[MEncoder-users] mencoder output

[Corey Hickey]

Marco wrote:
> On 3/6/06, Corey Hickey <bugfood-ml at fatooh.org> wrote:
> 
>>Marco wrote:
>>
>>>(2) >>> VDec: vo config request - 720 x 576 (preferred csp: Planar YV12)
>>>     >>> VDec: using Planar YV12 as output csp (no 0)
>>>     >>> Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
>>
>>Right here mencoder is specifying that the video should be scaled to
>>match the original 1.33:1 aspect ratio. The video doesn't actually get
>>encoded that way (see below) but will be scaled on playback. If you
>>don't want that to happen you can either:
>>
>>- rescale manually with the scale video filter
>>- prevent the aspect ratio from being used with the -noaspect option
>>- set the aspect manually with the dsize video filter
>>
>>There are probably other ways, but I always use the first option so I
>>don't pay attention to the others.
> 
> Doesn't the first option change the original ratio of a cropped image?

Yes, so if you do that you'll need to calculate the final dimensions
yourself, based on the cropped dimensions and how much the original
image was rescaled to meet the original aspect ratio.

The final aspect ratio won't necessarily be the same, because you
cropped the image. It may be close, or way off. If you want to do that,
you should read this section in the docs and the parts above it to gain
the proper context.

http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-dvd-mpeg4.html#menc-feat-dvd-mpeg4-resolution-bitrate-compute

-Corey