git.sesse.net Git - nageru/blob - theme.lua

   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.
   5 --
   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
  10 local transition_start = -2.0
  11 local transition_end = -1.0
  12 local zoom_src = 0.0
  13 local zoom_dst = 1.0
  14 local zoom_poi = 0   -- which input to zoom in on
  15 local fade_src_signal = 0
  16 local fade_dst_signal = 0
  17
  18 local input0_neutral_color = {0.5, 0.5, 0.5}
  19 local input1_neutral_color = {0.5, 0.5, 0.5}
  20
  21 local live_signal_num = 0
  22 local preview_signal_num = 1
  23
  24 -- Valid values for live_signal_num and preview_signal_num.
  25 local INPUT0_SIGNAL_NUM = 0
  26 local INPUT1_SIGNAL_NUM = 1
  27 local SBS_SIGNAL_NUM = 2
  28
  29 -- A “fake” signal number that signifies that we are fading from one input
  30 -- to the next.
  31 local FADE_SIGNAL_NUM = 3
  32
  33 -- The main live chain.
  34 function make_sbs_chain(hq)
  35         local chain = EffectChain.new(16, 9)
  36         local input0 = chain:add_live_input(true)
  37         input0:connect_signal(0)
  38         local input0_wb_effect = chain:add_effect(WhiteBalanceEffect.new())
  39         local input1 = chain:add_live_input(true)
  40         input1:connect_signal(1)
  41         local input1_wb_effect = chain:add_effect(WhiteBalanceEffect.new())
  42
  43         local resample_effect = nil
  44         local resize_effect = nil
  45         if (hq) then
  46                 resample_effect = chain:add_effect(ResampleEffect.new(), input0_wb_effect)
  47         else
  48                 resize_effect = chain:add_effect(ResizeEffect.new(), input0_wb_effect)
  49         end
  50
  51         local padding_effect = chain:add_effect(IntegralPaddingEffect.new())
  52         padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
  53
  54         local resample2_effect = nil
  55         local resize2_effect = nil
  56         if (hq) then
  57                 resample2_effect = chain:add_effect(ResampleEffect.new(), input1_wb_effect)
  58         else
  59                 resize2_effect = chain:add_effect(ResizeEffect.new(), input1_wb_effect)
  60         end
  61         local padding2_effect = chain:add_effect(IntegralPaddingEffect.new())
  62
  63         chain:add_effect(OverlayEffect.new(), padding_effect, padding2_effect)
  64         chain:finalize(hq)
  65
  66         return {
  67                 chain = chain,
  68                 input0 = {
  69                         input = input0,
  70                         white_balance_effect = input0_wb_effect,
  71                         resample_effect = resample_effect,
  72                         resize_effect = resize_effect,
  73                         padding_effect = padding_effect
  74                 },
  75                 input1 = {
  76                         input = input1,
  77                         white_balance_effect = input1_wb_effect,
  78                         resample_effect = resample2_effect,
  79                         resize_effect = resize2_effect,
  80                         padding_effect = padding2_effect
  81                 }
  82         }
  83 end
  84
  85 local main_chain_hq = make_sbs_chain(true)
  86 local main_chain_lq = make_sbs_chain(false)
  87
  88 -- A chain to fade between two inputs (live chain only)
  89 local fade_chain_hq = EffectChain.new(16, 9)
  90 local fade_chain_hq_input0 = fade_chain_hq:add_live_input(true)
  91 local fade_chain_hq_wb0_effect = fade_chain_hq:add_effect(WhiteBalanceEffect.new())
  92 local fade_chain_hq_input1 = fade_chain_hq:add_live_input(true)
  93 local fade_chain_hq_wb1_effect = fade_chain_hq:add_effect(WhiteBalanceEffect.new())
  94 fade_chain_hq_input0:connect_signal(0)
  95 fade_chain_hq_input1:connect_signal(1)
  96 local fade_chain_mix_effect = fade_chain_hq:add_effect(MixEffect.new(), fade_chain_hq_wb0_effect, fade_chain_hq_wb1_effect)
  97 fade_chain_hq:finalize(true)
  98
  99 -- A chain to show a single input on screen (HQ version).
 100 local simple_chain_hq = EffectChain.new(16, 9)
 101 local simple_chain_hq_input = simple_chain_hq:add_live_input(true)
 102 simple_chain_hq_input:connect_signal(0)  -- First input card. Can be changed whenever you want.
 103 local simple_chain_hq_wb_effect = simple_chain_hq:add_effect(WhiteBalanceEffect.new())
 104 simple_chain_hq:finalize(true)
 105
 106 -- A chain to show a single input on screen (LQ version).
 107 local simple_chain_lq = EffectChain.new(16, 9)
 108 local simple_chain_lq_input = simple_chain_lq:add_live_input(true)
 109 simple_chain_lq_input:connect_signal(0)  -- First input card. Can be changed whenever you want.
 110 local simple_chain_lq_wb_effect = simple_chain_lq:add_effect(WhiteBalanceEffect.new())
 111 simple_chain_lq:finalize(false)
 112
 113 -- Returns the number of outputs in addition to the live (0) and preview (1).
 114 -- Called only once, at the start of the program.
 115 function num_channels()
 116         return 3
 117 end
 118
 119 -- Returns the name for each additional channel (starting from 2).
 120 -- Called only once for each channel, at the start of the program.
 121 function channel_name(channel)
 122         if channel == 2 then
 123                 return "Input 1"
 124         elseif channel == 3 then
 125                 return "Input 2"
 126         elseif channel == 4 then
 127                 return "Side-by-side"
 128         end
 129 end
 130
 131 -- Returns if a given channel supports setting white balance (starting from 2).
 132 -- Called only once for each channel, at the start of the program.
 133 function supports_set_wb(channel)
 134         return channel == 2 or channel == 3
 135 end
 136
 137 -- Gets called with a new gray point when the white balance is changing.
 138 -- The color is in linear light (not sRGB gamma).
 139 function set_wb(channel, red, green, blue)
 140         if channel == 2 then
 141                 input0_neutral_color = { red, green, blue }
 142         elseif channel == 3 then
 143                 input1_neutral_color = { red, green, blue }
 144         end
 145 end
 146
 147 function finish_transitions(t)
 148         -- If live is SBS but de-facto single, make it so.
 149         if live_signal_num == SBS_SIGNAL_NUM and t >= transition_end and zoom_dst == 1.0 then
 150                 live_signal_num = zoom_poi
 151         end
 152
 153         -- If live is fade but de-facto single, make it so.
 154         if live_signal_num == FADE_SIGNAL_NUM and t >= transition_end then
 155                 live_signal_num = fade_dst_signal
 156         end
 157 end
 158
 159 -- Called every frame.
 160 function get_transitions(t)
 161         finish_transitions(t)
 162
 163         if live_signal_num == preview_signal_num then
 164                 return {}
 165         end
 166
 167         if live_signal_num == SBS_SIGNAL_NUM and t >= transition_start and t <= transition_end then
 168                 -- Zoom in progress.
 169                 return {"Cut"}
 170         end
 171
 172         if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
 173            (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
 174                 return {"Cut", "", "Fade"}
 175         end
 176
 177         -- Various zooms.
 178         if live_signal_num == SBS_SIGNAL_NUM and
 179            (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
 180                 return {"Cut", "Zoom in"}
 181         elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
 182                preview_signal_num == SBS_SIGNAL_NUM then
 183                 return {"Cut", "Zoom out"}
 184         end
 185
 186         return {"Cut"}
 187 end
 188
 189 function transition_clicked(num, t)
 190         if num == 0 then
 191                 -- Cut.
 192                 if live_signal_num == FADE_SIGNAL_NUM then
 193                         -- Ongoing fade; finish it immediately.
 194                         finish_transitions(transition_end)
 195                 end
 196
 197                 local temp = live_signal_num
 198                 live_signal_num = preview_signal_num
 199                 preview_signal_num = temp
 200
 201                 if live_signal_num == SBS_SIGNAL_NUM then
 202                         -- Just cut to SBS, we need to reset any zooms.
 203                         zoom_src = 1.0
 204                         zoom_dst = 0.0
 205                         transition_start = -2.0
 206                         transition_end = -1.0
 207                 end
 208         elseif num == 1 then
 209                 -- Zoom.
 210
 211                 finish_transitions(t)
 212
 213                 if live_signal_num == preview_signal_num then
 214                         -- Nothing to do.
 215                         return
 216                 end
 217
 218                 if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
 219                    (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
 220                         -- We can't zoom between these. Just make a cut.
 221                         io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
 222                         local temp = live_signal_num
 223                         live_signal_num = preview_signal_num
 224                         preview_signal_num = temp
 225                         return
 226                 end
 227
 228                 if live_signal_num == SBS_SIGNAL_NUM and
 229                    (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
 230                         -- Zoom in from SBS to single.
 231                         transition_start = t
 232                         transition_end = t + 1.0
 233                         zoom_src = 0.0
 234                         zoom_dst = 1.0
 235                         zoom_poi = preview_signal_num
 236                         preview_signal_num = SBS_SIGNAL_NUM
 237                 elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
 238                        preview_signal_num == SBS_SIGNAL_NUM then
 239                         -- Zoom out from single to SBS.
 240                         transition_start = t
 241                         transition_end = t + 1.0
 242                         zoom_src = 1.0
 243                         zoom_dst = 0.0
 244                         preview_signal_num = live_signal_num
 245                         zoom_poi = live_signal_num
 246                         live_signal_num = SBS_SIGNAL_NUM
 247                 end
 248         elseif num == 2 then
 249                 finish_transitions(t)
 250
 251                 -- Fade.
 252                 if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
 253                    (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
 254                         transition_start = t
 255                         transition_end = t + 1.0
 256                         fade_src_signal = live_signal_num
 257                         fade_dst_signal = preview_signal_num
 258                         preview_signal_num = live_signal_num
 259                         live_signal_num = FADE_SIGNAL_NUM
 260                 else
 261                         -- Fades involving SBS are ignored (we have no chain for it).
 262                 end
 263         end
 264 end
 265
 266 function channel_clicked(num)
 267         preview_signal_num = num
 268 end
 269
 270 -- Called every frame. Get the chain for displaying at input <num>,
 271 -- where 0 is live, 1 is preview, 2 is the first channel to display
 272 -- in the bottom bar, and so on up to num_channels()+1. t is the
 273 -- current time in seconds. width and height are the dimensions of
 274 -- the output, although you can ignore them if you don't need them
 275 -- (they're useful if you want to e.g. know what to resample by).
 276 --
 277 -- You should return two objects; the chain itself, and then a
 278 -- function (taking no parameters) that is run just before rendering.
 279 -- The function needs to call connect_signal on any inputs, so that
 280 -- it gets updated video data for the given frame. (You are allowed
 281 -- to switch which input your input is getting from between frames,
 282 -- but not calling connect_signal results in undefined behavior.)
 283 -- If you want to change any parameters in the chain, this is also
 284 -- the right place.
 285 --
 286 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
 287 -- if and only if num==0.
 288 function get_chain(num, t, width, height)
 289         if num == 0 then  -- Live.
 290                 if live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM then  -- Plain input.
 291                         prepare = function()
 292                                 simple_chain_hq_input:connect_signal(live_signal_num)
 293                                 set_neutral_color_from_signal(simple_chain_hq_wb_effect, live_signal_num)
 294                         end
 295                         return simple_chain_hq, prepare
 296                 elseif live_signal_num == FADE_SIGNAL_NUM then  -- Fade.
 297                         prepare = function()
 298                                 fade_chain_hq_input0:connect_signal(fade_src_signal)
 299                                 set_neutral_color_from_signal(fade_chain_hq_wb0_effect, fade_src_signal)
 300                                 fade_chain_hq_input1:connect_signal(fade_dst_signal)
 301                                 set_neutral_color_from_signal(fade_chain_hq_wb1_effect, fade_dst_signal)
 302                                 local tt = (t - transition_start) / (transition_end - transition_start)
 303                                 if tt < 0.0 then
 304                                         tt = 0.0
 305                                 elseif tt > 1.0 then
 306                                         tt = 1.0
 307                                 end
 308
 309                                 -- Make the fade look maybe a tad more natural, by pumping it
 310                                 -- through a sigmoid function.
 311                                 tt = 10.0 * tt - 5.0
 312                                 tt = 1.0 / (1.0 + math.exp(-tt))
 313
 314                                 fade_chain_mix_effect:set_float("strength_first", 1.0 - tt)
 315                                 fade_chain_mix_effect:set_float("strength_second", tt)
 316                         end
 317                         return fade_chain_hq, prepare
 318                 end
 319
 320                 -- SBS code (live_signal_num == SBS_SIGNAL_NUM).
 321                 if t > transition_end and zoom_dst == 1.0 then
 322                         -- Special case: Show only the single image on screen.
 323                         prepare = function()
 324                                 simple_chain_hq_input:connect_signal(INPUT0_SIGNAL_NUM)
 325                                 set_neutral_color(simple_chain_hq_wb_effect, input0_neutral_color)
 326                         end
 327                         return simple_chain_hq, prepare
 328                 end
 329                 prepare = function()
 330                         if t < transition_start then
 331                                 prepare_sbs_chain(main_chain_hq, zoom_src, width, height)
 332                         elseif t > transition_end then
 333                                 prepare_sbs_chain(main_chain_hq, zoom_dst, width, height)
 334                         else
 335                                 local tt = (t - transition_start) / (transition_end - transition_start)
 336                                 -- Smooth it a bit.
 337                                 tt = math.sin(tt * 3.14159265358 * 0.5)
 338                                 prepare_sbs_chain(main_chain_hq, zoom_src + (zoom_dst - zoom_src) * tt, width, height)
 339                         end
 340                 end
 341                 return main_chain_hq.chain, prepare
 342         end
 343         if num == 1 then  -- Preview.
 344                 num = preview_signal_num + 2
 345         end
 346         if num == INPUT0_SIGNAL_NUM + 2 then
 347                 prepare = function()
 348                         simple_chain_lq_input:connect_signal(0)
 349                         set_neutral_color(simple_chain_lq_wb_effect, input0_neutral_color)
 350                 end
 351                 return simple_chain_lq, prepare
 352         end
 353         if num == INPUT1_SIGNAL_NUM + 2 then
 354                 prepare = function()
 355                         simple_chain_lq_input:connect_signal(1)
 356                         set_neutral_color(simple_chain_lq_wb_effect, input1_neutral_color)
 357                 end
 358                 return simple_chain_lq, prepare
 359         end
 360         if num == SBS_SIGNAL_NUM + 2 then
 361                 prepare = function()
 362                         prepare_sbs_chain(main_chain_lq, 0.0, width, height)
 363                 end
 364                 return main_chain_lq.chain, prepare
 365         end
 366 end
 367
 368 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
 369         local srcx0 = 0.0
 370         local srcx1 = 1.0
 371         local srcy0 = 0.0
 372         local srcy1 = 1.0
 373
 374         -- Cull.
 375         if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
 376                 resample_effect:set_int("width", 1)
 377                 resample_effect:set_int("height", 1)
 378                 resample_effect:set_float("zoom_x", screen_width)
 379                 resample_effect:set_float("zoom_y", screen_height)
 380                 padding_effect:set_int("left", screen_width + 100)
 381                 padding_effect:set_int("top", screen_height + 100)
 382                 return
 383         end
 384
 385         -- Clip.
 386         if x0 < 0 then
 387                 srcx0 = -x0 / (x1 - x0)
 388                 x0 = 0
 389         end
 390         if y0 < 0 then
 391                 srcy0 = -y0 / (y1 - y0)
 392                 y0 = 0
 393         end
 394         if x1 > screen_width then
 395                 srcx1 = (screen_width - x0) / (x1 - x0)
 396                 x1 = screen_width
 397         end
 398         if y1 > screen_height then
 399                 srcy1 = (screen_height - y0) / (y1 - y0)
 400                 y1 = screen_height
 401         end
 402
 403         if resample_effect ~= nil then
 404                 -- High-quality resampling.
 405                 local x_subpixel_offset = x0 - math.floor(x0)
 406                 local y_subpixel_offset = y0 - math.floor(y0)
 407
 408                 -- Resampling must be to an integral number of pixels. Round up,
 409                 -- and then add an extra pixel so we have some leeway for the border.
 410                 local width = math.ceil(x1 - x0) + 1
 411                 local height = math.ceil(y1 - y0) + 1
 412                 resample_effect:set_int("width", width)
 413                 resample_effect:set_int("height", height)
 414
 415                 -- Correct the discrepancy with zoom. (This will leave a small
 416                 -- excess edge of pixels and subpixels, which we'll correct for soon.)
 417                 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
 418                 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
 419                 resample_effect:set_float("zoom_x", zoom_x)
 420                 resample_effect:set_float("zoom_y", zoom_y)
 421                 resample_effect:set_float("zoom_center_x", 0.0)
 422                 resample_effect:set_float("zoom_center_y", 0.0)
 423
 424                 -- Padding must also be to a whole-pixel offset.
 425                 padding_effect:set_int("left", math.floor(x0))
 426                 padding_effect:set_int("top", math.floor(y0))
 427
 428                 -- Correct _that_ discrepancy by subpixel offset in the resampling.
 429                 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
 430                 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
 431
 432                 -- Finally, adjust the border so it is exactly where we want it.
 433                 padding_effect:set_float("border_offset_left", x_subpixel_offset)
 434                 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
 435                 padding_effect:set_float("border_offset_top", y_subpixel_offset)
 436                 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
 437         else
 438                 -- Lower-quality simple resizing.
 439                 local width = round(x1 - x0)
 440                 local height = round(y1 - y0)
 441                 resize_effect:set_int("width", width)
 442                 resize_effect:set_int("height", height)
 443
 444                 -- Padding must also be to a whole-pixel offset.
 445                 padding_effect:set_int("left", math.floor(x0))
 446                 padding_effect:set_int("top", math.floor(y0))
 447         end
 448 end
 449
 450 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
 451 function round(x)
 452         return math.floor(x + 0.5)
 453 end
 454
 455 function lerp(a, b, t)
 456         return a + (b - a) * t
 457 end
 458
 459 function prepare_sbs_chain(chain, t, screen_width, screen_height)
 460         chain.input0.input:connect_signal(0)
 461         chain.input1.input:connect_signal(1)
 462         set_neutral_color(chain.input0.white_balance_effect, input0_neutral_color)
 463         set_neutral_color(chain.input1.white_balance_effect, input1_neutral_color)
 464
 465         -- First input is positioned (16,48) from top-left.
 466         local width0 = round(848 * screen_width/1280.0)
 467         local height0 = round(width0 * 9.0 / 16.0)
 468
 469         local top0 = 48 * screen_height/720.0
 470         local left0 = 16 * screen_width/1280.0
 471         local bottom0 = top0 + height0
 472         local right0 = left0 + width0
 473
 474         -- Second input is positioned (16,48) from the bottom-right.
 475         local width1 = round(384 * screen_width/1280.0)
 476         local height1 = round(216 * screen_height/720.0)
 477
 478         local bottom1 = screen_height - 48 * screen_height/720.0
 479         local right1 = screen_width - 16 * screen_width/1280.0
 480         local top1 = bottom1 - height1
 481         local left1 = right1 - width1
 482
 483         -- Interpolate between the fullscreen and side-by-side views.
 484         local scale0, tx0, tx0
 485         if zoom_poi == INPUT0_SIGNAL_NUM then
 486                 local new_left0 = lerp(left0, 0, t)
 487                 local new_right0 = lerp(right0, screen_width, t)
 488                 local new_top0 = lerp(top0, 0, t)
 489                 local new_bottom0 = lerp(bottom0, screen_height, t)
 490
 491                 scale0 = (new_right0 - new_left0) / width0  -- Same vertically and horizonally.
 492                 tx0 = new_left0 - left0 * scale0
 493                 ty0 = new_top0 - top0 * scale0
 494         else
 495                 local new_left1 = lerp(left1, 0, t)
 496                 local new_right1 = lerp(right1, screen_width, t)
 497                 local new_top1 = lerp(top1, 0, t)
 498                 local new_bottom1 = lerp(bottom1, screen_height, t)
 499
 500                 scale0 = (new_right1 - new_left1) / width1  -- Same vertically and horizonally.
 501                 tx0 = new_left1 - left1 * scale0
 502                 ty0 = new_top1 - top1 * scale0
 503         end
 504
 505         top0 = top0 * scale0 + ty0
 506         bottom0 = bottom0 * scale0 + ty0
 507         left0 = left0 * scale0 + tx0
 508         right0 = right0 * scale0 + tx0
 509
 510         top1 = top1 * scale0 + ty0
 511         bottom1 = bottom1 * scale0 + ty0
 512         left1 = left1 * scale0 + tx0
 513         right1 = right1 * scale0 + tx0
 514         place_rectangle(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, left0, top0, right0, bottom0, screen_width, screen_height, 1280, 720)
 515         place_rectangle(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, left1, top1, right1, bottom1, screen_width, screen_height, 1280, 720)
 516 end
 517
 518 function set_neutral_color(effect, color)
 519         effect:set_vec3("neutral_color", color[1], color[2], color[3])
 520 end
 521
 522 function set_neutral_color_from_signal(effect, signal)
 523         if signal == INPUT0_SIGNAL_NUM then
 524                 set_neutral_color(effect, input0_neutral_color)
 525         else
 526                 set_neutral_color(effect, input1_neutral_color)
 527         end
 528 end