+</section>
+<section>
+<title>Content Properties</title>
+
+<para>
+Below the content list are the controls to set content properties. To
+adjust the properties for a piece of content, click its name in the
+content list. The content property controls will then become active
+for that piece of content.
+</para>
+
+<para>
+The content properties are split up into four sections:
+<guilabel>Video</guilabel>, <guilabel>Audio</guilabel>,
+<guilabel>Subtitles</guilabel> and <guilabel>Timing</guilabel>. Not
+all of these sections will be active for all content types. The controls
+in each section are described below.
+</para>
+
+</section>
+
+<section>
+<title>Video</title>
+
+<para>
+The <guilabel>Video</guilabel> tab controls properties of the image, as shown in <xref linkend="fig-video-tab"/>.
+</para>
+
+<figure id="fig-video-tab">
+ <title>Video settings tab</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/video-tab&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<section>
+<title>Image type</title>
+
+<para>
+The first option on this tab is the ‘type’ of the video.
+This specifies how DCP-o-matic should interpret the video's image.
+<guilabel>2D</guilabel> is the default; this just takes the video
+image as a standard 2D frame. The other option <guilabel>3D
+left/right</guilabel> tells DCP-o-matic to interpret the frame as a
+left-right pair, as shown in <xref linkend="fig-3d-left-right"/>.
+</para>
+
+<figure id="fig-3d-left-right">
+ <title>3D left/right image type</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata scale="100" fileref="diagrams/3d-left-right&dia;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+This option can be used to generate a 3D DCP. Other means of creating
+3D will be added in the future.
+</para>
+
+</section>
+
+
+<!-- ============================================================== -->
+<section>
+<title>Filtering</title>
+
+<para>
+The ‘filters’ settings allow you to apply various video
+filters to the image. These may be useful to try to improve
+poor-quality sources like DVDs. You can set up the filters by clicking the
+<guilabel>Edit</guilabel> button next to the filters entry in the
+setup area of the DCP-o-matic window; this opens the filters selector
+as shown in <xref linkend="fig-filters"/>.
+</para>
+
+<figure id="fig-filters">
+ <title>Filters selector</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/filters&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+After changing the filters setup, you will need to regenerate the DCP
+to see the effect on the cinema screen. The preview in DCP-o-matic
+will update itself whenever filters are changed, though of course this
+image is much smaller and of lower resolution than a projected image!
+</para>
+</section>
+
+
+<!-- ============================================================== -->
+<section>
+<title>Other settings</title>
+
+<para>
+The ‘crop’ settings can be used to crop your content,
+which can be used to remove black borders from round the edges of DVD
+images, for example. The specified number of pixels will be trimmed
+from each edge, and the content image in the right of the window will
+be updated to show the effect of the crop.
+</para>
+
+<para>
+The <guilabel>Scale to</guilabel> option governs the shape that
+DCP-o-matic will scale the content's image into. Select the aspect
+ratio that your content should be presented in.
+</para>
+
+</section>
+<section>
+<title>Video description</title>
+
+<para>
+At the bottom of the video tab is a short description of what will
+happen to your video with the current settings. In the example of
+<xref linkend="fig-video-tab"/>, DCP-o-matic is telling you that the
+video file is 1920x1080 pixels (which is a ratio of 1.78:1). Since
+the controls specify ‘Flat’ for the ratio, DCP-o-matic
+scales the content image to 1998x1080, which is the DCI flat
+resolution at 2K.
+</para>
+
+<para>
+This description also gives the frame rate of the content and what
+will happen to it when it is played at the DCP's frame rate.
+<!-- XXX: link to more detailed discussion of this -->
+</para>
+
+</section>
+
+</section>
+
+<section>
+<title>Audio</title>
+
+<para>
+The <guilabel>Audio</guilabel> tab controls properties of the image, as shown in <xref linkend="fig-audio-tab"/>.
+</para>
+
+<figure id="fig-audio-tab">
+ <title>Audio settings tab</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/audio-tab&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<section>
+<title>Show audio</title>
+
+<para>
+The <guilabel>Show Audio</guilabel> button will instruct DCP-o-matic
+to examine the audio in your content and plot a graph of its level
+over time. This can be useful for getting a rough idea of how loud
+the sound will be in the cinema auditorium. A typical plot is shown
+in <xref linkend="fig-audio-plot"/>
+</para>
+
+<figure id="fig-audio-plot">
+ <title>Audio plot</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/audio-plot&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+The plot gives the audio level (vertical axis, in dB) with time
+(horizontal axis). 0dB represents full scale, so if there is anything
+near this you are in danger of clipping the projector's audio outputs.
+</para>
+
+<para>
+There are two plot types: the peak level and the RMS, which can be
+shown or hidden using the check-boxes on the right hand side of the
+window.
+</para>
+
+<para>
+The channel check-boxes will show or hide the plot(s) for
+the corresponding channels in the DCP.
+</para>
+
+<para>
+The smoothing slider applies a variable degree of temporal smoothing
+to the plots, which can make them easier to read in some cases.
+</para>
+
+<para>
+Obviously the audio plot is no substitute for listening in an
+auditorium, but it can be useful to get levels in the right rough area.
+</para>
+
+</section>
+
+<section>
+<title>The audio map</title>
+
+<para>
+The section at the bottom of the audio tab is the ‘audio
+map’. This governs how sound from the content will be arranged
+in the DCP.
+</para>
+
+<para>
+Down the left-hand side of the map is the list of audio channels in
+the currently-selected piece of content. Along the top is each
+channel in the DCP. A checked box means that the corresponding
+content channel will be copied into the corresponding DCP channel.
+</para>
+
+<para>
+Consider, for example, the case in <xref linkend="fig-audio-map-eg1"/>.
+</para>
+
+<figure id="fig-audio-map-eg1">
+ <title>Audio map example 1</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/audio-map-eg1&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+Here, we have two channels in the source which are mapped to left and
+right, respectively, in the DCP. If we modify that as in <xref
+linkend="fig-audio-map-eg2"/>
+</para>
+
+<figure id="fig-audio-map-eg2">
+ <title>Audio map example 2</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/audio-map-eg2&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+we now have the content's streams mapped to left and right and also
+mixed together and placed in the DCP's centre channel.
+</para>
+
+<figure id="fig-audio-map-eg3">
+ <title>Audio map example 3</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/audio-map-eg3&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+As a final example, the map in <xref linkend="fig-audio-map-eg3"/>
+shows the mapping of a 5.1 source into a 5.1 DCP.
+</para>
+
+</section>
+
+<section>
+<title>Other controls</title>
+
+<para>
+‘Audio Gain’ is used to alter the volume of the
+soundtrack. The specified gain (in dB) will be applied to each sound
+channel of your content before it is written to the DCP.
+</para>
+
+<para>
+If you use a sound processor that DCP-o-matic knows about, it can help
+you calculate changes in gain that you should apply. Say, for
+example, that you make a test DCP and find that you have to run it at
+volume 5 instead of volume 7 to get a good sound level in the screen.
+If this is the case, click the <guilabel>Calculate...</guilabel>
+button next to the audio gain entry, and the dialogue box in <xref
+linkend="fig-calculate-audio-gain"/> will open.
+</para>
+
+<figure id="fig-calculate-audio-gain">
+ <title>Calculating audio gain</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/calculate-audio-gain&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+For our example, put 5 in the first box and 7 in the second and click
+<guilabel>OK</guilabel>. DCP-o-matic will calculate the audio gain
+that it should apply to make this happen. Then you can re-make the
+DCP (this will be reasonably fast, as the video data will already have
+been done) and it should play back at the correct volume with 7 on
+your sound-rack fader.
+</para>
+
+<para>
+Current versions of DCP-o-matic only know about the Dolby CP750. If
+you use a different sound processor, and know the gain curve of its
+volume control, <ulink url="mailto:cth@carlh.net">get in
+touch</ulink>.
+</para>
+
+<para>
+<guilabel>Audio Delay</guilabel> is used to adjust the synchronisation
+between audio and video. A positive delay will move the audio later
+with respect to the video, and a negative delay will move it earlier.
+</para>
+
+<para>
+The <guilabel>Audio Stream</guilabel> option allows you to select the
+audio stream to use, if the content contains more than one. There
+might be different soundtrack languages, for example.
+</para>
+
+</section>