Change aspect ratio before or after encode

[mrcoolekin]

I have a DVD that I ripped and it's 720x480 with an AR of 16:9. When I ripped the DVD it's showing an AR of 4:3. Should I encode it as 4:3 and then let mkvtoolnix fix the AR for me or encode it as 16:9? I'm not sure if changing the AR will affect the quality of the encode.

[aedipuss]

depends. if you're encoding to a square pixel format like mp4 it should be 1:1 usually 854x480, if it's to mpeg-2 you can adjust the a/r.

[manono]

I have a DVD that I ripped and it's 720x480 with an AR of 16:9. When I ripped the DVD it's showing an AR of 4:3. Should I encode it as 4:3 and then let mkvtoolnix fix the AR for me or encode it as 16:9? I'm not sure if changing the AR will affect the quality of the encode.

Where are you getting the DARs if one app says 16:9 and another says 4:3? In any event, you want the one from the IFO because sometimes the VOBs are different but most players play the DAR as given in the IFOs.

When I ripped the DVD it's showing an AR of 4:3.

Or are you looking at the VOBs as stored in the DVD which is 3:2, not 4:3? 720/480=1.5.

I'm not sure if changing the AR will affect the quality of the encode.

If you're keeping it 720x480, the quality is the same whether 4:3 or 16:9. Why would you be changing the DAR anyway?

[mrcoolekin]

I was getting the AR from DGIndex. DGindex showed the AR was 16:9, but on the preview it was squished to looked 3:2 (sorry you are right it was 3:2 not 4:3).

I was changing the DAR so it looked correctly like on the DVD which was 16:9. So even if I encode the video as 3:2 or 16:9, the quality will be the same?

[poisondeathray]

yes quality will be the same if the encoded dimensions are the same

it doesn't matter where you change the DAR, at the stream level or container level (eg. with mkvmerge) . Technically , at the stream level (while you are encoding) is "better" and more compatible . e.g. if you re-wrap or swap containers (let's say mp4 container) , that information is gone if you use the container level , but it's part of the bitstream if you do it when encoding (so demuxing won't adverse affect it)

[manono]

I was changing the DAR so it looked correctly like on the DVD which was 16:9. So even if I encode the video as 3:2 or 16:9, the quality will be the same?

So when you play the DVD everything looks 'normal', right? And you know it's actually stored on the DVD at 720x480, right? That is, the VOBs before being resized at playback time look exactly as you see them in DGIndex. So, if keeping it at 720x480, and to answer your original question:

Should I encode it as 4:3 and then let mkvtoolnix fix the AR for me or encode it as 16:9?

As pdr suggested, set the 16:9 flag when encoding.

[mrcoolekin]

I was changing the DAR so it looked correctly like on the DVD which was 16:9. So even if I encode the video as 3:2 or 16:9, the quality will be the same?

So when you play the DVD everything looks 'normal', right? And you know it's actually stored on the DVD at 720x480, right? That is, the VOBs before being resized at playback time look exactly as you see them in DGIndex. So, if keeping it at 720x480, and to answer your original question:

Should I encode it as 4:3 and then let mkvtoolnix fix the AR for me or encode it as 16:9?

As pdr suggested, set the 16:9 flag when encoding.

Yes, manono, when I play the DVD it looks 'normals'. Yea, I knew it was stored on the DVD that why, so that's why I thought it was a better idea to encode it just like how it looked when I loaded the DVD in DGIndex and let mkvtoolnix flag the AR. I was sure the quality would suffer if I changed the AR during encoding, but poisondeathray answered that question that it doesn't. Thanks the both of you for answering my question.

[hello_hello]

How are you "previewing" the encode? It's quite possible that even if you set the correct aspect ratio when encoding, the "preview" will display without using it. So the preview will look "squished" but the encode should display correctly.

Personally I'd always aim to set the correct aspect ratio while encoding so it's written to the video stream. I'm pretty sure one of the Bluray players in this house obeys the aspect ratio in the video stream rather than the container aspect ratio, so remuxing to change the aspect ratio doesn't help there.

[jagabo]

I was getting the AR from DGIndex. DGindex showed the AR was 16:9, but on the preview it was squished to looked 3:2 (sorry you are right it was 3:2 not 4:3).

DgIndex makes no attempt to adjust for the DAR. It displays the video pixel-for-pixel on the screen. This is completely irrelevant to how you encode.

All my playback devices obey PAR/DAR flags so I always encode with the original frame size and PAR/DAR flags.

[hello_hello]

DGIndex does report the aspect ratio. I've no idea if most GUI's take DGIndex's word for it or if they look elsewhere, but the aspect ratio is listed in the d2v file even if DGIndex makes no use of it.

[manono]

DGIndex does report the aspect ratio. I've no idea if most GUI's take DGIndex's word for it or if they look elsewhere, but the aspect ratio is listed in the d2v file even if DGIndex makes no use of it.

DGIndex reports how the VOBs were encoded, yes. However, most DVD players take the DAR from the IFOs. It's not unheard of for the IFOs to report (correctly) that a DVD is 16:9, but the VOBs have been encoded incorrectly as 4:3. AutoGK is one app that gets the DAR information from the VOBs, and if they're supposed to really be played differently you have to go into the Hidden Options to override that choice.