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 io.write("hello from lua\n")
  10
  11 local transition_start = -2.0
  12 local transition_end = -1.0
  13 local zoom_src = 0.0
  14 local zoom_dst = 1.0
  15 local zoom_poi = 0   -- which input to zoom in on
  16 local fade_src = 0.0
  17 local fade_dst = 1.0
  18
  19 local live_signal_num = 0
  20 local preview_signal_num = 1
  21
  22 -- The main live chain.
  23 function make_sbs_chain(hq)
  24         local chain = EffectChain.new(16, 9)
  25         local input0 = chain:add_live_input()
  26         input0:connect_signal(0)
  27         local input1 = chain:add_live_input()
  28         input1:connect_signal(1)
  29
  30         local resample_effect = nil
  31         local resize_effect = nil
  32         if (hq) then
  33                 resample_effect = chain:add_effect(ResampleEffect.new(), input0)
  34         else
  35                 resize_effect = chain:add_effect(ResizeEffect.new(), input0)
  36         end
  37
  38         local padding_effect = chain:add_effect(IntegralPaddingEffect.new())
  39         padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 1.0)
  40
  41         local resample2_effect = nil
  42         local resize2_effect = nil
  43         if (hq) then
  44                 resample2_effect = chain:add_effect(ResampleEffect.new(), input1)
  45         else
  46                 resize2_effect = chain:add_effect(ResizeEffect.new(), input1)
  47         end
  48         -- Effect *saturation_effect = chain->add_effect(new SaturationEffect())
  49         -- CHECK(saturation_effect->set_float("saturation", 0.3f))
  50         local wb_effect = chain:add_effect(WhiteBalanceEffect.new())
  51         wb_effect:set_float("output_color_temperature", 3500.0)
  52         local padding2_effect = chain:add_effect(IntegralPaddingEffect.new())
  53
  54         chain:add_effect(OverlayEffect.new(), padding_effect, padding2_effect)
  55         chain:finalize(hq)
  56
  57         return {
  58                 chain = chain,
  59                 input0 = {
  60                         input = input0,
  61                         resample_effect = resample_effect,
  62                         resize_effect = resize_effect,
  63                         padding_effect = padding_effect
  64                 },
  65                 input1 = {
  66                         input = input1,
  67                         resample_effect = resample2_effect,
  68                         resize_effect = resize2_effect,
  69                         padding_effect = padding2_effect
  70                 }
  71         }
  72 end
  73
  74 local main_chain_hq = make_sbs_chain(true)
  75 local main_chain_lq = make_sbs_chain(false)
  76
  77 -- A chain to fade between two inputs (live chain only)
  78 local fade_chain_hq = EffectChain.new(16, 9)
  79 local fade_chain_hq_input0 = fade_chain_hq:add_live_input()
  80 local fade_chain_hq_input1 = fade_chain_hq:add_live_input()
  81 fade_chain_hq_input0:connect_signal(0)
  82 fade_chain_hq_input1:connect_signal(1)
  83 local fade_chain_mix_effect = fade_chain_hq:add_effect(MixEffect.new(), fade_chain_hq_input0, fade_chain_hq_input1)
  84 fade_chain_hq:finalize(true)
  85
  86 -- A chain to show a single input on screen (HQ version).
  87 local simple_chain_hq = EffectChain.new(16, 9)
  88 local simple_chain_hq_input = simple_chain_hq:add_live_input()
  89 simple_chain_hq_input:connect_signal(0)  -- First input card. Can be changed whenever you want.
  90 simple_chain_hq:finalize(true)
  91
  92 -- A chain to show a single input on screen (LQ version).
  93 local simple_chain_lq = EffectChain.new(16, 9)
  94 local simple_chain_lq_input = simple_chain_lq:add_live_input()
  95 simple_chain_lq_input:connect_signal(0)  -- First input card. Can be changed whenever you want.
  96 simple_chain_lq:finalize(false)
  97
  98 -- Returns the number of outputs in addition to the live (0) and preview (1).
  99 -- Called only once, at the start of the program.
 100 function num_channels()
 101         return 3
 102 end
 103
 104 function finish_transitions(t)
 105         -- If live is 2 (SBS) but de-facto single, make it so.
 106         if live_signal_num == 2 and t >= transition_end and zoom_dst == 1.0 then
 107                 live_signal_num = zoom_poi
 108         end
 109
 110         -- If live is 3 (fade) but de-facto single, make it so.
 111         if live_signal_num == 3 and t >= transition_end and fade_dst == 1.0 then
 112                 live_signal_num = 0
 113         end
 114         if live_signal_num == 3 and t >= transition_end and fade_dst == 0.0 then
 115                 live_signal_num = 1
 116         end
 117 end
 118
 119 -- Called every frame.
 120 function get_transitions(t)
 121         finish_transitions(t)
 122
 123         if live_signal_num == preview_signal_num then
 124                 return {}
 125         end
 126
 127         if live_signal_num == 2 and t >= transition_start and t <= transition_end then
 128                 -- Zoom in progress.
 129                 return {"Cut"}
 130         end
 131
 132         if (live_signal_num == 0 and preview_signal_num == 1) or
 133            (live_signal_num == 1 and preview_signal_num == 0) then
 134                 return {"Cut", "", "Fade"}
 135         end
 136
 137         -- Various zooms.
 138         if live_signal_num == 2 and (preview_signal_num == 0 or preview_signal_num == 1) then
 139                 return {"Cut", "Zoom in"}
 140         elseif (live_signal_num == 0 or live_signal_num == 1) and preview_signal_num == 2 then
 141                 return {"Cut", "Zoom out"}
 142         end
 143
 144         return {"Cut"}
 145 end
 146
 147 function transition_clicked(num, t)
 148         if num == 0 then
 149                 -- Cut.
 150                 if live_signal_num == 3 then
 151                         -- Ongoing fade; finish it immediately.
 152                         finish_transitions(transition_end)
 153                 end
 154
 155                 local temp = live_signal_num
 156                 live_signal_num = preview_signal_num
 157                 preview_signal_num = temp
 158
 159                 if live_signal_num == 2 then
 160                         -- Just cut to SBS, we need to reset any zooms.
 161                         zoom_src = 1.0
 162                         zoom_dst = 0.0
 163                         transition_start = -2.0
 164                         transition_end = -1.0
 165                 end
 166         elseif num == 1 then
 167                 -- Zoom.
 168
 169                 finish_transitions(t)
 170
 171                 if live_signal_num == preview_signal_num then
 172                         -- Nothing to do.
 173                         return
 174                 end
 175
 176                 if (live_signal_num == 0 and preview_signal_num == 1) or
 177                    (live_signal_num == 1 and preview_signal_num == 0) then
 178                         -- We can't zoom between these. Just make a cut.
 179                         io.write("Cutting from " .. live_signal_num .. " to " .. live_signal_num .. "\n")
 180                         local temp = live_signal_num
 181                         live_signal_num = preview_signal_num
 182                         preview_signal_num = temp
 183                         return
 184                 end
 185
 186                 if live_signal_num == 2 and (preview_signal_num == 0 or preview_signal_num == 1) then
 187                         -- Zoom in from SBS to single.
 188                         transition_start = t
 189                         transition_end = t + 1.0
 190                         zoom_src = 0.0
 191                         zoom_dst = 1.0
 192                         zoom_poi = preview_signal_num
 193                         preview_signal_num = 2
 194                 elseif (live_signal_num == 0 or live_signal_num == 1) and preview_signal_num == 2 then
 195                         -- Zoom out from single to SBS.
 196                         transition_start = t
 197                         transition_end = t + 1.0
 198                         zoom_src = 1.0
 199                         zoom_dst = 0.0
 200                         preview_signal_num = live_signal_num
 201                         zoom_poi = live_signal_num
 202                         live_signal_num = 2
 203                 end
 204         elseif num == 2 then
 205                 finish_transitions(t)
 206
 207                 -- Fade.
 208                 if live_signal_num == 0 and preview_signal_num == 1 then
 209                         transition_start = t
 210                         transition_end = t + 1.0
 211                         fade_src = 1.0
 212                         fade_dst = 0.0
 213                         preview_signal_num = 0
 214                         live_signal_num = 3
 215                 elseif live_signal_num == 1 and preview_signal_num == 0 then
 216                         transition_start = t
 217                         transition_end = t + 1.0
 218                         fade_src = 0.0
 219                         fade_dst = 1.0
 220                         preview_signal_num = 1
 221                         live_signal_num = 3
 222                 else
 223                         -- Fades involving SBS are ignored (we have no chain for it).
 224                 end
 225         end
 226 end
 227
 228 function channel_clicked(num)
 229         preview_signal_num = num
 230 end
 231
 232 -- Called every frame. Get the chain for displaying at input <num>,
 233 -- where 0 is live, 1 is preview, 2 is the first channel to display
 234 -- in the bottom bar, and so on up to num_channels()+1. t is the
 235 -- current time in seconds. width and height are the dimensions of
 236 -- the output, although you can ignore them if you don't need them
 237 -- (they're useful if you want to e.g. know what to resample by).
 238 --
 239 -- You should return two objects; the chain itself, and then a
 240 -- function (taking no parameters) that is run just before rendering.
 241 -- The function needs to call connect_signal on any inputs, so that
 242 -- it gets updated video data for the given frame. (You are allowed
 243 -- to switch which input your input is getting from between frames,
 244 -- but not calling connect_signal results in undefined behavior.)
 245 -- If you want to change any parameters in the chain, this is also
 246 -- the right place.
 247 --
 248 -- NOTE: The chain returned must be finalized with the Y'CbCr flag
 249 -- if and only if num==0.
 250 function get_chain(num, t, width, height)
 251         if num == 0 then  -- Live.
 252                 if live_signal_num == 0 or live_signal_num == 1 then  -- Plain inputs.
 253                         prepare = function()
 254                                 simple_chain_hq_input:connect_signal(live_signal_num)
 255                         end
 256                         return simple_chain_hq, prepare
 257                 elseif live_signal_num == 3 then  -- Fade.
 258                         prepare = function()
 259                                 fade_chain_hq_input0:connect_signal(0)
 260                                 fade_chain_hq_input1:connect_signal(1)
 261                                 local tt = (t - transition_start) / (transition_end - transition_start)
 262                                 if tt < 0.0 then
 263                                         tt = 0.0
 264                                 elseif tt > 1.0 then
 265                                         tt = 1.0
 266                                 end
 267
 268                                 tt = fade_src + tt * (fade_dst - fade_src)
 269
 270                                 -- Make the fade look maybe a tad more natural, by pumping it
 271                                 -- through a sigmoid function.
 272                                 tt = 10.0 * tt - 5.0
 273                                 tt = 1.0 / (1.0 + math.exp(-tt))
 274
 275                                 fade_chain_mix_effect:set_float("strength_first", tt)
 276                                 fade_chain_mix_effect:set_float("strength_second", 1.0 - tt)
 277                         end
 278                         return fade_chain_hq, prepare
 279                 end
 280
 281                 -- SBS code (live_signal_num == 2).
 282                 if t > transition_end and zoom_dst == 1.0 then
 283                         -- Special case: Show only the single image on screen.
 284                         prepare = function()
 285                                 simple_chain_hq_input:connect_signal(0)
 286                         end
 287                         return simple_chain_hq, prepare
 288                 end
 289                 prepare = function()
 290                         if t < transition_start then
 291                                 prepare_sbs_chain(main_chain_hq, zoom_src, width, height)
 292                         elseif t > transition_end then
 293                                 prepare_sbs_chain(main_chain_hq, zoom_dst, width, height)
 294                         else
 295                                 local tt = (t - transition_start) / (transition_end - transition_start)
 296                                 -- Smooth it a bit.
 297                                 tt = math.sin(tt * 3.14159265358 * 0.5)
 298                                 prepare_sbs_chain(main_chain_hq, zoom_src + (zoom_dst - zoom_src) * tt, width, height)
 299                         end
 300                 end
 301                 return main_chain_hq.chain, prepare
 302         end
 303         if num == 1 then  -- Preview.
 304                 num = preview_signal_num + 2
 305         end
 306         if num == 2 then
 307                 prepare = function()
 308                         simple_chain_lq_input:connect_signal(0)
 309                 end
 310                 return simple_chain_lq, prepare
 311         end
 312         if num == 3 then
 313                 prepare = function()
 314                         simple_chain_lq_input:connect_signal(1)
 315                 end
 316                 return simple_chain_lq, prepare
 317         end
 318         if num == 4 then
 319                 prepare = function()
 320                         prepare_sbs_chain(main_chain_lq, 0.0, width, height)
 321                 end
 322                 return main_chain_lq.chain, prepare
 323         end
 324 end
 325
 326 function place_rectangle(resample_effect, resize_effect, padding_effect, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height)
 327         local srcx0 = 0.0
 328         local srcx1 = 1.0
 329         local srcy0 = 0.0
 330         local srcy1 = 1.0
 331
 332         -- Cull.
 333         if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
 334                 resample_effect:set_int("width", 1)
 335                 resample_effect:set_int("height", 1)
 336                 resample_effect:set_float("zoom_x", screen_width)
 337                 resample_effect:set_float("zoom_y", screen_height)
 338                 padding_effect:set_int("left", screen_width + 100)
 339                 padding_effect:set_int("top", screen_height + 100)
 340                 return
 341         end
 342
 343         -- Clip.
 344         if x0 < 0 then
 345                 srcx0 = -x0 / (x1 - x0)
 346                 x0 = 0
 347         end
 348         if y0 < 0 then
 349                 srcy0 = -y0 / (y1 - y0)
 350                 y0 = 0
 351         end
 352         if x1 > screen_width then
 353                 srcx1 = (screen_width - x0) / (x1 - x0)
 354                 x1 = screen_width
 355         end
 356         if y1 > screen_height then
 357                 srcy1 = (screen_height - y0) / (y1 - y0)
 358                 y1 = screen_height
 359         end
 360
 361         if resample_effect ~= nil then
 362                 -- High-quality resampling.
 363                 local x_subpixel_offset = x0 - math.floor(x0)
 364                 local y_subpixel_offset = y0 - math.floor(y0)
 365
 366                 -- Resampling must be to an integral number of pixels. Round up,
 367                 -- and then add an extra pixel so we have some leeway for the border.
 368                 local width = math.ceil(x1 - x0) + 1
 369                 local height = math.ceil(y1 - y0) + 1
 370                 resample_effect:set_int("width", width)
 371                 resample_effect:set_int("height", height)
 372
 373                 -- Correct the discrepancy with zoom. (This will leave a small
 374                 -- excess edge of pixels and subpixels, which we'll correct for soon.)
 375                 local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
 376                 local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
 377                 resample_effect:set_float("zoom_x", zoom_x)
 378                 resample_effect:set_float("zoom_y", zoom_y)
 379                 resample_effect:set_float("zoom_center_x", 0.0)
 380                 resample_effect:set_float("zoom_center_y", 0.0)
 381
 382                 -- Padding must also be to a whole-pixel offset.
 383                 padding_effect:set_int("left", math.floor(x0))
 384                 padding_effect:set_int("top", math.floor(y0))
 385
 386                 -- Correct _that_ discrepancy by subpixel offset in the resampling.
 387                 resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
 388                 resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)
 389
 390                 -- Finally, adjust the border so it is exactly where we want it.
 391                 padding_effect:set_float("border_offset_left", x_subpixel_offset)
 392                 padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
 393                 padding_effect:set_float("border_offset_top", y_subpixel_offset)
 394                 padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
 395         else
 396                 -- Lower-quality simple resizing.
 397                 local width = round(x1 - x0)
 398                 local height = round(y1 - y0)
 399                 resize_effect:set_int("width", width)
 400                 resize_effect:set_int("height", height)
 401
 402                 -- Padding must also be to a whole-pixel offset.
 403                 padding_effect:set_int("left", math.floor(x0))
 404                 padding_effect:set_int("top", math.floor(y0))
 405         end
 406 end
 407
 408 -- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
 409 function round(x)
 410         return math.floor(x + 0.5)
 411 end
 412
 413 function lerp(a, b, t)
 414         return a + (b - a) * t
 415 end
 416
 417 function prepare_sbs_chain(chain, t, screen_width, screen_height)
 418         chain.input0.input:connect_signal(0)
 419         chain.input1.input:connect_signal(1)
 420
 421         -- First input is positioned (16,48) from top-left.
 422         local width0 = round(848 * screen_width/1280.0)
 423         local height0 = round(width0 * 9.0 / 16.0)
 424
 425         local top0 = 48 * screen_height/720.0
 426         local left0 = 16 * screen_width/1280.0
 427         local bottom0 = top0 + height0
 428         local right0 = left0 + width0
 429
 430         -- Second input is positioned (16,48) from the bottom-right.
 431         local width1 = round(384 * screen_width/1280.0)
 432         local height1 = round(216 * screen_height/720.0)
 433
 434         local bottom1 = screen_height - 48 * screen_height/720.0
 435         local right1 = screen_width - 16 * screen_width/1280.0
 436         local top1 = bottom1 - height1
 437         local left1 = right1 - width1
 438
 439         -- Interpolate between the fullscreen and side-by-side views.
 440         local scale0, tx0, tx0
 441         if zoom_poi == 0 then
 442                 local new_left0 = lerp(left0, 0, t)
 443                 local new_right0 = lerp(right0, screen_width, t)
 444                 local new_top0 = lerp(top0, 0, t)
 445                 local new_bottom0 = lerp(bottom0, screen_height, t)
 446
 447                 scale0 = (new_right0 - new_left0) / width0  -- Same vertically and horizonally.
 448                 tx0 = new_left0 - left0 * scale0
 449                 ty0 = new_top0 - top0 * scale0
 450         else
 451                 local new_left1 = lerp(left1, 0, t)
 452                 local new_right1 = lerp(right1, screen_width, t)
 453                 local new_top1 = lerp(top1, 0, t)
 454                 local new_bottom1 = lerp(bottom1, screen_height, t)
 455
 456                 scale0 = (new_right1 - new_left1) / width1  -- Same vertically and horizonally.
 457                 tx0 = new_left1 - left1 * scale0
 458                 ty0 = new_top1 - top1 * scale0
 459         end
 460
 461         top0 = top0 * scale0 + ty0
 462         bottom0 = bottom0 * scale0 + ty0
 463         left0 = left0 * scale0 + tx0
 464         right0 = right0 * scale0 + tx0
 465
 466         top1 = top1 * scale0 + ty0
 467         bottom1 = bottom1 * scale0 + ty0
 468         left1 = left1 * scale0 + tx0
 469         right1 = right1 * scale0 + tx0
 470         place_rectangle(chain.input0.resample_effect, chain.input0.resize_effect, chain.input0.padding_effect, left0, top0, right0, bottom0, screen_width, screen_height, 1280, 720)
 471         place_rectangle(chain.input1.resample_effect, chain.input1.resize_effect, chain.input1.padding_effect, left1, top1, right1, bottom1, screen_width, screen_height, 1280, 720)
 472 end