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Black Magic RGB to AJA RGB

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Matt Riley
Black Magic RGB to AJA RGB
on Feb 7, 2008 at 8:59:05 pm

I have some footage that was captured from HDCAM SR with a Black Magic system. It was captured at 10 Bit RGB (4:4:4).

When I try to open this footage on my Kona system, of course, the codecs aren't compatible. AJA's RGB codec must be different than Black Magic's RGB codec, right? I had gotten used to the interchangeable 4:2:2 codecs between the two systems, so this caught me a bit off guard.

So, the idea was to transcode the clips to AJA's codec so that I can edit the footage nicely with my Kona3 system. I thought this would be a task handled nicely by Compressor in batch for all the clips.

Here's the rub I have and am wondering if anyone else has seen this... The timecode in the clips is not being read correctly by Compressor. It's off by 7 seconds and 7 frames in the two clips I have tested.

For example, I have a clip that starts at timecode 02:00:30:00. Both QuickTime Player and Final Cut Pro show this as the starting timecode for the clip. When I drop this same clip into Compressor, it tells me the first frame has a timecode of 02:00:20:18. Ugh. I've verified this with multiple systems.

Has anyone else seen this?

Having consistent timecode is essential to an accurate workflow and this sure isn't it. Compressor is supposed to be able to do this kind of thing, since it even has a timecode burn filter but if it can't get the code right, what's the point?

-Matt

PS--The other reason I posted this in the Kona forum was to ensure I got my codec settings straight for the transcode. I used the AJA 10 bit RGB codec at full range (0-1024) setting and everything seems to turn out fine, except for the timecode. I verified this by dropping the original and the transcoded clips into After Effects and compared them using difference mode. I don't see any differences (it's all 100% black) but the range options in the AJA codec make me question whether or not I did it right.


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del chapple
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 1:37:35 am

can you copy and paste the time code track like you can with audio..? i'm going to try right now..


del

you cant hear my inner voice scream... can you..?


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del chapple
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 1:54:03 am

well it seemed to work, find your TC track in properties(apple J?) from your BM source copy it and paste it into your new aja codec'd file, but i take no responsibility for your computer exploding...

del

you cant hear my inner voice scream... can you..?


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matt Riley
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 3:04:00 am

Good idea. I may have to use that as a workaround very soon. I've got about 3 hrs of dailies headed my way and I don't think I want to push around the full-res. stuff for editorial so I'll need to make proxies. Thus the need for accurate timecode.

One thing that doesn't help with, though, is that I can't really use compressor's timecode filter then to burn in the timecode on the picture (very useful for wrangling multiple editors and fx houses).

Grrr... This should, um, work fine. But it's not. Argh. ;-)

-Matt



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Jeremy Garchow
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 3:17:17 am

Call AJA


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Chris Seguine
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 5:47:23 pm

What version of quicktime were these captured with and what version is on your system?

Compressor currently displays inaccurate timecode for reference movies, but we have not had a problem with normal clips.

If you open the clip in FCP does it display the correct timecode?

You could also use Episode to do the conversion, you can tell it to copy the original timecode, or set the timecode start.



---
Christopher Seguine
Sublime Films, San Francisco


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Matt Riley
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 5:53:39 pm

I'm not sure of the QT version they were captured under. I'll have to ask.

I have verified the problem with 3 systems now:

- G5, 10.5.1, Compressor 3.1.2, QuickTime 7.4
- Mac Pro, 10.5.1, Compressor 3.1.2, QuickTime 7.3.1
- G5, 10.4.11, Compressor 3.1.2, QuickTime 7.3.1

The only thing common to all these systems is the version of Compressor.

I just imported some P2 material last night, straight from the cards and when I drag those clips into Compressor the timecode is not correct, either. Arrr!

I still have some ideas to kick around. I'll post back if I find out anything.

-Matt



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Matt Riley
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 6:01:35 pm

[Chris Seguine] "You could also use Episode to do the conversion, you can tell it to copy the original timecode, or set the timecode start. "

I just tried using Episode but it gives me an error when trying to preview the file.

Not surprising to me. I have little confidence in Episode. Different thread. ;)

-Matt



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Matt Riley
Re: Black Magic RGB to AJA RGB
on Feb 8, 2008 at 9:15:05 pm

Hmmm... After doing some more testing I'm starting to wonder if the 24p part of the files is throwing Compressor off.

I had a few NTSC captures that I threw into Compressor and the TC showed up correctly in those. All the other media I've been trying has been 24p (P2/DVCPRO HD 720p/24 and 1080p 4:4:4).

I don't see any obvious way to have Compressor interpret the TC as base 24, though. Maybe that's not it. Just throwing ideas out there out of frustration.

-Matt



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scott compton
Re: Black Magic RGB to AJA RGB
on Sep 24, 2008 at 2:48:14 am

Hello. Working on a feature that is 1920x1080 23.98. My uncompressed 8bit quicktime starts at 00.59.58.00 with a 2pop. The first frame that the latest version of compressor shows in preview is 00.59.54.10

What a joke. any ideas from the crowd?

thanks


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Jeremy Garchow
Re: Black Magic RGB to AJA RGB
on Sep 24, 2008 at 3:21:50 am

For some reason, quicktime is unable to display 23.98 timecode.


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scott compton
Re: Black Magic RGB to AJA RGB
on Sep 24, 2008 at 3:24:41 am

Thanks Jerry.

Scott


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Jeremy Garchow
Re: Black Magic RGB to AJA RGB
on Sep 24, 2008 at 3:53:34 am

[scott compton] "Thanks Jerry.

Scott"




Sure Scoot,

Jeremy


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Matt Riley
Re: Black Magic RGB to AJA RGB
on Sep 24, 2008 at 11:39:24 pm

QuickTime seems quite capable of displaying 23.98 TC...

I still see my original issue, though. Here's exactly what happens:

I get files from telecine or P2, import them into FCP. No problem. TC looks fine (this is, of course, a rather important thing when conforming from an offline edit and receiving files back from telecine to create the online version of the spot).

If I want to make proxies of this media using Compressor - so that I don't have to have 50 GB of uncompressed HD files sitting on my SAN all the time - I drop the files into Compressor and setup the settings I want (photo jpeg, smaller size, etc.). However, if I look at the time code Compressor is displaying it does not match what is in the QuickTime file.

Just to prove myself right, I import the same source file into a new FCP project and the TC reads how I expect it to. Drop the same file into Compressor again and verify that Compressor is indeed displaying the TC incorrectly. Sometimes by a handful of frames, sometimes by a few seconds or more.

The only decent workaround I've found so far is to go ahead and do the encoding with Compressor with the incorrect TC. When Compressor is done, I take the new proxy files and drop them back into FCP. From there, I can see that indeed, the incorrect TC that Compressor was displaying has now been embedded into the files. Ugh. So, I import the original files into FCP for reference and modify the TC on each of the proxy files, one at a time, so that they match the original files' TC.

It works, as the modify TC tool in FCP instantly changes the TC embedded in the files. But, it is a tedious, manual process requiring me to type out the TC for each clip while looking at the TC from the original files. Very prone to errors if you aren't paying attention. However, I feel that having good proxy files that I can keep around without using much disk space (or overhead to playback from the SAN) is worth the extra effort.

It's really a shame this doesn't work like it should. I suppose I should file a bug report or something with Apple but it is hard to find the time some days, especially when I'm spending time correcting TC errors. ;-)

-Matt

PS--I see Compressor 3.0.4 is out now. I might give that a whirl and see if I have any better luck with that version. I'm not hopeful but it doesn't hurt to try.



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Jeremy Garchow
Re: Black Magic RGB to AJA RGB
on Sep 25, 2008 at 1:44:08 am

[Matt Riley] "QuickTime seems quite capable of displaying 23.98 TC... "

What version are you on?


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Matt Riley
Re: Black Magic RGB to AJA RGB
on Sep 25, 2008 at 1:55:18 am

QuickTime 7.5.5 (just did the 7.5.5 update a few minutes ago)
FCP 6.0.4
Compressor 3.0.4 (just did the application support 2008-003 update a few minutes ago)

As you can see, I did some updating all around this evening and will hopefully have time to test this yet again tonight. I'll let you know what I find.

-Matt



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Matt Riley
Re: Black Magic RGB to AJA RGB
on Sep 25, 2008 at 2:42:40 am

Okay, here is a quick test I just did to confirm the problem (for me, at least) still exists even with the absolute latest versions of everything installed.

I took three clips at random from a current project for analysis. These clips are from a telecine session at a high-end transfer house; they were captured from a D5 intermediate with a Black Magic card in a FCP system. When I import the clips into FCP here, I get the TC I'm expecting (so that my EDL conforms properly). Here are the starting TCs for each clip as FCP shows me:

Clip 1 -- 01:02:32:00
Clip 2 -- 01:03:19:00
Clip 3 -- 01:04:00:00

Now, if I open each one of those clips in QuickTime Player and set the display to show the TC, it shows these same values. This seems like new behavior to me. QuickTime Player says "Timecode: Non-Drop-Frame" from the pop-up menu in the lower left of the window where you can change the display options.

However, when I drop these clips into Compressor, here are the TCs Compressor shows me:

Clip 1 -- 01:02:28:06
Clip 2 -- 01:03:15:05
Clip 3 -- 01:03:56:04

Obviously, these aren't correct and represent a fairly significant workflow problem. :-(

What's Compressor doing? Does it think the clips have Drop-Frame TC instead of Non-Drop? I don't see any way to change this behavior in Compressor so I don't know if there is anything I can do about it. I don't deal with DF TC ever, so I don't know much about it.

Ideas?

-Matt



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Jeremy Garchow
Re: Black Magic RGB to AJA RGB
on Sep 25, 2008 at 3:56:13 pm

[Matt Riley] "Does it think the clips have Drop-Frame TC instead of Non-Drop?"

It can't discern the difference and Quicktime used to be the same way, but that seems to have changed now.

Jeremy


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del chapple
Re: Black Magic RGB to AJA RGB
on Sep 25, 2008 at 6:18:01 pm

A bug in compressor, whoda thought... Compressor (i bet) just cant discern 24f tc so maybe its assuming its DFTC bt from the 00:00:00:00 code. the diff between DF and NDF over an hour is 3 sec and 18 frames, which roughly seems to be what compressor is doing. as i said before if you need the TC track you can just copy it from the original and paste it into the proxy. theoretically it will work.

d

you cant hear my inner voice scream... can you..?


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Matt Riley
Re: Black Magic RGB to AJA RGB
on Sep 26, 2008 at 2:03:38 pm

While the copying TC track in QT player might work just fine, it's really not any better than having to use FCP's modify TC function to change things. Either way, it's still a manual process to fix something that should be handled by a program intended for automation with a batch-driven interface.

I wonder how hard it would be to write a nifty little AppleScript to do the dirty work for me? Something like copy the TC track from each clip in folder A (source folder) and replace the TC track of each clip in folder B (record folder), in order, of course.

I might look into this, although counting files and applying things in order is beyond my limited scripting capabilities at the moment. :-(

-Matt



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Matt Riley
Re: Black Magic RGB to AJA RGB
on Sep 28, 2008 at 3:07:53 am

I'm not alone:

http://discussions.apple.com/thread.jspa?threadID=1725001&tstart=0

Here's a link to submit feedback to Apple about Compressor. I've just sent them a link to this thread in the hopes that they can fix the problem or at least slap me around and tell me I'm doing something wrong.

http://www.apple.com/feedback/compressor.html




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