True real-time 24fps editing? (please reply in post on AJA IO cow)

[Walter Biscardi]

There is an Apple DV Advanced mode and of course there’s the DVCPro HD 24 mode which are both supplied by Apple and allow you to edit in true 24fps. I’m pretty sure both of these will work even with an Io system.

Walter Biscardi, Jr.
Creative Genius, Biscardi Creative Media
https://www.biscardicreative.com

Now in Production, “The Rough Cut,” https://www.theroughcutmovie.com

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Steve Covello]

I believe the capture sans pulldown function will only work under the following conditions: 1) you are capturing via firewire DV, not IO; 2) you are playing back a DVCPro acquired taped on a Panasonic playback product (camera, deck, etc.), not a Sony product; 3) you have the correct Easy Setup which corresponds to the kind of pulldown cadence (conventional, advance) that the footage was acquired.

The reason for this is that the DVCPro cameras record a flag data stream on tape along with the picture/sound. It is carried via firewire connection only, so SDI data doesn’t “see” the flags on tape. FCP cannot “see” the flags otherwise and can’t distinguish between pd and regular frames.

After you have captured, perhaps you could use the IO as a playback throughput device, but as far as I know, it cannot remove pulldown frames on capture via analog or SDI (I just checked the preset for IO and the Capture Settings allow for removal only from FW sources). Maybe there;s a hack for this but not that I’m aware of.

steve covello
double wide post

[Gary Adcock]

[walter biscardi] ” There is an Apple DV Advanced mode and of course there’s the DVCPro HD 24 mode which are both supplied by Apple and allow you to edit in true 24fps”

ah 2 things here the 24pA format is not 24.0 FPS (TRUE 24 frame) it is 23.98 also, secondly and most importantly

WHY do you need to work at 24.0

this is one of the biggeest mistakes one can make when trying to work at 24p as all of the Video to Film tools are based on the 23.98 TC rate NOT 24. 24p video is 23.976 FPS and when it is laid back to film it is done as feet and frames.

How are you going to handle your audio? the audio needs at 24.0 are different than audio at 23.98 and finding this out late usually doubles your audio post budget.

gary adcock

Studio37
HD and Film Consultation

[Alexander Serpico]

>WHY do you need to work at 24.0 ?

When the company that is doing effects work / final conform in 24fps, and insists that you give them a 24fps edl…

Simply converting a 30 fps edl just sort of works, but when every shot has a wacky speed change (and there is no burn in on the transfered footage) you’re kind of SOL. Of course the speed changes should have been done in the transfer (which this effects company supervised by the way… [can you guess my opinion of them?].

[Gary Adcock]

[isoprophlex] When the company that is doing effects work / final conform in 24fps, and insists that you give them a 24fps edl…

I’m not sure you got my meaning
I was not talking about a 30-24 edl conversion — my film outs are always conformed done at 23.98 and most of conforms I have worked on are not being done at 24 but at 23.98 –but everyone still calls it 24p.

The Kona cards will mirror most of the capibilities of the Ignighter, in my findings only the hardware cards are able to do 24.0 frame rates.

and again will will shoot yourself in the foot if you work at 24 and do not deal with the audio issues of a 24.0 (not 24p) frame rate.

gary adcock

Studio37
HD and Film Consultation

[Alexander Serpico]

>I was not talking about a 30-24 edl conversion

Neither was i (in my original post).

[Robert]

he reason for this is that the DVCPro cameras record a flag data stream on tape along with the picture/sound. It is carried via firewire connection only, so SDI data doesn’t “see” the flags on tape. FCP cannot “see” the flags otherwise and can’t distinguish between pd and regular frames.

Actually, this is not entirely true.

The flagged frame data does get encoded into the SDI stream. It gets embedded in the ancillary data space as user bits in the RP-188 timecode.

I don’t have the I/O, but I have the Kona2 and have worked with the Decklink Pro, and in both instances I could remove pulldown from SD and HD sources when digitizing from an SDI stream.

Check out this excerpt from the AJA Kona2 FAQ:

The KONA 2 board and drivers will handle VariCam duplicate frame removal during capture via the KONA 2 board’s uncompressed HD-SDI input for any “shooting” frame rate (it skips over any extra frames). However, Final Cut Pro can only capture video at the standard video frame rates as determined in the Capture Preset Editor dialog: 60, 59.94, 30. 29.97, 25, 24, 23.98, and 15 fps. So, for example, if you want to shoot and edit your movie at 12 fps, VariCam could capture it, and KONA 2 could digitize it, but you wouldn’t have a way to get FCP to make 12 fps clips or sequences.

When your “shooting” frame rate is the same as your “playback” frame rate, you can use the KONA 2 Easy Setup that matches. For example, if you are shooting at 23.98 fps and your intent is to capture/edit/playback the clip at 23.98 fps, then you can use the “AJA Kona2: 720p 23.98 Varicam” or “AJA Kona2: 720p 23.98 DVCProHD Varicam” Easy Setups and the card will automatically skip the duplicate VariCam frames and ONLY capture the 23.98 active frames/sec. Use the “… Varicam” setup if you want to capture Uncompressed 8-bit clips, and use the “… DVCProHD Varicam” setup if you want to capture DVCProHD compressed clips.

If you are deliberately over/under cranking the shooting rate in order to get a slow/fast motion effect (for example: shooting a clip at 48 fps with the intent to play it back at 1/2 speed in a 24 fps sequence), then you should use the “AJA Kona2: 720p 59.94 DVCProHD” Easy Setup to capture ALL of the frames (active + duplicates) – then process the resulting clip using the software Frame Rate Converter with a target frame rate of 23.98. The KONA 2 board extracts the VariCam flags from the RP-188 stream during capture and inserts them into the captured DVCProHD stream where the FRC can find them. Note that this ONLY works if you are capturing using DVCProHD compression. The KONA 2 board doesn’t do the slow/fast motion processing – this can only be done by the Frame Rate Converter using the VariCam flag bits inside the DVCProHD-compressed clips.

Question: How can I capture DVCProHD clips from a VTR and use the software Frame Rate Converter?

Answer: The software Frame Rate Converter works on DVCProHD clips that have the embedded VariCam flags (these are the flags that identify the “shooting” rate of the clip, and which frames are duplicates). You can capture DVCProHD clips from a VTR in two ways: via FireWire (which transfers the clips in their compressed DVCProHD format – and retains the embedded VariCam flags); or by connecting the HD-SDI output of the VTR to the KONA 2 input and capturing it as you would any other video clip. During playback, the Panasonic VTRs take the VariCam flags out of the compressed video and add them to the HD-SDI video stream as “RP188 Ancillary Data”. The KONA 2 hardware/software picks off the Ancillary Data while it is capturing and adds the VariCam flags back into the compressed DVCProHD clip where the FRC can find it.

There are two caveats to observe: for the KONA 2 solution you must be capturing using the DVCProHD codec (the FRC only works with DVCProHD compressed clips); and you must use the “AJA Kona2: 720p 59.94 DVCPro HD” capture preset (or the “AJA Kona2- 720p 59.94 DVCPro HD” Easy Setup). This setup tells the KONA 2 card to capture all frames (active + duplicates) so the FRC can use them. Although it sounds counterintuitive, the KONA 2 setups with “VariCam” in the name tell the board to automatically skip over any duplicate VariCam frames and only capture the active frames – which is only what you want to use if your shooting frame rate and editing/playback frame rate match (in which case you don’t need the FRC!).

I don’t know if this stuff applies to the i/o card, but in any event if you have aquired in any Panasonic 24p format (including the DVX-100), you should be able to ingest the material with pull down and then apply a reverse telecine (pull down removal) in cinema tools or FCP. The only time I have had a problem is when the proper cadence can’t be detected. I had this problem when trying to digitize DV via firewire from a Sony JH3 HDCAM vtr (which, incidently, does not play nice with firewire/FCP at all in my experience). The fix was do run the SD SDI thru a DPS frame sync to reclock the signal, and then digitize from the SDI stream. Then, a reverse telecine was performed in Cinema tools, if I remember correctly. The application was offline 24p editing for an HDCAM 24p feature.

Hope this is helpful,

Rob

[Dom Silverio]

Gary, most major Hollywood films are cut 24p – not 23.976 – with Avid Film Composer.
Choosing between the two depends on many little factors – the biggest being how is sound being handled.

[Gary Adcock]

[MPE] “most major Hollywood films are cut 24p – not 23.976 – with Avid Film Composer. Choosing between the two depends on many little factors – the biggest being how is sound being handled.”

“most hollywood films w/ Avid Film COmposer”

But more “film” content is cut every year by NFL films than motion pictures in Hollywood (according to kodak). Music Videos and commercials are produced with both 35mm and 16mm films and not cut at 24.0 but at 23.98–just becuase I have never heard of comercial cut at 24, yet I am sure that some have been.

Not everyone that working in motion picture film is in Hollywood nor do they wish to be.
Many people on this list make the assumption that 24p is really 24.0 FPS when it is really 23.98 and my comments here were directed at someone that did not appear to understand the difference.

I made the 23.98 vs 24fps mistake the additional charges in Post cost me most of the profit I was to make on the job. That is why I became outspoken on the 24Fps workflow. I taught 3 sessions on it at the past NAB. Next year I am adding the filmout workflow to my sessions for this very reason.

gary adcock

Studio37
HD and Film Consultation