Changing aspect ratio (reauthoring DVD)

[Turbo Sensonic]

A Swiss friend of mine gave me a music DVD which he had recorded from Swiss TV. He has authored the DVD by himself but the aspect ratio of the picture is incorrect. It seems that the broadcast has been 16:9 and he has authored the DVD as 4:3.

I've done couple of DVD authoring things before but this is something I don't know so I have to ask from you: is it possible to change the aspect ratio by demuxing the DVD and modifying the video file?

Here's a screenshot of the DVD:



Just to make sure what I mean, I put white frame around the picture. So its picture/video should fill in the whole screen and shouldn't have any black "stripes" above and below (like this DVD has).

I'd really appreciate if someone could answer to this question or even notify a link where I could find the answer. Thousand thanks in advance!

[MysticE]

Your post is kinda confusing. Your pic looks like what a 16:9 (approx) video would look like on a 4:3 TV.

[Pinstripes23]

You have to crop the black out then resize back to 720x576. Encode to 16:9, author and it should look like this on a WS TV:





personally I'd use avisynth to do this.

basic steps would be:

1) use dgindex to create .d2v file and extract audio
2) make a script for the .d2v file

LoadPlugin("\path\to\dgdecode.dll")
mpeg2source("\path\to\.d2v")
crop(16,74,-14,-70)
Lanczos4Resize(720,576)

3) Encode using an mpeg2 encoder that can import .avs files
4) Re-author using the new video

If your DVD has menus and other stuff you want to keep then it gets a bit more involved.

[Turbo Sensonic]

You have to crop the black out then resize back to 720x576. Encode to 16:9, author and it should look like this on a WS TV:

OK, how can I crop the black parts out?

[Pinstripes23]

I added to the post above^

[Turbo Sensonic]

I added to the post above^

Great! Thanks a lot!

[Turbo Sensonic]

If your DVD has menus and other stuff you want to keep then it gets a bit more involved.

Well, I can fix it with Vobblanker, can't I?

[wulf109]

If it was 16:9 and authored as 4:3 you might be able to correct it with IFOEDIT. Open the ifo file and change the video to 16:9 if it says 4:3

[Pinstripes23]

If your DVD has menus and other stuff you want to keep then it gets a bit more involved.

Well, I can fix it with Vobblanker, can't I?

Yea you probably have the right idea:

1) Demux with pgcdemux
2) Encode
3) Mux with Muxman
4) Replace with VobBlanker

[guns1inger]

I believe MysticE and Wulf are right. This doesn't need to be cropped and re-encoded, it just needs to be flagged correctly. You try IFOAR2WS. Wprst case, you will have to demux, reflag as 16:9 with reStream, then mux it back in. No re-encoding required.

[Turbo Sensonic]

I believe MysticE and Wulf are right. This doesn't need to be cropped and re-encoded, it just needs to be flagged correctly. You try IFOAR2WS. Wprst case, you will have to demux, reflag as 16:9 with reStream, then mux it back in. No re-encoding required.

OK, I'll try that first. Thanks!

[Pinstripes23]

I believe MysticE and Wulf are right. This doesn't need to be cropped and re-encoded, it just needs to be flagged correctly. You try IFOAR2WS. Wprst case, you will have to demux, reflag as 16:9 with reStream, then mux it back in. No re-encoding required.

I looked at the original screenshot from a 16:9 perspective and it looked too squashed vertically to me:




But let's see what Turbo Sensonic finds out

[manono]

I believe MysticE and Wulf are right.

I don't. I'm with Pinstripes23. It's widescreen or letterboxed 4:3. It was capped and encoded correctly. If he wants to make it 16:9, it'll require cropping and reencoding, as outlined by Pinstripes23.

Turbo Sensonic hasn't said that the figures looked stretched when he's viewing it. He's only complaining about the black bars above and below, typical of widescreen 4:3 material.

[Turbo Sensonic]

I believe MysticE and Wulf are right.

I don't. I'm with Pinstripes23. It's widescreen or letterboxed 4:3. It was capped and encoded correctly. If he wants to make it 16:9, it'll require cropping and reencoding, as outlined by Pinstripes23.

Turbo Sensonic hasn't said that the figures looked stretched when he's viewing it. He's only complaining about the black bars above and below, typical of widescreen 4:3 material.

Yes, the picture doesn't seem to be streched at all. The only problem is that there are black "bars" running above and below the picture when I'm playing that DVD. I'll try both suggestions that you gave, starting with cropping the videofile etc...

Let's see what comes up. I'll let you know.

[guns1inger]

It is a widescreen image - you will get black bars if it is correctly authored. Cropping won't get rid of them, as the player will just put them back.

[Turbo Sensonic]

Encode using an mpeg2 encoder that can import .avs files

Can you give me a suggestion of such encoder?

[manono]

Can you give me a suggestion of such encoder?

All of them. HCEnc is very good and free.

[Pinstripes23]

Encode using an mpeg2 encoder that can import .avs files

Can you give me a suggestion of such encoder?

https://www.videohelp.com/tools?listuser=&orderby=Rating&s=40#40

the best freeware is hcenc

[guns1inger]

However you will need some basic avisynth and DGindex knowledge to use it.

[Pinstripes23]

Cropping won't get rid of them, as the player will just put them back.

Only if it is viewed on a 4:3 TV and encoded and authored as 16:9.

[Turbo Sensonic]

OK, I cropped the video file and created D2V file. Now I have to encode it with MPEG encoder, right? So put there 720x576 as picture size and 16:9 as aspect ratio?

[manono]

Did you create an .avs follwing Pinstripes23's instructions earlier? Test it first in VDub(Mod), before opening it in the encoder. And which encoder are you using? Because a colorspace conversion should probably be added as the last line in the script. What it is depends on the encoder you use.

LoadPlugin("\path\to\dgdecode.dll") 
mpeg2source("\path\to\.d2v") 
crop(16,74,-14,-70) 
Lanczos4Resize(720,576)

[Turbo Sensonic]

Did you create an .avs follwing Pinstripes23's instructions earlier? Test it first in VDub(Mod), before opening it in the encoder. And which encoder are you using? Because a colorspace conversion should probably be added as the last line in the script. What it is depends on the encoder you use.

LoadPlugin("\path\to\dgdecode.dll") 
mpeg2source("\path\to\.d2v") 
crop(16,74,-14,-70) 
Lanczos4Resize(720,576)

No, I didn't. I don't know how to create an AVS file. I cropped the video file (m2v) and encoded it as 16:9. The picture got stretched horisontaly but the black bars appeared again above and below the picture. Could someone please tell me, how to create an AVS file?

BTW, I tested all aspect ratios for encoding: 4:3 -> doesn't work (black bars appear), 16:9 ->doesn't work (black bars appear), 1:1 seems to work (no black bars, although the program tells that 1:1 aspect ratio is not supported by DVD).

Software I used: the ones you suggested me: dgindex for cropping the video file, HCEnc for encoding.

[guns1inger]

The image is 16:9. You cannot make it fit on a 4:3 screen without black bars unless you crop off the left and/or right ends.

[Turbo Sensonic]

The image is 16:9. You cannot make it fit on a 4:3 screen without black bars unless you crop off the left and/or right ends.

Yep, the image/picture's right aspect ratio should be 16:9 but it has been authored incorrectly as 4:3. When I cropped it with dgindex, it showed me that the videofile's aspect ratio is 4:3.

What I did was cropping the .m2v video file with dgindex, saving .d2v file and encoding it with HCEnc as 16:9 (using that .d2v file as source). I didn't create any AVS file since I don't know how to create one

[manono]

Yep, the image/picture's right aspect ratio should be 16:9 but it has been authored incorrectly as 4:3. When I cropped it with dgindex, it showed me that the videofile's aspect ratio is 4:3.

No, it hasn't been authored incorrectly as 4:3. DGIndex is showing you the correct DAR. You said yourself it plays with the people not being stretched. It's perfectly possible and quite common to have widescreen video encoded as 4:3, and this is one such case.

As for the .avs, install AviSynth. Make a .txt file renamed with the extension .avs. Don't crop in DGIndex. Do it in the AviSynth script file. So, make maybe a Video.avs. Inside have that script made by Pinstripes23 and quoted by me, but with the paths adjusted for where you are storing your DGDecode.dll (comes with the DGMPGDec package), and the D2V you made using DGIndex. Open the Video.avs in VDub(Mod) and scroll around. If there are any error messages, post them here. You are most likely to have error messages relating to the paths, but if you can't figure them out and fix them, post them here, along with the complete script you're using. If all is OK with the script, then open it in HCEnc and encode for 16:9. Here's what a similar script might look like on my computer:

LoadPlugin("D:\AviSynth Stuff\Dlls\DGDecode.dll")
MPEG2Source("E:\Movie\Movie.d2v")
Crop(16,74,-14,-70) 
Lanczos4Resize(720,576)

[Turbo Sensonic]

OK, I'll try it and let you know about the results.

Edit: now my other computer is doing the encoding and I have to wait for an hour. It seemed to be OK but I'll wait until I'll see the results.

BTW, if a videofile or a DVD is encoded any other aspect ratio than 4:3 or 16:9, how to then put right numbers to the "crop" command line of .avs file? I mean, is there a "rule of the thumb" to write down the right numbers to the "crop" command line of .avs file?

[stars]

Hi...

If the video was taken from satellite the source is 4:3...

SRG newer transmitts in 16:9...

But if the clip was taken from there DVB-T I dont know but the picture looks like
a 16:9 letterbox image...

As they have said in earlier post

cut of the black bars (if the pic have aspect 1.78 eg 720x404) add a 20 pix black bar at the top
and botton. This is for the overscan that the tv has. so you wont lose any picture...
reszie to 720x576 encode and author the DVD with the 16:9 flag
Use Avisynth or edit and frameserve with VirtualdubMOD, HC encoder would be the best chooies... for encoding


stars....

[Turbo Sensonic]

Done and with success!

Thank you to everyone who gave their valuable hints to me!

BTW, I still have another DVD, which is authored incorrectly. I presume that it's neither 4:3 or 16:9 so in order to find out the right aspect ratio I should run Gspot, right? But how about those numbers which are in the crop command line of AVS file? How to determine the right values in order to get the aspect ratio fixed?

[Pinstripes23]

cut of the black bars (if the pic have aspect 1.78 eg 720x404) add a 20 pix black bar at the top
and botton. This is for the overscan that the tv has. so you wont lose any picture...

Adding bars at the top and bottom after cropping them out will distort the AR if he is going for 16:9. To compensate he would have to add black borders to the left and right.