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 function make_sbs_chain(hq)
21 local chain = EffectChain.new(16, 9)
22 local input0 = chain:add_live_input()
23 input0:connect_signal(0)
24 local input1 = chain:add_live_input()
25 input1:connect_signal(1)
27 local resample_effect = nil
28 local resize_effect = nil
30 resample_effect = chain:add_effect(ResampleEffect.new(), input0)
32 resize_effect = chain:add_effect(ResizeEffect.new(), input0)
35 local padding_effect = chain:add_effect(IntegralPaddingEffect.new())
36 padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
38 local resample2_effect = nil
39 local resize2_effect = nil
41 resample2_effect = chain:add_effect(ResampleEffect.new(), input1)
43 resize2_effect = chain:add_effect(ResizeEffect.new(), input1)
45 -- Effect *saturation_effect = chain->add_effect(new SaturationEffect())
46 -- CHECK(saturation_effect->set_float("saturation", 0.3f))
47 local wb_effect = chain:add_effect(WhiteBalanceEffect.new())
48 wb_effect:set_float("output_color_temperature", 3500.0)
49 local padding2_effect = chain:add_effect(IntegralPaddingEffect.new())
51 chain:add_effect(OverlayEffect.new(), padding_effect, padding2_effect)
58 resample_effect = resample_effect,
59 resize_effect = resize_effect,
60 padding_effect = padding_effect
64 resample_effect = resample2_effect,
65 resize_effect = resize2_effect,
66 padding_effect = padding2_effect
71 local main_chain_hq = make_sbs_chain(true)
72 local main_chain_lq = make_sbs_chain(false)
74 -- A chain to show a single input on screen (HQ version).
75 local simple_chain_hq = EffectChain.new(16, 9)
76 local simple_chain_hq_input = simple_chain_hq:add_live_input()
77 simple_chain_hq_input:connect_signal(0); -- First input card. Can be changed whenever you want.
78 simple_chain_hq:finalize(true)
80 -- A chain to show a single input on screen (LQ version).
81 local simple_chain_lq = EffectChain.new(16, 9)
82 local simple_chain_lq_input = simple_chain_lq:add_live_input()
83 simple_chain_lq_input:connect_signal(0); -- First input card. Can be changed whenever you want.
84 simple_chain_lq:finalize(false)
86 -- Returns the number of outputs in addition to the live (0) and preview (1).
87 -- Called only once, at the start of the program.
88 function num_channels()
92 -- Called every frame.
93 function get_transitions()
94 return {"Cut", "Fade", "Zoom!"}
97 function transition_clicked(num, t)
98 -- local temp = live_signal_num
99 -- live_signal_num = preview_signal_num
100 -- preview_signal_num = temp
105 local temp = zoom_src
110 function channel_clicked(num, t)
111 -- Presumably change the preview here.
112 io.write("STUB: channel_clicked\n")
115 -- Called every frame. Get the chain for displaying at input <num>,
116 -- where 0 is live, 1 is preview, 2 is the first channel to display
117 -- in the bottom bar, and so on up to num_channels()+1. t is the
118 -- current time in seconds. width and height are the dimensions of
119 -- the output, although you can ignore them if you don't need them
120 -- (they're useful if you want to e.g. know what to resample by).
122 -- You should return two objects; the chain itself, and then a
123 -- function (taking no parameters) that is run just before rendering.
124 -- The function needs to call connect_signal on any inputs, so that
125 -- it gets updated video data for the given frame. (You are allowed
126 -- to switch which input your input is getting from between frames,
127 -- but not calling connect_signal results in undefined behavior.)
128 -- If you want to change any parameters in the chain, this is also
131 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
132 -- if and only if num==0.
133 function get_chain(num, t, width, height)
134 if num == 0 then -- Live.
135 if t > zoom_end and zoom_dst == 1.0 then
136 -- Special case: Show only the single image on screen.
138 simple_chain_hq_input:connect_signal(live_signal_num)
140 return simple_chain_hq, prepare
143 if t < zoom_start then
144 prepare_sbs_chain(main_chain_hq, zoom_src, width, height)
145 elseif t > zoom_end then
146 prepare_sbs_chain(main_chain_hq, zoom_dst, width, height)
148 local tt = (t - zoom_start) / (zoom_end - zoom_start)
150 tt = math.sin(tt * 3.14159265358 * 0.5)
151 prepare_sbs_chain(main_chain_hq, zoom_src + (zoom_dst - zoom_src) * tt, width, height)
154 return main_chain_hq.chain, prepare
156 if num == 1 then -- Preview.
158 simple_chain_lq_input:connect_signal(preview_signal_num)
160 return simple_chain_lq, prepare
164 simple_chain_lq_input:connect_signal(0)
166 return simple_chain_lq, prepare
170 simple_chain_lq_input:connect_signal(1)
172 return simple_chain_lq, prepare
176 prepare_sbs_chain(main_chain_lq, 0.0, width, height)
178 return main_chain_lq.chain, prepare
182 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height)
189 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
190 resample_effect:set_int("width", 1)
191 resample_effect:set_int("height", 1)
192 resample_effect:set_float("zoom_x", screen_width)
193 resample_effect:set_float("zoom_y", screen_height)
194 padding_effect:set_int("left", screen_width + 100)
195 padding_effect:set_int("top", screen_height + 100)
199 -- Clip. (TODO: Clip on upper/left sides, too.)
200 if x1 > screen_width then
201 srcx1 = (screen_width - x0) / (x1 - x0)
204 if y1 > screen_height then
205 srcy1 = (screen_height - y0) / (y1 - y0)
209 if resample_effect ~= nil then
210 -- High-quality resampling.
211 local x_subpixel_offset = x0 - math.floor(x0)
212 local y_subpixel_offset = y0 - math.floor(y0)
214 -- Resampling must be to an integral number of pixels. Round up,
215 -- and then add an extra pixel so we have some leeway for the border.
216 local width = math.ceil(x1 - x0) + 1
217 local height = math.ceil(y1 - y0) + 1
218 resample_effect:set_int("width", width)
219 resample_effect:set_int("height", height)
221 -- Correct the discrepancy with zoom. (This will leave a small
222 -- excess edge of pixels and subpixels, which we'll correct for soon.)
223 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
224 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
225 resample_effect:set_float("zoom_x", zoom_x)
226 resample_effect:set_float("zoom_y", zoom_y)
227 resample_effect:set_float("zoom_center_x", 0.0)
228 resample_effect:set_float("zoom_center_y", 0.0)
230 -- Padding must also be to a whole-pixel offset.
231 padding_effect:set_int("left", math.floor(x0))
232 padding_effect:set_int("top", math.floor(y0))
234 -- Correct _that_ discrepancy by subpixel offset in the resampling.
235 resample_effect:set_float("left", -x_subpixel_offset / zoom_x)
236 resample_effect:set_float("top", -y_subpixel_offset / zoom_y)
238 -- Finally, adjust the border so it is exactly where we want it.
239 padding_effect:set_float("border_offset_left", x_subpixel_offset)
240 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
241 padding_effect:set_float("border_offset_top", y_subpixel_offset)
242 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
244 -- Lower-quality simple resizing.
245 local width = round(x1 - x0)
246 local height = round(y1 - y0)
247 resize_effect:set_int("width", width)
248 resize_effect:set_int("height", height)
250 -- Padding must also be to a whole-pixel offset.
251 padding_effect:set_int("left", math.floor(x0))
252 padding_effect:set_int("top", math.floor(y0))
256 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
258 return math.floor(x + 0.5)
261 function prepare_sbs_chain(chain, t, screen_width, screen_height)
262 chain.input0.input:connect_signal(live_signal_num)
263 chain.input1.input:connect_signal(1)
265 -- First input is positioned (16,48) from top-left.
266 local width0 = round(848 * screen_width/1280.0)
267 local height0 = round(width0 * 9.0 / 16.0)
269 local top0 = 48 * screen_height/720.0
270 local left0 = 16 * screen_width/1280.0
271 local bottom0 = top0 + height0
272 local right0 = left0 + width0
274 -- Second input is positioned (16,48) from the bottom-right.
275 local width1 = 384 * screen_width/1280.0
276 local height1 = 216 * screen_height/720.0
278 local bottom1 = screen_height - 48 * screen_height/720.0
279 local right1 = screen_width - 16 * screen_width/1280.0
280 local top1 = bottom1 - height1
281 local left1 = right1 - width1
283 -- Interpolate between the fullscreen and side-by-side views.
284 local scale0 = 1.0 + t * (1280.0 / 848.0 - 1.0)
285 local tx0 = 0.0 + t * (-left0 * scale0)
286 local ty0 = 0.0 + t * (-top0 * scale0)
288 top0 = top0 * scale0 + ty0
289 bottom0 = bottom0 * scale0 + ty0
290 left0 = left0 * scale0 + tx0
291 right0 = right0 * scale0 + tx0
293 top1 = top1 * scale0 + ty0
294 bottom1 = bottom1 * scale0 + ty0
295 left1 = left1 * scale0 + tx0
296 right1 = right1 * scale0 + tx0
297 place_rectangle(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, left0, top0, right0, bottom0, screen_width, screen_height)
298 place_rectangle(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, left1, top1, right1, bottom1, screen_width, screen_height)