how to change video aspect ratio in m2v file

[krishnakumar684]

Dear friends


i would like change video aspect ratio 16:9 to 2.39:1 in m2v video only file , how to do this ? anyone know pls letme know

[roma_turok]

The m2v file its for DVD VIDEO?

[jagabo]

i would like change video aspect ratio 16:9 to 2.39:1 in m2v video only file , how to do this ? anyone know pls letme know

MPEG 2 only directly supports a few aspect ratios: 4:3, 16:9, 2.21:1 display aspect ratio, and 1:1 pixel aspect ratio. The closest you can come is 2.21:1. But if you're making a DVD you can't use that -- DVD only supports 4:3 and 16:9.

To convert your 16:9 DAR M2V to 2.39:1 DAR you would have to add (or modify) a "sequence display extension". Set the DAR subframe to ~540x480 NTSC, or 540x576 PAL. Many players pay no attention to the sequence display extension and will continue to display the video as 16:9. And I'm pretty sure this will not legal for DVD players.

I think you can use ReStream to add or modify a sequence display extension.

[krishnakumar684]

m2v video only file for dcp making purpose the source file of (opendcp software) digital cinema package , CinemaScope aspect ratio is 2.39:1 anamorphic , and i want to make mpeg2 dcp not jpeg2000 format

source file need for me m2v video file only , aspect ratio 2.39:1, 24fps, pixel 1920 * 806 how to make the file anyone knows pls letme know

[roma_turok]

Like jagabo said try ReStream program

[racer-x]

Restream has worked for me in the past, but I'm pretty sure it will only let you select 4:3 or 16:9 AR. It's been quite a few years since I've used it however..............

[roma_turok]

If Restream don't work for you, try MPGPatcher

[krishnakumar684]

there is no 2.39:1 aspect ratio in Restream , 2.21 is the maximum aspect ratio in Restream , how to make 2.39:1 m2v video file , 24fps, 1920* 806 , it s for digital cinema purpose i will encoding in opendcp software

[krishnakumar684]

same problem in MPGpatcher, its dosn't export 2.39:1 aspect ratio, m2v video file

[El Heggunte]

You will have to (re-)encode to 1920x808, and set the aspect ratio to 1:1 (square pixels).

AFAIK there is no MPEG-2 encoder that supports non-mod8 frame dimensions.

[aedipuss]

you have to re-encode your video 1:1 if you want 1920x806. then by definition it is close to 2.39:1 (it's 2.38:1)

[manono]

Yeah, I don't get it. If the output is to be a 2.39:1 ratio, you don't need to do anything at all to the M2V (except to resize it and reencode to whatever output format). Is the M2V 720x576 at the moment? If so, a more serious question is how you're going to upsize it.

i would like change video aspect ratio 16:9 to 2.39:1 in m2v video only file , how to do this ? anyone know pls letme know

It can't be done.

[smrpix]

Your image size must be: Scope (2048×858 or 4096×1716), ~2.39:1 aspect ratio
mpeg2 may need to be wrapped in an mxf container

http://en.wikipedia.org/wiki/Digital_Cinema_Package
http://dcimovies.com/specification/DCI_DCSS_v12_with_errata_2012-1010.pdf

Highly recommend you do not improvise on the specs.

[jagabo]

there is no 2.39:1 aspect ratio in Restream , 2.21 is the maximum aspect ratio in Restream ,

I already explained that. You set the DAR to 16:9 then use a sequence display extension to specify what sub-portion of the frame holds that 16:9 DAR. That makes the entire frame wider. For example, with 720x480 frame size you would set the DAR to 16:9 then add a sequence display extension that specifies the 16:9 picture is in a 540x480 portion of the frame. That makes the full frame wider than 16:9:

1.778 * 720 / 540 = 2.37:1

But many players will not respect the sequence display extension, especially if it makes the full frame wider than 16:9.

how to make 2.39:1 m2v video file , 24fps, 1920* 806 , it s for digital cinema purpose i will encoding in opendcp software

Your frame size is nearly 2:39:1 to start (1920 / 806 = 2.38:1). Set the pixel aspect ratio to 1:1, ie, square. Some encoders won't like the 806 frame height. You may need to use 800 or 808 instead.

[manono]

I already explained that. You set the DAR to 16:9 then use a sequence display extension to specify what sub-portion of the frame holds that 16:9 DAR. That makes the entire frame wider.

Yeah, but if he's starting with a 720x576 16:9 M2V (?), stretching it out won't do any good because it already plays in the correct aspect ratio. Maybe there are no black bars and it's 16:9 720x304 , but that's such important information I think he'd have mentioned that to begin with.

I also think this is all academic if the final resolution is to be something like 1920x806. There's just too much missing information to say anything definitive. If it's already 1920x806 it's a pretty rookie question for someone doing this for a company and using very advanced software.

[jagabo]

but if he's starting with a 720x576 16:9 M2V (?), stretching it out won't do any good because it already plays in the correct aspect ratio.

Not if it's supposed to play 2.39:1.

I also think this is all academic if the final resolution is to be something like 1920x806.

Yes, that's what he eventually said. So he just encodes square pixel.

[poisondeathray]

MPEG2 DCP isn't even DCI compliant , so it would probably be a waste of time anyway

[manono]

but if he's starting with a 720x576 16:9 M2V (?), stretching it out won't do any good because it already plays in the correct aspect ratio.

Not if it's supposed to play 2.39:1.

I was thinking, and should have said, that it had letterboxing so that the active video already plays in the correct aspect ratio.

Again, though, what's someone doing a professional job using professional and very expensive software even doing here asking a question such as this?

[jagabo]

but if he's starting with a 720x576 16:9 M2V (?), stretching it out won't do any good because it already plays in the correct aspect ratio.

Not if it's supposed to play 2.39:1.

I was thinking, and should have said, that it had letterboxing so that the active video already plays in the correct aspect ratio.

But then, presumably, he wouldn't be here asking how to make has 16:9 DAR M2V into a 2.39:1 DAR M2V.

I just tried the technique and only one player I have played it correctly: Windows Media Player! VLC, MPCHC, MPC, KMPlayer, PotPlayer, and SMPlayer all played with the wrong aspect ratio (16:9) or crashed!

Again, though, what's someone doing a professional job using professional and very expensive software even doing here asking a question such as this?

Dunno.

[krishnakumar684]

hi friends

in india 60% cinema theater using mpeg 2 dcp server , so iam making my ad film in mpeg 2 dcp format first time, the problem is my dcp encoding software (opendcp) dosn't give proper output if iam using 1.1 suqre pixel 2.39:1 aspect ratio, the open dcp software support only m2v video file, non square pixel 2.39:1 aspect ratio , so how to make source file for my opendcp encoding software , i want need mpeg 2dcp anamorphic 2.39:1 ratio, non suqare pixel 24fps, and how to make 16:9 DAR M2V into a 2.39:1 DAR M2V ?
any friend knows pls letme know

thanks & regards
krishnakumar

[jagabo]

You've already been told what to do. What is the frame size of your source? What frame size do you want the new file to be? Upload a sample of the video you're trying to make 2.39:1 DAR.

[smrpix]

It looks like dcinemaforum.com has a lot of practical information

[jagabo]

The aspect ratio flag in an MPEG 2 video is a 4 bit integer. Of the 16 possible values, only 4 have been defined. From the MPEG 2 spec:



So the only way to get a 2.39:1 DAR image is to use 2.39:1 frame dimensions and square pixel encoding, or to use one of the other DAR flags (2.21:1, 16:9 or 4:3) and add a sequence display extension to indirectly specify the DAR of the full frame.

For example, using a 720x480 frame and 16:9 DAR flag, you can set the sequence display extension to 540 (x480). That will give full 720 pixel wide frame a DAR of ~2.37:1.

Or set the sequence display extension to 536 to get a DAR of ~2.39:1. But I don't know if 536 (neither mod 8 nor mod 16) is legal.

And again, many players ignore the sequence display extension. So this is not a reliable method.

Of course, there's one other method: Add borders to the top/bottom of your 2.39 video (~1920x803) to fill out a 16:9 frame (1920x1080) and encode square pixel. That's what's done on Blu-ray discs. But that will require re-encoding.