+<para>
+Consider, as a somewhat over-the-top example, that we have a 720 x 576
+image which is letterboxed with 36 black pixels each at the top and
+bottom, and the video content within the letterbox should be presented
+in the DCP at ratio of 2.39:1 within a 1.85:1 frame (such as might
+happen with a trailer). The source image is shown in <xref
+linkend="fig-pipeline1"/>.
+</para>
+
+<figure id="fig-pipeline1">
+ <title>Example image to demonstrate video processing</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata scale="100" fileref="diagrams/pipeline1&dia;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+DCP-o-matic runs through the following steps when preparing an image for a DCP:
+</para>
+
+<itemizedlist>
+<listitem>Crop</listitem>
+<listitem>Scale</listitem>
+<listitem>Place in container</listitem>
+</itemizedlist>
+
+<para>
+First, some amount of the image can be cropped. This is almost always
+used to remove black borders (letterboxing and/or pillarboxing) around
+images.
+</para>
+
+<para>
+In our example image, we would use 36 pixels of crop from the top and
+bottom. This would give the new image shown in <xref
+linkend="fig-pipeline2"/>.
+</para>
+
+<figure id="fig-pipeline2">
+ <title>Example image after cropping</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata scale="100" fileref="diagrams/pipeline2&dia;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+The next step is to scale the image. Since this content should be
+presented in a 2.39:1 aspect ratio inside a 1.85:1 DCP we would select
+<guilabel>Scope</guilabel> from the <guilabel>Scale to</guilabel>
+option in the <guilabel>Video</guilabel> tab and
+<guilabel>Flat</guilabel> from the <guilabel>Container</guilabel>
+option in the <guilabel>DCP</guilabel> tab.
+</para>
+
+<para>The <guilabel>Scale to</guilabel> option should always be set to
+the aspect ratio at which the content should be seen. The
+<guilabel>Container</guilabel> option should be set to the preset that
+you want to use on the projector. Of course, these two settings will
+often be the same.
+</para>
+
+<para>
+Given the scaling and container information, DCP-o-matic will look at
+the DCP's container size, and then scale the source image up until one
+or both of its dimensions (width, height or both) fits the size of the
+container, all the while preserving the desired aspect ratio.
+</para>
+
+<para>
+In our example here, the DCP's container is specified as 1.85:1 (so
+that the DCP will play back correctly using the projector's
+‘Flat’ preset). At 2K, 1.85:1 is 1998 pixels by 1080.
+Scaling the source up whilst preserving its 1.85:1 aspect ratio will
+result in the image hitting the sides of the container first, at a
+size of 1998 x 836. This gives us a new version of the image as shown
+in <xref linkend="fig-pipeline3"/>.
+</para>
+
+<figure id="fig-pipeline3">
+ <title>Example image after cropping and scaling</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata scale="100" fileref="diagrams/pipeline3&dia;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+The final step is to place the image into the DCP. In this case,
+since we have a 2.39:1 image that should be presented as a 1.85:1 DCP,
+we have set the <guilabel>container</guilabel> in the
+<guilabel>DCP</guilabel> tab to be Scope. Since the content has been
+scaled to 1998 x 836, and a Flat container is 1998 x 1080, there will
+be some black bars at the top and bottom of the image. DCP-o-matic
+shares out this black equally, as shown in <xref
+linkend="fig-pipeline3"/>.
+</para>
+
+<figure id="fig-pipeline4">
+ <title>Example image in the DCP</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata scale="100" fileref="diagrams/pipeline4&dia;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+</section>
+
+</chapter>
+
+<chapter xml:id="ch-dcp" xmlns="http://docbook.org/ns/docbook" version="5.0" xml:lang="en">
+<title>DCP settings</title>
+
+<para>
+This chapter describes the settings that apply to the whole DCP. The
+controls for these settings are in the <guilabel>DCP</guilabel> tab of
+the main window, as shown in <xref linkend="fig-dcp-tab"/>.
+</para>
+
+<figure id="fig-dcp-tab">
+ <title>DCP settings tab</title>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="screenshots/dcp-tab&scs;"/>
+ </imageobject>
+ </mediaobject>
+</figure>
+
+<para>
+The first thing here is the name. This is generally set to the title
+of the film that is being encoded. If <guilabel>Use ISDCF
+name</guilabel> is not ticked, the name that you specify will be used
+as-is for the name of the DCP. If <guilabel>Use ISDCF name</guilabel>
+is ticked, the name that you enter will be used as part of a
+ISDCF-compliant name.
+</para>
+
+<para>
+Underneath the name field is a preview of the name that the DCP will
+get. To use a ISDCF-compliant name, tick the <guilabel>Use ISDCF
+name</guilabel> check-box. The ISDCF name will be composed using details
+of your content's soundtrack, the current date and other things that
+can be specified in the ISDCF name details dialogue box, which you can
+open by clicking on the <guilabel>Details</guilabel> button.
+</para>
+
+<para>
+If you want to take the ISDCF-compliant name that DCP-o-matic
+generates and modify it, click <guilabel>Copy as name</guilabel> and
+the ISDCF name will be copied into the <guilabel>Name</guilabel> box.
+You can then edit it as you wish. The DCP name should not matter (in
+that it should not affect how the DCP ingests or plays) but
+projectionists will appreciate it if you use the standard naming
+scheme as it makes it easier to identify details of the content.
+</para>
+
+<para>
+The <guilabel>Content Type</guilabel> option can be
+‘feature’, ‘trailer’ or whatever; select the
+required type from the drop-down list. On some projection systems
+this will affect where your content appears in the projector's server
+user interface, so take care to select an appropriate type.
+</para>
+
+<para>
+The <guilabel>Signed</guilabel> check-box sets whether or not the DCP
+is signed. This is rarely important; if in doubt, tick it.
+</para>
+
+<para>
+The <guilabel>Encrypted</guilabel> check-box will set whether the DCP
+should be encrypted or not. If this is ticked, the DCP will require a
+KDM to play back. Encryption is discussed in <xref
+linkend="ch-encryption"/>.
+</para>
+
+<para>
+If you use encryption DCP-o-matic will generate a random encryption
+key for you. To specify your own key, click the
+<guilabel>Edit..</guilabel> button next to the key.
+</para>
+
+<para>
+The <guilabel>Standard</guilabel> option specifies which of the two
+DCP standards DCP-o-matic should use. If in doubt, use SMPTE (the
+more modern of the two).
+</para>
+
+<para>
+At the bottom of the DCP tab are a further two tabs, one each to
+contain the settings for the DCP's video and audio parts.
+</para>
+
+<para>
+The <guilabel>Container</guilabel> option sets the ratio of the image
+in the DCP. If this ratio is different to the ratio used for any
+content, DCP-o-matic will pad the content with black. In simple cases
+this should be set to the same ratio as that for the the primary piece
+of video content. Alternatively, you might want to pillarbox a small
+format into a Flat container: in this case, select the small format
+for the content's ratio and ‘Flat’ for the DCP.
+</para>
+
+<para>
+The <guilabel>Frame Rate</guilabel> control sets the frame rate of
+your DCP. This can be a little tricky to get right. Ideally, you
+want it to be the same as the video content that you are using. If it
+is not the same, DCP-o-matic must resort to some tricks to alter your
+content to fit the specified frame rate. Frame rates are discussed in
+more detail in <xref linkend="ch-frame-rates"/>.
+</para>
+
+<para>
+The <guilabel>Use best</guilabel> button sets the DCP video frame rate
+to what DCP-o-matic thinks is the best given the content that you have
+added.
+</para>
+
+<para>
+The <guilabel>3D</guilabel> button will set your DCP to 3D mode if it
+is checked. A 3D DCP will then be created, and any 2D content will be
+made 3D compatible by repeating the same frame for both left and right
+eyes. A 3D DCP can be played back on many 3D systems (e.g. Dolby 3D,
+Real-D etc.) but not on a 2D system.
+</para>
+
+<para>
+The <guilabel>Resolution</guilabel> tab allows you to choose the
+resolution for your DCP. Use 2K unless you have content that is of
+high enough resolution to be worth presenting in 4K.
+</para>
+
+<para>
+The <guilabel>JPEG2000 bandwidth</guilabel>; setting changes how big
+the final image files used within the DCP will be. Larger numbers
+will give better quality, but correspondingly larger DCPs. The
+bandwidth can be between 50 and 250 megabits per second (Mbit/s).
+Most commercial DCPs use bit rates between 75 and 125 MBit/s.
+</para>
+
+<para>
+The <guilabel>Audio Channels</guilabel> control sets the number of
+audio channels that the DCP will have. If the DCP has any channels
+for which there is no content audio they will be replaced by silence.
+You can only set an even number of channels here, since that is
+required by the DCI standard. If you want an odd number of channels,
+set the DCP channel count to one greater than you need and the
+unused channel will be filled with silence.
+</para>
+
+<para>
+The <guilabel>Processor</guilabel> control allows you to select a
+process to apply to the audio before it goes into the DCP. Two processes are currently provided:
+</para>
+
+<itemizedlist>
+<listitem>Mid-side decode — this will take a L/R
+stereo input and extract the common part (corresponding to the
+‘Mid’ in a mid-side signal) into the DCP's centre channel.
+The remaining L/R parts will be kept in the L/R channels of the DCP.
+This may be useful to make near-field L/R mixes more compatible with
+cinema audio systems.</listitem>
+<listitem>Stereo to 5.1 up-mixer A — this will take a stereo input and up-mix it to ‘fake’ 5.1. The input L/R are treated as follows:
+<itemizedlist>
+<listitem>DCP L is input L bandpass-filtered between 1.9kHz and 4.8kHz.</listitem>
+<listitem>DCP R is input R bandpass-filtered between 1.9kHz and 4.8kHz.</listitem>
+<listitem>DCP C is input L mixed with input R, taken down by 3dB and then bandpass-filtered between 150Hz and 1.9kHz.</listitem>
+<listitem>DCP Lfe is input L mixed with input R, taken down by 3dB and then bandpass-filtered between 20Hz and 150Hz.</listitem>
+<listitem>DCP Ls is input L bandpass-filtered between 4.8kHz and 20kHz.</listitem>
+<listitem>DCP Rs is input R bandpass-filtered between 4.8kHz and 20kHz.</listitem>
+</itemizedlist>
+</listitem>
+</itemizedlist>
+
+<para>
+This upmixing algorithm is due to Gérald Maruccia.
+</para>
+
+
+<!-- ============================================================== -->
+<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>
+
+</chapter>
+
+<chapter xml:id="ch-encryption" xmlns="http://docbook.org/ns/docbook" version="5.0" xml:lang="en">
+<title>Encryption</title>
+
+<para>
+It is not required that DCPs be encrypted, but they can be. This
+chapter discusses the basic principles of DCP encryption, and how
+DCP-o-matic can create encrypted DCPs and KDMs for them.
+</para>
+
+
+<!-- ============================================================== -->
+<section>
+<title>Basics</title>
+
+<para>
+DCPs can be encrypted. This means that the picture and sound data are
+encoded in such a way that only cinemas ‘approved’ by the
+DCP's creators can read them. In particular, this means copies of the
+DCP can be distributed by insecure means: if an ne'er-do-well called
+Mallory obtains a hard drive containing an encrypted DCP, there is no
+way that he can play it. Only those cinemas who receive a correct key
+delivery message (KDM) can play the DCP.
+</para>
+
+
+<!-- ============================================================== -->
+<section>
+<title>How it works (in a nutshell)</title>
+
+<para>
+This section attempts to summarise how DCP encryption works. You can
+skip it if you like. You may need some knowledge of encryption
+methods to understand it.
+</para>
+
+<para>
+We suppose that we are trying to send a DCP to
+Alice's cinema without a troublemaker called Mallory being able to
+watch it himself.
+</para>
+
+<para>
+There are two main families of encryption techniques. The first,
+symmetric-key encryption, allows us to encode some data using some
+numeric key. After encoding, no-one can decode the data unless they
+know the key.
+</para>
+
+<para>
+The first step in a DCP encryption is to encode its data with some key
+using symmetric-key encryption. The encrypted DCP can then be sent
+anywhere, safe in the knowledge that even if Mallory got hold of a
+copy, he could not decrypt it.
+</para>
+
+<para>
+Alice, however, needs to know the key so she can play the DCP in her
+cinema. A simple approach might be for us to send Alice the key.
+However, if Mallory can intercept the DCP, he might also be able to
+intercept our communication of the key to Alice. Furthermore, if Alice
+happened to know Mallory, she could just send him a copy of the key.
+</para>
+
+<para>
+The clever bit in the process requires the use of public-key
+encryption. With this technique we can encrypt a block of data using
+some ‘public’ key. That data can then only be decrypted
+using a corresponding private key which is
+<emphasis>different</emphasis> to the public key. The private and
+public keys form a pair which are related mathematically, but it is
+extremely hard (or rather, virtually impossible) to derive the private
+key from the public key.
+</para>
+
+<para>
+Public-key encryption allows us to distribute the DCP's key to Alice
+securely. The manufacturer of Alice's projector generates a public
+and private key. They hide the private key deep inside the bowels of
+the projector (inside an integrated circuit) where no-one can read it.
+They then make the public key available to anyone who is interested.
+</para>
+
+<para>
+We take our DCP's symmetric key and encrypt it using the public key of
+Alice's projector. We send the result to Alice over email (using a
+format called a Key Delivery Message, or KDM). Her projector then
+decrypts our message using its private key, yielding the magic
+symmetric key which can decrypt the DCP.
+</para>
+
+<para>
+If is fine if Mallory intercepts our email to Alice, since the only
+key which can decrypt the message is the private key buried inside
+Alice's projector. The projector manufacturer is very careful that
+no-one ever finds out what this key is. Our DCP is secure: only Alice
+can play it back, since only her projector knows the key (even Alice
+does not).
+</para>
+
+</section>
+</section>
+
+
+<!-- ============================================================== -->
+<section>
+<title>Encryption using DCP-o-matic</title>
+
+<para>
+There are two steps to distributing an encrypted DCP. First, the
+DCP's data must be encrypted, and secondly KDMs must be generated for
+those cinemas that are allowed to play the DCP.
+</para>
+
+<para>
+The first part is simple: ticking the <guilabel>Encrypted</guilabel>
+box in the <guilabel>DCP</guilabel> tab of DCP-o-matic will encrypt
+the DCP using a random key that DCP-o-matic generates. The key will
+be written to the film's metadata file, which should be kept
+secure.
+</para>
+
+<para>
+A DCP that is generated with the <guilabel>Encrypted</guilabel> box
+ticked will not play on any projector as-is (it will be marked as
+‘locked’, or whatever the projector manufacturer's term
+is).
+</para>
+
+<para>
+The second part is to generate KDMs for the cinemas that you wish to
+allow to play your DCP. This is done using the <guilabel>Make
+KDMs</guilabel> option on the <guilabel>Jobs</guilabel> menu. This
+will open the KDM dialogue box, as shown in <xref linkend="fig-kdm"/>.
+</para>
+
+<figure id="fig-kdm">
+ <title>KDM dialog</title>