Hd-SDI output

Keith Wakeham · December 22nd, 2005, 10:15 AM

I'm curious if anyone knows if the output is segmented in frame mode over hd-sdi or is it non segmented.

For those who don't know segmented frames are it takes a progressive (or a frame in canons case) and ships it out over two fields. So the image is still progressive, just that the transport of the image is more akin to interlaced.

From what I've read in the manual it says I think in 24F mode it actually does a 3:2 pulldown and outputs 60i. Can anyone confirm? How about 30F mode?

Thanks, would really help for something that I'm working on and since I don't have a H1 I can't find out.

Shannon Rawls · December 22nd, 2005, 10:42 AM

Keith,

Found this info here: http://videosystems.com/mag/video_canon_xl_3/

here's what he says in his review/article....

At any rate, what comes out of the HD-SDI spigot is always uncompressed 1080/60i. Newly minted synthetic progressive frames must therefore be segmented into halves in order to fit the 60i cadence. For instance in 30PsF (progressive segmented frames/second), a progressive frame's odd lines are first output, then even lines, amounting to 60 half-frames per second, all of which are reassembled into intact progressive scans upon playback. This introduces the unique irony that 30F, which began life interlaced at 60i, is output as 30PsF at 60i.

24F comes out the HD-SDI spigot as 24PsF, with 2:3 pulldown added to pad 48 half-frames into a total of 60 segments. Downstream devices like NLEs that recognize segmented progressive frames and 24p repeat flags will readily ingest Canon's PsF stream and restore either 30F or 24F “progressive” frames upon playback.

So, essentially, it's treating it the same way a Sony F900 records 24p to it's big huge HDCAM tapes. Thought those that might be curious like we were as to why it always said 60i when connected via HD-SDI.

- ShannonRawls.com

David Newman · December 22nd, 2005, 11:06 AM

The second paragraph isn't completely accurate. 24PsF is a mode over HD-SDI used for 24p presentation and capture, there is no pulldown to 60i, this is a 48Hz video system. However, the Canon does do pulldown to 60i, this just not called 24PsF (the part I was correcting.) 2:3 pulldown to 60i over is fine for viewing but a lot harder for post, as most decks/capture software will not restore the 24p data. At CineForm we recently added this pulldown extract for real-time captures of 24p using Prospect HD or the new Wafian HR-1. Same info my my blog : http://cineform.blogspot.com/2005/12...er-hd-sdi.html More info on the IndieFilmLive blog : http://indiefilmlive.blogspot.com/20...ion-modes.html

Keith Wakeham · December 22nd, 2005, 11:23 AM

Thanks, that really helps a whole lot. I really wish when they implemented features like HD-SDI they would disclose as much info as possible and not leave little gaps.

Shannon Rawls · December 22nd, 2005, 12:27 PM

That's why I like CineForm...

New Motto: CINEFORM, "We fix all the f****k-ups!"

- ShannonRawls.com

December 22nd, 2005, 10:15 AM	#1
Keith Wakeham Major Player Join Date: Jan 2005 Location: St. John's, NL, Canada Posts: 416	Hd-SDI output - segmented or not segmented I'm curious if anyone knows if the output is segmented in frame mode over hd-sdi or is it non segmented. For those who don't know segmented frames are it takes a progressive (or a frame in canons case) and ships it out over two fields. So the image is still progressive, just that the transport of the image is more akin to interlaced. From what I've read in the manual it says I think in 24F mode it actually does a 3:2 pulldown and outputs 60i. Can anyone confirm? How about 30F mode? Thanks, would really help for something that I'm working on and since I don't have a H1 I can't find out. __________________ www.engr.mun.ca/~wakeham/index.htm

December 22nd, 2005, 10:42 AM	#2
Shannon Rawls Major Player Join Date: Nov 2003 Location: Los Angeles, California Posts: 853	Keith, Found this info here: http://videosystems.com/mag/video_canon_xl_3/ here's what he says in his review/article.... At any rate, what comes out of the HD-SDI spigot is always uncompressed 1080/60i. Newly minted synthetic progressive frames must therefore be segmented into halves in order to fit the 60i cadence. For instance in 30PsF (progressive segmented frames/second), a progressive frame's odd lines are first output, then even lines, amounting to 60 half-frames per second, all of which are reassembled into intact progressive scans upon playback. This introduces the unique irony that 30F, which began life interlaced at 60i, is output as 30PsF at 60i. 24F comes out the HD-SDI spigot as 24PsF, with 2:3 pulldown added to pad 48 half-frames into a total of 60 segments. Downstream devices like NLEs that recognize segmented progressive frames and 24p repeat flags will readily ingest Canon's PsF stream and restore either 30F or 24F “progressive” frames upon playback. So, essentially, it's treating it the same way a Sony F900 records 24p to it's big huge HDCAM tapes. Thought those that might be curious like we were as to why it always said 60i when connected via HD-SDI. - ShannonRawls.com __________________ Shannon W. Rawls ~ Motion Picture Producer & huge advocate of Digital Acquisition.

December 22nd, 2005, 11:06 AM	#3
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	The second paragraph isn't completely accurate. 24PsF is a mode over HD-SDI used for 24p presentation and capture, there is no pulldown to 60i, this is a 48Hz video system. However, the Canon does do pulldown to 60i, this just not called 24PsF (the part I was correcting.) 2:3 pulldown to 60i over is fine for viewing but a lot harder for post, as most decks/capture software will not restore the 24p data. At CineForm we recently added this pulldown extract for real-time captures of 24p using Prospect HD or the new Wafian HR-1. Same info my my blog : http://cineform.blogspot.com/2005/12...er-hd-sdi.html More info on the IndieFilmLive blog : http://indiefilmlive.blogspot.com/20...ion-modes.html __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

December 22nd, 2005, 11:23 AM	#4
Keith Wakeham Major Player Join Date: Jan 2005 Location: St. John's, NL, Canada Posts: 416	Thanks, that really helps a whole lot. I really wish when they implemented features like HD-SDI they would disclose as much info as possible and not leave little gaps. __________________ www.engr.mun.ca/~wakeham/index.htm

December 22nd, 2005, 12:27 PM	#5
Shannon Rawls Major Player Join Date: Nov 2003 Location: Los Angeles, California Posts: 853	That's why I like CineForm... New Motto: CINEFORM, "We fix all the f**k-ups!" - ShannonRawls.com __________________ Shannon W. Rawls ~ Motion Picture Producer & huge advocate of Digital Acquisition.