Editing with GH 50mbps mov files

[William Hohauser]

The first editing I did with the new GH3 50 mbps mov files was on my MacBook Pro laptop with an eSATA RAID 4 array using Final Cut Pro X. Smooth sailing.

Now I am trying edit the same files on an 8-core MacPro with an ATI Radeon HD 5870 video card but off a RAID 0 portable drive on FireWire 800. It may be 5400rpm not 7200rpm. The GH3 files now stutter and go out of sync while the hacked GH2 AVCHD 35mbps files play fine. Transcoding the GH3 files to the same drive eliminates the stuttering so it seems that drive speed isn't the problem.

Anyone else have an issue with these files?

[Dan Carter]

Same issue here with Thunderbolt drive William. Transcoding "Optimizing" solved my issue as well. In my case, I believe it's a lack of RAM (4GB).

[William Hohauser]

I have 16GB of RAM on my MacPro so that shouldn't be an issue. It's that the files work on a quad-core laptop with less memory and a less powerful video card is curious to me. I wonder if there is something odd about the mov files coming out of the camera.

[Jeff Harper]

Sounds to me it's firewire holding you back. It's so slow.

[Jack Zhang]

The 5870 is an older card, so GPU based acceleration may not be optimal on those cards. I believe the Macbook Pros of recent have a Discrete Nvidia GPU along with the Intel graphics. You could try installing a Nvidia 680 (since that is supported with a little bit of elbow grease) and see if that makes a difference.

[Jeff Harper]

Transcoding to a more editable format will allow you to work on a drive that otherwise may be too slow, which might explain why transcoded files will play smoothly and the originals will not. Just a thought.

[William Hohauser]

I am coming to the thought that the video card isn't able to decode AVCHD files that are 50mbps or over. To be sure I will test some straight AVCHD files from the camera. The same drive and FireWire 800 connection has no problem with larger transcoded files so probably that's not the problem. I should experiment with the 72mbps intraframe codecs as well.

Perhaps foolishly, I am waiting for the promised MacPro upgrade that's been promised so a new video card isn't in the cards at the moment.

[Jeff Harper]

William, I've used Cineform files which are much larger than original avchd, but they edit much smoother in Vegas than the original AVCHD files. I'm not sure, but I don't think it's the size of the files that determine how difficult they are to edit, but the codec. I could be wrong, I'm not technically savvy, but as I said that's been my experience with AVCHD and Cineform.

As you probably know better than I, AVCHD was designed as a delivery format and is just not editor friendly. I still don't understand why they have not come up with something better.

[Dan Carter]

Originally Posted by William Hohauser

I am coming to the thought that the video card isn't able to decode AVCHD files that are 50mbps or over. To be sure I will test some straight AVCHD files from the camera. The same drive and FireWire 800 connection has no problem with larger transcoded files so probably that's not the problem. I should experiment with the 72mbps intraframe codecs as well.

Perhaps foolishly, I am waiting for the promised MacPro upgrade that's been promised so a new video card isn't in the cards at the moment.

Actually, AVCHD max Bit Rate is 28Mbps, and the MOV Bit Rates are 50 & 72Mbps. The Frame Rate appears to be my issue. Below 60p all is well, at 60p problems grow as the project gets larger.

I'll be interested in the result of your ALL-Intra experience William. My ALL-I landscape tests produced massive moire.

[William Hohauser]

I made some test 24p files and here is how it went on my 2009 MacPro with an ATI 5870 graphics card:

AVCHD / 24mbps: Smooth playback
MOV h.264 / 50 mbps: Jerky with stalls
MOV h.264/ 72 mbps all-intra: Smooth playback
ProRes 1080i 30p / 166mbps (made thru the HDMI with a BlackMagic UltraRecorder) Smooth playback

The conclusion here is that my system just can't handle standard GOP h.264 at 50mbps, however all intra frame h.264 will work fine directly in my edit system.

Regarding the BlackMagic UltraRecorder; I haven't been able to get it to record 24p out of the HDMI although I know the camera will output it. I have seen 24p on my LCD TVs at home, it looks OK and the TVs say they are receiving 24p. The GH2 camera does not put out 24p. Something about the UltraRecorder makes the GH3's HDMI circuit switch to 1080i 29.97 even though the camera is recording in 24p at the same time. The resulting ProRes recording is not usable due to strange motion artifacts. This is better than earlier in December when the UltraRecorder didn't see the GH3 at all but a software update changed that. I will test some 30p recordings in the near future.

[Alan Halfhill]

I have shot 30p files and here is how it went on my 2011 MacBook Pro Thunderbolt with 16 gigs of RAM editing FCPX.

AVCHD / 24mbps: Smooth playback
MOV h.264 / 50 mbps: Jerky
MOV h.264/ 72 mbps all-intra: Smooth playback
ProRes 1080 30p / 166mbps transcoded MOV h.264 / 50 mbps: Smooth playback

The conclusion here is that my system just can't handle standard GOP h.264 at 50mbps very well, however all intra frame h.264 works fine directly in my edit system.

[Dan Carter]

Thanks for the updates William & Alan. Looks like we're all experiencing the same issue with MOV h.264 50Mbps, and that it may not be a RAM issue.