Images of 30P, 24p, and 60i

[Steve Mullen]

Originally Posted by Douglas Spotted Eagle

I haven't seen a specific question, Steve, so I don't know how to answer your comment that I've "refused" to answer anything.

Here are the requests made to YOU while you had time to argue about OT "DVCPRO HD support in Vegas -- so you were obviously not all that busy.

Stephen van Vuuren
... though I would like to see details as exactly how workflow works with it.

Steve Mullen
Could you outline the capture, edit, and the addition of pulldown during export.

Specifically, are you dropping frames during capture or skipping frames during editing. If the former, is the MPEG-2 being decoded? If so, is it re-encoded to MPEG-2 or recompressed to an intermediate codec?

Stephen van Vuuren
... the real issue I'm interested in is how good the Vegas V1 support is. I would like to hear some detailed DR60 workflow:

(1) How are the files saved?
(2) What are the stream details?
(3) What shooting modes are supported?
(4) File naming, folders?
(5) Transfer speeds?


Stephen van Vuuren
But despite all the fun in Sony vs. Panny, I'm still interested in Spot's report on DR60 workflow...

Steve Mullen
ONCE AGAIN we are OT.

It would be very helpful if you would provide a detailed explanation of the V1's SCNA mode and the Vegas support of the V1. I have to wonder why, given the topic of this thread you have yet to respond to this very simple request. One that has also been made at the Vegas site.

It would be great if we got this information before the V1's arrive and folks puzzle through the V1 errata sheet on SCNA!

Tony Tremble
Should we expect 24P ,25P ,30P to be as good as 50i, 60i with updates to NLEs?

From what you and Thomas are discussing it appears that NLEs treat Progressive HDV differently to Interlaced. As the Progressive images from the Sony are Interlaced this may/is causing the loss in quality over 50i, 60i. So can the quality be improved with updates to NLEs or is this a fundamental limitation of Progressive segmented frames in the HDV context?

[Douglas Spotted Eagle]

Originally Posted by Steve Mullen

It would be very helpful if you would provide a detailed explanation of the V1's SCNA mode and the Vegas support of the V1. I have to wonder why, given the topic of this thread you have yet to respond to this very simple request. One that has also been made at the Vegas site.

Once again for the third time.....

There is NO "SCNA" mode in the V1U. It's a typo. Plain. Simple. Easy.

SCNA="scan" with the letters N and A transposed.
As for the rest...I've answered all those questions at least once.

[Steve Mullen]

[QUOTE=Douglas Spotted Eagle]

So here goes:
1. The "SCNA" mode mentioned in the addendum that has had everyone speculating about what it means is......

Typo for "SCAN" mode.

2. There is no 24PA mode on the V1, please don't put words in my mouth, especially when I've taken *great* pains to explain why there is no PA mode with a GOP structure.

A) I never said YOU claimed there was. It came from this post: "the production HVR-V1U has an additional progressive scan mode not listed in the core manual ... . In addition to selectable 30p and 24p modes, there is an additional "24A" mode (also referred to as "24pSCNA" in long form).

B) Sorry, I did miss the fact it seems to be 24A or 24pSCAN. I'm the one who mixed these into 24PA. Big deal -- this is something you could have clarified days ago when the 24pSCNA post appeared.


There are two modes in the V1.
~one mode freezes the end frame/stop so that every segment begins with a perfect 3:2 cadence when the camcorder is started.
~one mode does not.

Various NLE's may or may not be able to manage the second mode; all NLE's manage the first mode correctly, or should.
Vegas intelligently supports both modes through reading of subcode.

That's the answer to the Vegas question on the V1.

From all this I gather that:

A) the "non 24A" mode was designed in a way that it doesn't always complete a 15-frame GOP. Because if it always did -- then the next GOP would start with an I-frame of a new 2-3 pulldown cycle.

B) And, rather than enhance the old mode -- a new mode called 24A was added.

But here's the big question -- if "Vegas intelligently supports both modes through reading of subcode" what's the reason for the new 24A mode? Seems to me if the old mode can be handled, there's no stated clear reason for the new mode.

There's also Tony and Tom's questions: given the issues of field recorded progressive -- should an NLE use different filtering for I verses P video? And, if so -- does Vegas do so?


Lastly, I gather that other than playback pauses -- 24A is the same in all other ways as non-24A. Correct?

[Thomas Smet]

mpeg-2 uses two different forms of 4:2:0 sampling. One for interlaced encoding and one for progressive encoding. Progressive encoding uses true 2x2 pixel blocks for chroma which are very clean and easy to predict and look normal. Interlaced encoding does this same 2x2 chroma pixel block but for each field. So what it is doing is encoding 60 images at 1440x540 and then interleves them together to encode as 1440x1080. The problem is that odd lines will have a different chroma then the even lines because they represent two different monents in time.

With 60i footage it isn't a big deal because on a HDTV the fields get bobbed out anyways and are viewed as the 1440x540 like they were before they were encoded. The correct chroma samples are shown with the correct field. On a digital HDTV interlaced footage will always be viewed as 60p. This is even true on SD interlaced material since the display is not an interlaced device. On a tube based TV this is not an issue either because it is designed to show one field at a time.

All of this only affects chroma and should not affect the luma or detail in any way so it is not why the images are softer.

Since SONY is the first and only HDV company to put progressive in an interlaced video stream this has not really shown up before except for in 24p DVD's being played from not so good DVD players. The decoder needs to understand to decode the chroma in the proper way or else it just assumes it is interlaced and it will split the chroma out as 1440x540x60p instead of just 1440x1080x30p. This is what causes the jagged color lines on very saturated objects. This is very true for red objects.

Every NLE that can edit HDV should already have a decoder able to do this sort of thing because many HDV cameras do their progressive as true progressive. The problem is how to tell the decoder that the stream is 1080p and not 1080i. I am hoping SONY had enough brains to add this into the update for Vegas which is why I tried bringing it up months ago on here. In Liquid we can tell the program to deal with the footage as non interlaced or interlaced but I'm not sure if this would adjust the decoder at all. I need to test this out but I'm not sure if Liquid will handle this the correct way yet or not. Since I have no 24p footage from the V1 it is hard to test.

Steve try the m2t file from those images in Liquid and right click on the clip and select properties and tell it to use non interlaced instead of top field first. You can then go to export to file and select image and make sure you set the resolution and format for the still image. Oh yeah and set a mark in and markout (I) (O) on the still image you want or it will export the whole clip as an image sequence.

From the look of those images FCP is assuming 24p,25p,30p,50i,60i are all 60i and is decoding them as interlaced video. This may ok for some people but those interested in visual effects may view this as a problem. I'm sure FCP will be updated to fix this but who knows how long that may be. You may have to use some other tool to decode the video first.

For Cineform users you may not notice an issue either assuming the decoder Cineform uses is smart enough to realize the difference. Cineform upconverts the chroma from 4:2:0 to 4:2:2 which really gets rid of any concern here. What may be a problem however is if Cineform can tell the difference between 30p and 60i since they both look like a 60i video. Cineform may also have to be updated which I'm sure they will do very very fast if they have not already.

If you never plan on doing and effects work or keying this may never even be an issue for you. This is in no way a defect of the camera but just the nature of mpeg-2. That is why Canon chose to go with a unorthodox form of HDV for the F modes. It was the only way to trully have progressive frames with 1080 mpeg-2. For normal viewing on a interlaced TV or digital HDTV you may never notice normal footage or normal edited footage having any issue becuase of how it is displayed. If you do plan on doing any extreme color correction work, keying, heavy effects work, scaling up, printing stills or transferring to film then you have a good chance of seeing this sort of thing.

My suggestion for effects artists is to make sure the decoder for your NLE will know how to deal with this, wait until it does, get a new NLE or use HDMI which is 4:2:2.

Again my only reason for bringing this up now as well as a few months ago is the hope that the NLE's realize there is a correct way and a not so correct way of decoding P inside of an I. If they do not then we should wait until they do. I still think true progressive is better but if done the correct way P in I can look very good. Although true progressing encoding is still a cleaner form of encoding per bitrate and I would have really liked to see SONY use the same method as Canon but I understand the reason for not wanting to and it makes sense from a certain point of view.

[Tony Tremble]

Steve, Thomas thank you both for flagging this issue. I have learnt more about HDV encoding than I ever thought I needed to!!! :)

With a bit of luck we'll get NLE updates in anticipation of fully function 25P cameras. :)

Cheers both

TT

[Chris Hurd]

Originally Posted by Steve Mullen

this is something you could have clarified days ago when the 24pSCNA post appeared.

Let's all go a little easier on each other, please. With so much international and/or domestic travel going on, plus real-world shooting, work, etc., it's a wonder that this forum is as active as it is. I certainly don't expect anyone to camp out on the forum and answer questions as soon as they're asked, let alone see every little thing that gets posted (and if we do have people that could manage such a thing around their real-life commitments, I would find that disturbing)!

[Steve Mullen]

Used the new version of Vegas with 24p from my prototype.

Used the new Preset.

Two questions -- why given video uses 48kHz -- does the Audio tab have audio preset to 44.1kHz? And, why is the TC still set to 29.97fps when the Preset is 23.934fps?

[Bob Grant]

I believe that in fact the DV spec specifies audio at 32KHz, 44.1KHz and 48KHz, this is the first time I've heard of 44.1 being used though, wierd.

[Steve Mullen]

Originally Posted by Bob Grant

I believe that in fact the DV spec specifies audio at 32KHz, 44.1KHz and 48KHz, this is the first time I've heard of 44.1 being used though, wierd.

Yes, I'm not sure why Vegas defines audio to be 44.1. But, it's got tons of CD audio stuff -- so maybe it relates to non-video audio.

[Steve Mullen]

Originally Posted by Thomas Smet

I need to test this out but I'm not sure if Liquid will handle this the correct way yet or not. Since I have no 24p footage from the V1 it is hard to test.

Used Liquid to capture the three clips and pulled snapshots as you advised. Here they are. There's an extra #3 because toward the end of the clip there was a brightness increase. (Didn't see this with Vegas.)

[Douglas Spotted Eagle]

Originally Posted by Bob Grant

I believe that in fact the DV spec specifies audio at 32KHz, 44.1KHz and 48KHz, this is the first time I've heard of 44.1 being used though, wierd.

Bob, while the DV spec allows for all three sample rates, as you know, Vegas doesn't care about sample rate on the timeline, and will always render video to 48K, and always convert resample all rates to 48K/16bit without any issue.
Open a new project in Vegas without instructing the file properties to be 48k, and it's audio properties will always be 44.1 by default. Changing it up to 48k or down to 32K or any other bitrate won't change anything until you go to render. The default DV and MPEG templates are all compliant at 48K, so regardless of what sample format, codec, resolution you put on the timeline, Vegas will always conform the content to either the project settings as a temporary measure, or to the output template format.
The previous post suggests that Vegas is importing the audio at 44.1. This is simply an error of not understanding how Vegas works. Looking at the content's audio properties will reveal the sample rate of the content, which is irrelevant to the project properties.
To verify this, right click the event's audio, and choose "properties." The subsequent dialog will provide specific information about that event/audio settings. Set the project properties to 12k, 2 bit, and you'll not hear a change in the audio. Capture audio from a camcorder that recorded 48k/16bit audio, and you'll still get 48k/16bit audio even if the project settings are 12k/2bit. Vegas does nothing to a file on capture, save it be for writing header information about the file.

[Steve Mullen]

Originally Posted by Douglas Spotted Eagle

The previous post suggests that Vegas is importing the audio at 44.1. This is simply an error of not understanding how Vegas works. Looking at the content's audio properties will reveal the sample rate of the content, which is irrelevant to the project properties.

Sorry, but you are making an incorrect assumption. Obviously the captured audio is 48kHz.

I was not sure why Vegas would have a Project default of 44.1 when today most everything VIDEO is 48kHz. After all Vegas is a video NLE. My question was why the default would be 44.1 when it "should" be 48?

Likewise, once one selects a 24p Project Template -- the TC "should" auto change to 24 because that's what it is.

[Steve Mullen]

It appears that in non-24A mode, shorter than 15-frame GOPs are possible as you can see below. You'll see mostly 15-frame GOPs, but there are several shorter GOPs.

But, since the subcodes are used by Vegas this shouldn't matter -- thus, it's still totally unclear why the 24A mode had to be added. Maybe Apple wanted it.

The program, G-spot, is shown on the left. In this case it has processed JVC 6-frame video. It's a wonderful PC tool!

[Chris Rentzel]

I'm not as technically inclined as a lot of you are, so let's break it down: how is the 24P mode of this camera? Are you more impressed, not as impressed, or in the middle somewhere?

[Douglas Spotted Eagle]

Sorry, but you are making an incorrect assumption. Obviously the captured audio is 48kHz..

Again...it's lack of understanding how Vegas functions.
Project properties are the property of the PROJECT. Just as you can import 29.97 to a 23.976 timeline/project, you can import 23.976 to a 29.97 timeline/project. Just as you can import a 32K/12bit file to a 44.1 project, and output it to a 48K file. Vegas doesn't care, it just conforms to whatever the user instructs it to conform to at render.
If you want a 23.976 project, then instruct Vegas to open a 23.976 project and switch your t/c view to fit.

I was not sure why Vegas would have a Project default of 44.1 when today most everything VIDEO is 48kHz. After all Vegas is a video NLE. My question was why the default would be 44.1 when it "should" be 48?

No, Vegas isn't just an NLE. It's a video app/NLE, and an audio app/DAW. Or both. It's whatever it needs to be for the user. Vegas began life as an audio editor.
Tal Bergman (producer of all of Rod Stewart's recent works) Rick Springfield, Dave Mustaine, Cy Curnin, Snake Sabo, and thousands of others don't ever touch the video side of the application. They use the audio side only. Vegas is the only system that has won both Emmy's and Grammy's with only internal application use (that I'm aware of).

Likewise, once one selects a 24p Project Template -- the TC "should" auto change to 24 because that's what it is.

Vegas is a chameleon, and expects the user to have some modicum of understanding as to how to set up a project. If all your projects are 23.976, then tell Vegas to only open 23.976 projects with 48k/16bit audio. I have Vegas set to open up with 24bit, 48k audio. Sometimes I'll set it to 24/96, and on rare occasion, 24/192. Sometimes I'm in an HD resolution project, and sometimes I'm in an SD resolution project. Sometimes I have no video at all. Sometimes, I have 23.976 on the timeline, but need to read 29.97DF because I'm interfacing with external audio gear. Sometimes I need 29.97NDF because I'm interfacing with other external audio gear or with external video decks.
Premiere, Avid, Edius, Liquid, FCP don't change their project settings when you bring in media of a different resolution, framerate, bitdepth, or sample rate, and how could any application do so with so many different media formats being brought to the timeline these days? Nothing does, and it's not sensible to expect it to do so.
Vegas tries to be as much all things to all people as it can be, while excelling at certain tasks, both audio and video. While it may not work the way *you* believe it should, it does work quite well.

Originally Posted by Chris Rentzel

I'm not as technically inclined as a lot of you are, so let's break it down: how is the 24P mode of this camera? Are you more impressed, not as impressed, or in the middle somewhere?

Chris, I believe most people are very impressed with the cam and it's 24p modes. Read the threads by others that have had access to the camcorder, those that have now received theirs from resellers, etc, and no one has had a complaint about the image quality of the US-distributed camcorders. There is an apparent issue that Sony has not commented upon, related to the Euro version, or the "E" issue and 25p. B&H has delivered loads of them at this point; their camcorder department manager seems to be exceptionally impressed with the camcorder, and sales bear that out. Users in this forum are very happy. There are some nice pictures for you to observe in this thread, or downloadable from this community as well for you to work with if you'd like.
If you're asking if it's significantly better than other camcorders that offer 1920 x 1080, 24p/30p output, the answer is subjective. Having shot both the Canon A1 and the Sony V1, there are things I like about both. Overall, I personally prefer the Sony V1, but I'll gladly shoot the Canon as well. The Sony V1 with the DR60 hard drive system makes for a fairly unbeatable system in it's price class.
I apologize for your confusion; this thread meanders like a drunken cat on a bumpy road.