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 -- TODO: Deal with inputs that are different from our native 1280x720 resolution.
12 local transition_start = -2.0
13 local transition_end = -1.0
16 local zoom_poi = 0 -- which input to zoom in on
17 local fade_src_signal = 0
18 local fade_dst_signal = 0
20 local input0_neutral_color = {0.5, 0.5, 0.5}
21 local input1_neutral_color = {0.5, 0.5, 0.5}
23 local live_signal_num = 0
24 local preview_signal_num = 1
26 -- Valid values for live_signal_num and preview_signal_num.
27 local INPUT0_SIGNAL_NUM = 0
28 local INPUT1_SIGNAL_NUM = 1
29 local SBS_SIGNAL_NUM = 2
30 local STATIC_SIGNAL_NUM = 3
32 -- “fake” signal number that signifies that we are fading from one input
34 local FADE_SIGNAL_NUM = 4
36 -- The main live chain.
37 function make_sbs_chain(hq)
38 local chain = EffectChain.new(16, 9)
39 local input0 = chain:add_live_input(true)
40 input0:connect_signal(0)
41 local input0_wb_effect = chain:add_effect(WhiteBalanceEffect.new())
42 local input1 = chain:add_live_input(true)
43 input1:connect_signal(1)
44 local input1_wb_effect = chain:add_effect(WhiteBalanceEffect.new())
46 local resample_effect = nil
47 local resize_effect = nil
49 resample_effect = chain:add_effect(ResampleEffect.new(), input0_wb_effect)
51 resize_effect = chain:add_effect(ResizeEffect.new(), input0_wb_effect)
54 local padding_effect = chain:add_effect(IntegralPaddingEffect.new())
55 padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
57 local resample2_effect = nil
58 local resize2_effect = nil
60 resample2_effect = chain:add_effect(ResampleEffect.new(), input1_wb_effect)
62 resize2_effect = chain:add_effect(ResizeEffect.new(), input1_wb_effect)
64 local padding2_effect = chain:add_effect(IntegralPaddingEffect.new())
66 chain:add_effect(OverlayEffect.new(), padding_effect, padding2_effect)
73 white_balance_effect = input0_wb_effect,
74 resample_effect = resample_effect,
75 resize_effect = resize_effect,
76 padding_effect = padding_effect
80 white_balance_effect = input1_wb_effect,
81 resample_effect = resample2_effect,
82 resize_effect = resize2_effect,
83 padding_effect = padding2_effect
88 local main_chain_hq = make_sbs_chain(true)
89 local main_chain_lq = make_sbs_chain(false)
91 -- A chain to fade between two inputs, of which either can be a picture
92 -- or a live input. In practice only used live, but we still support the
94 function make_fade_chain(input0_live, input1_live, hq)
95 local chain = EffectChain.new(16, 9)
97 local input0, wb0_effect, input0_last, input1, wb1_effect, input1_last
100 input0 = chain:add_live_input(true)
101 wb0_effect = chain:add_effect(WhiteBalanceEffect.new())
102 input0:connect_signal(0)
103 input0_last = wb0_effect
105 input0 = chain:add_effect(ImageInput.new("bg.jpeg"))
110 input1 = chain:add_live_input(true)
111 wb1_effect = chain:add_effect(WhiteBalanceEffect.new())
112 input1:connect_signal(1)
113 input1_last = wb1_effect
115 input1 = chain:add_effect(ImageInput.new("bg.jpeg"))
119 local mix_effect = chain:add_effect(MixEffect.new(), input0_last, input1_last)
126 white_balance_effect = wb0_effect
130 white_balance_effect = wb1_effect
132 mix_effect = mix_effect
136 -- Chains to fade between two inputs, in various configurations.
137 local fade_chains = {}
138 for input0_type, input0_live in pairs({static = false, live = true}) do
139 fade_chains[input0_type] = {}
140 for input1_type, input1_live in pairs({static = false, live = true}) do
141 fade_chains[input0_type][input1_type] = {}
142 for _, hq in pairs({true, false}) do
143 fade_chains[input0_type][input1_type][hq] = make_fade_chain(input0_live, input1_live, hq)
148 -- A chain to show a single input on screen (HQ version).
149 local simple_chain_hq = EffectChain.new(16, 9)
150 local simple_chain_hq_input = simple_chain_hq:add_live_input(true)
151 simple_chain_hq_input:connect_signal(0) -- First input card. Can be changed whenever you want.
152 local simple_chain_hq_wb_effect = simple_chain_hq:add_effect(WhiteBalanceEffect.new())
153 simple_chain_hq:finalize(true)
155 -- A chain to show a single input on screen (LQ version).
156 local simple_chain_lq = EffectChain.new(16, 9)
157 local simple_chain_lq_input = simple_chain_lq:add_live_input(true)
158 simple_chain_lq_input:connect_signal(0) -- First input card. Can be changed whenever you want.
159 local simple_chain_lq_wb_effect = simple_chain_lq:add_effect(WhiteBalanceEffect.new())
160 simple_chain_lq:finalize(false)
162 -- A chain to show a single static picture on screen (HQ version).
163 local static_chain_hq = EffectChain.new(16, 9)
164 local static_chain_hq_input = static_chain_hq:add_effect(ImageInput.new("bg.jpeg"))
165 static_chain_hq:finalize(true)
167 -- A chain to show a single static picture on screen (LQ version).
168 local static_chain_lq = EffectChain.new(16, 9)
169 local static_chain_lq_input = static_chain_lq:add_effect(ImageInput.new("bg.jpeg"))
170 static_chain_lq:finalize(false)
172 -- Returns the number of outputs in addition to the live (0) and preview (1).
173 -- Called only once, at the start of the program.
174 function num_channels()
178 -- Returns the name for each additional channel (starting from 2).
179 -- Called only once for each channel, at the start of the program.
180 function channel_name(channel)
183 elseif channel == 3 then
185 elseif channel == 4 then
186 return "Side-by-side"
187 elseif channel == 5 then
188 return "Static picture"
192 -- Returns if a given channel supports setting white balance (starting from 2).
193 -- Called only once for each channel, at the start of the program.
194 function supports_set_wb(channel)
195 return channel == 2 or channel == 3
198 -- Gets called with a new gray point when the white balance is changing.
199 -- The color is in linear light (not sRGB gamma).
200 function set_wb(channel, red, green, blue)
202 input0_neutral_color = { red, green, blue }
203 elseif channel == 3 then
204 input1_neutral_color = { red, green, blue }
208 function finish_transitions(t)
209 -- If live is SBS but de-facto single, make it so.
210 if live_signal_num == SBS_SIGNAL_NUM and t >= transition_end and zoom_dst == 1.0 then
211 live_signal_num = zoom_poi
214 -- If live is fade but de-facto single, make it so.
215 if live_signal_num == FADE_SIGNAL_NUM and t >= transition_end then
216 live_signal_num = fade_dst_signal
220 -- Called every frame.
221 function get_transitions(t)
222 finish_transitions(t)
224 if live_signal_num == preview_signal_num then
228 if live_signal_num == SBS_SIGNAL_NUM and t >= transition_start and t <= transition_end then
233 if (live_signal_num == INPUT0_SIGNAL_NUM or
234 live_signal_num == INPUT1_SIGNAL_NUM or
235 live_signal_num == STATIC_SIGNAL_NUM) and
236 (preview_signal_num == INPUT0_SIGNAL_NUM or
237 preview_signal_num == INPUT1_SIGNAL_NUM or
238 preview_signal_num == STATIC_SIGNAL_NUM) then
239 return {"Cut", "", "Fade"}
243 if live_signal_num == SBS_SIGNAL_NUM and
244 (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
245 return {"Cut", "Zoom in"}
246 elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
247 preview_signal_num == SBS_SIGNAL_NUM then
248 return {"Cut", "Zoom out"}
254 function transition_clicked(num, t)
257 if live_signal_num == FADE_SIGNAL_NUM then
258 -- Ongoing fade; finish it immediately.
259 finish_transitions(transition_end)
262 local temp = live_signal_num
263 live_signal_num = preview_signal_num
264 preview_signal_num = temp
266 if live_signal_num == SBS_SIGNAL_NUM then
267 -- Just cut to SBS, we need to reset any zooms.
270 transition_start = -2.0
271 transition_end = -1.0
276 finish_transitions(t)
278 if live_signal_num == preview_signal_num then
283 if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
284 (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
285 -- We can't zoom between these. Just make a cut.
286 io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
287 local temp = live_signal_num
288 live_signal_num = preview_signal_num
289 preview_signal_num = temp
293 if live_signal_num == SBS_SIGNAL_NUM and
294 (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
295 -- Zoom in from SBS to single.
297 transition_end = t + 1.0
300 zoom_poi = preview_signal_num
301 preview_signal_num = SBS_SIGNAL_NUM
302 elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
303 preview_signal_num == SBS_SIGNAL_NUM then
304 -- Zoom out from single to SBS.
306 transition_end = t + 1.0
309 preview_signal_num = live_signal_num
310 zoom_poi = live_signal_num
311 live_signal_num = SBS_SIGNAL_NUM
314 finish_transitions(t)
317 if (live_signal_num ~= preview_signal_num) and
318 (live_signal_num == INPUT0_SIGNAL_NUM or
319 live_signal_num == INPUT1_SIGNAL_NUM or
320 live_signal_num == STATIC_SIGNAL_NUM) and
321 (preview_signal_num == INPUT0_SIGNAL_NUM or
322 preview_signal_num == INPUT1_SIGNAL_NUM or
323 preview_signal_num == STATIC_SIGNAL_NUM) then
325 transition_end = t + 1.0
326 fade_src_signal = live_signal_num
327 fade_dst_signal = preview_signal_num
328 preview_signal_num = live_signal_num
329 live_signal_num = FADE_SIGNAL_NUM
331 -- Fades involving SBS are ignored (we have no chain for it).
336 function channel_clicked(num)
337 preview_signal_num = num
340 -- Called every frame. Get the chain for displaying at input <num>,
341 -- where 0 is live, 1 is preview, 2 is the first channel to display
342 -- in the bottom bar, and so on up to num_channels()+1. t is the
343 -- current time in seconds. width and height are the dimensions of
344 -- the output, although you can ignore them if you don't need them
345 -- (they're useful if you want to e.g. know what to resample by).
347 -- <signals> is basically an exposed InputState, which you can use to
348 -- query for information about the signals at the point of the current
349 -- frame. In particular, you can call get_width() and get_height()
350 -- for any signal number, and use that to e.g. assist in chain selection.
352 -- You should return two objects; the chain itself, and then a
353 -- function (taking no parameters) that is run just before rendering.
354 -- The function needs to call connect_signal on any inputs, so that
355 -- it gets updated video data for the given frame. (You are allowed
356 -- to switch which input your input is getting from between frames,
357 -- but not calling connect_signal results in undefined behavior.)
358 -- If you want to change any parameters in the chain, this is also
361 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
362 -- if and only if num==0.
363 function get_chain(num, t, width, height, signals)
364 if num == 0 then -- Live.
365 if live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM then -- Plain input.
367 simple_chain_hq_input:connect_signal(live_signal_num)
368 set_neutral_color_from_signal(simple_chain_hq_wb_effect, live_signal_num)
370 return simple_chain_hq, prepare
371 elseif live_signal_num == STATIC_SIGNAL_NUM then -- Static picture.
374 return static_chain_hq, prepare
375 elseif live_signal_num == FADE_SIGNAL_NUM then -- Fade.
376 local input0_type = (fade_src_signal == STATIC_SIGNAL_NUM) and "static" or "live"
377 local input1_type = (fade_dst_signal == STATIC_SIGNAL_NUM) and "static" or "live"
378 local chain = fade_chains[input0_type][input1_type][true]
380 if input0_type == "live" then
381 chain.input0.input:connect_signal(fade_src_signal)
382 set_neutral_color_from_signal(chain.input0.white_balance_effect, fade_src_signal)
384 if input1_type == "live" then
385 chain.input1.input:connect_signal(fade_dst_signal)
386 set_neutral_color_from_signal(chain.input1.white_balance_effect, fade_dst_signal)
388 local tt = calc_fade_progress(t, transition_start, transition_end)
390 chain.mix_effect:set_float("strength_first", 1.0 - tt)
391 chain.mix_effect:set_float("strength_second", tt)
393 return chain.chain, prepare
396 -- SBS code (live_signal_num == SBS_SIGNAL_NUM).
397 if t > transition_end and zoom_dst == 1.0 then
398 -- Special case: Show only the single image on screen.
400 simple_chain_hq_input:connect_signal(INPUT0_SIGNAL_NUM)
401 set_neutral_color(simple_chain_hq_wb_effect, input0_neutral_color)
403 return simple_chain_hq, prepare
406 if t < transition_start then
407 prepare_sbs_chain(main_chain_hq, zoom_src, width, height)
408 elseif t > transition_end then
409 prepare_sbs_chain(main_chain_hq, zoom_dst, width, height)
411 local tt = (t - transition_start) / (transition_end - transition_start)
413 tt = math.sin(tt * 3.14159265358 * 0.5)
414 prepare_sbs_chain(main_chain_hq, zoom_src + (zoom_dst - zoom_src) * tt, width, height)
417 return main_chain_hq.chain, prepare
419 if num == 1 then -- Preview.
420 num = preview_signal_num + 2
422 if num == INPUT0_SIGNAL_NUM + 2 then
424 simple_chain_lq_input:connect_signal(0)
425 set_neutral_color(simple_chain_lq_wb_effect, input0_neutral_color)
427 return simple_chain_lq, prepare
429 if num == INPUT1_SIGNAL_NUM + 2 then
431 simple_chain_lq_input:connect_signal(1)
432 set_neutral_color(simple_chain_lq_wb_effect, input1_neutral_color)
434 return simple_chain_lq, prepare
436 if num == SBS_SIGNAL_NUM + 2 then
438 prepare_sbs_chain(main_chain_lq, 0.0, width, height)
440 return main_chain_lq.chain, prepare
442 if num == STATIC_SIGNAL_NUM + 2 then
445 return static_chain_lq, prepare
449 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
456 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
457 resample_effect:set_int("width", 1)
458 resample_effect:set_int("height", 1)
459 resample_effect:set_float("zoom_x", screen_width)
460 resample_effect:set_float("zoom_y", screen_height)
461 padding_effect:set_int("left", screen_width + 100)
462 padding_effect:set_int("top", screen_height + 100)
468 srcx0 = -x0 / (x1 - x0)
472 srcy0 = -y0 / (y1 - y0)
475 if x1 > screen_width then
476 srcx1 = (screen_width - x0) / (x1 - x0)
479 if y1 > screen_height then
480 srcy1 = (screen_height - y0) / (y1 - y0)
484 if resample_effect ~= nil then
485 -- High-quality resampling.
486 local x_subpixel_offset = x0 - math.floor(x0)
487 local y_subpixel_offset = y0 - math.floor(y0)
489 -- Resampling must be to an integral number of pixels. Round up,
490 -- and then add an extra pixel so we have some leeway for the border.
491 local width = math.ceil(x1 - x0) + 1
492 local height = math.ceil(y1 - y0) + 1
493 resample_effect:set_int("width", width)
494 resample_effect:set_int("height", height)
496 -- Correct the discrepancy with zoom. (This will leave a small
497 -- excess edge of pixels and subpixels, which we'll correct for soon.)
498 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
499 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
500 resample_effect:set_float("zoom_x", zoom_x)
501 resample_effect:set_float("zoom_y", zoom_y)
502 resample_effect:set_float("zoom_center_x", 0.0)
503 resample_effect:set_float("zoom_center_y", 0.0)
505 -- Padding must also be to a whole-pixel offset.
506 padding_effect:set_int("left", math.floor(x0))
507 padding_effect:set_int("top", math.floor(y0))
509 -- Correct _that_ discrepancy by subpixel offset in the resampling.
510 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
511 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
513 -- Finally, adjust the border so it is exactly where we want it.
514 padding_effect:set_float("border_offset_left", x_subpixel_offset)
515 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
516 padding_effect:set_float("border_offset_top", y_subpixel_offset)
517 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
519 -- Lower-quality simple resizing.
520 local width = round(x1 - x0)
521 local height = round(y1 - y0)
522 resize_effect:set_int("width", width)
523 resize_effect:set_int("height", height)
525 -- Padding must also be to a whole-pixel offset.
526 padding_effect:set_int("left", math.floor(x0))
527 padding_effect:set_int("top", math.floor(y0))
531 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
533 return math.floor(x + 0.5)
536 function lerp(a, b, t)
537 return a + (b - a) * t
540 function prepare_sbs_chain(chain, t, screen_width, screen_height)
541 chain.input0.input:connect_signal(0)
542 chain.input1.input:connect_signal(1)
543 set_neutral_color(chain.input0.white_balance_effect, input0_neutral_color)
544 set_neutral_color(chain.input1.white_balance_effect, input1_neutral_color)
546 -- First input is positioned (16,48) from top-left.
547 local width0 = round(848 * screen_width/1280.0)
548 local height0 = round(width0 * 9.0 / 16.0)
550 local top0 = 48 * screen_height/720.0
551 local left0 = 16 * screen_width/1280.0
552 local bottom0 = top0 + height0
553 local right0 = left0 + width0
555 -- Second input is positioned (16,48) from the bottom-right.
556 local width1 = round(384 * screen_width/1280.0)
557 local height1 = round(216 * screen_height/720.0)
559 local bottom1 = screen_height - 48 * screen_height/720.0
560 local right1 = screen_width - 16 * screen_width/1280.0
561 local top1 = bottom1 - height1
562 local left1 = right1 - width1
564 -- Interpolate between the fullscreen and side-by-side views.
565 local scale0, tx0, tx0
566 if zoom_poi == INPUT0_SIGNAL_NUM then
567 local new_left0 = lerp(left0, 0, t)
568 local new_right0 = lerp(right0, screen_width, t)
569 local new_top0 = lerp(top0, 0, t)
570 local new_bottom0 = lerp(bottom0, screen_height, t)
572 scale0 = (new_right0 - new_left0) / width0 -- Same vertically and horizonally.
573 tx0 = new_left0 - left0 * scale0
574 ty0 = new_top0 - top0 * scale0
576 local new_left1 = lerp(left1, 0, t)
577 local new_right1 = lerp(right1, screen_width, t)
578 local new_top1 = lerp(top1, 0, t)
579 local new_bottom1 = lerp(bottom1, screen_height, t)
581 scale0 = (new_right1 - new_left1) / width1 -- Same vertically and horizonally.
582 tx0 = new_left1 - left1 * scale0
583 ty0 = new_top1 - top1 * scale0
586 top0 = top0 * scale0 + ty0
587 bottom0 = bottom0 * scale0 + ty0
588 left0 = left0 * scale0 + tx0
589 right0 = right0 * scale0 + tx0
591 top1 = top1 * scale0 + ty0
592 bottom1 = bottom1 * scale0 + ty0
593 left1 = left1 * scale0 + tx0
594 right1 = right1 * scale0 + tx0
595 place_rectangle(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, left0, top0, right0, bottom0, screen_width, screen_height, 1280, 720)
596 place_rectangle(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, left1, top1, right1, bottom1, screen_width, screen_height, 1280, 720)
599 function set_neutral_color(effect, color)
600 effect:set_vec3("neutral_color", color[1], color[2], color[3])
603 function set_neutral_color_from_signal(effect, signal)
604 if signal == INPUT0_SIGNAL_NUM then
605 set_neutral_color(effect, input0_neutral_color)
607 set_neutral_color(effect, input1_neutral_color)
611 function calc_fade_progress(t, transition_start, transition_end)
612 local tt = (t - transition_start) / (transition_end - transition_start)
619 -- Make the fade look maybe a tad more natural, by pumping it
620 -- through a sigmoid function.
622 tt = 1.0 / (1.0 + math.exp(-tt))