<!-- ============================================================== -->
<section>
-<title>Subtitles</title>
+<title>Timed text (subtitles and closed captions)</title>
<para>
-The subtitles tab contains settings related to subtitles in your
-content, as shown in <xref linkend="fig-subtitles-tab"/>.
+The timed text tab contains settings related to subtitles and closed captions in your
+content, as shown in <xref linkend="fig-timed-text-tab"/>.
</para>
-<figure id="fig-subtitles-tab">
- <title>Subtitle settings tab</title>
+<figure id="fig-timed-text-tab">
+ <title>Timed text settings tab</title>
<mediaobject>
<imageobject>
- <imagedata fileref="screenshots/subtitles-tab&scs;"/>
+ <imagedata fileref="screenshots/timed-text-tab&scs;"/>
</imageobject>
</mediaobject>
</figure>
+<para>
+Depending on where timed text comes from it can sometimes be used as
+either an open subtitle (to be overlaid onto the cinema screen and so
+seen by everybody) or as a closed caption (to be displayed to
+individual viewers using a special system such as the Doremi
+CaptiView™)
+</para>
+
<para>
DCP-o-matic can either:
</para>
<itemizedlist>
- <listitem>Extract subtitles that are embedded in video files, or</listitem>
- <listitem>Use subtitles from SubRip (<code>.srt</code>), SubStation
+ <listitem>Extract timed text that is embedded in video files, or</listitem>
+ <listitem>Use timed text from SubRip (<code>.srt</code>), SubStation
Alpha (<code>.ssa</code> or <code>.ass</code>) or DCP XML files. You may find the great
free program <ulink
url="http://www.nikse.dk/subtitleedit/">Subtitle Edit</ulink> useful
</itemizedlist>
<para>
-Embedded subtitles are usually represented using a set of bitmaps,
-especially on files that have come from DVD or BluRay. Such subtitles
-can (currently) only be ‘burnt’ into the DCP (that is,
-they are included in the image and not overlaid by the projector).
+Embedded timed text is usually represented using a set of bitmaps,
+especially on files that have come from DVD or BluRay. Such text can
+be used as a subtitle, but not a closed caption (since the closed
+captioning system requires the text to be delivered as
+character codes rather than an image).
</para>
+<para>In contrast, SubRip, SubStation Alpha or DCP text can be used as either a subtitle or a closed caption.</para>
+
<para>
-With SubRip, SubStation Alpha or DCP subtitles you have the choice to
-either burn-in or include the subtitles as separate subtitle
+With subtitles you have the further choice of whether to burn the
+subtitles into the image or include them as a separate subtitle
‘asset’ within your DCP (in which case the projector
overlays them onto the image on playback). The difference between
burn-in and overlay is illustrated by <xref linkend="fig-burn-in"/>
</para>
<para>
-Select the <guilabel>Use Subtitles</guilabel> check-box to enable
-the subtitles in the selected content.
+Select the <guilabel>Use as</guilabel> check-box to enable the timed
+text in the selected content, then choose what you want to use the
+text for: open subtitles or closed captions.
</para>
<para>
Select the <guilabel>Burn subtitles into image</guilabel> check-box to
-burn these subtitles into the image; if this is not ticked the
+burn subtitles into the image; if this is not ticked the
subtitles will be included separately in the DCP to be rendered by the
-projector. This check-box will always be ticked if you are using
-embedded ‘image’ subtitles.
+projector.
</para>
<para>
The <guilabel>X Offset</guilabel> and <guilabel>Y Offset</guilabel>
-controls move the subtitles around within the image. The offsets are
-expressed as a percentage of the video frame size; 100% X offset is
-the entire width of the frame, and 100% Y offset is the entire height.
-Hence, to move the subtitles down by half the frame height you would
-use a Y offset of 50%.
+controls move subtitles around within the image. These controls have
+no effect for closed captions. The offsets are expressed as a
+percentage of the video frame size; 100% X offset is the entire width
+of the frame, and 100% Y offset is the entire height. Hence, to move
+the subtitles down by half the frame height you would use a Y offset
+of 50%.
</para>
<para>
The <guilabel>X Scale</guilabel> and <guilabel>Y Scale</guilabel>
-controls scale the subtitles. Scale values of 1 make the subtitles
-the same size (relative to the size of the image) as they are on the
-original. Values lower than 1 make them smaller, and values higher
-make them larger. You can stretch the subtitles in either direction
-by specifying different values for X and Y scale. Subtitles from DVD
-and Blu Ray sources are frequently larger (relative to the video
-frame) than those typically used for DCP, so it is often useful to
-scale such subtitles down using these controls.
+controls scale subtitles. These controls have no effect for closed
+captions. Scale values of 1 make the subtitles the same size
+(relative to the size of the image) as they are on the original.
+Values lower than 1 make them smaller, and values higher make them
+larger. You can stretch the subtitles in either direction by
+specifying different values for X and Y scale. Subtitles from DVD and
+Blu Ray sources are frequently larger (relative to the video frame)
+than those typically used for DCP, so it is often useful to scale such
+subtitles down using these controls.
</para>
<para>
The <guilabel>Line spacing</guilabel> control adjusts the line spacing
-of the subtitles. This only works for non-embedded (text) subtitles.
+of the subtitles. This only works for subtitles that did not come from bitmaps.
</para>
<para>
</para>
<para>
-If you are using non-embedded (text) subtitles you can see the
+If you are using non-image (text) subtitles or closed captions you can see the
subtitle text and timings by clicking the <guilabel>View...</guilabel>
button, or specify the fonts that should be used by clicking <guilabel>Fonts...</guilabel>.
</para>
<para>
With any subtitles you can click <guilabel>Appearance...</guilabel> to
-change how the subtitles look.
+change how the subtitles look. Some of the controls in the
+<guilabel>Apperance</guilabel> only apply to burnt-in subtitles, as
+only limited control is available for subtitles rendered by the
+projection system.
</para>
</section>