一句英文翻譯

[mini]

個人用 Dr.eye結果翻的怪怪的
The button is not available when AVI is selected, as such a file would not display correctly.
不知哪為高手能翻的口語化一點 (就只要這一句就好了~Thx)

全文是
This section generates highly precise resizing instructions for certain types of MPEG source files,
using Jukka Aho's algorithm described at http://www.iki.fi/znark/video/conversion/.
The target type is chosen by selecting one of four buttons associated
with standard MPEG formats (VCD, DVD, etc.)
Button tooltips give additional info.

A fifth button, labeled [AVI],
is used to calculate for conversions to AVI or other PC formats which use [square pixels].
Since there is no fixed target size for AVI files,
[+] and [-] buttons are provided to adjust the calculation for larger or sizes,
as required.
16:9 [anamorphic] source material is automatically detected,
indicated, and accounted for in all calculations. Additionally,
a [16:9] target button is available to adjust the calculation when an anamorphic target is desired,
which is possible regardless of the source material's type.
The button is not available when AVI is selected,
as such a file would not display correctly.