All I-Frame (72 Mbps) editing with VideoStudio

[pvreditor]

The new Panasonic Lumix DMC-GH3 is a higher-end mirrorless digital camera that takes good photos, and is also touted as having been designed for high-quality video. It has a variety of recording modes for video, including AVCHD, MP4 and MOV. Within MOV, there is an "All I-Frame" recording mode that can save video at a rate of 72 Mbps -- MUCH higher than AVCHD and MP4.

I just got a GH3 a couple days ago, and one of the first things I wanted to to see was if I could edit 72 Mbps all I-Frame video files on VideoStudio x4, which is the version of VS that I have. And there's good news and bad news:

The good news is that the GH3's 72 Mbps files load, play and edit in VideoStudio x4. I did a couple of crossfades, a wipe effect, titles, video in an overlay track and titles, and it all worked normally. The editing experience on my 2nd-generation Intel i7 computer is fairly smooth, even playing through the effects without a problem.

The bad news is that the finished file (which I rendered at AVCHD 1080i) is rather jerky during pans. Here is the finished test video that I uploaded to YouTube:

http://www.youtube.com/watch?v=mc9VL2txOMU

Looking at the source video clips, there's no jerkiness in the video as I pan -- that happened when I rendered the video. I will try this test again with other output formats, such as WMV, 1080p and MP4, just to see if that makes a difference.

Anyway, I thought everyone here would like to know about this.

Bob Kovacs
http://www.bobkovacs.com

[Ken Berry]

Is the original video fully progressive or interlaced? I don't really know anything about the all i-frame business, but suspect that would imply progressive video... If it is indeed progressive and you produced, as you say, 1080i, then in effect VS has to throw away one frame in every two -- hence jerkiness.

What bitrate did you use for output -- one from a default VS template or did you manage to make a custom template to match the original properties?

[pvreditor]

Is the original video fully progressive or interlaced? I don't really know anything about the all i-frame business, but suspect that would imply progressive video... If it is indeed progressive and you produced, as you say, 1080i, then in effect VS has to throw away one frame in every two -- hence jerkiness.

What bitrate did you use for output -- one from a default VS template or did you manage to make a custom template to match the original properties?

All good questions. The menu in the camera says that it is 1080/30p. I used the default VS template, which I assume is 1080/60i at 17 Mbps. You know what they say about assuming, though.

If I were to make a custom template for rendering, what do you suggest for the settings?

Bob Kovacs
http://www.bobkovacs.com

[Ken Berry]

Well, at the most basic, I would certainly use 30p throughout -- and that's 30 full frames per second, and not 60 interlaced half-frames per second...

You could also try using the Add route in Make Movie Template Manager, and use one of your original clips from the Lumix as the target. Not sure if that will necessarily work, though...

[pvreditor]

Okay, I rendered again, this time using what I believe is 1080p. Still quite a bit of jerkiness on pans, although it might be a little better. I will work on some custom settings, but I have a couple of larger projects to get out of the way first.

Bob Kovacs
http://www.bobkovacs.com

[Ken Berry]

The only other thing I can think of is that you may have used 60p and not 30p... in which case VS would be inventing new frames by copying existing ones, and again this would produce jerkiness.

While this might sound as though I am trying to teach grandma to suck eggs, I also wonder if the sort of jerkiness you are seeing is more in the nature of the shimmer you get when panning done in high def is too fast. I am sure you will be aware that professional videographers tend to avoid panning in high def, or else they make the pan verrrry slow and only covering a relatively short distance. While not claiming at all to be anywhere near professional, I have found that a floating head tripod is absolutely essential when dealing with high def video, even if my camcorder has decent inbuilt stabilisation.

[pvreditor]

If I look at the source video, the pans are smooth... or at least without the jerkiness I see in the rendered video. I'll keep working on this, as it is something that it would be wonderful for VS to do.

In the meantime, the Panasonic GH3 makes very nice AVCHD video, and VideoStudio edits that with no problem.

Bob Kovacs
http://www.bobkovacs.com

[erdna]

Do you watch your source video from yr local harddisk? What player do you use for playback? Did you try to render as a high bitrate (up to 60Mbps) mpeg2 instead of avchd?

[pvreditor]

Do you watch your source video from yr local harddisk? What player do you use for playback? Did you try to render as a high bitrate (up to 60Mbps) mpeg2 instead of avchd?

Yes, I watched the source video from my hard disk, using Windows Media Player. So far, I have not yet tried to render in any other formats besides AVCHD (1080i and 1080p) at 17 Mbps. I have LOTS of work this week that has taken time away from me exploring this issue further, but I should be able to get back to it next week.

Bob Kovacs
http://www.bobkovacs.com

[pvreditor]

I had time this week to experiment more with this and I can't find a format will render the pans as smoothly as they look in the source clips. I tried MP4 at 20 Mbps (as high as it will go with x4) and WMV, and both show the same jerky pans as AVCHD. I looked at all the codecs to see if I could customize them for the highest possible bit rates, and nothing helped. With AVCHD, I could apparently push the rendered bit rate to 18 Mbps, but that did not smooth out the pans. I will keep poking at things and will report if there's a way to do this cleanly.

Bob Kovacs
http://www.bobkovacs.com

[erdna]

And high bitrate mpeg2 e.g.60Mbps?

[pvreditor]

And high bitrate mpeg2 e.g.60Mbps?

I looked and didn't see a way to create MPEG2 video with a resolution higher than 720 x 480. Does VideoStudio allow MPEG2 to be rendered at 1920 x 1080 and at high bitrates?

Bob Kovacs
http://www.bobkovacs.com

[erdna]

Yes. Share>create video file> custom>select m2t>options....uncheck AVCHD and select mpeg2 instead of h264

[Ken Berry]

Just by way of explanation, the Blu-Ray format comes in essentially three flavours: high def transport stream mpeg-2; high def mpeg-4 (AVCHD) and, less commonly, VC-1. HDV is also, of course, high def mpeg-2, though with pretty fixed properties.

[pvreditor]

Yes. Share>create video file> custom>select m2t>options....uncheck AVCHD and select mpeg2 instead of h264

Just by way of explanation, the Blu-Ray format comes in essentially three flavours: high def transport stream mpeg-2; high def mpeg-4 (AVCHD) and, less commonly, VC-1. HDV is also, of course, high def mpeg-2, though with pretty fixed properties.

Thank you both for clarifying that.

I selected MPEG2, set the bit rate to 60 Mbps and the result was not good... worse than rendering in AVCHD. During pans, edges were sawtoothed and the pan was even jerkier than with AVCHC. Not good. I'm open for any ideas.

Bob Kovacs
http://www.bobkovacs.com