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.
10 local transition_start = -2.0
11 local transition_end = -1.0
14 local zoom_poi = 0 -- which input to zoom in on
18 local live_signal_num = 0
19 local preview_signal_num = 1
21 -- The main live chain.
22 function make_sbs_chain(hq)
23 local chain = EffectChain.new(16, 9)
24 local input0 = chain:add_live_input(true)
25 input0:connect_signal(0)
26 local input1 = chain:add_live_input(true)
27 input1:connect_signal(1)
29 local resample_effect = nil
30 local resize_effect = nil
32 resample_effect = chain:add_effect(ResampleEffect.new(), input0)
34 resize_effect = chain:add_effect(ResizeEffect.new(), input0)
37 local padding_effect = chain:add_effect(IntegralPaddingEffect.new())
38 padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
40 local resample2_effect = nil
41 local resize2_effect = nil
43 resample2_effect = chain:add_effect(ResampleEffect.new(), input1)
45 resize2_effect = chain:add_effect(ResizeEffect.new(), input1)
47 -- Effect *saturation_effect = chain->add_effect(new SaturationEffect())
48 -- CHECK(saturation_effect->set_float("saturation", 0.3f))
49 local wb_effect = chain:add_effect(WhiteBalanceEffect.new())
50 wb_effect:set_float("output_color_temperature", 3500.0)
51 local padding2_effect = chain:add_effect(IntegralPaddingEffect.new())
53 chain:add_effect(OverlayEffect.new(), padding_effect, padding2_effect)
60 resample_effect = resample_effect,
61 resize_effect = resize_effect,
62 padding_effect = padding_effect
66 resample_effect = resample2_effect,
67 resize_effect = resize2_effect,
68 padding_effect = padding2_effect
73 local main_chain_hq = make_sbs_chain(true)
74 local main_chain_lq = make_sbs_chain(false)
76 -- A chain to fade between two inputs (live chain only)
77 local fade_chain_hq = EffectChain.new(16, 9)
78 local fade_chain_hq_input0 = fade_chain_hq:add_live_input(true)
79 local fade_chain_hq_input1 = fade_chain_hq:add_live_input(true)
80 fade_chain_hq_input0:connect_signal(0)
81 fade_chain_hq_input1:connect_signal(1)
82 local fade_chain_mix_effect = fade_chain_hq:add_effect(MixEffect.new(), fade_chain_hq_input0, fade_chain_hq_input1)
83 fade_chain_hq:finalize(true)
85 -- A chain to show a single input on screen (HQ version).
86 local simple_chain_hq = EffectChain.new(16, 9)
87 local simple_chain_hq_input = simple_chain_hq:add_live_input(true)
88 simple_chain_hq_input:connect_signal(0) -- First input card. Can be changed whenever you want.
89 simple_chain_hq:finalize(true)
91 -- A chain to show a single input on screen (LQ version).
92 local simple_chain_lq = EffectChain.new(16, 9)
93 local simple_chain_lq_input = simple_chain_lq:add_live_input(true)
94 simple_chain_lq_input:connect_signal(0) -- First input card. Can be changed whenever you want.
95 simple_chain_lq:finalize(false)
97 -- Returns the number of outputs in addition to the live (0) and preview (1).
98 -- Called only once, at the start of the program.
99 function num_channels()
103 -- Returns the name for each additional channel (starting from 2).
104 -- Called only once for each channel, at the start of the program.
105 function channel_name(channel)
108 elseif channel == 3 then
111 return "Side-by-side"
115 -- Returns if a given channel supports setting white balance (starting from 2).
116 -- Called only once for each channel, at the start of the program.
117 function supports_set_wb(channel)
118 return channel == 2 or channel == 3
121 function finish_transitions(t)
122 -- If live is 2 (SBS) but de-facto single, make it so.
123 if live_signal_num == 2 and t >= transition_end and zoom_dst == 1.0 then
124 live_signal_num = zoom_poi
127 -- If live is 3 (fade) but de-facto single, make it so.
128 if live_signal_num == 3 and t >= transition_end and fade_dst == 1.0 then
131 if live_signal_num == 3 and t >= transition_end and fade_dst == 0.0 then
136 -- Called every frame.
137 function get_transitions(t)
138 finish_transitions(t)
140 if live_signal_num == preview_signal_num then
144 if live_signal_num == 2 and t >= transition_start and t <= transition_end then
149 if (live_signal_num == 0 and preview_signal_num == 1) or
150 (live_signal_num == 1 and preview_signal_num == 0) then
151 return {"Cut", "", "Fade"}
155 if live_signal_num == 2 and (preview_signal_num == 0 or preview_signal_num == 1) then
156 return {"Cut", "Zoom in"}
157 elseif (live_signal_num == 0 or live_signal_num == 1) and preview_signal_num == 2 then
158 return {"Cut", "Zoom out"}
164 function transition_clicked(num, t)
167 if live_signal_num == 3 then
168 -- Ongoing fade; finish it immediately.
169 finish_transitions(transition_end)
172 local temp = live_signal_num
173 live_signal_num = preview_signal_num
174 preview_signal_num = temp
176 if live_signal_num == 2 then
177 -- Just cut to SBS, we need to reset any zooms.
180 transition_start = -2.0
181 transition_end = -1.0
186 finish_transitions(t)
188 if live_signal_num == preview_signal_num then
193 if (live_signal_num == 0 and preview_signal_num == 1) or
194 (live_signal_num == 1 and preview_signal_num == 0) then
195 -- We can't zoom between these. Just make a cut.
196 io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
197 local temp = live_signal_num
198 live_signal_num = preview_signal_num
199 preview_signal_num = temp
203 if live_signal_num == 2 and (preview_signal_num == 0 or preview_signal_num == 1) then
204 -- Zoom in from SBS to single.
206 transition_end = t + 1.0
209 zoom_poi = preview_signal_num
210 preview_signal_num = 2
211 elseif (live_signal_num == 0 or live_signal_num == 1) and preview_signal_num == 2 then
212 -- Zoom out from single to SBS.
214 transition_end = t + 1.0
217 preview_signal_num = live_signal_num
218 zoom_poi = live_signal_num
222 finish_transitions(t)
225 if live_signal_num == 0 and preview_signal_num == 1 then
227 transition_end = t + 1.0
230 preview_signal_num = 0
232 elseif live_signal_num == 1 and preview_signal_num == 0 then
234 transition_end = t + 1.0
237 preview_signal_num = 1
240 -- Fades involving SBS are ignored (we have no chain for it).
245 function channel_clicked(num)
246 preview_signal_num = num
249 -- Called every frame. Get the chain for displaying at input <num>,
250 -- where 0 is live, 1 is preview, 2 is the first channel to display
251 -- in the bottom bar, and so on up to num_channels()+1. t is the
252 -- current time in seconds. width and height are the dimensions of
253 -- the output, although you can ignore them if you don't need them
254 -- (they're useful if you want to e.g. know what to resample by).
256 -- You should return two objects; the chain itself, and then a
257 -- function (taking no parameters) that is run just before rendering.
258 -- The function needs to call connect_signal on any inputs, so that
259 -- it gets updated video data for the given frame. (You are allowed
260 -- to switch which input your input is getting from between frames,
261 -- but not calling connect_signal results in undefined behavior.)
262 -- If you want to change any parameters in the chain, this is also
265 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
266 -- if and only if num==0.
267 function get_chain(num, t, width, height)
268 if num == 0 then -- Live.
269 if live_signal_num == 0 or live_signal_num == 1 then -- Plain inputs.
271 simple_chain_hq_input:connect_signal(live_signal_num)
273 return simple_chain_hq, prepare
274 elseif live_signal_num == 3 then -- Fade.
276 fade_chain_hq_input0:connect_signal(0)
277 fade_chain_hq_input1:connect_signal(1)
278 local tt = (t - transition_start) / (transition_end - transition_start)
285 tt = fade_src + tt * (fade_dst - fade_src)
287 -- Make the fade look maybe a tad more natural, by pumping it
288 -- through a sigmoid function.
290 tt = 1.0 / (1.0 + math.exp(-tt))
292 fade_chain_mix_effect:set_float("strength_first", tt)
293 fade_chain_mix_effect:set_float("strength_second", 1.0 - tt)
295 return fade_chain_hq, prepare
298 -- SBS code (live_signal_num == 2).
299 if t > transition_end and zoom_dst == 1.0 then
300 -- Special case: Show only the single image on screen.
302 simple_chain_hq_input:connect_signal(0)
304 return simple_chain_hq, prepare
307 if t < transition_start then
308 prepare_sbs_chain(main_chain_hq, zoom_src, width, height)
309 elseif t > transition_end then
310 prepare_sbs_chain(main_chain_hq, zoom_dst, width, height)
312 local tt = (t - transition_start) / (transition_end - transition_start)
314 tt = math.sin(tt * 3.14159265358 * 0.5)
315 prepare_sbs_chain(main_chain_hq, zoom_src + (zoom_dst - zoom_src) * tt, width, height)
318 return main_chain_hq.chain, prepare
320 if num == 1 then -- Preview.
321 num = preview_signal_num + 2
325 simple_chain_lq_input:connect_signal(0)
327 return simple_chain_lq, prepare
331 simple_chain_lq_input:connect_signal(1)
333 return simple_chain_lq, prepare
337 prepare_sbs_chain(main_chain_lq, 0.0, width, height)
339 return main_chain_lq.chain, prepare
343 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
350 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
351 resample_effect:set_int("width", 1)
352 resample_effect:set_int("height", 1)
353 resample_effect:set_float("zoom_x", screen_width)
354 resample_effect:set_float("zoom_y", screen_height)
355 padding_effect:set_int("left", screen_width + 100)
356 padding_effect:set_int("top", screen_height + 100)
362 srcx0 = -x0 / (x1 - x0)
366 srcy0 = -y0 / (y1 - y0)
369 if x1 > screen_width then
370 srcx1 = (screen_width - x0) / (x1 - x0)
373 if y1 > screen_height then
374 srcy1 = (screen_height - y0) / (y1 - y0)
378 if resample_effect ~= nil then
379 -- High-quality resampling.
380 local x_subpixel_offset = x0 - math.floor(x0)
381 local y_subpixel_offset = y0 - math.floor(y0)
383 -- Resampling must be to an integral number of pixels. Round up,
384 -- and then add an extra pixel so we have some leeway for the border.
385 local width = math.ceil(x1 - x0) + 1
386 local height = math.ceil(y1 - y0) + 1
387 resample_effect:set_int("width", width)
388 resample_effect:set_int("height", height)
390 -- Correct the discrepancy with zoom. (This will leave a small
391 -- excess edge of pixels and subpixels, which we'll correct for soon.)
392 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
393 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
394 resample_effect:set_float("zoom_x", zoom_x)
395 resample_effect:set_float("zoom_y", zoom_y)
396 resample_effect:set_float("zoom_center_x", 0.0)
397 resample_effect:set_float("zoom_center_y", 0.0)
399 -- Padding must also be to a whole-pixel offset.
400 padding_effect:set_int("left", math.floor(x0))
401 padding_effect:set_int("top", math.floor(y0))
403 -- Correct _that_ discrepancy by subpixel offset in the resampling.
404 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
405 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
407 -- Finally, adjust the border so it is exactly where we want it.
408 padding_effect:set_float("border_offset_left", x_subpixel_offset)
409 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
410 padding_effect:set_float("border_offset_top", y_subpixel_offset)
411 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
413 -- Lower-quality simple resizing.
414 local width = round(x1 - x0)
415 local height = round(y1 - y0)
416 resize_effect:set_int("width", width)
417 resize_effect:set_int("height", height)
419 -- Padding must also be to a whole-pixel offset.
420 padding_effect:set_int("left", math.floor(x0))
421 padding_effect:set_int("top", math.floor(y0))
425 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
427 return math.floor(x + 0.5)
430 function lerp(a, b, t)
431 return a + (b - a) * t
434 function prepare_sbs_chain(chain, t, screen_width, screen_height)
435 chain.input0.input:connect_signal(0)
436 chain.input1.input:connect_signal(1)
438 -- First input is positioned (16,48) from top-left.
439 local width0 = round(848 * screen_width/1280.0)
440 local height0 = round(width0 * 9.0 / 16.0)
442 local top0 = 48 * screen_height/720.0
443 local left0 = 16 * screen_width/1280.0
444 local bottom0 = top0 + height0
445 local right0 = left0 + width0
447 -- Second input is positioned (16,48) from the bottom-right.
448 local width1 = round(384 * screen_width/1280.0)
449 local height1 = round(216 * screen_height/720.0)
451 local bottom1 = screen_height - 48 * screen_height/720.0
452 local right1 = screen_width - 16 * screen_width/1280.0
453 local top1 = bottom1 - height1
454 local left1 = right1 - width1
456 -- Interpolate between the fullscreen and side-by-side views.
457 local scale0, tx0, tx0
458 if zoom_poi == 0 then
459 local new_left0 = lerp(left0, 0, t)
460 local new_right0 = lerp(right0, screen_width, t)
461 local new_top0 = lerp(top0, 0, t)
462 local new_bottom0 = lerp(bottom0, screen_height, t)
464 scale0 = (new_right0 - new_left0) / width0 -- Same vertically and horizonally.
465 tx0 = new_left0 - left0 * scale0
466 ty0 = new_top0 - top0 * scale0
468 local new_left1 = lerp(left1, 0, t)
469 local new_right1 = lerp(right1, screen_width, t)
470 local new_top1 = lerp(top1, 0, t)
471 local new_bottom1 = lerp(bottom1, screen_height, t)
473 scale0 = (new_right1 - new_left1) / width1 -- Same vertically and horizonally.
474 tx0 = new_left1 - left1 * scale0
475 ty0 = new_top1 - top1 * scale0
478 top0 = top0 * scale0 + ty0
479 bottom0 = bottom0 * scale0 + ty0
480 left0 = left0 * scale0 + tx0
481 right0 = right0 * scale0 + tx0
483 top1 = top1 * scale0 + ty0
484 bottom1 = bottom1 * scale0 + ty0
485 left1 = left1 * scale0 + tx0
486 right1 = right1 * scale0 + tx0
487 place_rectangle(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, left0, top0, right0, bottom0, screen_width, screen_height, 1280, 720)
488 place_rectangle(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, left1, top1, right1, bottom1, screen_width, screen_height, 1280, 720)