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