Quote:
Originally Posted by frekili
Hi Lordsmurf, in your opinion Pro-res HQ digital copies of PAL Hi8 tapes played with a Sony EV-s9000 and converted to Pro-Res HQ files with a AJA io HD ,can be considered as archival copies? Thanks
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You have multiple ProRes formats, and three ProRes422 (LT, normal, and HQ). ProRes is lossy, but was designed to be visually lossless. The "magic" of how this is achieved really is not magic at all: the bitrates are high. For SD, even higher than MPEG-2 broadcast/BD specs, which can be archival.
So, the answer is:
YES, maybe. 
It really depends on the source. Samples needed, attach a tiny clip (fleeting seconds, less than 00mb total) to a thread.
Quote:
Originally Posted by JPMedia
Short answer, no.
ProRes is a video codec with lossy video compression. You need a lossless video codec such as HuffYUV or Lagarith for archival master copies of your analog captures. |
Lossless is an intermediary codec, not to be confused with archival. Archives can also be intended to watch, so must be in some sort of pseudo-delivery format. And both ProRes and MPEG meet that demand. ProRes is actually a delivery format in broadcast, not just intermediary in home/studio.
I keep a lot of master copies as high bitrate MPEG, both 4:2:0 (a compromise) and 4:2:2 (not always compatible with home viewing, but computer fine). Note that the MPEG also has low GOP, not long GOP. Sony, for example, considers some MPEG to be good enough for an intermediary, not just delivery. It's a wide format, many options.
Quote:
Originally Posted by sanlyn
- designed for pristine higher resolution digital source, not for noisy VHS or hi8 analog.
- lossless is practically a requirement for restoration and repair.
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These two points are important:
Noise is the enemy of all compression.
"Archives" should mean that editing is done, restoration is done, it's simply being stored now. Unfortunately, "archiving" has multiple definitions, but most should agree it's done after a project has been completed. The idea that you'll redo it in the future is actually a fairly recent phenomena, so "archiving" is often overkill -- especially when the source has been given the best treatment possible (TBC, color correction, max SD resolution). When I think future methods may improve something, only then will I saw the large lossless file.
