question about anamorphice encoding

[.vaLk.]

Hi, I'd first like to say how much I appreciate this place and how nice it is. Now I have a question: I convert all of my DVDs with mkv (with the x264 codec) and I just started using anamorphic encoding to stretch the picture on playback. Now I was wondering how I could get the res to be stretched further, because so far they're only outputted a few pixels wider and I've seen other ones that have been almost doubled in size. I'm using MeGUI to make all of my AVI synths and to encode the videos.

Thanks for your time! :D

[Sagekilla]

Well it depends really.. If you have a 16:9 anamorphically encoded DVD video, you can simply keep the resolution @ 720x480 and feed it to x264 with a flag to resize to 16:9 with --sar 32:27. Obviously, the closer to the original resolution you are the higher quality it's going to end up being (encoding at 720x480 stretched to 853x480 will be higher quality than 640x480 stretched to 853x480 for example.) However, subjectively speaking, you may actually not notice any real difference in the video even though 720x480 will have a higher horizontal resolution than 640x480.


If you really wanna try that, you can just do something like:
Lanczos4Resize (560,480) --sar 1632:1071, or if you're really daring try Lanczos4Resize(480,480) with --sar 16:9

[Gilron]

I'm not sure if I understood the question correctly, but if you are using MKV container you could just set the Display Aspect Ratio you prefer to the container so that the media player would stretch your anamorphic encoding into what you requested.

[Blue_MiSfit]

Now I was wondering how I could get the res to be stretched further, because so far they're only outputted a few pixels wider and I've seen other ones that have been almost doubled in size


This confuses me as well.

The whole point of anamorphic encoding is to not touch your source at all - to preserve all of the resolution, and to then scale UP on playback (I.E. stretch out horizontally) instead of scaling DOWN on playback (I.E. strech down vertically).

This way you minimize loss of resolution, particularly vertical resolution which matters a lot more.

Wanting to stretch more or less is sort of missing the point. Your film has a native aspect ratio. When you determine what it is, set that as the DAR when you mux the video with mkvtoolnix. It will then automatically scale on playback.

~MiSfit

[Sagekilla]

This confuses me as well.

The whole point of anamorphic encoding is to not touch your source at all - to preserve all of the resolution, and to then scale UP on playback (I.E. stretch out horizontally) instead of scaling DOWN on playback (I.E. strech down vertically).

This way you minimize loss of resolution, particularly vertical resolution which matters a lot more.

Wanting to stretch more or less is sort of missing the point. Your film has a native aspect ratio. When you determine what it is, set that as the DAR when you mux the video with mkvtoolnix. It will then automatically scale on playback.

~MiSfit

I think what he means is he wants to compress the video at an even lower resolution than normal so he can get smaller file sizes even while retaining most of the quality when stretched back.

I did a simple test and resizing from 640x480 to 854x480 had very little perceptible quality loss compared to 720x480 native.