to sdi converter) - sdi in (computer via USB 3.0)
In this process the Canopus is only used for picture adjustments.

Or i could just get rid of most of it, get a TBC and Intensity Pro card or something without having to convert the signal to SDI first.

[smrpix]

Typical Avid installations tend to use either blackmagic intensity or matrox series capture devices.
http://www.matrox.com/video/en/products/mxo2_mini/
https://www.blackmagicdesign.com/products/intensity