[jogiba]

That is a faster data pipeline than the EOS 500D / Rebel T1i in 1920x1080 @20fps mode.

[falconeye]

That is a faster data pipeline than the EOS 500D / Rebel T1i in 1920x1080 @20fps mode.

Yeah. But note the ambiguity if 30fps applies to all three modes or just 720p?

720p @ 30Hz is a 67% increase in data rate over 1536/768x1024 @ 21Hz on the K20D. I can believe this.

[Saaby]

Let's talk about interframe vs intraframe compression for just a second here.

I just spent a week shooting with a Panasonic HVX-200. It uses DVCPro 50 and DVCPro HD codecs. 1 gig per minute! It's using an intraframe compression codec.

I've also shot some stuff with AVCHD cameras. The footage they shoot takes up at most about half the space of footage shoot in DVCPro. AVCHD is an interframe compression codec.

So what does that mean? Well intraframe means that there is compression, but each frame is individually compressed.

Interframe compression codecs are totally different beasts. The camera records frame 1, and then for frame 2 it just records everything that changed between frame 1 and frame 2. If you make big changes, then that bit of video is recorded at higher bandwidth -- but if you're shooting a mostly static scene, than the video is pretty low bandwidth.

YouTube, Vimeo, and Digital Cable all use forms of interframe compression. This is why sometimes -- let's take YouTube for example -- when I click the "HD" button, the video will switch into "HD" quality, but at first I just see a big green square, and then *the image kind of pixelates in -- it doesn't have all the information to start with, so that's what you get.

AVCHD is, as has been noted here, a lot harder to work with in editing and such. It's usually not so bad to play, but when you start jumping around...you jump to frame 13 and the computer has to look at frames 8-12 before it can build frame 13.

There is a workaround, several I am sure, but the one I am referring to is the method Apple (Among others, I'm sure) uses in iMovie and Final Cut Pro, and that is to convert the AVCHD footage into a different format if you want to edit it.

That's a lot of technical babble and speak, but I just wanted to give that background to state that, based on my understanding of how these things work, I'd be VERY surprised to see the K-7 recording uncompressed images. That just takes a lot of bandwidth and storage space.

If I had to guess, I'd say they're going to do MJPEG, or maybe AVCHD. MJPEG is my first guess though.

[xxxxx]

Seems AVCHD is becoming mature. As a new camera, I'd bet on that.

[jay]

If I had to guess, I'd say they're going to do MJPEG, or maybe AVCHD. MJPEG is my first guess though.

MJPEG is a terrible, inefficient, old codec.

The PCI video capture cards from the 90s used that codec to compress video. As an atheist, I don't do a lot of praying -- but I PRAY TO GOD they don't use MJPEG on the K-7.

I don't understand your apparent beef with interframe compression -- it maintains much higher image quality image for the bandwidth it occupies. And any modern computer is more than capable of editing the video smoothly. Besides, you could always uncompress it in your edit suite if you're concerned about rendering time while you're working on the timeline.

I think people are worried about this compression scheme too much. MPEG4 would be the ideal candidate for video on this device. It's very efficient and makes use of cutting-edge algorithms so moderate-bitrate (in the same area that class-4 SDHC cards can record in) MPEG4 video would be killer. It's a widely-used standard that most professional NLE's can work with easily.

Regarding the form factor "issue" -- this is a non-issue. Any professional is going to have this thing mounted to a fluid-filled head on a tripod/dolly/jib/crane at all times. Honestly -- if the image quality is there, the form factor doesn't matter at all. You could easily build it up with a rail system, matte box, giant EVF, optical viewfinder extender, follow-focus control, etc.

Regarding the comment about consumers being disapointed with 24p video -- the main film look is super shallow DOF. When I'm shooting on a Sony 2/3" professional HD camera, with long, fast (f/1.2ish) glass, in a well-lit scene, the footage looks straight out of a movie. Even though it's 30p.

But, 24p does help. As well as the gamma curve. Haha, that used to be the big deal -- that's how you'd get the "film look" -- with gamma correction. Then everyone realized, "no, that's not right. we have to spend $500,000 on lenses and lighting gear and a 35mm film camera to get that film look"

I think a large-sensor D-SLR that's compact and can output uncompressed video from the HDMI port, plus record in a good-quality lossy-compressed standard would be the nail in the coffin for 1/3" prosumer video cameras.

The big giants of the video field have been really lazy and not very innovative -- and now it's time for them to pay.

[nosnoop]

MJPEG is a terrible, inefficient, old codec.

Inefficient, yes; cos it's intraframe only. But terrible? The bad experience you had was entirely due to the low quality JPG compression used. MJPEG can be in very high quality and rival the quality any other codec; obviously the downside is the high bitrate and storage space required. But current Class 6 SDHC is more than capable of coping with high quality MJPEG bitrate. It's just like having only seen 1 star JPG output and condemning that JPG compression is terrible for still image.

And any modern computer is more than capable of editing the video smoothly.

Have you tried using a duo core computer to edit AVCHD natively?

It's a widely-used standard that most professional NLE's can work with easily.

Most professional NLE? Isn't the consumer market that Pentax has to worry first? Don't misunderstand that I am against MPEG4. I have AVCHD HD camcorder myself, and I have first hand experience learning the pain that comes with it for editing. As a result, I upgraded to an i7 PC which finally makes life easy again. But not everyone is prepared to do that.

Any professional is going to have this thing mounted to a fluid-filled head on a tripod/dolly/jib/crane at all times.

If this camera can only be used effectively by professionals, then Pentax would be in big trouble. First and foremost is the consumer market. If the pro find the use for it, then it is a bonus.

[Saaby]

I don't understand your apparent beef with interframe compression -- it maintains much higher image quality image for the bandwidth it occupies. And any modern computer is more than capable of editing the video smoothly. Besides, you could always uncompress it in your edit suite if you're concerned about rendering time while you're working on the timeline.

etc.

Since you quoted me, I'm going to guess that was directed at me. I must have been misunderstood, I have no issues with interframe compression at all! Nevertheless, it does require more computing power to work with. You can get around that by converting to an intermediate codec for editing, and that's fine -- I think that anybody who whines about having to do that (Digitally, often faster than realtime) obviously hasn't spent much time capturing footage from tape

The only reason my wager is on MJPEG is because this would really be Pentax's first major entry into the world of video. I am guessing (hoping!) they are focusing more of their effort on making a stellar stills camera. So for a photo-oriented camera from a photo-oriented company, on their first entry into the market, MJPEG just seems more realistic.

As jay noted, MJPEG can be quite good. The codec is definitely a player in creating quality video, but it's just a supporting player, and many good things can make up for a slightly less good codec.

It's funny because this is exactly the debacle that's going on with the GH1 right now...if it's being let down by anything, it's that the AVCHD is locked at 17 mbps (Mbps? My capitalization is probably wrong on that, and with mbps/Mbps it matters. So sorry. ) when it would really benefit from 24 mbps.


But hey
In all this talking about Codecs, I forgot to mention something that I thought was interesting from the press info:

The K-7 is also equipped with an HDMI terminal...

Jay said it already, so I'll just repeat his words:

I think a large-sensor D-SLR that's compact and can output uncompressed video from the HDMI port...would be the nail in the coffin for 1/3" prosumer video cameras.

Whoever is first to market with a sub $3000 camera that will do uncompressed HDMI out...wins.

[Saaby]

I forgot to attach this to my earlier posting.

[PNTXFTW12]

I forgot to attach this to my earlier posting.

Ahh, so that explains why when im watching an HD .mkv mastroka video, and i slide the navigating slider to a further point in the video, the video lags for a bit and shows me a bit of what i was previously viewing, blurring in with the current point of the video, before there's a serious change in the footage.

[raz]

If this camera can only be used effectively by professionals, then Pentax would be in big trouble. First and foremost is the consumer market. If the pro find the use for it, then it is a bonus.

Any DSLR camera shooting video is not easy to work with. Shallow DOF, manual focusing - is not for the average camcorder consumer who prefer to have everything in focus.

Btw, any information if the video mode is stabilized ? On K20D, SR works when shooting "video" or using live view ?

[nosnoop]

Any DSLR camera shooting video is not easy to work with. Shallow DOF, manual focusing - is not for the average camcorder consumer who prefer to have everything in focus.

Well, I was hoping that contrast AF would be possible during movie. GH1 does.

[karl79]

--- EXCEPT FOR ONE POINT ---

The K-7 may not do any video compression at all, just JPG. If there is no time limit, this may be a VERY interesting feature for DSLR videographers which then have full control over compression quality.

Absolutely!

The way they mention the "high quality STILL IMAGE recording at 720p" I assume that it has to record and store the frames as single images NOT implemented in a video codec, so it shouldn't be Mjpeg but single jpgs that can be imported as image sequence into your NLE...and that would be interesting indeed!

I'm just not sure how this can be done without a timelimit? I'm not familiar with the K20D, but I guess you can only record in burst mode for a very short time, and this would be a kind of burst mode right?

[raz]

Well, I was hoping that contrast AF would be possible during movie. GH1 does.

I didn't know GH1 does that, would be great if K7 would do this too

[claude21]

it would be better actually if the K-7 could record movies in a container (avi, mov...) because recording stills in sequence could lead into huge files directory... which is not good for flash media and become slow on many occasions.

I would prefer the H264 codec for video because it's very efficient. Serious editing still need converting video files to proprietary "lossless" codecs. I use canopus HQ codec, it's very good. Mac user's usually use ProRes codec.
Sequence 2 converted using MJPEG codec show a file size of 348 Mo instead of 97 Mo with the H264 format, thus 3.58x increase in size for an lower quality result.

I've done a little test converting some HD footage from my video cam. Converting 2 sequences of 1920x1080 60i to 1280x720 30p with MJPEG codec at different quality (75,85,95)


here are the results :

[falconeye]

I've done a little test converting some HD footage from my video cam. Converting 2 sequences of 1920x1080 60i to 1280x720 30p with MJPEG codec at different quality (75,85,95)
here are the results :

This is an interesting statistics. Thanks a lot.

Let me quote the figures:
1280x720p footage, size per frame:

Q=95: 115 kB
Q=85: 55 kB
Q=75: 40 kB

If you look up at my little experiment in post #172 https://www.pentaxforums.com/forums/592891-post172.html you'll see that even MJPEG Quality 95 only corresponds to JPG compression quality 2 or 3 of 12 (One star * quality at best).

So, while MJPEG as such is fine, I fear that compression parameters are rather aggressive by default.


But it's all speculation. Let's await next week