Software Frame Rate Coversion – Varicam offspeed to 25p

[Gary Adcock]

[Enzo Tedeschi] “Supposedly for PAL it needs to be 60, and for NTSC 59.94. But I will say this – my understanding is that 59.94 and 60 are the same thing (someone’s going to lay into me for that one)”

nope that is correct, it sets the camera timebase to integer( whole numbers for PAL ) or non integer (for NTSC) the DoP was correct if shooting 25p to set the camera to 60hrz

“If you do some googling, you’ll see there’s some conflicting arguments on that one. BUT… the 1200A deck says it doesn’t support 60 over firwire, only 59.94.”

the 1200 & 1400 decks will not convert from 59.94 to 60hrz if the tape was not shot in that manner, but the decks WILL play 60hrz material if it was shot in-camera over FW. I do it all the time

gary adcock
Cow Leader
Post Instructor at Varicamp.

[Enzo Tedeschi]

Thanks, Gary.

“the 1200 & 1400 decks will not convert from 59.94 to 60hrz if the tape was not shot in that manner, but the decks WILL play 60hrz material if it was shot in-camera over FW. I do it all the time ”

It’s interesting as I remember the documentation for the 1200 deck specifically listing 720p60 as not compatible with firewire. Don’t get me wrong – I don’t doubt you for a moment (I think it’s more likely that our DOP shot 60 rather than 59.94). Just odd.

Do you know of anywhere I can find a whitepaper or something similar on the format? Specifically, I’m intrigued by the difference between 59.94 and 60htz, and the implications – it’s escaping me at the moment.

Also, do you see any holes in my approach?

Enzo Tedeschi
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[Gary Adcock]

[Enzo Tedeschi] “It’s interesting as I remember the documentation for the 1200 deck specifically listing 720p60 as not compatible with firewire. Don’t get me wrong – I don’t doubt you for a moment (I think it’s more likely that our DOP shot 60 rather than 59.94). Just odd.”

remember that there are 2 revs of this deck, and maybe you are looking at the original version of the manual.

your DoP shot that correctly, you do not get “round” number frame rates when shooting at 59,94 so your 25p footage is something like 25.724 fps in actuality

“Do you know of anywhere I can find a whitepaper or something similar on the format? Specifically, I’m intrigued by the difference between 59.94 and 60htz, and the implications – it’s escaping me at the moment.”

it has to do with matching the timebase used in NTSC for the US and Japan. by offsetting the timebase to sync with the 29.97 timing used, it allows the deck to do realtime down conversions to NTSC without any post processing, Conversely Setting to 60hrz allows that same deck to be used on the rest of the very large planet.

ciao

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

[Enzo Tedeschi]

Thanks, Gary.

Didn’t realise there were 2 revs of the deck.

It is a very big planet, which is why I’m surprised at the lack of support for 25p in FCP so far.

Anyhow, thanks for your time.

Enzo Tedeschi
____________________________
Editor
http://www.outpostpps.com
Sydney, Australia

Outpost / YouTube – http://www.youtube.com/outpostpps
Outpost / Podcast – http://www.outpostpps.com/podcast/
Outpost / Blog – http://www.outpostpps.com/blog
Outpost / MySpace – http://www.myspace.com/outpostpps

[Gary Adcock]

[Enzo Tedeschi] “It is a very big planet, which is why I’m surprised at the lack of support for 25p in FCP so far. “

they are too busy working on phones…

I cannot agree more, the support for integer frame rates is pitiful.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

[Enzo Tedeschi]

[gary adcock] “they are too busy working on phones…”

Haha! Bet you it plays 25fpsa just fine 😉

Enzo Tedeschi
____________________________
Editor
http://www.outpostpps.com
Sydney, Australia

Outpost / YouTube – http://www.youtube.com/outpostpps
Outpost / Podcast – http://www.outpostpps.com/podcast/
Outpost / Blog – http://www.outpostpps.com/blog
Outpost / MySpace – http://www.myspace.com/outpostpps