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 = 0.0
  16 local fade_dst = 1.0
  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 and fade_dst == 1.0 then
 155                 live_signal_num = INPUT0_SIGNAL_NUM
 156         end
 157         if live_signal_num == FADE_SIGNAL_NUM and t >= transition_end and fade_dst == 0.0 then
 158                 live_signal_num = INPUT1_SIGNAL_NUM
 159         end
 160 end
 161
 162 -- Called every frame.
 163 function get_transitions(t)
 164         finish_transitions(t)
 165
 166         if live_signal_num == preview_signal_num then
 167                 return {}
 168         end
 169
 170         if live_signal_num == SBS_SIGNAL_NUM and t >= transition_start and t <= transition_end then
 171                 -- Zoom in progress.
 172                 return {"Cut"}
 173         end
 174
 175         if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
 176            (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
 177                 return {"Cut", "", "Fade"}
 178         end
 179
 180         -- Various zooms.
 181         if live_signal_num == SBS_SIGNAL_NUM and
 182            (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
 183                 return {"Cut", "Zoom in"}
 184         elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
 185                preview_signal_num == SBS_SIGNAL_NUM then
 186                 return {"Cut", "Zoom out"}
 187         end
 188
 189         return {"Cut"}
 190 end
 191
 192 function transition_clicked(num, t)
 193         if num == 0 then
 194                 -- Cut.
 195                 if live_signal_num == FADE_SIGNAL_NUM then
 196                         -- Ongoing fade; finish it immediately.
 197                         finish_transitions(transition_end)
 198                 end
 199
 200                 local temp = live_signal_num
 201                 live_signal_num = preview_signal_num
 202                 preview_signal_num = temp
 203
 204                 if live_signal_num == SBS_SIGNAL_NUM then
 205                         -- Just cut to SBS, we need to reset any zooms.
 206                         zoom_src = 1.0
 207                         zoom_dst = 0.0
 208                         transition_start = -2.0
 209                         transition_end = -1.0
 210                 end
 211         elseif num == 1 then
 212                 -- Zoom.
 213
 214                 finish_transitions(t)
 215
 216                 if live_signal_num == preview_signal_num then
 217                         -- Nothing to do.
 218                         return
 219                 end
 220
 221                 if (live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM) or
 222                    (live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM) then
 223                         -- We can't zoom between these. Just make a cut.
 224                         io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
 225                         local temp = live_signal_num
 226                         live_signal_num = preview_signal_num
 227                         preview_signal_num = temp
 228                         return
 229                 end
 230
 231                 if live_signal_num == SBS_SIGNAL_NUM and
 232                    (preview_signal_num == INPUT0_SIGNAL_NUM or preview_signal_num == INPUT1_SIGNAL_NUM) then
 233                         -- Zoom in from SBS to single.
 234                         transition_start = t
 235                         transition_end = t + 1.0
 236                         zoom_src = 0.0
 237                         zoom_dst = 1.0
 238                         zoom_poi = preview_signal_num
 239                         preview_signal_num = SBS_SIGNAL_NUM
 240                 elseif (live_signal_num == INPUT0_SIGNAL_NUM or live_signal_num == INPUT1_SIGNAL_NUM) and
 241                        preview_signal_num == SBS_SIGNAL_NUM then
 242                         -- Zoom out from single to SBS.
 243                         transition_start = t
 244                         transition_end = t + 1.0
 245                         zoom_src = 1.0
 246                         zoom_dst = 0.0
 247                         preview_signal_num = live_signal_num
 248                         zoom_poi = live_signal_num
 249                         live_signal_num = SBS_SIGNAL_NUM
 250                 end
 251         elseif num == 2 then
 252                 finish_transitions(t)
 253
 254                 -- Fade.
 255                 if live_signal_num == INPUT0_SIGNAL_NUM and preview_signal_num == INPUT1_SIGNAL_NUM then
 256                         transition_start = t
 257                         transition_end = t + 1.0
 258                         fade_src = 1.0
 259                         fade_dst = 0.0
 260                         preview_signal_num = 0
 261                         live_signal_num = FADE_SIGNAL_NUM
 262                 elseif live_signal_num == INPUT1_SIGNAL_NUM and preview_signal_num == INPUT0_SIGNAL_NUM then
 263                         transition_start = t
 264                         transition_end = t + 1.0
 265                         fade_src = 0.0
 266                         fade_dst = 1.0
 267                         preview_signal_num = 1
 268                         live_signal_num = FADE_SIGNAL_NUM
 269                 else
 270                         -- Fades involving SBS are ignored (we have no chain for it).
 271                 end
 272         end
 273 end
 274
 275 function channel_clicked(num)
 276         preview_signal_num = num
 277 end
 278
 279 -- Called every frame. Get the chain for displaying at input <num>,
 280 -- where 0 is live, 1 is preview, 2 is the first channel to display
 281 -- in the bottom bar, and so on up to num_channels()+1. t is the
 282 -- current time in seconds. width and height are the dimensions of
 283 -- the output, although you can ignore them if you don't need them
 284 -- (they're useful if you want to e.g. know what to resample by).
 285 --
 286 -- You should return two objects; the chain itself, and then a
 287 -- function (taking no parameters) that is run just before rendering.
 288 -- The function needs to call connect_signal on any inputs, so that
 289 -- it gets updated video data for the given frame. (You are allowed
 290 -- to switch which input your input is getting from between frames,
 291 -- but not calling connect_signal results in undefined behavior.)
 292 -- If you want to change any parameters in the chain, this is also
 293 -- the right place.
 294 --
 295 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
 296 -- if and only if num==0.
 297 function get_chain(num, t, width, height)
 298         if num == 0 then  -- Live.
 299                 if live_signal_num == INPUT0_SIGNAL_NUM then  -- Plain input.
 300                         prepare = function()
 301                                 simple_chain_hq_input:connect_signal(INPUT0_SIGNAL_NUM)
 302                                 set_neutral_color(simple_chain_hq_wb_effect, input0_neutral_color)
 303                         end
 304                         return simple_chain_hq, prepare
 305                 elseif live_signal_num == INPUT1_SIGNAL_NUM then -- Plain input.
 306                         prepare = function()
 307                                 simple_chain_hq_input:connect_signal(INPUT1_SIGNAL_NUM)
 308                                 set_neutral_color(simple_chain_hq_wb_effect, input1_neutral_color)
 309                         end
 310                         return simple_chain_hq, prepare
 311                 elseif live_signal_num == FADE_SIGNAL_NUM then  -- Fade.
 312                         prepare = function()
 313                                 fade_chain_hq_input0:connect_signal(0)
 314                                 set_neutral_color(fade_chain_hq_wb0_effect, input0_neutral_color)
 315                                 fade_chain_hq_input1:connect_signal(1)
 316                                 set_neutral_color(fade_chain_hq_wb1_effect, input1_neutral_color)
 317                                 local tt = (t - transition_start) / (transition_end - transition_start)
 318                                 if tt < 0.0 then
 319                                         tt = 0.0
 320                                 elseif tt > 1.0 then
 321                                         tt = 1.0
 322                                 end
 323
 324                                 tt = fade_src + tt * (fade_dst - fade_src)
 325
 326                                 -- Make the fade look maybe a tad more natural, by pumping it
 327                                 -- through a sigmoid function.
 328                                 tt = 10.0 * tt - 5.0
 329                                 tt = 1.0 / (1.0 + math.exp(-tt))
 330
 331                                 fade_chain_mix_effect:set_float("strength_first", tt)
 332                                 fade_chain_mix_effect:set_float("strength_second", 1.0 - tt)
 333                         end
 334                         return fade_chain_hq, prepare
 335                 end
 336
 337                 -- SBS code (live_signal_num == SBS_SIGNAL_NUM).
 338                 if t > transition_end and zoom_dst == 1.0 then
 339                         -- Special case: Show only the single image on screen.
 340                         prepare = function()
 341                                 simple_chain_hq_input:connect_signal(INPUT0_SIGNAL_NUM)
 342                                 set_neutral_color(simple_chain_hq_wb_effect, input0_neutral_color)
 343                         end
 344                         return simple_chain_hq, prepare
 345                 end
 346                 prepare = function()
 347                         if t < transition_start then
 348                                 prepare_sbs_chain(main_chain_hq, zoom_src, width, height)
 349                         elseif t > transition_end then
 350                                 prepare_sbs_chain(main_chain_hq, zoom_dst, width, height)
 351                         else
 352                                 local tt = (t - transition_start) / (transition_end - transition_start)
 353                                 -- Smooth it a bit.
 354                                 tt = math.sin(tt * 3.14159265358 * 0.5)
 355                                 prepare_sbs_chain(main_chain_hq, zoom_src + (zoom_dst - zoom_src) * tt, width, height)
 356                         end
 357                 end
 358                 return main_chain_hq.chain, prepare
 359         end
 360         if num == 1 then  -- Preview.
 361                 num = preview_signal_num + 2
 362         end
 363         if num == INPUT0_SIGNAL_NUM + 2 then
 364                 prepare = function()
 365                         simple_chain_lq_input:connect_signal(0)
 366                         set_neutral_color(simple_chain_lq_wb_effect, input0_neutral_color)
 367                 end
 368                 return simple_chain_lq, prepare
 369         end
 370         if num == INPUT1_SIGNAL_NUM + 2 then
 371                 prepare = function()
 372                         simple_chain_lq_input:connect_signal(1)
 373                         set_neutral_color(simple_chain_lq_wb_effect, input1_neutral_color)
 374                 end
 375                 return simple_chain_lq, prepare
 376         end
 377         if num == SBS_SIGNAL_NUM + 2 then
 378                 prepare = function()
 379                         prepare_sbs_chain(main_chain_lq, 0.0, width, height)
 380                 end
 381                 return main_chain_lq.chain, prepare
 382         end
 383 end
 384
 385 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
 386         local srcx0 = 0.0
 387         local srcx1 = 1.0
 388         local srcy0 = 0.0
 389         local srcy1 = 1.0
 390
 391         -- Cull.
 392         if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
 393                 resample_effect:set_int("width", 1)
 394                 resample_effect:set_int("height", 1)
 395                 resample_effect:set_float("zoom_x", screen_width)
 396                 resample_effect:set_float("zoom_y", screen_height)
 397                 padding_effect:set_int("left", screen_width + 100)
 398                 padding_effect:set_int("top", screen_height + 100)
 399                 return
 400         end
 401
 402         -- Clip.
 403         if x0 < 0 then
 404                 srcx0 = -x0 / (x1 - x0)
 405                 x0 = 0
 406         end
 407         if y0 < 0 then
 408                 srcy0 = -y0 / (y1 - y0)
 409                 y0 = 0
 410         end
 411         if x1 > screen_width then
 412                 srcx1 = (screen_width - x0) / (x1 - x0)
 413                 x1 = screen_width
 414         end
 415         if y1 > screen_height then
 416                 srcy1 = (screen_height - y0) / (y1 - y0)
 417                 y1 = screen_height
 418         end
 419
 420         if resample_effect ~= nil then
 421                 -- High-quality resampling.
 422                 local x_subpixel_offset = x0 - math.floor(x0)
 423                 local y_subpixel_offset = y0 - math.floor(y0)
 424
 425                 -- Resampling must be to an integral number of pixels. Round up,
 426                 -- and then add an extra pixel so we have some leeway for the border.
 427                 local width = math.ceil(x1 - x0) + 1
 428                 local height = math.ceil(y1 - y0) + 1
 429                 resample_effect:set_int("width", width)
 430                 resample_effect:set_int("height", height)
 431
 432                 -- Correct the discrepancy with zoom. (This will leave a small
 433                 -- excess edge of pixels and subpixels, which we'll correct for soon.)
 434                 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
 435                 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
 436                 resample_effect:set_float("zoom_x", zoom_x)
 437                 resample_effect:set_float("zoom_y", zoom_y)
 438                 resample_effect:set_float("zoom_center_x", 0.0)
 439                 resample_effect:set_float("zoom_center_y", 0.0)
 440
 441                 -- Padding must also be to a whole-pixel offset.
 442                 padding_effect:set_int("left", math.floor(x0))
 443                 padding_effect:set_int("top", math.floor(y0))
 444
 445                 -- Correct _that_ discrepancy by subpixel offset in the resampling.
 446                 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
 447                 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
 448
 449                 -- Finally, adjust the border so it is exactly where we want it.
 450                 padding_effect:set_float("border_offset_left", x_subpixel_offset)
 451                 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
 452                 padding_effect:set_float("border_offset_top", y_subpixel_offset)
 453                 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
 454         else
 455                 -- Lower-quality simple resizing.
 456                 local width = round(x1 - x0)
 457                 local height = round(y1 - y0)
 458                 resize_effect:set_int("width", width)
 459                 resize_effect:set_int("height", height)
 460
 461                 -- Padding must also be to a whole-pixel offset.
 462                 padding_effect:set_int("left", math.floor(x0))
 463                 padding_effect:set_int("top", math.floor(y0))
 464         end
 465 end
 466
 467 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
 468 function round(x)
 469         return math.floor(x + 0.5)
 470 end
 471
 472 function lerp(a, b, t)
 473         return a + (b - a) * t
 474 end
 475
 476 function prepare_sbs_chain(chain, t, screen_width, screen_height)
 477         chain.input0.input:connect_signal(0)
 478         chain.input1.input:connect_signal(1)
 479         set_neutral_color(chain.input0.white_balance_effect, input0_neutral_color)
 480         set_neutral_color(chain.input1.white_balance_effect, input1_neutral_color)
 481
 482         -- First input is positioned (16,48) from top-left.
 483         local width0 = round(848 * screen_width/1280.0)
 484         local height0 = round(width0 * 9.0 / 16.0)
 485
 486         local top0 = 48 * screen_height/720.0
 487         local left0 = 16 * screen_width/1280.0
 488         local bottom0 = top0 + height0
 489         local right0 = left0 + width0
 490
 491         -- Second input is positioned (16,48) from the bottom-right.
 492         local width1 = round(384 * screen_width/1280.0)
 493         local height1 = round(216 * screen_height/720.0)
 494
 495         local bottom1 = screen_height - 48 * screen_height/720.0
 496         local right1 = screen_width - 16 * screen_width/1280.0
 497         local top1 = bottom1 - height1
 498         local left1 = right1 - width1
 499
 500         -- Interpolate between the fullscreen and side-by-side views.
 501         local scale0, tx0, tx0
 502         if zoom_poi == 0 then
 503                 local new_left0 = lerp(left0, 0, t)
 504                 local new_right0 = lerp(right0, screen_width, t)
 505                 local new_top0 = lerp(top0, 0, t)
 506                 local new_bottom0 = lerp(bottom0, screen_height, t)
 507
 508                 scale0 = (new_right0 - new_left0) / width0  -- Same vertically and horizonally.
 509                 tx0 = new_left0 - left0 * scale0
 510                 ty0 = new_top0 - top0 * scale0
 511         else
 512                 local new_left1 = lerp(left1, 0, t)
 513                 local new_right1 = lerp(right1, screen_width, t)
 514                 local new_top1 = lerp(top1, 0, t)
 515                 local new_bottom1 = lerp(bottom1, screen_height, t)
 516
 517                 scale0 = (new_right1 - new_left1) / width1  -- Same vertically and horizonally.
 518                 tx0 = new_left1 - left1 * scale0
 519                 ty0 = new_top1 - top1 * scale0
 520         end
 521
 522         top0 = top0 * scale0 + ty0
 523         bottom0 = bottom0 * scale0 + ty0
 524         left0 = left0 * scale0 + tx0
 525         right0 = right0 * scale0 + tx0
 526
 527         top1 = top1 * scale0 + ty0
 528         bottom1 = bottom1 * scale0 + ty0
 529         left1 = left1 * scale0 + tx0
 530         right1 = right1 * scale0 + tx0
 531         place_rectangle(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, left0, top0, right0, bottom0, screen_width, screen_height, 1280, 720)
 532         place_rectangle(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, left1, top1, right1, bottom1, screen_width, screen_height, 1280, 720)
 533 end
 534
 535 function set_neutral_color(effect, color)
 536         effect:set_vec3("neutral_color", color[1], color[2], color[3])
 537 end