1 -- The theme is what decides what's actually shown on screen, what kind of
2 -- transitions are available (if any), and what kind of inputs there are,
3 -- if any. In general, it drives the entire display logic by creating Movit
4 -- chains, setting their parameters and then deciding which to show when.
6 -- Themes are written in Lua, which reflects a simplified form of the Movit API
7 -- where all the low-level details (such as texture formats) are handled by the
8 -- C++ side and you generally just build chains.
9 io.write("hello from lua\n");
11 local live_signal_num = 0;
12 local preview_signal_num = 1;
14 -- The main live chain. Currently just about input 0 with some color correction.
15 local main_chain = EffectChain.new(16, 9);
16 local input0 = main_chain:add_live_input();
17 input0:connect_signal(0);
18 local resample_effect = main_chain:add_effect(ResampleEffect.new(), input0);
19 resample_effect:set_int("width", 320);
20 resample_effect:set_int("height", 180);
21 local wb_effect = main_chain:add_effect(WhiteBalanceEffect.new(), resample_effect);
22 main_chain:finalize(true);
23 -- local input1 = main_chain.add_input(Inputs.create(1));
24 -- local resample_effect = main_chain.add_effect(ResampleEffect.new(), input0);
25 -- local padding_effect = main_chain.add_effect(IntegralPaddingEffect.new());
27 -- A chain to show a single input on screen.
28 local simple_chain = EffectChain.new(16, 9);
29 local simple_chain_input = simple_chain:add_live_input();
30 simple_chain_input:connect_signal(0); -- First input card. Can be changed whenever you want.
31 simple_chain:finalize(false);
33 -- Returns the number of outputs in addition to the live (0) and preview (1).
34 -- Called only once, at the start of the program.
35 function num_channels()
39 -- Called every frame.
40 function get_transitions()
41 return {"Cut", "Fade", "Zoom!"};
44 function transition_clicked(num, t)
45 -- Only a cut for now.
46 local temp = live_signal_num;
47 live_signal_num = preview_signal_num;
48 preview_signal_num = temp;
51 function channel_clicked(num, t)
52 -- Presumably change the preview here.
53 io.write("STUB: channel_clicked\n");
56 -- Called every frame. Get the chain for displaying at input <num>,
57 -- where 0 is live, 1 is preview, 2 is the first channel to display
58 -- in the bottom bar, and so on up to num_channels()+1. t is the
59 -- current time in seconds. width and height are the dimensions of
60 -- the output, although you can ignore them if you don't need them
61 -- (they're useful if you want to e.g. know what to resample by).
63 -- You should return two objects; the chain itself, and then a
64 -- function (taking no parameters) that is run just before rendering.
65 -- The function needs to call connect_signal on any inputs, so that
66 -- it gets updated video data for the given frame. (You are allowed
67 -- to switch which input your input is getting from between frames,
68 -- but not calling connect_signal results in undefined behavior.)
69 -- If you want to change any parameters in the chain, this is also
72 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
73 -- if and only if num==0.
74 function get_chain(num, t, width, height)
75 if num == 0 then -- Live.
77 input0:connect_signal(live_signal_num);
78 wb_effect:set_float("output_color_temperature", 3500.0 + t * 100.0);
80 return main_chain, prepare;
82 if num == 1 then -- Preview.
84 simple_chain_input:connect_signal(preview_signal_num);
86 return simple_chain, prepare;
90 simple_chain_input:connect_signal(0);
92 return simple_chain, prepare;
96 simple_chain_input:connect_signal(1);
98 return simple_chain, prepare;