Clarification Needed for a Rather Confusing Process

[Adam Stanislav]

No, I am not annoyed. I am glad you got it all straightened out. :)

I think the main reason Canon calls it 24f is for marketing purposes. It makes it sound like film, even if it is video.

[Garrett Low]

Hey Mark,

I'm having to jog my memory to when I had my Canons but Canon's 24F is actually laying down true 23.976fps. They labeled it 24F because the sensor in is actually not a progressive sensor and the way they build their progressive image is to take two images with a slight shift (this is where my memory is fuzzy, I don't believe there is a temporal shift in Canons flavor of progressive HDV) and creates the progressive image. So on the tape or on a solid state unit via the firewire, there is no pull down.

The issue is taking the feed from the SDI or HD-SDI out. In order to make the signal coming out of there compatible with all monitors, most SDI signals are 60i. That means in order to feed a 24p signal you of the SDI you need to introduce pull down and the frame is acutally broken into two identical half frames (each frame has every other line). So the Flash XDR or NF will actually be reading a 60i signal unless you can have the camera output 24PsF which the XDR and NF will then understand and create a 24fps file with no pull down.

As far as why Canon called their progressive form F instead of p isn't because they didn't want to pay any royalties. And, in fact as I said, the tape actually is recording a progressive image. It was to differentiate them from the other makers way of creating a progressive image from a non progressive imaging chip. The big issue when the XL H1 and XH series cameras came out was that if you recorded in Canon's 24F, only Canon cameras could play them back. And since Canon did not make a deck it became an issue for post production as people were worried that they would were their cameras down if they used them as decks in post. Then they created the HV series which for a lot of people, myself included, became their deck.

Hope that's not too long winded but I thought a little clarification was in order.

Garrett

[Peter Moretti]

You guys have done an AMAZING JOB explaining all this.

... But there is one issue that Mark mentioned that still sounds odd. The nano files w/ the pulldown removed should be 23.976 not true 24P. But he is saying that the files will not import into an Avid 23.976 project, but will into a 24P project.

This sounds like something is wonky.

Like I said above, I'd gladly try importing a small portion of the file to MC and see what I can come up w/.

[Mark Job]

Originally Posted by Garrett Low

Hey Mark,
Hope that's not too long winded but I thought a little clarification was in order.

Garrett

...Hey Garrett: No, thank you so much for that extra info. I really appreciated knowing this. I didn't realize Canon's way of doing this was way more involved than what I earlier understood. So you're saying the Canon XL H series cameras are actually recording a 23.976 fps progressive image onto the HDV tape. I bet the processing circuitry and internal processing CPU was something of an electronic work of art to make a helical scanning internal miniature VTR record a progressive image. This is complex stuff ! Frankly, I'm amazed any of this stuff works at all !

[Mark Job]

Originally Posted by Peter Moretti

You guys have done an AMAZING JOB explaining all this.

... But there is one issue that Mark mentioned that still sounds odd. The nano files w/ the pulldown removed should be 23.976 not true 24P. But he is saying that the files will not import into an Avid 23.976 project, but will into a 24P project.

This sounds like something is wonky.

Like I said above, I'd gladly try importing a small portion of the file to MC and see what I can come up w/.

...Hi Peter: Yeah ! What the xxxx ! I just can't wrap my mind around this fact ! I had a face to face conversation with the Canadian National Broadcast Manager for Avid Media Design's this past Thursday Morning in Montreal, and we discussed Convergent Designs's Flash XDR and Nano Flash device at great length. I'm pushing to get some of the bugs out of the function of importing mixed frame rates and mixed resolutions (Including SD) into whatever speed or format Media Composer editing project you please. This is the way the new Media Composer is supposed to work, but it doesn't work properly.

Also, Avid's AMA feature *does not work* with the flavour of Sony XDCAM HD 4:2:2 video files that CD records in their XDR & Nano. This is no fault of Convergent Design per se, it is because the programmers have written the current Media Composer to look for Sony XDCAM HD 4:2:2 files in the certain structure extant on an XDCAM disk. If the XDCAM HD files are not in that exact layout structure, then MC returns an AMA error ! I pointed out to the Avid editors and technicians present in the demo meeting that I thought Convergent Design had to write them in the way they do, or else their recorders simply would not function correctly, so maybe it's time to broaden the file structure search parameters to include Convergent Design's current file structure layout of XDCAM HD as they exist on recorded CF card media coming out of the Nano & Flash XDR.

**Dan & Mike, are you reading this ? I'm pushing as carefully from my end as I can regarding this subject, and I do believe I was heard. Let's hope we can get both higher data rate Long GOP, as well as correct Media Composer AMA working straight from Nanos, Nexto's, and Flash XDR's without the need to import the material.

**Just think about it. What if you could simply plug in your Nano to a laptop via the FireWire and have Avid simply make *Pointers (AMA) to the card sitting in a Nano recorder itself, or sitting in a Nexto and read that in bins and drag that onto the editing time line and play and edit it in realtime **without* having to clip import all this CF card material ? Wow ! But I digress.

[Piotr Wozniacki]

Originally Posted by Adam Stanislav

When TV was invented, it was 60i in the US, 50i in Europe. When color was added, they slowed it down to 60000 / 1001 and 50000 / 1001 respectively.

Adam, your explanation of the video cadence intricacies has been one of the best I heard/saw.

However, one thing comes as a surprise to me: I always thought that we Europeans can afford to know nothing about it, as the Area 50 (PAL) always uses (and actually IS) round integer numbers (25 fps, 25p, 50i). But you made me realize that it's not so for the very same reasons as with NTSC (accommodating the color info) - hence 50i is really 50000/1001...

If so, why all NLE uses integers (for both 50 and 25 fps)?

[Peter Moretti]

Originally Posted by Mark Job

...Hi Peter: Yeah ! What the xxxx ! I just can't wrap my mind around this fact ! I had a face to face conversation with the Canadian National Broadcast Manager for Avid Media Design's this past Thursday Morning in Montreal, and we discussed Convergent Designs's Flash XDR and Nano Flash device at great length. I'm pushing to get some of the bugs out of the function of importing mixed frame rates and mixed resolutions (Including SD) into whatever speed or format Media Composer editing project you please. This is the way the new Media Composer is supposed to work, but it doesn't work properly.

Also, Avid's AMA feature *does not work* with the flavour of Sony XDCAM HD 4:2:2 video files that CD records in their XDR & Nano. This is no fault of Convergent Design per se, it is because the programmers have written the current Media Composer to look for Sony XDCAM HD 4:2:2 files in the certain structure extant on an XDCAM disk. If the XDCAM HD files are not in that exact layout structure, then MC returns an AMA error ! I pointed out to the Avid editors and technicians present in the demo meeting that I thought Convergent Design had to write them in the way they do, or else their recorders simply would not function correctly, so maybe it's time to broaden the file structure search parameters to include Convergent Design's current file structure layout of XDCAM HD as they exist on recorded CF card media coming out of the Nano & Flash XDR.

**Dan & Mike, are you reading this ? I'm pushing as carefully from my end as I can regarding this subject, and I do believe I was heard. Let's hope we can get both higher data rate Long GOP, as well as correct Media Composer AMA working straight from Nanos, Nexto's, and Flash XDR's without the need to import the material.

**Just think about it. What if you could simply plug in your Nano to a laptop via the FireWire and have Avid simply make *Pointers (AMA) to the card sitting in a Nano recorder itself, or sitting in a Nexto and read that in bins and drag that onto the editing time line and play and edit it in realtime **without* having to clip import all this CF card material ? Wow ! But I digress.

Mark, send me a small nano file and I'll see what I can make out of it. There are a lot of moving parts to all this and w/o a file, I can't shed much light on it.

[Adam Stanislav]

Originally Posted by Piotr Wozniacki

If so, why all NLE uses integers (for both 50 and 25 fps)?

They are probably just rounding it up.