Resize & aspect
- Resize
- Example

Resize & aspect

Resize

Specify horizontal and vertical size

“No aspect ratio correction” selected: Stretched or shrinked to the specified size.
“Keep original aspect ratio” selected: Stretched or shrinked until either width or height touch the specified size using the original aspect ratio. Black borders are added, if necessary.
Manually configured: Stretched or shrinked until either width or height touch the specified size using the specified aspect ratio. Black borders are added, if necessary.

Specify horizontal size

Height is calculated automatically to keep original aspect ratio.
“No aspect ratio correction” and “Keep original aspect ratio” give the same result.
Manually configured: You can specify aspect ratio manually.

Specify aspect ratio

Height is calculated based on width. (Let's call it a box here.)
“No aspect ratio correction” selected: Stretched to fill the box.
“Keep original aspect ratio” selected: Stretched or shrinked until either width or height touch the box using the original aspect ratio. Black borders are added, if necessary.
Manually configured: Stretched or shrinked until either width or height touch the box using the specified aspect ratio. Black borders are added, if necessary.

Expand to next multiply of

Both width and height are expanded to the next multiple of the specified value. For example, if you specify 100, 320×160 becomes 400×200. You may want to use this mode when ffdshow connects to a filter which does not work with width or height of non-multiple of 16.
“Keep original aspect ratio” and “Manual” work in this mode too.

Multiply by

Both horizontal and vertical sizes are stretched using the specified magnification ratio.

Resize to screen resolution

The output resolution will match your video card's resolution. Recommended if you have a flat panel display and a multi-core CPU.

Process pixel aspect ratio internally

If checked (by default), resize to the size taking into account pixel aspect ratio (SAR), and fix output SAR 1:1.
If unchecked, output SAR equals input SAR and the video renderer (or any downstream filter) handles it.

Following situation: You have a projector with 1280×720 resolution and you want to play a DVD whose pixel aspect ratio (SAR) changes during playback. How to configure ffdshow's resize options properly?

“Specify horizontal and vertical size” → “1280×720”.
Select “Keep original aspect ratio”.
Make sure “Process pixel aspect ratio internally” is checked.
If you are using Media Player Classic, uncheck “View” → “Video Frame” → “Keep Aspect Ratio”.