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 (called “scenes”), setting their parameters and then deciding which
7 -- Themes are written in Lua, which reflects a simplified form of the Movit API
8 -- where all the low-level details (such as texture formats) and alternatives
9 -- (e.g. turning scaling on or off) are handled by the C++ side and you
10 -- generally just build scenes.
13 transition_start = -2.0,
14 transition_end = -1.0,
16 transition_src_signal = 0,
17 transition_dst_signal = 0,
20 {0.5, 0.5, 0.5}, -- Input 0.
21 {0.5, 0.5, 0.5} -- Input 1.
25 preview_signal_num = 1
28 -- Valid values for live_signal_num and preview_signal_num.
29 local INPUT0_SIGNAL_NUM = 0
30 local INPUT1_SIGNAL_NUM = 1
31 local SBS_SIGNAL_NUM = 2
32 local STATIC_SIGNAL_NUM = 3
34 -- Valid values for transition_type. (Cuts are done directly, so they need no entry.)
35 local NO_TRANSITION = 0
36 local ZOOM_TRANSITION = 1 -- Also for slides.
37 local FADE_TRANSITION = 2
39 function make_sbs_input(scene)
41 input = scene:add_input(),
42 resample_effect = scene:add_effect({ResampleEffect.new(), ResizeEffect.new()}),
43 wb_effect = scene:add_effect(WhiteBalanceEffect.new()),
44 padding_effect = scene:add_effect(IntegralPaddingEffect.new())
48 -- The main live scene.
49 function make_sbs_scene()
50 local scene = Scene.new(16, 9)
52 local input0 = make_sbs_input(scene)
53 input0.input:display(0)
54 input0.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
56 local input1 = make_sbs_input(scene)
57 input1.input:display(1)
58 input1.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 0.0)
60 scene:add_effect(OverlayEffect.new(), input0.padding_effect, input1.padding_effect)
69 local sbs_scene = make_sbs_scene()
71 function make_fade_input(scene)
73 input = scene:add_input(),
74 resample_effect = scene:add_optional_effect(ResampleEffect.new()), -- Activated if scaling.
75 wb_effect = scene:add_optional_effect(WhiteBalanceEffect.new()) -- Activated for video inputs.
79 -- A scene to fade between two inputs, of which either can be a picture
80 -- or a live input. Only used live.
81 function make_fade_scene()
82 local scene = Scene.new(16, 9)
83 local input0 = make_fade_input(scene)
84 local input1 = make_fade_input(scene)
85 local mix_effect = scene:add_effect(MixEffect.new(), input0.wb_effect, input1.wb_effect)
86 scene:finalize(true) -- Only used live.
92 mix_effect = mix_effect
95 local fade_scene = make_fade_scene()
97 -- A scene to show a single input on screen.
98 local scene = Scene.new(16, 9)
99 local simple_scene = {
101 input = scene:add_input(),
102 resample_effect = scene:add_effect({ResampleEffect.new(), ResizeEffect.new(), IdentityEffect.new()}),
103 wb_effect = scene:add_effect(WhiteBalanceEffect.new())
107 -- A scene to show a single static picture on screen.
108 local static_image = ImageInput.new("bg.jpeg") -- Also used as input to other scenes.
109 local static_scene = Scene.new(16, 9)
110 static_scene:add_input(static_image) -- Note: Locks this input to images only.
111 static_scene:finalize()
113 -- Set some global state.
114 Nageru.set_channel_name(SBS_SIGNAL_NUM + 2, "Side-by-side")
115 Nageru.set_channel_name(STATIC_SIGNAL_NUM + 2, "Static picture")
118 -- Returns the number of outputs in addition to the live (0) and preview (1).
119 -- Called only once, at the start of the program.
120 function num_channels()
124 function is_plain_signal(num)
125 return num == INPUT0_SIGNAL_NUM or num == INPUT1_SIGNAL_NUM
129 -- Returns, given a channel number, which signal it corresponds to (starting from 0).
130 -- Should return -1 if the channel does not correspond to a simple signal
131 -- (one connected to a capture card, or a video input). The information is used for
132 -- whether right-click on the channel should bring up a context menu or not,
133 -- typically containing an input selector, resolution menu etc.
135 -- Called once for each channel, at the start of the program.
136 -- Will never be called for live (0) or preview (1).
137 function channel_signal(channel)
140 elseif channel == 3 then
148 -- Called every frame. Returns the color (if any) to paint around the given
149 -- channel. Returns a CSS color (typically to mark live and preview signals);
150 -- "transparent" is allowed.
151 -- Will never be called for live (0) or preview (1).
152 function channel_color(channel)
153 if state.transition_type ~= NO_TRANSITION then
154 if channel_involved_in(channel, state.transition_src_signal) or
155 channel_involved_in(channel, state.transition_dst_signal) then
159 if channel_involved_in(channel, state.live_signal_num) then
163 if channel_involved_in(channel, state.preview_signal_num) then
169 function channel_involved_in(channel, signal_num)
170 if is_plain_signal(signal_num) then
171 return channel == (signal_num + 2)
173 if signal_num == SBS_SIGNAL_NUM then
174 return (channel == 2 or channel == 3)
176 if signal_num == STATIC_SIGNAL_NUM then
177 return (channel == 5)
183 -- Returns if a given channel supports setting white balance (starting from 2).
184 -- Called only once for each channel, at the start of the program.
185 function supports_set_wb(channel)
186 return is_plain_signal(channel - 2)
190 -- Gets called with a new gray point when the white balance is changing.
191 -- The color is in linear light (not sRGB gamma).
192 function set_wb(channel, red, green, blue)
193 if is_plain_signal(channel - 2) then
194 state.neutral_colors[channel - 2 + 1] = { red, green, blue }
198 function finish_transitions(t)
199 if state.transition_type ~= NO_TRANSITION and t >= state.transition_end then
200 state.live_signal_num = state.transition_dst_signal
201 state.transition_type = NO_TRANSITION
205 function in_transition(t)
206 return t >= state.transition_start and t <= state.transition_end
210 -- Called every frame.
211 function get_transitions(t)
212 if in_transition(t) then
213 -- Transition already in progress, the only thing we can do is really
214 -- cut to the preview. (TODO: Make an “abort” and/or “finish”, too?)
218 finish_transitions(t)
220 if state.live_signal_num == state.preview_signal_num then
221 -- No transitions possible.
225 if (is_plain_signal(state.live_signal_num) or state.live_signal_num == STATIC_SIGNAL_NUM) and
226 (is_plain_signal(state.preview_signal_num) or state.preview_signal_num == STATIC_SIGNAL_NUM) then
227 return {"Cut", "", "Fade"}
231 if state.live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(state.preview_signal_num) then
232 return {"Cut", "Zoom in"}
233 elseif is_plain_signal(state.live_signal_num) and state.preview_signal_num == SBS_SIGNAL_NUM then
234 return {"Cut", "Zoom out"}
240 function swap_preview_live()
241 local temp = state.live_signal_num
242 state.live_signal_num = state.preview_signal_num
243 state.preview_signal_num = temp
246 function start_transition(type_, t, duration)
247 state.transition_start = t
248 state.transition_end = t + duration
249 state.transition_type = type_
250 state.transition_src_signal = state.live_signal_num
251 state.transition_dst_signal = state.preview_signal_num
256 -- Called when the user clicks a transition button.
257 function transition_clicked(num, t)
260 if in_transition(t) then
261 -- Ongoing transition; finish it immediately before the cut.
262 finish_transitions(state.transition_end)
268 finish_transitions(t)
270 if state.live_signal_num == state.preview_signal_num then
275 if is_plain_signal(state.live_signal_num) and is_plain_signal(state.preview_signal_num) then
276 -- We can't zoom between these. Just make a cut.
277 io.write("Cutting from " .. state.live_signal_num .. " to " .. state.live_signal_num .. "\n")
282 if (state.live_signal_num == SBS_SIGNAL_NUM and is_plain_signal(state.preview_signal_num)) or
283 (state.preview_signal_num == SBS_SIGNAL_NUM and is_plain_signal(state.live_signal_num)) then
284 start_transition(ZOOM_TRANSITION, t, 1.0)
287 finish_transitions(t)
290 if (state.live_signal_num ~= state.preview_signal_num) and
291 (is_plain_signal(state.live_signal_num) or
292 state.live_signal_num == STATIC_SIGNAL_NUM) and
293 (is_plain_signal(state.preview_signal_num) or
294 state.preview_signal_num == STATIC_SIGNAL_NUM) then
295 start_transition(FADE_TRANSITION, t, 1.0)
297 -- Fades involving SBS are ignored (we have no scene for it).
303 function channel_clicked(num)
304 state.preview_signal_num = num
307 function setup_fade_input(state, input, signals, signal_num, width, height)
308 if signal_num == STATIC_SIGNAL_NUM then
309 input.input:display(static_image)
310 input.wb_effect:disable()
312 -- We assume this is already correctly scaled at load time.
313 input.resample_effect:disable()
315 input.input:display(signal_num)
316 input.wb_effect:enable()
317 set_neutral_color(input.wb_effect, state.neutral_colors[signal_num - INPUT0_SIGNAL_NUM + 1])
319 if (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height) then
320 input.resample_effect:enable()
321 input.resample_effect:set_int("width", width)
322 input.resample_effect:set_int("height", height)
324 input.resample_effect:disable()
329 function needs_scale(signals, signal_num, width, height)
330 if signal_num == STATIC_SIGNAL_NUM then
331 -- We assume this is already correctly scaled at load time.
334 assert(is_plain_signal(signal_num))
335 return (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height)
338 function setup_simple_input(state, signals, signal_num, width, height, hq)
339 simple_scene.input:display(signal_num)
340 if needs_scale(signals, signal_num, width, height) then
342 simple_scene.resample_effect:choose(ResampleEffect) -- High-quality resampling.
344 simple_scene.resample_effect:choose(ResizeEffect) -- Low-quality resampling.
346 simple_scene.resample_effect:set_int("width", width)
347 simple_scene.resample_effect:set_int("height", height)
349 simple_scene.resample_effect:disable() -- No scaling.
351 set_neutral_color_from_signal(state, simple_scene.wb_effect, signal_num)
355 -- Called every frame. Get the scene for displaying at input <num>,
356 -- where 0 is live, 1 is preview, 2 is the first channel to display
357 -- in the bottom bar, and so on up to num_channels()+1. t is the
358 -- current time in seconds. width and height are the dimensions of
359 -- the output, although you can ignore them if you don't need them
360 -- (they're useful if you want to e.g. know what to resample by).
362 -- <signals> is basically an exposed InputState, which you can use to
363 -- query for information about the signals at the point of the current
364 -- frame. In particular, you can call get_width() and get_height()
365 -- for any signal number, and use that to e.g. assist in scene selection.
367 -- You should return scene to use, after having set any parameters you
368 -- want to set (through set_int() etc.). The parameters will be snapshot
369 -- at return time and used during rendering.
370 function get_scene(num, t, width, height, signals)
371 local input_resolution = {}
372 for signal_num=0,1 do
374 width = signals:get_width(signal_num),
375 height = signals:get_height(signal_num),
376 interlaced = signals:get_interlaced(signal_num),
377 is_connected = signals:get_is_connected(signal_num),
378 has_signal = signals:get_has_signal(signal_num),
379 frame_rate_nom = signals:get_frame_rate_nom(signal_num),
380 frame_rate_den = signals:get_frame_rate_den(signal_num)
383 if res.interlaced then
384 -- Convert height from frame height to field height.
385 -- (Needed for e.g. place_rectangle.)
386 res.height = res.height * 2
388 -- Show field rate instead of frame rate; really for cosmetics only
389 -- (and actually contrary to EBU recommendations, although in line
390 -- with typical user expectations).
391 res.frame_rate_nom = res.frame_rate_nom * 2
394 input_resolution[signal_num] = res
396 local text_res = signals:get_human_readable_resolution(signal_num)
397 Nageru.set_channel_name(signal_num + 2, "Input " .. (signal_num + 1) .. " (" .. text_res .. ")")
400 if num == 0 then -- Live.
401 finish_transitions(t)
402 if state.transition_type == ZOOM_TRANSITION then
403 -- Transition in or out of SBS.
404 prepare_sbs_scene(state, calc_zoom_progress(state, t), state.transition_type, state.transition_src_signal, state.transition_dst_signal, width, height, input_resolution, true)
405 return sbs_scene.scene
406 elseif state.transition_type == NO_TRANSITION and state.live_signal_num == SBS_SIGNAL_NUM then
408 prepare_sbs_scene(state, 0.0, NO_TRANSITION, 0, SBS_SIGNAL_NUM, width, height, input_resolution, true)
409 return sbs_scene.scene
410 elseif state.transition_type == FADE_TRANSITION then
411 setup_fade_input(state, fade_scene.input0, signals, state.transition_src_signal, width, height)
412 setup_fade_input(state, fade_scene.input1, signals, state.transition_dst_signal, width, height)
414 local tt = calc_fade_progress(t, state.transition_start, state.transition_end)
415 fade_scene.mix_effect:set_float("strength_first", 1.0 - tt)
416 fade_scene.mix_effect:set_float("strength_second", tt)
418 return fade_scene.scene
419 elseif is_plain_signal(state.live_signal_num) then
420 setup_simple_input(state, signals, state.live_signal_num, width, height, true)
421 return simple_scene.scene
422 elseif state.live_signal_num == STATIC_SIGNAL_NUM then -- Static picture.
428 if num == 1 then -- Preview.
429 num = state.preview_signal_num + 2
432 -- Individual preview inputs.
433 if is_plain_signal(num - 2) then
434 setup_simple_input(state, signals, num - 2, width, height, false)
435 return simple_scene.scene
437 if num == SBS_SIGNAL_NUM + 2 then
438 prepare_sbs_scene(state, 0.0, NO_TRANSITION, 0, SBS_SIGNAL_NUM, width, height, input_resolution, false)
439 return sbs_scene.scene
441 if num == STATIC_SIGNAL_NUM + 2 then
446 function place_rectangle(input, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height, hq)
447 input.padding_effect:set_int("width", screen_width)
448 input.padding_effect:set_int("height", screen_height)
451 if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
452 input.resample_effect:choose(ResizeEffect) -- Low-quality resizing.
453 input.resample_effect:set_int("width", 1)
454 input.resample_effect:set_int("height", 1)
455 input.padding_effect:set_int("left", screen_width + 100)
456 input.padding_effect:set_int("top", screen_height + 100)
467 srcx0 = -x0 / (x1 - x0)
471 srcy0 = -y0 / (y1 - y0)
474 if x1 > screen_width then
475 srcx1 = (screen_width - x0) / (x1 - x0)
478 if y1 > screen_height then
479 srcy1 = (screen_height - y0) / (y1 - y0)
484 -- High-quality resampling. Go for the actual effect (returned by choose())
485 -- since we want to set zoom_*, which will give an error if set on ResizeEffect.
486 local resample_effect = input.resample_effect:choose(ResampleEffect)
488 local x_subpixel_offset = x0 - math.floor(x0)
489 local y_subpixel_offset = y0 - math.floor(y0)
491 -- Resampling must be to an integral number of pixels. Round up,
492 -- and then add an extra pixel so we have some leeway for the border.
493 local width = math.ceil(x1 - x0) + 1
494 local height = math.ceil(y1 - y0) + 1
495 resample_effect:set_int("width", width)
496 resample_effect:set_int("height", height)
498 -- Correct the discrepancy with zoom. (This will leave a small
499 -- excess edge of pixels and subpixels, which we'll correct for soon.)
500 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
501 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
502 resample_effect:set_float("zoom_x", zoom_x)
503 resample_effect:set_float("zoom_y", zoom_y)
504 resample_effect:set_float("zoom_center_x", 0.0)
505 resample_effect:set_float("zoom_center_y", 0.0)
507 -- Padding must also be to a whole-pixel offset.
508 input.padding_effect:set_int("left", math.floor(x0))
509 input.padding_effect:set_int("top", math.floor(y0))
511 -- Correct _that_ discrepancy by subpixel offset in the resampling.
512 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
513 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
515 -- Finally, adjust the border so it is exactly where we want it.
516 input.padding_effect:set_float("border_offset_left", x_subpixel_offset)
517 input.padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
518 input.padding_effect:set_float("border_offset_top", y_subpixel_offset)
519 input.padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
521 -- Lower-quality simple resizing.
522 input.resample_effect:choose(ResizeEffect)
524 local width = round(x1 - x0)
525 local height = round(y1 - y0)
526 input.resample_effect:set_int("width", width)
527 input.resample_effect:set_int("height", height)
529 -- Padding must also be to a whole-pixel offset.
530 input.padding_effect:set_int("left", math.floor(x0))
531 input.padding_effect:set_int("top", math.floor(y0))
533 -- No subpixel stuff.
534 input.padding_effect:set_float("border_offset_left", 0.0)
535 input.padding_effect:set_float("border_offset_right", 0.0)
536 input.padding_effect:set_float("border_offset_top", 0.0)
537 input.padding_effect:set_float("border_offset_bottom", 0.0)
541 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
543 return math.floor(x + 0.5)
546 function lerp(a, b, t)
547 return a + (b - a) * t
550 function lerp_pos(a, b, t)
552 x0 = lerp(a.x0, b.x0, t),
553 y0 = lerp(a.y0, b.y0, t),
554 x1 = lerp(a.x1, b.x1, t),
555 y1 = lerp(a.y1, b.y1, t)
559 function pos_from_top_left(x, y, width, height, screen_width, screen_height)
560 local xs = screen_width / 1280.0
561 local ys = screen_height / 720.0
565 x1 = round(xs * (x + width)),
566 y1 = round(ys * (y + height))
570 function prepare_sbs_scene(state, t, transition_type, src_signal, dst_signal, screen_width, screen_height, input_resolution, hq)
571 set_neutral_color(sbs_scene.input0.wb_effect, state.neutral_colors[1])
572 set_neutral_color(sbs_scene.input1.wb_effect, state.neutral_colors[2])
574 -- First input is positioned (16,48) from top-left.
575 -- Second input is positioned (16,48) from the bottom-right.
576 local pos0 = pos_from_top_left(16, 48, 848, 477, screen_width, screen_height)
577 local pos1 = pos_from_top_left(1280 - 384 - 16, 720 - 216 - 48, 384, 216, screen_width, screen_height)
579 local pos_fs = { x0 = 0, y0 = 0, x1 = screen_width, y1 = screen_height }
581 if transition_type == NO_TRANSITION then
583 affine_param = { sx = 1.0, sy = 1.0, tx = 0.0, ty = 0.0 } -- Identity.
585 -- Zooming to/from SBS view into or out of a single view.
586 assert(transition_type == ZOOM_TRANSITION)
588 if src_signal == SBS_SIGNAL_NUM then
592 assert(dst_signal == SBS_SIGNAL_NUM)
597 if signal == INPUT0_SIGNAL_NUM then
598 affine_param = find_affine_param(pos0, lerp_pos(pos0, pos_fs, real_t))
599 elseif signal == INPUT1_SIGNAL_NUM then
600 affine_param = find_affine_param(pos1, lerp_pos(pos1, pos_fs, real_t))
604 -- NOTE: input_resolution is not 1-indexed, unlike usual Lua arrays.
605 place_rectangle_with_affine(sbs_scene.input0, pos0, affine_param, screen_width, screen_height, input_resolution[0].width, input_resolution[0].height, hq)
606 place_rectangle_with_affine(sbs_scene.input1, pos1, affine_param, screen_width, screen_height, input_resolution[1].width, input_resolution[1].height, hq)
609 -- Find the transformation that changes the first rectangle to the second one.
610 function find_affine_param(a, b)
611 local sx = (b.x1 - b.x0) / (a.x1 - a.x0)
612 local sy = (b.y1 - b.y0) / (a.y1 - a.y0)
616 tx = b.x0 - a.x0 * sx,
617 ty = b.y0 - a.y0 * sy
621 function place_rectangle_with_affine(input, pos, aff, screen_width, screen_height, input_width, input_height, hq)
622 local x0 = pos.x0 * aff.sx + aff.tx
623 local x1 = pos.x1 * aff.sx + aff.tx
624 local y0 = pos.y0 * aff.sy + aff.ty
625 local y1 = pos.y1 * aff.sy + aff.ty
627 place_rectangle(input, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height, hq)
630 function set_neutral_color(effect, color)
631 effect:set_vec3("neutral_color", color[1], color[2], color[3])
634 function set_neutral_color_from_signal(state, effect, signal)
635 if is_plain_signal(signal) then
636 set_neutral_color(effect, state.neutral_colors[signal - INPUT0_SIGNAL_NUM + 1])
640 function calc_zoom_progress(state, t)
641 if t < state.transition_start then
643 elseif t > state.transition_end then
646 local tt = (t - state.transition_start) / (state.transition_end - state.transition_start)
648 return math.sin(tt * 3.14159265358 * 0.5)
652 function calc_fade_progress(t, transition_start, transition_end)
653 local tt = (t - transition_start) / (transition_end - transition_start)
660 -- Make the fade look maybe a tad more natural, by pumping it
661 -- through a sigmoid function.
663 tt = 1.0 / (1.0 + math.exp(-tt))