DVL-Digest 599 - Postings: Index FASTEST delivery to the US? SDI or FireWire??? - (2) FASTEST delivery to the US? - "Perry" Peter Melly: So are you saying that it does only real time transmission and that the video data rate is then a max of 128Kb/s? This would mean the pictures are compressed around 1000:1 and are therefore quite remarkable! Remember I saw them full screen, with no obvious reduced frame rate or pixel doubling. It had VERY obvious compression artefacts with lots of mosquito trails on moving objects, very restricted colour mapping, and some blockiness. If there was anyway you could find the exact parameters used for this transmission, (6.00 news on BBC1, Tues Aug29) then I'm sure we'd all be interested. I've seen the future of News inserts, it wasn't pretty but it worked and it must be cheap, and presumably it will get better. For this quality, consumer DV cameras are overkill! Perry Mitchell Video Facilities http://www.perrybits.co.uk/ SDI or FireWire??? - "Perry" Alan Berstein posted: >If I have a SDI output from an AVID or HENYR system, I understand that the DS-MAX from Promax has an opthin to convert SDI to FireWire. Is their any quality issue their?? is SDI beter than FireWire in terms of quality?? and by using a converter like the DA-MAX going from SDI to FireWire is their any loss? Ofcourse this would be using FCP.< SDI is uncompressed video of potentially 10 bit resolution. Firewire (DV) is 5:1 compressed video of 8 bit resolution. If the Avid (or Henyr?) is on full uncompressed quality then the Firewire will cause losses, mainly by reduced color resolution and some minor compression artefacts. Presumably you need Firewire to record onto a DV/DVCAM/DVCPRO tape format which will force these losses anyway. Perry Mitchell Video Facilities http://www.perrybits.co.uk/ SDI or FireWire??? - "Perry" From: Dave Haynie [mailto:dhaynie@jersey.net] Sent: Wednesday, August 30, 2000 08:40 To: DV-L@dvcentral.org Subject: Re: SDI or FireWire??? On Wed, 30 Aug 2000 13:38:32 -0000, "Perry" [perry.mitchell@btinternet.com] jammed all night, and by sunrise was overheard remarking: > >If I have a SDI output from an AVID or HENYR system, I understand that the > > DS-MAX from Promax has an opthin to convert SDI to FireWire. Is their any > >quality issue their?? is SDI beter than FireWire in terms of quality?? and > >by using a converter like the DA-MAX going from SDI to FireWire is their any > >loss? Ofcourse this would be using FCP.< > SDI is uncompressed video of potentially 10 bit resolution. Firewire (DV) > is 5:1 compressed video of 8 bit resolution. Actually, not quite. Firewire is not a video format of any kind, it's simply a high speed serial data bus. Whatever you ship across it arrives at the other end, simple as that. Now, in most cases, the thing at the other end may well be a DV or miniDV camcorder. DV (as you parenthesize) is a 5:1 compressed video format of 8-bit resolution. But one could just as easily have a hard drive, another computer, or various other things at the other end of that Firewire interconnect. > If the Avid (or Henyr?) is on > full uncompressed quality then the Firewire will cause losses, mainly by > reduced color resolution and some minor compression artefacts. Again, sending a video file over Firewire causes no loss of any kind. Encoding it into the DV file format is what causes that loss, regardless of what you do with it afterwards. -- Dave Haynie | V.P. Technology, Met@box AG | http://www.metabox.de "If you're gonna have delusions, you might as well go for the really satisfying ones" -Marcus Cole ------(cut off when replying)------------------------------- All about DV-L: http://www.DVCentral.org/thelist.html (diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-) [up] |
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