4 Welcome to Nageru! For simple use, you can jump right in and make yourself
5 comfortable (at least if you have the :doc:`hardware requirements <hardware>`
6 in place), but if you prefer a gentler introduction, this is the place.
9 Introduction to the M/E workflow
10 --------------------------------
12 Nageru, like most hardware video mixers, is based on the **mixer/effects**
13 workflow, or just M/E for short. (Don't ask why “mixer” or “effects”;
14 the name is confusing and mostly historical.)
16 The basic idea of M/E is that you have two main displays, *preview* and *live*.
17 Every time you want to change what's shown to the viewer, you first bring it
18 up on the preview display, verify that it indeed contains something you'd like
19 to show to your viewers, and only then start a transition to move the preview
20 display onto the live display (which mirrors exactly what the viewers see).
21 After the transition is done, the preview and live displays switch, allowing
22 the operator to either switch back or to pull a new source onto the preview
25 In Nageru, the available transitions at any time are governed by the
26 :doc:`theme </theme>`. However, generally a simple cut (moving immediately
27 from live to preview) will nearly always be an option. Other effects include
28 fades and zooms, but availability will depend on what sources are involved in the
32 A brief tour of the Nageru UI
33 -----------------------------
35 The basic Nageru UI with the default theme looks like this:
37 .. image:: images/basic-ui.png
39 First a word about user input: Nageru can be controlled by the mouse or
40 keyboard, but most operators will prefer using both hands on the keyboard.
41 Like on a real mixing console, you use your left hand to select sources for
42 preview (using the 1–9 keys) and the right hand to choose a transition
43 (using J, K or L). In addition, audio can be controlled using a MIDI controller
44 if you want to; see the :doc:`audio <audio>` page for more information.
50 The preview and live displays are the most important part of the UI,
51 and thus take up the bulk of the space. In addition, we have the list
52 of channels and scenes (the side-by-side view and the static image)
53 along the bottom. As you can see, we have only
54 one (rather boring) input connected, and it is live. The other input is
55 disconnected and thus shows only a test color. These correspond to pressing
56 the 1 and 2 keys on the keyboard to activate preview, respectively—or you can
57 left-click on them do achieve the same effect. (Right-clicking will bring up
58 :ref:`the video card context menu <context-menu>`; see below.)
60 Similarly, we have a side-by-side view; it is composed of a big image of
61 input 1 and a smaller one of input 2. (If you are unhappy which is which,
62 you can switch the two inputs; again, see below.)
64 Finally, we have a static image. The one included with Nageru is rather
65 bland and generic, but it works as a generic pause image when you don't
66 really want anything on the screen.
68 For any given channel, you can see that it is active in the live or preview
69 by looking at its border. If it's got a red border, as in the leftmost
70 input, it's live (either on its own, or as part of the side-by-side view).
71 Similarly, if it's got a green border, as in the second input (you can
72 see it if you look closely; it's a somewhat lighter shade of green),
73 it will be marked with green. On conflict, red (live) wins, since it is
74 the most important piece of information.
80 Whenever you have a different channel pulled up on the preview from
81 on the live display, you will see that the three buttons in the middle
82 offer you various **transitions**. Selecting any of them (either by
83 the displayed hotkey, or using the mouse) will *swap* the preview and
84 live inputs, effectively making the preview live. If you use “cut”,
85 this will happen nearly instantly; the two other options, zoom
86 (only available with the side-by-side view) and fade (*not* available
87 with the side-by-side view) take some time, as you can see in the live view.
89 A good operator knows to use the right transition at the right time,
90 so that the end result does not distract from the actual message
91 of the video. In particular, too frequent switching between sources
92 will probably be perceived as disturbing.
98 The look of the audio strip will vary significantly with what audio
99 mode you are in; the default is the simple mode, but multichannel
100 is much more powerful. Both modes, as well as the level meters on
101 the right, are explained in detail in the section about :doc:`audio <audio>`.
107 The menu bar does not contain a lot of interesting information,
108 but it does have a few elements that are useful for configuration.
109 The video menu contains the following elements:
111 * **Begin new video segment:** Nageru is constantly recording
112 your stream to disk in a near-lossless H.264 stream
113 (you cannot turn it off, because experience shows you'd probably
114 forget to turn it back on again in time for actual use);
115 see :doc:`streaming` for more information. This option allows
116 you to end the current file and begin a new one—the two files
117 can be spliced back later for a 100% seamless result if you wish,
118 so this is a lossless operation. It is typically useful
119 to do this right before and after the event itself starts,
120 so as to facilitate easier editing later.
122 You can achieve the same effect as this option by sending
123 SIGHUP to the Nageru process.
125 * **Change x264 bitrate:** See :doc:`streaming` for more information.
127 * **Exit:** Exits Nageru, obviously.
129 The audio menu is explained in the section on :doc:`audio <audio>`.
131 Finally, the menu bar also hosts the disk space meter. This shows
132 how much disk you have left before Nageru will error out and die;
133 it also tries to estimate how much real time this corresponds to,
134 based on the last 30 seconds of recording.
139 The video card context menu
140 '''''''''''''''''''''''''''
142 If you right-click on a channel that corresponds to a video input
143 (ie., not the side-by-side view or static image), a simple context menu
146 .. image:: images/context-menu.png
148 The options presented are as follows:
150 * **Input source:** Connect this video input to a different physical card,
151 taking effect immediately. The theme supports only two inputs
152 at a time (you can :doc:`write your own <theme>` that support many
153 more if you wish), but if you start Nageru with a higher value
154 for the “--num-cards” option (aka -c), you can choose any of the
155 available ones here. This option is also useful if you want to
156 switch the two cards, since input 1 is bigger in side-by-side mode.
157 (See also the “--map-signal” option, aka -m.)
159 * **Video input:** If a card supports multiple kinds of inputs
160 (e.g. has both HDMI and analog inputs), you can select which one here.
162 * **Audio input:** Similar, just for audio. “Embedded” means
163 an audio stream that is included in the HDMI or SDI signal.
165 * **Input mode:** Choose the video input mode to use. Note that the USB
166 cards autodetect the mode, and you cannot override it even if you wanted to.
167 For PCI cards, autodetection is not supported (even for the select few
168 cards that can handle it in hardware), but a simple option (“Scan”)
169 is available to try all modes in turn until a signal is received.
171 * **Use as audio source:** See the :doc:`audio <audio>` page for more
172 information. For simple audio only; unavailable in multichannel mode.
174 * **Use as master clock:** The output stream needs exactly one stream
175 as master clock. The frame rate and clocked will be locked exactly
176 to it, so use the most important input here. A signal that keeps getting
177 unplugged and replugged might not be the best candidate, although the
178 PCI cards have fallback internal clocking when the signal is lost
179 (the USB cards fall back to a strange mode of about 30.13 Hz).