GH1(3) & CS5 Premiere Question (AVC-Intra transcoding if not native 24p/25p?)

Lucas Adamson

Lucas Adamson

Well-known member
Camera: GH1(3) Pal. lpowell's J (reliability) settings.
Software: CS5 Premiere
Platform: Mac OSX Snow Leopard on Macbook Pro Core 2 Duo 2.66Mhz with 4GB RAM (no cuda card :crybaby: )


I've just bought and installed CS5 Production Premium on my Macbook Pro (migrated from FCS). I'm shooting GH1(3) with lpowell's j settings, an I have two questions.

1. Is there any advantage in trans-coding from AVCHD in CS5? I am using lpowell's J reliability settings, in which there is no "native 24/25" checking, so on import, I get the red line above footage and it needs immediate rendering. Would transcoding (to AVC-intra or other) change that? In other words, can I transcode to make it native, or am I missing something in my understanding?

2. Is there a good way to pull-down from 30p to 25p (for MPEG 720p30 footage) I am in PAL-land.

Many thanks
Lucas
 
I'm using CS5 on Win7, patched to work with an nVidia GTX260 video card. If you can upgrade your Mac with a CUDA card I'd highly recommend it. I recently converted a number of interlaced GH1 1080p files to 720p, and Premiere CS5 displayed them just as smoothly before and after conversion.

Regardless of whether you can upgrade your video card, I'd definitely recommend deinterlacing your 1080p video files. There are many subtle things that can go awry with interlaced video and I would want to make sure it's correctly deinterlaced before attempting to edit the files. If you want to maintain interoperability with Final Cut, Cineform is a good option for both deinterlacing and transcoding to a portable format.

For 30p to 25p conversion, I'd suggest trying After Effects using its Motion Blur but not its Frame Blending option. I've used Motion Blur with very good results to convert 720p60 to 30p. Frame Blending is very likely to cause ghosting.
 
lpowell said:
For 30p to 25p conversion, I'd suggest trying After Effects using its Motion Blur but not its Frame Blending option. I've used Motion Blur with very good results to convert 720p60 to 30p. Frame Blending is very likely to cause ghosting.
Click to expand...

I didn't think 'motion blur' worked that way in AE... I was under the impression that motion blur was only applied to objects that AE 'moved' via keyframing. In order to 'motion blur' in a live clip, AE would have to understand what was 'moving' frame to frame... whereas, frame blending would use frame content and 'average' the frames for the resulting output, hence no need to 'know' what was moving in a frame.
 
You need a cuda card, gt 240 with 1 gb ddr5 is the best bang for the buck, last I checked. DDR5 makes a difference. I paid about ~85 on sale, but I think that's still ballpark.
Once you have the Nvidia card, and rewrite the accepted card file, which takes 20 seconds in a text editor, and enable the Nvidia driver using whatever software version you are using, you will see a huge difference when you select hardware+mercury in CS5. Since you are going PAL, you don't need pulldown, of course. Lpowell knows way more than I will ever know, but I personally DO remove pulldown but do NOT deinterlace for 24p. However, before doing a big project, it is always a good idea to export of few fragments and analyze then frame by frame.
One reason to use an intermediate codec is if you are going to do a lot of cutting.
 
I wish I cuda get one of those cards for my Macbook Pro but it's not going to happen. ;)

I'll re-phrase what I really want to know:

What codec (available on CS5) should I use to transcode from 50i wrapped 25p to get 25pN footage that looks amazing and can be edited freely? Also I'm using a second card to get native AVCHD 25pN - what should I transcode that to to get freely editable material?

Many thanks my loves. Thanks for your patience
 
Lucas Adamson said:
What codec (available on CS5) should I use to transcode from 50i wrapped 25p to get 25pN footage that looks amazing and can be edited freely?
Click to expand...
Two choices:

AVC-Intra @ 100Mbps - All I-frames in 4:2:2 10-bit color depth, along with large file sizes
XDCAM HD422 @ 50Mbps - Long-GOP MPEG-2 in 4:2:2 10-bit color depth, much smaller file size

In Premiere CS5, AVC-Intra options are found under the "P2 Movie" Export Settings Format dialog.
XDCAM options are found under "MPEG2 MXF". (Be sure to check the "Render at maximum depth" option.)

I've gotten excellent results converting GH1 MJPEG videos to XDCAM HD422.
 
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Thanks for that. Is it better that I import into Premiere and then export to XDCam, and then re-import it, or should I do it in the Media-Encoder application? Perhaps it doesn't matter...

EDIT:

I exported a file from Premiere into XDCam 422 max depth Full HD and then re-imported it and dragged the MXF file onto the new sequence button to make a matching sequence, and it will barely play for me, even at 1/4 quality. The audio cuts out, the video stutters - totally un-editable.

Is this because I'm a second class CS5 user with no CUDA credentials?

What's my best option?

EDIT 2: Of course, with the exported file on my laptop drive, it won't be optimum ;) I will move it now.
 
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Lucas Adamson said:
Is it better that I import into Premiere and then export to XDCam, and then re-import it, or should I do it in the Media-Encoder application?

I exported a file from Premiere into XDCam 422 max depth Full HD and then re-imported it and dragged the MXF file onto the new sequence button to make a matching sequence, and it will barely play for me, even at 1/4 quality. The audio cuts out, the video stutters - totally un-editable.

Is this because I'm a second class CS5 user with no CUDA credentials?
Click to expand...
It doesn't matter whether you export to XDCAM from Premiere or directly in Media Encoder. Same result.

XDCAM HD422 50Mbps videos scrub and play back seamlessly in Premiere CS5 on my Win7 6-core nVidia workstation. These are MPEG-2 videos, so they should not demand as much CPU bandwidth to decode as AVC/H.264. Sorry to hear your laptop is having trouble with them.
 
I don't mean to be the bearer of less than good tidings, but you are going to be better off getting a machine that runs cuda AND a four core-minimum-processor. Otherwise you could be really waiting around for the video. Maybe even spend a few hundred for a PC so equipped. It makes a huge difference. Even the bottom-of-the-line four core and a cheap GT 240 will give you RT Mercury.
 
Well thanks Dave - honest and probably true.

Problem there is that I've just bought the Mac version of CS5 Production Premium, and I'm pretty certain it's not transferable. Also, having used a mac for 15 years, and never a PC, I would hate to swap over - it's the wrong direction for me. Perhaps a newer Macbook Pro with the integral Cuda card would be best option, as Mac Pros are too expensive for me.

The AVCHD footage does edit almost perfectly to be honest. I thought I might make it easier by transcoding, but it seems nothing is as efficient as AVCHD, and so there isn't really an option to transcode to something that is a.) non artefact enducing and b.) smaller or equal file sized and easier to cut. Those two methods recommended by lpowell are non-artefact enducing transcodes but lead to larger files, so intrinsically harder to cut, or so it seems.

Probably simply de-interlacing from 25p (50i) AVCHD to 25pN AVCHD is my best bet. Will that help?
 
Lucas, you're fine without CUDA-enabled Mercury Playback Engine. I have CS5 on my Core-i7 Hackintosh with a GTS250/1GB GPU, which is not an officially supported CUDA card for MPE. Until I did the CUDA hack to enable MPE on the system, I did a fair amount of work in CS5 without it and I can tell you that at least on my system, the lack of hardware MPE is not the deal breaker everyone says it is. Yes, it's nice to have, especially if you can get it without having to buy a new GPU. But if you're used to the relative speed of CS5 on a C2D MacBook Pro, you're plenty fine without it. We've all been using FCP on Macs for years without being able to view effects until they're rendered, so its not like the lack of hardware MPE is a step backwards when using CS5.



Lucas Adamson said:
Well thanks Dave - honest and probably true.

Problem there is that I've just bought the Mac version of CS5 Production Premium, and I'm pretty certain it's not transferable. Also, having used a mac for 15 years, and never a PC, I would hate to swap over - it's the wrong direction for me. Perhaps a newer Macbook Pro with the integral Cuda card would be best option, as Mac Pros are too expensive for me.

The AVCHD footage does edit almost perfectly to be honest. I thought I might make it easier by transcoding, but it seems nothing is as efficient as AVCHD, and so there isn't really an option to transcode to something that is a.) non artefact enducing and b.) smaller or equal file sized and easier to cut. Those two methods recommended by lpowell are non-artefact enducing transcodes but lead to larger files, so intrinsically harder to cut, or so it seems.

Probably simply de-interlacing from 25p (50i) AVCHD to 25pN AVCHD is my best bet. Will that help?
Click to expand...
 
Lucas Adamson said:
Problem there is that I've just bought the Mac version of CS5 Production Premium, and I'm pretty certain it's not transferable...

The AVCHD footage does edit almost perfectly to be honest. I thought I might make it easier by transcoding, but it seems nothing is as efficient as AVCHD, and so there isn't really an option to transcode to something that is a.) non artefact enducing and b.) smaller or equal file sized and easier to cut.
Click to expand...
Adobe licenses are transferable between computers, so you should be able to upgradeto a faster Macbook at any time:
http://prodesigntools.com/move-adobe-cs5-between-computers-or-windows-to-mac.html

However, it doesn't make sense that your Mac would be able to edit AVCHD files more smoothly than XDCAM. Without a CUDA card, AVCHD demands much more processing power to decode than MPEG-2 video, so AVCHD should be noticeably slower, regardless of file size. If you are seeing serious stuttering during playback, I'd suspect your hard drive is near full, in serious need of defragmenting, or not functioning properly. Upgrading your Mac with a 7200rpm 500+ MB hard disk is another an inexpensive option.
 
Oh that's good to know lpowell, about the cross-grading. I will probably stick with Mac though, but thanks.

Regarding the XDCam 422 50Mb footage, it is stuttery even on my external firewire Seagate Barracuda 7200Rpm hard drive. Perhaps it needs de-fragging - I don't know! I will try and clean it up and keep experimenting with the XDCam then. Thanks for re-confirming that I should stick at this path.

EDIT:

I took a single 25pN AVCHD clip and transcoded it to XDCam 4:2:2 50Mbps. The file's image qualities look identical to me, but the transcoded file has double the average data rate per second, from 3.6MB/s for AVCHD to 7.1MB/s (56.8Mb/s) for the XDCam.

LPowell, how can that be easier for my system to deal with? Double the date rate sounds like a lot (56.8Mb/s on average!!) I am getting audio drop-outs and occasional stutters. It's worse than the AVCHD in fact. It doesn't seem to fit in with your idea that it is easier to deal with, or perhaps I'm missing something important???

If it's my hard drive as you say, I have a G-tech, Firewire 800, 7200rpm, 3.5", 1TB HDD in the post, so that will be the test of that I guess.

Many thanks for all of your help, including the hack settings which I use.
 
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Lucas Adamson said:
I took a single 25pN AVCHD clip and transcoded it to XDCam 4:2:2 50Mbps. The file's image qualities look identical to me, but the transcoded file has double the average data rate per second, from 3.6MB/s for AVCHD to 7.1MB/s (56.8Mb/s) for the XDCam.

LPowell, how can that be easier for my system to deal with? Double the date rate sounds like a lot (56.8Mb/s on average!!)
Click to expand...
XDCAM uses MPEG-2 which is much less demanding on the computer's processor than AVCHD. 50Mbps is not an extremely high data rate - the SD card used in the GH1 can handle it without difficulty. You should be seeing much faster performance than that from your hard disk. I'd suspect it's something to do with the Firewire connection. You might try running a test on your internal hard disk for a comparison.
 
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