Guide:Typesetting/Frequently asked questions

What is typesetting?
See the Typesetting article.

What is a sign?
A sign is any text that appears in the video. The text does not have to appear on signage for it to be called a sign. Signs are the main work material for typesetters.

What is a mask?
A mask is a drawing that obscures the original sign so that new text can be added on top. Masks are often employed to make the final sign look cleaner or to make typesetting the sign easier.

Why does my sign appear in Aegisub but not in mpv?
One possible reason is that your ASS events are longer than mpv's preroll threshold. When seeking through a video in a Matroska container, mpv reads data before the seek target to find subtitle events that should be displayed at the seek point. By default, the threshold is 10 seconds; anything beyond that is not rendered. To prevent subtitles from disappearing in these situations, each ASS event should be no longer than 10 seconds in duration. can be used to do this splitting.

This issue is applicable to all players and is not limited to mpv. The threshold for other players may be less or more than 10 seconds, and there may even be players with no preroll. The same fix applies to these other players, with the durations adjusted to accommodate the target player.

Why does my text still have a hard edge around the fill even though I'm using layers?
The fill color of the bottom layer likely does not match the layer's border color. If the bottom layer's fill color does not match the border, the fill of that layer will appear with a hard edge, which will peek through the blurred edge of the top layer. To prevent the hard edge, the same color should be used for the border and fill of the bottom layer.

For high values of blur, even using the same color will still produce a hard edge on the fill. Use the shad trick instead in these cases.

I used the color picker. Why does the color of my sign look off?
Selecting colors that match the original sign is not always as simple as sampling the color of a single pixel. Reasons why the color looks off may include:


 * The sample is taken from a place too far away from where the sign is. The closer the sample is to the position where the sign will be, the more likely the color will blend in properly. To resolve, pick a sample closer to the sign.
 * The original sign has a gradient. If the gradient is strong enough or the sign spans enough of the gradient's length, the difference in color will be apparent on the end further away from the sample. To resolve, apply a gradient to the sign.
 * The source video is noisy. Noise and grain produce color variation between individual pixels, so sampling from a single pixel will generally not result in a color that matches the perceived color of the original sign. To resolve, use an average sample from a larger area; an external tool will be needed for taking an average sample since Aegisub does not have such a function. Optionally recreate the noise texture.
 * Certain effects that decrease the intensity of the color are applied to the sign. Increased alpha reduces the opacity of the sign, allowing the color underneath to show through and blend with the sign's color. Blur decreases the intensity of the color at the edges and it can create an optical illusion that alters the perceived color. To resolve, manually adjust the color to counter the reduced intensity. If it is not possible to do so, try adding another layer.
 * The surrounding colors create an optical illusion. The brain interprets colors not in isolation, but in context with surrounding colors and patterns. For example, colors will look brighter against dark backgrounds and darker against light backgrounds. To resolve, manually adjust the color to account for the context.

How do I deal with masks for signs that fade?
Attempting to fade a mask using will result in the original sign peeking through during the fade. This is often not desirable. There are a number of ways to work around the issue:


 * Rework the sign to avoid having to mask. Nothing gets obscured when not masking, so the issue becomes irrelevant.
 * Move the sign to an area away from the original sign so they do not overlap. Same as above, the issue is irrelevant because nothing is obscured.
 * Shorten or remove the fade. A sign often does not look out of place even if it does not match the transition of the original exactly.
 * Extend the duration of the sign to start before the original sign fades in or after the original sign fades out. Your sign will be mostly opaque when the original sign fades, so your sign will obscure the original.
 * Redraw the background underneath the original sign so that the original sign never appears. This mask, which should be fully visible for at least the duration of the sign, will cover the original sign, giving you a clean slate to add your sign on top as if the original weren't there.
 * Keep the mask fully opaque and animate the color instead. This works well for signs that fade to or from a color, or signs that appear over a background that's largely a single color.
 * Apply a hardsubbed mask to remove the original sign. This is often considered a last resort as it alters the source video and requires help from an encoder.
 * Fade regularly and do nothing. If the fade is short and it is not too distracting, it may not be worth it to try to fix it.

The same techniques apply to crossfades, but they may be more difficult to deal with since the signs should not bleed into the pre- and post-fade scenes.

What is the shad trick?
The shad trick refers to the technique of using the layer's shadow instead of its border and fill. Using this technique enables the use of high blur without hard edges as well as -able motion, among other things.

To use the shad trick:


 * 1) set,  and  to the same color
 * 2) set  to hide the border and fill
 * 3) * It is important that these are set to  and not  . If set to the latter, the shadow will not appear.
 * 4) set  to enable the shadow

How do I adjust the line spacing when using ?
There is no way to configure line spacing in ASS. The best way to adjust the line spacing reliably across renderers, especially for typesetting purposes, is to break the lines into two events and position them separately. If the lines need to be on a single event for whatever reason, there exists a hack: set to a very far away point (  is safe for FHD), rotate the first line by a very small fraction of a degree, then reset the rotation for the second line.