\item[Aspect Ratio] aspect ratio may be automatically set to $4:3$ or $16:9$. Aspect ratio would better be defined as the size of the display, monitor, or TV which will be used to view the output. If you measure your old TV, which supposedly is $4:3$ and your latest digital TV, which is supposedly $16:9$, you will see that those ratios aren't always correct anyway. Then measure your laptop monitor, your desktop monitor, and your neighbor's, and lo and behold, the ratios don't fit either of the purported \textit{standard} aspect ratio. Maintaining square pixels via scaling is more important in the long run.
\item[Use FFMPEG] this is user's choice; it is recommended and faster but more difficult to modify due to numerous options. For blu-ray, ffmpeg must be used and is not an available option.
\item[Resize Tracks] change track width and height as explained previously. The size is adjusted to the largest frame size needed.
\item[Aspect Ratio] aspect ratio may be automatically set to $4:3$ or $16:9$. Aspect ratio would better be defined as the size of the display, monitor, or TV which will be used to view the output. If you measure your old TV, which supposedly is $4:3$ and your latest digital TV, which is supposedly $16:9$, you will see that those ratios aren't always correct anyway. Then measure your laptop monitor, your desktop monitor, and your neighbor's, and lo and behold, the ratios don't fit either of the purported \textit{standard} aspect ratio. Maintaining square pixels via scaling is more important in the long run.
\item[Use FFMPEG] this is user's choice; it is recommended and faster but more difficult to modify due to numerous options. For blu-ray, ffmpeg must be used and is not an available option.
\item[Resize Tracks] change track width and height as explained previously. The size is adjusted to the largest frame size needed.