16:9 to 4:3

[ultrabrutal]

I have a miniDV tape where I by mistake made a few scenes in 16:9 instead of 4:3... Now I wish to reencode the clips in 4:3 with black borders for use in my DVD (Pinnacle Studio 9). Studio 9 does not allow 16:9 material in a 4:3 DVD...

Do anyone have any recommendations for me?

[bb]

You could try to open the DV video in VirtualDub, add the black borders, resize to 4:3, and reencode using a DV codec. With a little luck you'll be able to open the (pseudo) type-2 file in Studio 9.

bb

[ultrabrutal]

Thanks for the reply! :)

I tried opening the avi in virtualdub (latest stable), but I get an error saying I need VFW codec as my DirectShow codec won't cut it...

Is there another way, maybe use something like CCE to add the borders and encode as MPEG2? I should have no problems using other formats than DV (AVI) in Studio9.

[ultrabrutal]

Nevermind, I tried TMPGEnc and figured out how to change the target size to 720x432 which gave me my black borders. Perfect :)

[bb]

Oh, of course...
You didn't say that you were using TMPGEnc. My recommendation was targeted towards keeping it DV. The new ("experimental") VirtualDub 1.6.0 should be able to open your DV files, but well... you solved your problem already.

bb

[SeeMoreDigital]

Hi ultrabrutal,

As a matter of interest. Is your DV camcoder able to capture in "real" 16:9 or is it 4:3 cropped to look like 16:9?


Cheers

[ultrabrutal]

bb, I didn't use tmpegenc... I just tried it out :) since I'm doing dvd's out of my dv material it does not really matter what format the fixed caps has, as long as I can use them in Studio9.

SeeMoreDigital, well it's a 4 year old DV cam, and as far as I know only a few home cams can do real 16:9. My brother-in-law has a new Sony which set him back like $1500. It does real 16:9.
Mine however fakes it by cropping. So I actually stopped recording in this fake mode, since so much picture quality is lost.
My next cam will be true 16:9, but I'm holding back until they contain harddrives and record in MPEG2 instead of DV...

:)

[SeeMoreDigital]

Originally posted by ultrabrutal
...My next cam will be true 16:9, but I'm holding back until they contain harddrives and record in MPEG2 instead of DV... I know what you mean.

A few days ago a friend of mine borrowed (off an movie set) an JVC GR-PD1 semi-pro camcorder.

What an amazing bit of kit it is too. It captures directly to miniDV tape in high bitrate progressive Mpeg2... awesome!


Cheers

[ulfschack]

Allthough I can't for the world think of a good reason to wanna encode directly to mpeg2 ... unless ofcourse you've got a really great mpeg editing software like m2-edit, which still has to cope with the rather tight restraints of the mpeg-2 format, like gops, b-frames and such.

The true wide screen is a long awaited feature. Even the canon XM2, which boasts real 16:9, fakes it in a way that makes it unwanted for me at least. I hope that Sony delivers the real deal!

cheers

[theReal]

I can't for the world think of a good reason to wanna encode directly to mpeg2 Me neither! MPEG2 is bad for editing.
The only MPEG-based camcorder I'd really love to have is Sony's PDW 530 XDCAM (http://bssc.sel.sony.com/Professional/markets/optical/cameras.html) - it records to MPEG IMX, a modified MPEG format with variable Data rates up to 50MBit. It uses blue-ray optical discs with 23.3GB.
List price 34,000 USD without lens, dream on... :rolleyes: ;)

[SeeMoreDigital]

Hmmm!

I must admit I did not think to keep any of the high bitrate Mpeg2 miniDV taped recordings...

I guess it would be interesting to know if such high bitrate Mpeg2 streams actually contain any b-frames ;)


Cheers

[theReal]

I must admit I did not think to keep any of the high bitrate Mpeg2 miniDV taped recordings...Do you mean DV is based on MPEG2?

The true wide screen is a long awaited feature. Even the canon XM2, which boasts real 16:9, fakes it in a way that makes it unwanted for me at least. I hope that Sony delivers the real deal!Do you mean the real 16:9 that i.e. the Canon XL1E records is also fake 16:9? I don't know the XM2 - does it also record anamorphic 16:9 like the XL1E and is this not the real thing?

[SeeMoreDigital]

Originally posted by theReal
Do you mean DV is based on MPEG2?In the case of the JVC GR-PD1, yes. It does encode high-bitrate Mpeg2 staight onto miniDV tape!

Originally posted by theReal
Do you mean the real 16:9 that i.e. the Canon XL1E records is also fake 16:9? I don't know the XM2 - does it also record anamorphic 16:9 like the XL1E and is this not the real thing? A few of the newer Sony camcorders can encode anamorphic 16:9 images using 720x480/576 pixels. So of the early models hard coded black mates into the frame, to simulate 16:9...


Cheers

[bb]

Originally posted by SeeMoreDigital
In the case of the JVC GR-PD1, yes. It does encode high-bitrate Mpeg2 staight onto miniDV tape!
Talking about "DV" we have both, the software (DV codec) and the hardware (tape, camcorder, etc.) in mind. Thus I wouldn't say "DV is based on MPEG-2".

bb

[theReal]

I was talking about the codec (software). It's not based on mpeg2, right? Now if this camcorder, JVC GR-PD1, records MPEG2 onto MiniDV tape then I'd say it's not a DV camcorder, it's an MPEG2 camcorder that records to MiniDV tapes.

[SeeMoreDigital]

If you have a look at this review (http://www.simplydv.co.uk/Reviews/jvc_grpd1.html) you will see the JVC GR-PD1 can in fact capture to "DV.avi" and Mpeg2.

That said, I would have assumed because "DV" stands for "digital video", in theory, all the relevant formats would be up for discussion here and not just DV.avi's "domestic format".

That's a bit like saying DVD is for Mpeg2 only ;)


Cheers

[bb]

Of course we can talk about MPEG-2 camcorders here, too, although this forum is called "DV".

DV and MPEG-2 codecs are both based on the DCT (discrete cosine transform), so they share some common technology. The main difference is that MPEG-2 is designed to exploit the redundancy between frames by calculating motion vectors and introducing P- and B-frames. But there's I-frame only MPEG-2 as well, which is even more similar to DV (and MJPEG, by the way).

DV is typically less compressed (only 5:1) than MPEG-2, which leads to the conclusion that DV has higher quality. In conjunction with camcorders MPEG-2 is used to save space, for direct DVD recording, or to store high-definition video.

bb

[SeeMoreDigital]

Thanks bb,

I wish now, that I had had more time to spend with this camcorder and that I had kept some of the recordings.

You mention that Mpeg2 is (typically) designed to introduce P-frames and B-frames. But if the bitrate is high enough, I'm wondering whether B-frames are necessary at all.

I suppose this next question might be better placed elsewhere on the forum, but do you know if there is a theoretical "top out" limit for Mpeg2, per a given pixel frame size?


Cheers

[bb]

Originally posted by SeeMoreDigital
But if the bitrate is high enough, I'm wondering whether B-frames are necessary at all.
They are not. You can encode MPEG-2 using I- and P-frames only, or I-frames only. This does not conform to the DVD standard.

On the other hand you should keep in mind that the strength of MPEG-2 is the reduction of temporal redundancy by using P- and B-frames. If you want to achieve maximum quality, DV or MJPEG are better choices, and because of their keyframe-only nature these two formats are predestined for editing purposes.

Originally posted by SeeMoreDigital
I suppose this next question might be better placed elsewhere on the forum, but do you know if there is a theoretical "top out" limit for Mpeg2, per a given pixel frame size?
We have drifted away from ultrabrutal's original question, but well...

There must be a "top out" limit for MPEG-2, at least as soon as you reach the "MJPEG lossless" area. But I don't know how to calculate this limit. The same is true for other DCT based codecs, e.g. DivX or XviD from the MPEG-4 department.

bb

[SeeMoreDigital]

Thanks again bb :)


Cheers