[Cin] removing letter boxing while preserving aspect

[Andrea paz]

I have added the tip to the manual; see if it is okay. I also attach a
txt file for those who want to correct or improve the tip.

To be put at the end of section 3.2:

A tip on how to eliminate Letterbox/Pillarbox black bands in the Set
Format window can be found here: \nameref{sub:remove_letterbox}.


To be put at the end of section 19.7.11:

\subsection{How to remove letterbox/pillarbox bands}%
\label{sub:remove_letterbox}

To remove the horizontal black bands of the letterbox or the vertical
black bands of the pillarbox we need to change the \textit{size} and
\textit{aspect ratio} of the source by cropping.
For example, if we want to remove the letterbox from a $4:3$ frame to
leave only the content with aspect ratio $3:2$, we can act on the
project format by doing the following steps:

\begin{enumerate}
    \item Check the size of the base W of the original frame in pixels;

    \texttt{Resource} window $\rightarrow$ \texttt{RMB} on Asset
$\rightarrow$ \texttt{Info} $\rightarrow$ \texttt{Detail}; e.g. W =
768 px
    \item Obtain the height of the figure in $3:2$, i.e., without the
black bands; H can be obtained from the formula:

    $\frac{3}{2} = \frac{W}{H}$ \quad from which $H = \frac{768 \times
2}{3}$; \qquad e.g., H = 512 px
    \item Note that $W \times H = 768 \times 512$ is just the crop we
are looking for to switch from $4:3$ frame to $3:2$ frame without
letterbox
    \item Open \textit{Set Format} window: \texttt{Settings
$\rightarrow$ Format}
    \item Change $H = 512$ and set \textit{Display Aspect Ratio} to
$3:2$; press \texttt{Apply} and \texttt{OK}. Note that we leave W
unchanged, since the frame width does not change.
    \item If needed, act on the \textit{Camera} tool to get the
desired viewport.
\end{enumerate}

\paragraph{Note:} in complex situations, with multiple sources of
different sizes, it may be appropriate to premise an additional step
to the second: change the size of the track on the Timeline via
\texttt{RMB $\rightarrow$ Resize track}.
In this way we crop the track to match it to the project format that
we will change in the next step. This way we avoid possible unwanted
distortions.

In the case of the pillarbox, we will leave H unchanged while
calculating the new value of W. The formula $\frac{x}{y} =
\frac{W}{H}$ is valid for any aspect ratio ($4:3; 16:9; 2.35:1$; etc)
-------------- next part --------------
How to remove letterbox/pillarbox bands

To remove the horizontal black bands of the letterbox or the vertical black bands of the pillarbox we need to change the size and aspect ratio of the source by cropping.
For example, if we want to remove the letterbox from a 4:3 frame to leave only the content with aspect ratio 3:2, we can act on the project format by doing the following steps:

1- Check the size of the base W of the original frame in pixels; e.g., W = 768 px
2- Obtain the height of the figure in 3:2, i.e., without the black bands; H can be obtained from the formula 3/2 = W/H, from which H = (768 x 2)/3; e.g., H = 512 px
3- Note that WxH = 768 x 512 is just the crop we are looking for to switch from 4:3 frame to 3:2 frame without letterbox
4- Open Set Format window: Settings --> Format
5- Change H to 512 and set Display Aspect Ratio to 3:2; press Apply and OK. Note that we leave W unchanged, since the frame width does not change.
6- If needed, act on the Camera tool to get the desired viewport.

Note: in complex situations, with multiple sources of different sizes, it may be appropriate to premise an additional step to the second: change the size of the track on the timeline via RMB --> Resize track.
In this way we crop the track to match it to the project format that we will change in the next step. This way we avoid possible unwanted distortions.

In the case of the pillarbox, we will leave H unchanged while calculating the new value of W. The formula x/y = W/H is valid for any aspect ratio (4:3; 16:9; 2.35:1; etc)