-We can use the \textit{Proxy 1:1} in two ways: setting "1" as \textit{Scale factor}, or check the \textit{Rescaled to project size (FFMPEG only)} button. In this mode we don't have scaling, i.e. downsize, but only variations of the codec parameters that allow to maintain the original resolution. The advantage is that you can use filters that require the original size to work well. Please note that if we set any scaling, by activating the \textit{Rescaled to project size (FFMPEG only)} button we automatically lose scaling and enter Proxy 1:1 mode.
+We can use the \textit{Proxy 1:1} in two ways: setting "1" as \textit{Scale factor}, or check the \textit{Rescaled to project size (FFMPEG only)} button. In this mode we don't have scaling, i.e. downsize, but only variations of the codec parameters that allow to maintain the original resolution. The advantage is that you can use filters that require the original size to work well. Please note that if we set any scaling, by activating the \textit{Rescaled to project size (FFMPEG only)} button we automatically lose scaling and enter Proxy 1:1 mode. The size of your video is scaled down of the \textit{Scale factor} but, then, it is rescaled up to the project format. For example, your format project is $1920x1080$ and Proxy's Scale factor is $\frac{1}{4}$, then your videos will be scaled down to $480x270$ and then up-scaled to $1920x1080$. For an old computer, this option is not recommended.