How to get the Highest Quality from DVD -> xVid or whatever is better?

[mistafro]

Can someone tell me how to get the absolute best quality besides the actual vob file from a DVD, right now I am using Avi DIVX Menucoder 2-pass with all the rest of the options enabled, I click best for the video bitrate, anything better?

[Case]

You could give "MP4 H.264 x264" a try. Is there any particular reason you are looking for something other than AVI DivX mencoder? Anything about that codec that you're unhappy with?

"Absolute best" is an impossible question. Your 'best' may be very different from what I think is 'best', because we all have different criteria. E.g., do you want a small file size (smaller is better?) or do you want a quality as close as possible to the original? How close is good enough? Do you need a specified file size? Do you need compatibility with a certain device? Do you need objective video quality (PSNR/VQM/SSIM) or do you have subjective opinions on video quality. How do you tell two very good but different encodings apart? If someone says codec X is better than codec Y, how could he prove that to you? What are you looking for in a 'best' solution?

There's also a funny thread about 'Best' in the Feedback forum.

[mistafro]

I really don't care about file size, I don't expect it to be the same size as DVD though, I expect some savings in space.

I want it as close to DVD quality as possible, I am playing these on Xbox Media Center which can play almost any file type.

[jagabo]

With Xvid use single pass, target quantizer mode with the quantizer set to 2 (constant quality encoding). Use the same 720x480 frame size and aspect ratio as the DVD. If the file size that delivers is too large, and you think you can live with lesser quality, use a higher quantizer value, 3, 4, 5...

As Case pointed out, h.264 or x.264 (open source equivalent) will get you smaller file sizes. But it will take much longer to encode.

[mistafro]

Hi, is Xvid or Divx better? Also on Xvid you say target quantizer to 2, that is the default setting where it says QMin?

[jagabo]

Hi, is Xvid or Divx better?

I find Xvid to be a little better than Divx. The difference isn't huge though.

Also on Xvid you say target quantizer to 2, that is the default setting where it says QMin?

On the main Xvid Configuration dialog, set Encoding Type to Single Pass. Right below that is a button. If it says Target Bitrate, click on it to make it say Target Quantizer. Right next to it is the quantizer value to use.

At Q=1 the results will be nearly indistinguishable from the source. But the result may be a file larger than the MPEG2 source.

At Q=2 the results will still be nearly identical to the source. The final file size will probably be about half the size of an MPEG2 source.

At Q=3 the result will show a little macroblocking if you look at enlarged still frames. They won't be noticeable at normal playback speed. The file will be smaller.

As you use higher quantizer values the image quality will get worse and the file will get smaller.

Note that Xvid and Divx encode B-VOPs with higher quantizer values (lower image quality) than I and P frames. If you want every frame to have the highest quality, disable B-VOPs. (Actually, Xvid allows you to use the same quantizer for B-VOPs but there's no point in doing this -- the result will visually be the same as an encoding without B-VOPs.) But again, at normal playback speeds you're not likely to notice much of a difference.

With Target Quantizer (constant quality) encoding you know the quality of the output but not the file size. With 2-pass VBR you know the file size of the output but not the quality. If you create an Xvid file using constant quantizer encoding, then create another using 2-pass encoding with the same average bitrate (ie, the same file size), the image quality will be nearly identical.

[tbluewater]

Can someone tell me how to get the absolute best quality besides the actual vob file from a DVD, right now I am using Avi DIVX Menucoder 2-pass with all the rest of the options enabled, I click best for the video bitrate, anything better?

What determines quality most is not any of the MPEG-4 fuctions but bitrate. Why do DVDs show you good quality video despite the fact that they use MPEG-2? Bitrate is all that matters.

[jagabo]

What determines quality most is not any of the MPEG-4 fuctions but bitrate.

If you work in Constant Quantizer mode you don't need to worry about bitrate. You decide what quality you want, every frame is encoded with whatever bitrate is necessary to achieve that quality.

[captvanhalen]

On the main Xvid Configuration dialog, set Encoding Type to Single Pass. Right below that is a button. If it says Target Bitrate, click on it to make it say Target Quantizer. Right next to it is the quantizer value to use.

Eh, what's all this then?

Jagabo, i do not see this option. I am using ffmpegX v0.0.9x. I only see tabs for Summary, Video, Audio, Filters, Options and Tools. I do not see "Encoding Type" or "Target Bitrate/Quantizer" ... are these controls in a newer version?

Thanks

[jagabo]

Sorry, I had forgotten this thread was regarding ffmpegx. I don't know if ffmpegx gives you access to target quantizer encoding.

[captvanhalen]

Sorry, I had forgotten this thread was regarding ffmpegx. I don't know if ffmpegx gives you access to target quantizer encoding.

throws laptop out window

Seriously though, thanks for answering so quickly jagabo.