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 zoom_start = -2.0
16 local live_signal_num = 0
17 local preview_signal_num = 1
19 -- The main live chain.
20 local main_chain = EffectChain.new(16, 9)
21 local input0 = main_chain:add_live_input()
22 input0:connect_signal(0)
23 local input1 = main_chain:add_live_input()
24 input1:connect_signal(1)
25 local resample_effect = main_chain:add_effect(ResampleEffect.new(), input0)
26 local padding_effect = main_chain:add_effect(IntegralPaddingEffect.new())
27 padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
29 local resample2_effect = main_chain:add_effect(ResampleEffect.new(), input1)
30 -- Effect *saturation_effect = main_chain->add_effect(new SaturationEffect())
31 -- CHECK(saturation_effect->set_float("saturation", 0.3f))
32 local wb_effect = main_chain:add_effect(WhiteBalanceEffect.new())
33 wb_effect:set_float("output_color_temperature", 3500.0)
34 local padding2_effect = main_chain:add_effect(IntegralPaddingEffect.new())
36 main_chain:add_effect(OverlayEffect.new(), padding_effect, padding2_effect)
37 main_chain:finalize(true)
39 -- A chain to show a single input on screen (HQ version).
40 local simple_chain_hq = EffectChain.new(16, 9)
41 local simple_chain_hq_input = simple_chain_hq:add_live_input()
42 simple_chain_hq_input:connect_signal(0); -- First input card. Can be changed whenever you want.
43 simple_chain_hq:finalize(true)
45 -- A chain to show a single input on screen (LQ version).
46 local simple_chain_lq = EffectChain.new(16, 9)
47 local simple_chain_lq_input = simple_chain_lq:add_live_input()
48 simple_chain_lq_input:connect_signal(0); -- First input card. Can be changed whenever you want.
49 simple_chain_lq:finalize(false)
51 -- Returns the number of outputs in addition to the live (0) and preview (1).
52 -- Called only once, at the start of the program.
53 function num_channels()
57 -- Called every frame.
58 function get_transitions()
59 return {"Cut", "Fade", "Zoom!"}
62 function transition_clicked(num, t)
63 -- local temp = live_signal_num
64 -- live_signal_num = preview_signal_num
65 -- preview_signal_num = temp
75 function channel_clicked(num, t)
76 -- Presumably change the preview here.
77 io.write("STUB: channel_clicked\n")
80 -- Called every frame. Get the chain for displaying at input <num>,
81 -- where 0 is live, 1 is preview, 2 is the first channel to display
82 -- in the bottom bar, and so on up to num_channels()+1. t is the
83 -- current time in seconds. width and height are the dimensions of
84 -- the output, although you can ignore them if you don't need them
85 -- (they're useful if you want to e.g. know what to resample by).
87 -- You should return two objects; the chain itself, and then a
88 -- function (taking no parameters) that is run just before rendering.
89 -- The function needs to call connect_signal on any inputs, so that
90 -- it gets updated video data for the given frame. (You are allowed
91 -- to switch which input your input is getting from between frames,
92 -- but not calling connect_signal results in undefined behavior.)
93 -- If you want to change any parameters in the chain, this is also
96 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
97 -- if and only if num==0.
98 function get_chain(num, t, width, height)
99 if num == 0 then -- Live.
100 if t > zoom_end and zoom_dst == 1.0 then
101 -- Special case: Show only the single image on screen.
103 simple_chain_hq_input:connect_signal(live_signal_num)
105 return simple_chain_hq, prepare
108 if t < zoom_start then
109 prepare_sbs_chain(zoom_src, width, height)
110 elseif t > zoom_end then
111 prepare_sbs_chain(zoom_dst, width, height)
113 local tt = (t - zoom_start) / (zoom_end - zoom_start)
115 tt = math.sin(tt * 3.14159265358 * 0.5)
116 prepare_sbs_chain(zoom_src + (zoom_dst - zoom_src) * tt, width, height)
119 return main_chain, prepare
121 if num == 1 then -- Preview.
123 simple_chain_lq_input:connect_signal(preview_signal_num)
125 return simple_chain_lq, prepare
129 simple_chain_lq_input:connect_signal(0)
131 return simple_chain_lq, prepare
135 simple_chain_lq_input:connect_signal(1)
137 return simple_chain_lq, prepare
141 function place_rectangle(resample_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height)
148 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
149 resample_effect:set_int("width", 1)
150 resample_effect:set_int("height", 1)
151 resample_effect:set_float("zoom_x", screen_width)
152 resample_effect:set_float("zoom_y", screen_height)
153 padding_effect:set_int("left", screen_width + 100)
154 padding_effect:set_int("top", screen_height + 100)
158 -- Clip. (TODO: Clip on upper/left sides, too.)
159 if x1 > screen_width then
160 srcx1 = (screen_width - x0) / (x1 - x0)
163 if y1 > screen_height then
164 srcy1 = (screen_height - y0) / (y1 - y0)
168 local x_subpixel_offset = x0 - math.floor(x0)
169 local y_subpixel_offset = y0 - math.floor(y0)
171 -- Resampling must be to an integral number of pixels. Round up,
172 -- and then add an extra pixel so we have some leeway for the border.
173 local width = math.ceil(x1 - x0) + 1
174 local height = math.ceil(y1 - y0) + 1
175 resample_effect:set_int("width", width)
176 resample_effect:set_int("height", height)
178 -- Correct the discrepancy with zoom. (This will leave a small
179 -- excess edge of pixels and subpixels, which we'll correct for soon.)
180 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
181 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
182 resample_effect:set_float("zoom_x", zoom_x)
183 resample_effect:set_float("zoom_y", zoom_y)
184 resample_effect:set_float("zoom_center_x", 0.0)
185 resample_effect:set_float("zoom_center_y", 0.0)
187 -- Padding must also be to a whole-pixel offset.
188 padding_effect:set_int("left", math.floor(x0))
189 padding_effect:set_int("top", math.floor(y0))
191 -- Correct _that_ discrepancy by subpixel offset in the resampling.
192 resample_effect:set_float("left", -x_subpixel_offset / zoom_x)
193 resample_effect:set_float("top", -y_subpixel_offset / zoom_y)
195 -- Finally, adjust the border so it is exactly where we want it.
196 padding_effect:set_float("border_offset_left", x_subpixel_offset)
197 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
198 padding_effect:set_float("border_offset_top", y_subpixel_offset)
199 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
202 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
204 return math.floor(x + 0.5)
207 function prepare_sbs_chain(t, screen_width, screen_height)
208 input0:connect_signal(live_signal_num)
209 input1:connect_signal(1)
211 -- First input is positioned (16,48) from top-left.
212 local width0 = round(848 * screen_width/1280.0)
213 local height0 = round(width0 * 9.0 / 16.0)
215 local top0 = 48 * screen_height/720.0
216 local left0 = 16 * screen_width/1280.0
217 local bottom0 = top0 + height0
218 local right0 = left0 + width0
220 -- Second input is positioned (16,48) from the bottom-right.
221 local width1 = 384 * screen_width/1280.0
222 local height1 = 216 * screen_height/720.0
224 local bottom1 = screen_height - 48 * screen_height/720.0
225 local right1 = screen_width - 16 * screen_width/1280.0
226 local top1 = bottom1 - height1
227 local left1 = right1 - width1
229 -- Interpolate between the fullscreen and side-by-side views.
230 local scale0 = 1.0 + t * (1280.0 / 848.0 - 1.0)
231 local tx0 = 0.0 + t * (-left0 * scale0)
232 local ty0 = 0.0 + t * (-top0 * scale0)
234 top0 = top0 * scale0 + ty0
235 bottom0 = bottom0 * scale0 + ty0
236 left0 = left0 * scale0 + tx0
237 right0 = right0 * scale0 + tx0
239 top1 = top1 * scale0 + ty0
240 bottom1 = bottom1 * scale0 + ty0
241 left1 = left1 * scale0 + tx0
242 right1 = right1 * scale0 + tx0
243 place_rectangle(resample_effect, padding_effect, left0, top0, right0, bottom0, screen_width, screen_height)
244 place_rectangle(resample2_effect, padding2_effect, left1, top1, right1, bottom1, screen_width, screen_height)