AviDemux and Aspect Ratios

[bitwerks]

When I load an avi file and select Automatic-DVD it always seems to default to 1:1 for the source aspect ratio even though the aspect ratio is 1:1.773 (16:9).

Is AviDemux referring to the pixel aspect ratio (whjch gspot agrees is 1:1) or is it referring to the display aspect ratio? Using the 16:9 setting appears to provide good results but I wanted to be sure it doesn't know something which I do not... :)

Many thanks

[LoRd_MuldeR]

When I load an avi file and select Automatic-DVD it always seems to default to 1:1 for the source aspect ratio even though the aspect ratio is 1:1.773 (16:9).

This has been explained one million times. Avidemux shows the video "as-is". It doesn't apply any PAR/DAR in its internal preview :rolleyes:

Anyway, you can set up whatever PAR you need in the encoder configuration dialog, including the "As Input" option.

BTW: PAR means "Pixel Aspect Ratio", not "Display Aspect Ratio" (DAR). But you can calculate "DAR = (width / height) * PAR" easily ;)

(The good thing about working with PAR instead of DAR is that the PAR doesn't change when you crop the video)

[bitwerks]

Thanks Lord Mulder for the 1 millionth and 1 explanation.

My search skills must be getting rusty as I did search before posting. Perhaps we could add it to the FAQ (which I read as well)?

It has been functioning very well with me overriding the 1:1 with 16:9. I just had a nagging feeling that perhaps the tool knew something which I didn't. BTW, I'm reasonably sure I correctly described PAR and DAR. Not that I'm smart, I just read it on the gspot help page :-)

Thanks again for a great tool!

-bitwerks

(who freely admits to being a software developer and not a video guru)

[Nexin]

Gspot latest version can give for avi files the conversion needed to change to aspect ration you want 16:9, 4:3 etc. Where do we input those figures into AviDemux, is there somewhere.

I know it looks more like for avisynth, but would be helpful if not using avisynth to have input for those. Maybe it would make getting the aspect for the output correct each time.

I wonder also if there is a program that can similar that gspot does, but for other formats such as mpeg2 or ts files.

Maybe AviDemux could have such a feature built in. Then it would mean not needing to load into gspot or any other software first, to get picture size change values to input in AviDemux. To change the output aspect each time, have alook at gspot with an avi file loaded and see if possible. In gspot click on the +avi-, dvd, vcd, 16.9 4:3 buttons etc for values to change, for what i'm refering to.

[LoRd_MuldeR]

Maybe AviDemux could have such a feature built in. Then it would mean not needing to load into gspot or any other software first, to get picture size change values to input in AviDemux.

The feature already is there. Open your eyes :rolleyes:

http://img15.imageshack.us/img15/4559/admaspectratio.th.jpg (http://img15.imageshack.us/img15/4559/admaspectratio.jpg)

[Nexin]

What i was thing was something like xxx:xxx:xxx:xxx input for resizing. Have seen this on other softwares for example. I think its like the input for avi synth (unsure). Where each xxx represent part of the resize equation.

No matter i have just seen another software mediacoder, it has this to make video resizing simple (mediacoder Picture > Crop option). Maybe sometime avidemux will have this input with video popup window to make it simple to adjust. ;)

[LoRd_MuldeR]

You mean something like this? :confused:

http://img6.imageshack.us/img6/5789/admaspectresize.th.jpg (http://img6.imageshack.us/img6/5789/admaspectresize.jpg)

[Nexin]

OH you beaut what... and so much better than mediacoder, flip that is really easy to use. Can we have a buton to play the video, so with other options we can see the difference if possible. I just tried with xvid as video a 360x288 pal video, doubling it to 720x576 i see blocky pixels. If i did the same with a media player classic for instance (video frame > double size) i see no blockiness. Or have i misunderstood something between the two.

Not a problem since the avidemux mplayer resize is the best i have seen. That i can easily see onscreen the adjustment before my eyes, as to what the aspect video output will be before transcoding. :D

[LoRd_MuldeR]

Can we have a buton to play the video, so with other options we can see the difference if possible.

There is a "Play" button in the main window, so what else do you need?

Note that you can switch between "input" (unfiltered original video) and "output" (preview filtered video) in the main window view ;)

[bitwerks]

There are a pile of great features in the tool. I just need to take an evening and play around with it. I usually use it while under a time constraint which is never a good idea...

-bitwerks