XA10 questions at DVinfo.net

Federico Perale · September 19th, 2011, 04:24 AM

hi guys
why has canon included a native 24p mode in the US version, and not a native 25p for PAL land?
you only get 25p in 50i

it seems like (quoting from a post in Vimeo) "...Panasonic and Sony were stupid enough to not include native 25p and 30p rates into Blu-ray spec, which AVCHD is an offspring of. So, no native 25p and 30p in AVCHD either. Apparently, Sony and Panasonic wanted fillmakers to shoot their movies in 24p even for the European market, but many camera manufacturers have forgotten to add 24p mode into 50Hz cameras. So now you guys in Europe are stuck with either shooting and distributing 25PsF, or you have to buy two cams: one with 50i for the news, another with 24p for the movies..."

also.... would it be a problem to mix footage shot at 25p (in 50i) with native 25p shot with a canon 5D pal?

Fed

Don Palomaki · September 19th, 2011, 07:14 PM

Might relate in part to import tariffs, VAT, etc.rules.

Jeff Harper · September 23rd, 2011, 09:35 AM

Or buy the XF100 which I think will do it all with a factory upgrade.

Rainer Halbich · October 19th, 2011, 03:43 PM

I think I know why. PAL does not need the native 25p.

I am not 100% sure of this but I will try to explain.

Normal pf24 makes use of a 60i steam to save the 24fps file, but this is where it becomes complicated, How do you divide 24 progressive frames into 60i frames and then bring it back again to 24p when you dump the footage to your computer?

In order to spread 24 progressive frames into 60 interlaced fields, a process called 'telecine' is used. The 24p footage is again broken up into two fields (odd and even lines), and is re-inserted into 60i by following the pattern 2-3-2-3-2-3 etc. Here is a representation of how it looks. Let's say that individual progressive frames are A B C D E F etc. When they are broken up, they become individual fields A1 A2 B1 B2 C1 C2 D1 D2, etc. The resulting 60i stream also contains individual fields. The 2-3 interlacing goes like this:

A1 A2 B1 B2 B1 C2 C1 D2 D1 D2 E1 E2 F1 F2 F1 G2 etc.

In other words, it goes AA BBB CC DDD EE FFF, but uses odd or even halves of each progressive frame in alternating succession. When this stream is played back, it will be the smoothest approximation of 24p within a 60i stream.

With PAL this is easy, you don't need the "telecine" process. If you multiply 25 frames you end up with 50 frames, and with a PAL camera this will be embedded in a 50i stream. The frame rates already matches. (a1 a2 b1 b2 c1 c2 d1 d2....)

In other words, PF25 is as close to real film as it gets, to have native 25p is irrelevant. This is why I am so in love with PAL, it is easy to use with anything.

September 19th, 2011, 04:24 AM	#1
Federico Perale Major Player Join Date: Apr 2010 Location: London Posts: 410	XA10 questions hi guys why has canon included a native 24p mode in the US version, and not a native 25p for PAL land? you only get 25p in 50i it seems like (quoting from a post in Vimeo) "...Panasonic and Sony were stupid enough to not include native 25p and 30p rates into Blu-ray spec, which AVCHD is an offspring of. So, no native 25p and 30p in AVCHD either. Apparently, Sony and Panasonic wanted fillmakers to shoot their movies in 24p even for the European market, but many camera manufacturers have forgotten to add 24p mode into 50Hz cameras. So now you guys in Europe are stuck with either shooting and distributing 25PsF, or you have to buy two cams: one with 50i for the news, another with 24p for the movies..." also.... would it be a problem to mix footage shot at 25p (in 50i) with native 25p shot with a canon 5D pal? Fed

September 19th, 2011, 07:14 PM	#2
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,489	Re: XA10 questions Might relate in part to import tariffs, VAT, etc.rules. __________________ dpalomaki@dspalomaki.com

September 23rd, 2011, 09:35 AM	#3
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: XA10 questions Or buy the XF100 which I think will do it all with a factory upgrade. __________________ "The horror of what I saw on the timeline cannot be described."

October 19th, 2011, 03:43 PM	#4
Rainer Halbich Regular Crew Join Date: Apr 2009 Location: South Africa Posts: 41	Re: XA10 questions I think I know why. PAL does not need the native 25p. I am not 100% sure of this but I will try to explain. Normal pf24 makes use of a 60i steam to save the 24fps file, but this is where it becomes complicated, How do you divide 24 progressive frames into 60i frames and then bring it back again to 24p when you dump the footage to your computer? In order to spread 24 progressive frames into 60 interlaced fields, a process called 'telecine' is used. The 24p footage is again broken up into two fields (odd and even lines), and is re-inserted into 60i by following the pattern 2-3-2-3-2-3 etc. Here is a representation of how it looks. Let's say that individual progressive frames are A B C D E F etc. When they are broken up, they become individual fields A1 A2 B1 B2 C1 C2 D1 D2, etc. The resulting 60i stream also contains individual fields. The 2-3 interlacing goes like this: A1 A2 B1 B2 B1 C2 C1 D2 D1 D2 E1 E2 F1 F2 F1 G2 etc. In other words, it goes AA BBB CC DDD EE FFF, but uses odd or even halves of each progressive frame in alternating succession. When this stream is played back, it will be the smoothest approximation of 24p within a 60i stream. With PAL this is easy, you don't need the "telecine" process. If you multiply 25 frames you end up with 50 frames, and with a PAL camera this will be embedded in a 50i stream. The frame rates already matches. (a1 a2 b1 b2 c1 c2 d1 d2....) In other words, PF25 is as close to real film as it gets, to have native 25p is irrelevant. This is why I am so in love with PAL, it is easy to use with anything. Last edited by Rainer Halbich; October 19th, 2011 at 04:22 PM.