git.sesse.net Git - nageru/blob - nageru/scene.cpp

   1 #include <assert.h>
   2 extern "C" {
   3 #include <lauxlib.h>
   4 #include <lua.hpp>
   5 }
   6
   7 #ifdef HAVE_CEF
   8 #include "cef_capture.h"
   9 #endif
  10 #include "ffmpeg_capture.h"
  11 #include "flags.h"
  12 #include "image_input.h"
  13 #include "input_state.h"
  14 #include "lua_utils.h"
  15 #include "scene.h"
  16 #include "theme.h"
  17
  18 using namespace movit;
  19 using namespace std;
  20
  21 static bool display(Block *block, lua_State *L, int idx);
  22
  23 EffectType current_type(const Block *block)
  24 {
  25         return block->alternatives[block->currently_chosen_alternative]->effect_type;
  26 }
  27
  28 int find_index_of(const Block *block, EffectType val)
  29 {
  30         for (size_t idx = 0; idx < block->alternatives.size(); ++idx) {
  31                 if (block->alternatives[idx]->effect_type == val) {
  32                         return idx;
  33                 }
  34         }
  35         return -1;
  36 }
  37
  38 string get_declaration_point(lua_State *L)
  39 {
  40         lua_Debug ar;
  41         lua_getstack(L, 1, &ar);
  42         lua_getinfo(L, "nSl", &ar);
  43         char buf[256];
  44         snprintf(buf, sizeof(buf), "%s:%d", ar.source, ar.currentline);
  45         return buf;
  46 }
  47
  48 Scene::Scene(Theme *theme, float aspect_nom, float aspect_denom)
  49         : theme(theme), aspect_nom(aspect_nom), aspect_denom(aspect_denom), resource_pool(theme->get_resource_pool()) {}
  50
  51 size_t Scene::compute_chain_number(bool is_main_chain) const
  52 {
  53         assert(chains.size() > 0);
  54         assert(chains.size() % 2 == 0);
  55         bitset<256> disabled = find_disabled_blocks(size_t(-1));
  56
  57         size_t chain_number = compute_chain_number_for_block(blocks.size() - 1, disabled);
  58         assert(chain_number < chains.size() / 2);
  59         if (is_main_chain) {
  60                 chain_number += chains.size() / 2;
  61         }
  62         return chain_number;
  63 }
  64
  65 size_t Scene::compute_chain_number_for_block(size_t block_idx, const bitset<256> &disabled) const
  66 {
  67         Block *block = blocks[block_idx];
  68         size_t chain_number;
  69
  70         size_t currently_chosen_alternative;
  71         if (disabled.test(block_idx)) {
  72                 // It doesn't matter, so pick the canonical choice
  73                 // (this is the only one that is actually instantiated).
  74                 currently_chosen_alternative = block->canonical_alternative;
  75         } else {
  76                 currently_chosen_alternative = block->currently_chosen_alternative;
  77         }
  78         assert(currently_chosen_alternative < block->alternatives.size());
  79
  80         if (block_idx == 0) {
  81                 assert(block->cardinality_base == 1);
  82                 chain_number = currently_chosen_alternative;
  83         } else {
  84                 chain_number = compute_chain_number_for_block(block_idx - 1, disabled) + block->cardinality_base * currently_chosen_alternative;
  85         }
  86         return chain_number;
  87 }
  88
  89 bitset<256> Scene::find_disabled_blocks(size_t chain_idx) const
  90 {
  91         assert(blocks.size() < 256);
  92
  93         // The find_disabled_blocks() recursion logic needs only one pass by itself,
  94         // but the disabler logic is not so smart, so we just run multiple times
  95         // until it converges.
  96         bitset<256> prev, ret;
  97         do {
  98                 find_disabled_blocks(chain_idx, blocks.size() - 1, /*currently_disabled=*/false, &ret);
  99                 prev = ret;
 100
 101                 // Propagate DISABLE_IF_OTHER_DISABLED constraints (we can always do this).
 102                 for (Block *block : blocks) {
 103                         if (ret.test(block->idx)) continue;  // Already disabled.
 104
 105                         EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
 106                         if (chosen_type == IDENTITY_EFFECT) {
 107                                 ret.set(block->idx);
 108                                 continue;
 109                         }
 110
 111                         for (const Block::Disabler &disabler : block->disablers) {
 112                                 Block *other = blocks[disabler.block_idx];
 113                                 EffectType chosen_type = other->alternatives[other->chosen_alternative(chain_idx)]->effect_type;
 114                                 bool other_disabled = ret.test(disabler.block_idx) || chosen_type == IDENTITY_EFFECT;
 115                                 if (other_disabled && disabler.condition == Block::Disabler::DISABLE_IF_OTHER_DISABLED) {
 116                                         ret.set(block->idx);
 117                                         break;
 118                                 }
 119                         }
 120                 }
 121
 122                 // We cannot propagate DISABLE_IF_OTHER_ENABLED in all cases;
 123                 // the problem is that if A is disabled if B is enabled,
 124                 // then we cannot disable A unless we actually know for sure
 125                 // that B _is_ enabled. (E.g., imagine that B is disabled
 126                 // if C is enabled -- we couldn't disable A before we knew if
 127                 // C was enabled or not!)
 128                 //
 129                 // We could probably fix a fair amount of these, but the
 130                 // primary use case for DISABLE_IF_OTHER_ENABLED is really
 131                 // mutual exclusion; A must be disabled if B is enabled
 132                 // _and_ vice versa. These loops cannot be automatically
 133                 // resolved; it would depend on what A and B is. Thus,
 134                 // we simply declare this kind of constraint to be a promise
 135                 // from the user, not something that we'll solve for them.
 136         } while (prev != ret);
 137         return ret;
 138 }
 139
 140 void Scene::find_disabled_blocks(size_t chain_idx, size_t block_idx, bool currently_disabled, bitset<256> *disabled) const
 141 {
 142         if (currently_disabled) {
 143                 disabled->set(block_idx);
 144         }
 145         Block *block = blocks[block_idx];
 146         EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
 147         for (size_t input_idx = 0; input_idx < block->inputs.size(); ++input_idx) {
 148                 if (chosen_type == IDENTITY_EFFECT && input_idx > 0) {
 149                         // Multi-input effect that has been replaced by
 150                         // IdentityEffect, so every effect but the first are
 151                         // disabled and will not participate in the chain.
 152                         find_disabled_blocks(chain_idx, block->inputs[input_idx], /*currently_disabled=*/true, disabled);
 153                 } else {
 154                         // Just keep on recursing down.
 155                         find_disabled_blocks(chain_idx, block->inputs[input_idx], currently_disabled, disabled);
 156                 }
 157         }
 158 }
 159
 160 bool Scene::is_noncanonical_chain(size_t chain_idx) const
 161 {
 162         bitset<256> disabled = find_disabled_blocks(chain_idx);
 163         assert(blocks.size() < 256);
 164         for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
 165                 Block *block = blocks[block_idx];
 166                 if (disabled.test(block_idx) && block->chosen_alternative(chain_idx) != block->canonical_alternative) {
 167                         return true;
 168                 }
 169
 170                 // Test if we're supposed to be disabled by some other block being enabled;
 171                 // the disabled bit mask does not fully capture this.
 172                 if (!disabled.test(block_idx)) {
 173                         for (const Block::Disabler &disabler : block->disablers) {
 174                                 if (disabler.condition == Block::Disabler::DISABLE_IF_OTHER_ENABLED &&
 175                                     !disabled.test(disabler.block_idx)) {
 176                                         return true;
 177                                 }
 178                         }
 179
 180                         // Auto white balance is always disabled for image inputs.
 181                         if (block->white_balance_controller_block != nullptr) {
 182                                 const Block *input = block->white_balance_controller_block;
 183                                 if (input->alternatives[input->chosen_alternative(chain_idx)]->effect_type == IMAGE_INPUT) {
 184                                         return true;
 185                                 }
 186                         }
 187                 }
 188         }
 189         return false;
 190 }
 191
 192 int Scene::add_input(lua_State* L)
 193 {
 194         assert(lua_gettop(L) == 1 || lua_gettop(L) == 2);
 195         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 196
 197         Block *block = new Block;
 198         block->declaration_point = get_declaration_point(L);
 199         block->idx = scene->blocks.size();
 200         if (lua_gettop(L) == 1) {
 201                 // No parameter given, so a flexible input.
 202                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR));
 203                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_WITH_DEINTERLACE));
 204                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_PLANAR));
 205                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_BGRA));
 206                 block->alternatives.emplace_back(new EffectBlueprint(IMAGE_INPUT));
 207         } else {
 208                 // Input of a given type. We'll specialize it here, plus connect the input as given.
 209                 if (lua_isnumber(L, 2)) {
 210                         block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR));
 211                         block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_WITH_DEINTERLACE));
 212 #ifdef HAVE_SRT
 213                         if (global_flags.srt_port >= 0) {
 214                                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_PLANAR));
 215                         }
 216 #endif
 217 #ifdef HAVE_CEF
 218                 } else if (luaL_testudata(L, 2, "HTMLInput")) {
 219                         block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_BGRA));
 220 #endif
 221                 } else if (luaL_testudata(L, 2, "VideoInput")) {
 222                         FFmpegCapture *capture = *(FFmpegCapture **)luaL_checkudata(L, 2, "VideoInput");
 223                         if (capture->get_current_pixel_format() == bmusb::PixelFormat_8BitYCbCrPlanar) {
 224                                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_PLANAR));
 225                         } else {
 226                                 assert(capture->get_current_pixel_format() == bmusb::PixelFormat_8BitBGRA);
 227                                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_BGRA));
 228                         }
 229                 } else if (luaL_testudata(L, 2, "ImageInput")) {
 230                         block->alternatives.emplace_back(new EffectBlueprint(IMAGE_INPUT));
 231                 } else {
 232                         luaL_error(L, "add_input() called with something that's not a signal (a signal number, a HTML input, or a VideoInput)");
 233                 }
 234                 bool ok = display(block, L, 2);
 235                 assert(ok);
 236         }
 237         block->is_input = true;
 238         scene->blocks.push_back(block);
 239
 240         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 241 }
 242
 243 Block *Scene::find_block_from_arg(lua_State *L, Scene *scene, int idx)
 244 {
 245         if (luaL_testudata(L, idx, "Block")) {
 246                 return *(Block **)luaL_checkudata(L, idx, "Block");
 247         } else {
 248                 EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, idx, "EffectBlueprint");
 249
 250                 // Search through all the blocks to figure out which one contains this effect.
 251                 for (Block *block : scene->blocks) {
 252                         if (find(block->alternatives.begin(), block->alternatives.end(), blueprint) != block->alternatives.end()) {
 253                                 return block;
 254                         }
 255                 }
 256                 luaL_error(L, "Input effect in parameter #%d has not been added to this scene", idx - 1);
 257                 return nullptr;  // Dead code.
 258         }
 259 }
 260
 261 void Scene::find_inputs_for_block(lua_State *L, Scene *scene, Block *block, int first_input_idx)
 262 {
 263         if (lua_gettop(L) == first_input_idx - 1) {
 264                 // Implicitly the last added effect.
 265                 assert(!scene->blocks.empty());
 266                 block->inputs.push_back(scene->blocks.size() - 1);
 267                 return;
 268         }
 269
 270         for (int idx = first_input_idx; idx <= lua_gettop(L); ++idx) {
 271                 block->inputs.push_back(find_block_from_arg(L, scene, idx)->idx);
 272         }
 273 }
 274
 275 int Scene::add_effect(lua_State* L)
 276 {
 277         assert(lua_gettop(L) >= 2);
 278         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 279
 280         Block *block = new Block;
 281         block->declaration_point = get_declaration_point(L);
 282         block->idx = scene->blocks.size();
 283
 284         if (lua_istable(L, 2)) {
 285                 size_t len = lua_objlen(L, 2);
 286                 for (size_t i = 0; i < len; ++i) {
 287                         lua_rawgeti(L, 2, i + 1);
 288                         EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, -1, "EffectBlueprint");
 289                         block->alternatives.push_back(blueprint);
 290                         lua_settop(L, -2);
 291                 }
 292         } else {
 293                 EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, 2, "EffectBlueprint");
 294                 block->alternatives.push_back(blueprint);
 295         }
 296
 297         int identity_index = find_index_of(block, IDENTITY_EFFECT);
 298         if (identity_index == -1) {
 299                 block->canonical_alternative = 0;
 300         } else {
 301                 // Pick the IdentityEffect as the canonical alternative, in case it
 302                 // helps us disable more stuff.
 303                 block->canonical_alternative = identity_index;
 304         }
 305
 306         find_inputs_for_block(L, scene, block);
 307         scene->blocks.push_back(block);
 308
 309         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 310 }
 311
 312 int Scene::add_optional_effect(lua_State* L)
 313 {
 314         assert(lua_gettop(L) >= 2);
 315         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 316
 317         Block *block = new Block;
 318         block->declaration_point = get_declaration_point(L);
 319         block->idx = scene->blocks.size();
 320
 321         EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, 2, "EffectBlueprint");
 322         block->alternatives.push_back(blueprint);
 323
 324         // An IdentityEffect will be the alternative for when the effect is disabled.
 325         block->alternatives.push_back(new EffectBlueprint(IDENTITY_EFFECT));
 326
 327         block->canonical_alternative = 1;
 328
 329         find_inputs_for_block(L, scene, block);
 330         scene->blocks.push_back(block);
 331
 332         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 333 }
 334
 335 const Block *Scene::find_root_input_block(lua_State *L, const Block *block)
 336 {
 337         if (block->is_input) {
 338                 assert(block->inputs.size() == 0);
 339                 return block;
 340         }
 341
 342         const Block *ret = nullptr;
 343         for (size_t input_idx : block->inputs) {
 344                 const Block *parent = find_root_input_block(L, blocks[input_idx]);
 345                 if (parent != nullptr) {
 346                         if (ret != nullptr) {
 347                                 luaL_error(L, "add_white_balance() was connected to more than one input");
 348                         }
 349                         ret = parent;
 350                 }
 351         }
 352         return ret;
 353 }
 354
 355 int Scene::add_white_balance(lua_State* L)
 356 {
 357         assert(lua_gettop(L) >= 1);
 358         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 359
 360         Block *block = new Block;
 361         block->declaration_point = get_declaration_point(L);
 362         block->idx = scene->blocks.size();
 363
 364         block->alternatives.push_back(new EffectBlueprint(WHITE_BALANCE_EFFECT));
 365         block->alternatives.push_back(new EffectBlueprint(IDENTITY_EFFECT));
 366
 367         block->canonical_alternative = 1;
 368
 369         if (lua_gettop(L) == 1) {
 370                 // The last added effect is implicitly both the input and gives the white balance controller.
 371                 assert(!scene->blocks.empty());
 372                 block->inputs.push_back(scene->blocks.size() - 1);
 373                 block->white_balance_controller_block = scene->find_root_input_block(L, block);
 374         } else if (lua_gettop(L) == 2) {
 375                 // The given effect is both the input and the white balance controller.
 376                 block->inputs.push_back(find_block_from_arg(L, scene, 2)->idx);
 377                 block->white_balance_controller_block = scene->find_root_input_block(L, block);
 378         } else if (lua_gettop(L) == 3) {
 379                 // We have explicit input and white balance controller.
 380                 block->inputs.push_back(find_block_from_arg(L, scene, 2)->idx);
 381                 block->white_balance_controller_block = find_block_from_arg(L, scene, 3);
 382         } else {
 383                 luaL_error(L, "add_white_balance([input], [white_balance_controller]) takes zero, one or two arguments");
 384         }
 385         if (block->white_balance_controller_block == nullptr || !block->white_balance_controller_block->is_input) {
 386                 luaL_error(L, "add_white_balance() does not get its white balance from an input");
 387         }
 388
 389         scene->blocks.push_back(block);
 390
 391         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 392 }
 393
 394 Effect *Scene::instantiate_effects(const Block *block, size_t chain_idx, Scene::Instantiation *instantiation)
 395 {
 396         // Find the chosen alternative for this block in this instance.
 397         EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
 398
 399         vector<Effect *> inputs;
 400         for (size_t input_idx : block->inputs) {
 401                 inputs.push_back(instantiate_effects(blocks[input_idx], chain_idx, instantiation));
 402
 403                 // As a special case, we allow IdentityEffect to take only one input
 404                 // even if the other alternative (or alternatives) is multi-input.
 405                 // Thus, even if there are more than one inputs, instantiate only
 406                 // the first one.
 407                 if (chosen_type == IDENTITY_EFFECT) {
 408                         break;
 409                 }
 410         }
 411
 412         Effect *effect;
 413         switch (chosen_type) {
 414         case LIVE_INPUT_YCBCR:
 415         case LIVE_INPUT_YCBCR_WITH_DEINTERLACE:
 416         case LIVE_INPUT_YCBCR_PLANAR:
 417         case LIVE_INPUT_BGRA: {
 418                 bool deinterlace = (chosen_type == LIVE_INPUT_YCBCR_WITH_DEINTERLACE);
 419                 bool override_bounce = !deinterlace;  // For most chains, this will be fine. Reconsider if we see real problems somewhere; it's better than having the user try to understand it.
 420                 bmusb::PixelFormat pixel_format;
 421                 if (chosen_type == LIVE_INPUT_BGRA) {
 422                         pixel_format = bmusb::PixelFormat_8BitBGRA;
 423                 } else if (chosen_type == LIVE_INPUT_YCBCR_PLANAR) {
 424                         pixel_format = bmusb::PixelFormat_8BitYCbCrPlanar;
 425                 } else if (global_flags.bit_depth > 8) {
 426                         pixel_format = bmusb::PixelFormat_10BitYCbCr;
 427                 } else {
 428                         pixel_format = bmusb::PixelFormat_8BitYCbCr;
 429                 }
 430                 LiveInputWrapper *input = new LiveInputWrapper(theme, instantiation->chain.get(), pixel_format, override_bounce, deinterlace, /*user_connectable=*/true);
 431                 effect = input->get_effect();  // Adds itself to the chain, so no need to call add_effect().
 432                 instantiation->inputs.emplace(block->idx, input);
 433                 break;
 434         }
 435         case IMAGE_INPUT: {
 436                 ImageInput *input = new ImageInput;
 437                 instantiation->chain->add_input(input);
 438                 instantiation->image_inputs.emplace(block->idx, input);
 439                 effect = input;
 440                 break;
 441         }
 442         default:
 443                 effect = instantiate_effect(instantiation->chain.get(), chosen_type);
 444                 instantiation->chain->add_effect(effect, inputs);
 445                 break;
 446         }
 447         instantiation->effects.emplace(block->idx, effect);
 448         return effect;
 449 }
 450
 451 int Scene::finalize(lua_State* L)
 452 {
 453         bool only_one_mode = false;
 454         bool chosen_mode = false;
 455         if (lua_gettop(L) == 2) {
 456                 only_one_mode = true;
 457                 chosen_mode = checkbool(L, 2);
 458         } else {
 459                 assert(lua_gettop(L) == 1);
 460         }
 461         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 462         Theme *theme = get_theme_updata(L);
 463
 464         size_t base = 1;
 465         for (Block *block : scene->blocks) {
 466                 block->cardinality_base = base;
 467                 base *= block->alternatives.size();
 468         }
 469
 470         const size_t cardinality = base;
 471         size_t real_cardinality = 0;
 472         for (size_t chain_idx = 0; chain_idx < cardinality; ++chain_idx) {
 473                 if (!scene->is_noncanonical_chain(chain_idx)) {
 474                         ++real_cardinality;
 475                 }
 476         }
 477         const size_t total_cardinality = real_cardinality * (only_one_mode ? 1 : 2);
 478         if (total_cardinality > 200) {
 479                 print_warning(L, "The given Scene will instantiate %zu different versions. This will take a lot of time and RAM to compile; see if you could limit some options by e.g. locking the input type in some cases (by giving a fixed input to add_input()).\n",
 480                         total_cardinality);
 481         }
 482
 483         Block *output_block = scene->blocks.back();
 484         for (bool is_main_chain : { false, true }) {
 485                 for (size_t chain_idx = 0; chain_idx < cardinality; ++chain_idx) {
 486                         if ((only_one_mode && is_main_chain != chosen_mode) ||
 487                             scene->is_noncanonical_chain(chain_idx)) {
 488                                 scene->chains.emplace_back();
 489                                 continue;
 490                         }
 491
 492                         Scene::Instantiation instantiation;
 493                         instantiation.chain.reset(new EffectChain(scene->aspect_nom, scene->aspect_denom, theme->get_resource_pool()));
 494                         scene->instantiate_effects(output_block, chain_idx, &instantiation);
 495
 496                         add_outputs_and_finalize(instantiation.chain.get(), is_main_chain);
 497                         scene->chains.emplace_back(move(instantiation));
 498                 }
 499         }
 500         return 0;
 501 }
 502
 503 int find_card_to_connect(Theme *theme, lua_State *L, const Block *block)
 504 {
 505         if (block->signal_type_to_connect == Block::CONNECT_SIGNAL) {
 506                 return theme->map_signal_to_card(block->signal_to_connect);
 507 #ifdef HAVE_CEF
 508         } else if (block->signal_type_to_connect == Block::CONNECT_CEF) {
 509                 return block->cef_to_connect->get_card_index();
 510 #endif
 511         } else if (block->signal_type_to_connect == Block::CONNECT_VIDEO) {
 512                 return block->video_to_connect->get_card_index();
 513         } else if (block->signal_type_to_connect == Block::CONNECT_NONE) {
 514                 luaL_error(L, "An input in a scene was not connected to anything (forgot to call display())");
 515         } else {
 516                 assert(false);
 517         }
 518         return -1;
 519 }
 520
 521 std::pair<movit::EffectChain *, std::function<void()>>
 522 Scene::get_chain(Theme *theme, lua_State *L, unsigned num, const InputState &input_state)
 523 {
 524         // For video inputs, pick the right interlaced/progressive version
 525         // based on the current state of the signals.
 526         InputStateInfo info(input_state);
 527         for (Block *block : blocks) {
 528                 if (block->is_input && block->signal_type_to_connect == Block::CONNECT_SIGNAL) {
 529                         int card_index = theme->map_signal_to_card(block->signal_to_connect);
 530                         if (info.last_interlaced[card_index]) {
 531                                 assert(info.last_pixel_format[card_index] == bmusb::PixelFormat_8BitYCbCr ||
 532                                        info.last_pixel_format[card_index] == bmusb::PixelFormat_10BitYCbCr);
 533                                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR_WITH_DEINTERLACE);
 534                         } else if (info.last_pixel_format[card_index] == bmusb::PixelFormat_8BitYCbCrPlanar) {
 535                                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR_PLANAR);
 536                         } else if (info.last_pixel_format[card_index] == bmusb::PixelFormat_8BitBGRA) {
 537                                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_BGRA);
 538                         } else {
 539                                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR);
 540                         }
 541                         if (block->currently_chosen_alternative == -1) {
 542                                 fprintf(stderr, "ERROR: Input connected to a video card pixel format that it was not ready for.\n");
 543                                 abort();
 544                         }
 545                 }
 546         }
 547
 548         // Find all auto white balance blocks, turn on and off the effect as needed,
 549         // and fetch the actual white balance set (it is stored in Theme).
 550         map<Block *, array<float, 3>> white_balance;
 551         for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
 552                 Block *block = blocks[block_idx];
 553                 const Block *input = block->white_balance_controller_block;
 554                 if (input == nullptr) {
 555                         continue;  // Not an auto white balance block.
 556                 }
 557
 558                 EffectType chosen_type = current_type(input);
 559                 if (chosen_type == IMAGE_INPUT) {
 560                         // Image inputs never get white balance applied.
 561                         block->currently_chosen_alternative = find_index_of(block, IDENTITY_EFFECT);
 562                         continue;
 563                 }
 564
 565                 assert(chosen_type == LIVE_INPUT_YCBCR ||
 566                        chosen_type == LIVE_INPUT_YCBCR_WITH_DEINTERLACE ||
 567                        chosen_type == LIVE_INPUT_YCBCR_PLANAR ||
 568                        chosen_type == LIVE_INPUT_BGRA);
 569                 int card_idx = find_card_to_connect(theme, L, input);
 570                 RGBTriplet wb = theme->get_white_balance_for_card(card_idx);
 571                 if (fabs(wb.r - 1.0) < 1e-3 && fabs(wb.g - 1.0) < 1e-3 && fabs(wb.b - 1.0) < 1e-3) {
 572                         // Neutral white balance.
 573                         block->currently_chosen_alternative = find_index_of(block, IDENTITY_EFFECT);
 574                 } else {
 575                         block->currently_chosen_alternative = find_index_of(block, WHITE_BALANCE_EFFECT);
 576                         white_balance.emplace(block, array<float, 3>{ wb.r, wb.g, wb.b });
 577                 }
 578         }
 579
 580         // Pick out the right chain based on the current selections,
 581         // and snapshot all the set variables so that we can set them
 582         // in the prepare function even if they're being changed by
 583         // the Lua code later.
 584         bool is_main_chain = (num == 0);
 585         size_t chain_idx = compute_chain_number(is_main_chain);
 586         if (is_noncanonical_chain(chain_idx)) {
 587                 // This should be due to promise_to_disable_if_enabled(). Find out what
 588                 // happened, to give the user some help.
 589                 bitset<256> disabled = find_disabled_blocks(chain_idx);
 590                 for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
 591                         Block *block = blocks[block_idx];
 592                         if (disabled.test(block_idx)) continue;
 593                         for (const Block::Disabler &disabler : block->disablers) {
 594                                 if (disabler.condition == Block::Disabler::DISABLE_IF_OTHER_ENABLED &&
 595                                     !disabled.test(disabler.block_idx)) {
 596                                         fprintf(stderr, "Promise declared at %s violated.\n", disabler.declaration_point.c_str());
 597                                         abort();
 598                                 }
 599                         }
 600                 }
 601                 assert(false);  // Something else happened, seemingly.
 602         }
 603         const Scene::Instantiation &instantiation = chains[chain_idx];
 604         EffectChain *effect_chain = instantiation.chain.get();
 605
 606         map<LiveInputWrapper *, int> cards_to_connect;
 607         map<ImageInput *, string> images_to_select;
 608         map<pair<Effect *, string>, int> int_to_set;
 609         map<pair<Effect *, string>, float> float_to_set;
 610         map<pair<Effect *, string>, array<float, 3>> vec3_to_set;
 611         map<pair<Effect *, string>, array<float, 4>> vec4_to_set;
 612         for (const auto &index_and_input : instantiation.inputs) {
 613                 Block *block = blocks[index_and_input.first];
 614                 EffectType chosen_type = current_type(block);
 615                 if (chosen_type == LIVE_INPUT_YCBCR ||
 616                     chosen_type == LIVE_INPUT_YCBCR_WITH_DEINTERLACE ||
 617                     chosen_type == LIVE_INPUT_YCBCR_PLANAR ||
 618                     chosen_type == LIVE_INPUT_BGRA) {
 619                         LiveInputWrapper *input = index_and_input.second;
 620                         cards_to_connect.emplace(input, find_card_to_connect(theme, L, block));
 621                 }
 622         }
 623         for (const auto &index_and_input : instantiation.image_inputs) {
 624                 Block *block = blocks[index_and_input.first];
 625                 ImageInput *input = index_and_input.second;
 626                 if (current_type(block) == IMAGE_INPUT) {
 627                         images_to_select.emplace(input, block->pathname);
 628                 }
 629         }
 630         for (const auto &index_and_effect : instantiation.effects) {
 631                 Block *block = blocks[index_and_effect.first];
 632                 Effect *effect = index_and_effect.second;
 633
 634                 bool missing_width = (current_type(block) == RESIZE_EFFECT ||
 635                         current_type(block) == RESAMPLE_EFFECT ||
 636                         current_type(block) == PADDING_EFFECT);
 637                 bool missing_height = missing_width;
 638
 639                 // Get the effects currently set on the block.
 640                 if (current_type(block) != IDENTITY_EFFECT) {  // Ignore settings on optional effects.
 641                         if (block->int_parameters.count("width") && block->int_parameters["width"] > 0) {
 642                                 missing_width = false;
 643                         }
 644                         if (block->int_parameters.count("height") && block->int_parameters["height"] > 0) {
 645                                 missing_height = false;
 646                         }
 647                         for (const auto &key_and_tuple : block->int_parameters) {
 648                                 int_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 649                         }
 650                         for (const auto &key_and_tuple : block->float_parameters) {
 651                                 float_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 652                         }
 653                         if (white_balance.count(block)) {
 654                                 vec3_to_set.emplace(make_pair(effect, "neutral_color"), white_balance[block]);
 655                         }
 656                         for (const auto &key_and_tuple : block->vec3_parameters) {
 657                                 vec3_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 658                         }
 659                         for (const auto &key_and_tuple : block->vec4_parameters) {
 660                                 vec4_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 661                         }
 662                 }
 663
 664                 // Parameters set on the blueprint itself override those that are set for the block,
 665                 // so they are set afterwards.
 666                 if (!block->alternatives.empty()) {
 667                         EffectBlueprint *blueprint = block->alternatives[block->currently_chosen_alternative];
 668                         if (blueprint->int_parameters.count("width") && blueprint->int_parameters["width"] > 0) {
 669                                 missing_width = false;
 670                         }
 671                         if (blueprint->int_parameters.count("height") && blueprint->int_parameters["height"] > 0) {
 672                                 missing_height = false;
 673                         }
 674                         for (const auto &key_and_tuple : blueprint->int_parameters) {
 675                                 int_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 676                         }
 677                         for (const auto &key_and_tuple : blueprint->float_parameters) {
 678                                 float_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 679                         }
 680                         for (const auto &key_and_tuple : blueprint->vec3_parameters) {
 681                                 vec3_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 682                         }
 683                         for (const auto &key_and_tuple : blueprint->vec4_parameters) {
 684                                 vec4_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 685                         }
 686                 }
 687
 688                 if (missing_width || missing_height) {
 689                         fprintf(stderr, "WARNING: Unset or nonpositive width/height for effect declared at %s "
 690                                 "when getting scene for signal %u; setting to 1x1 to avoid crash.\n",
 691                                 block->declaration_point.c_str(), num);
 692                         int_to_set[make_pair(effect, "width")] = 1;
 693                         int_to_set[make_pair(effect, "height")] = 1;
 694                 }
 695         }
 696
 697         lua_pop(L, 1);
 698
 699         auto setup_chain = [L, theme, cards_to_connect, images_to_select, int_to_set, float_to_set, vec3_to_set, vec4_to_set, input_state]{
 700                 lock_guard<mutex> lock(theme->m);
 701
 702                 // Set up state, including connecting cards.
 703                 for (const auto &input_and_card : cards_to_connect) {
 704                         LiveInputWrapper *input = input_and_card.first;
 705                         input->connect_card(input_and_card.second, input_state);
 706                 }
 707                 for (const auto &input_and_filename : images_to_select) {
 708                         input_and_filename.first->switch_image(input_and_filename.second);
 709                 }
 710                 for (const auto &effect_and_key_and_value : int_to_set) {
 711                         Effect *effect = effect_and_key_and_value.first.first;
 712                         const string &key = effect_and_key_and_value.first.second;
 713                         const int value = effect_and_key_and_value.second;
 714                         if (!effect->set_int(key, value)) {
 715                                 luaL_error(L, "Effect refused set_int(\"%s\", %d) (invalid key?)", key.c_str(), value);
 716                         }
 717                 }
 718                 for (const auto &effect_and_key_and_value : float_to_set) {
 719                         Effect *effect = effect_and_key_and_value.first.first;
 720                         const string &key = effect_and_key_and_value.first.second;
 721                         const float value = effect_and_key_and_value.second;
 722                         if (!effect->set_float(key, value)) {
 723                                 luaL_error(L, "Effect refused set_float(\"%s\", %f) (invalid key?)", key.c_str(), value);
 724                         }
 725                 }
 726                 for (const auto &effect_and_key_and_value : vec3_to_set) {
 727                         Effect *effect = effect_and_key_and_value.first.first;
 728                         const string &key = effect_and_key_and_value.first.second;
 729                         const float *value = effect_and_key_and_value.second.data();
 730                         if (!effect->set_vec3(key, value)) {
 731                                 luaL_error(L, "Effect refused set_vec3(\"%s\", %f, %f, %f) (invalid key?)", key.c_str(),
 732                                                 value[0], value[1], value[2]);
 733                         }
 734                 }
 735                 for (const auto &effect_and_key_and_value : vec4_to_set) {
 736                         Effect *effect = effect_and_key_and_value.first.first;
 737                         const string &key = effect_and_key_and_value.first.second;
 738                         const float *value = effect_and_key_and_value.second.data();
 739                         if (!effect->set_vec4(key, value)) {
 740                                 luaL_error(L, "Effect refused set_vec4(\"%s\", %f, %f, %f, %f) (invalid key?)", key.c_str(),
 741                                                 value[0], value[1], value[2], value[3]);
 742                         }
 743                 }
 744         };
 745         return make_pair(effect_chain, move(setup_chain));
 746 }
 747
 748 bool display(Block *block, lua_State *L, int idx)
 749 {
 750         if (lua_isnumber(L, idx)) {
 751                 int signal_idx = luaL_checknumber(L, idx);
 752                 block->signal_type_to_connect = Block::CONNECT_SIGNAL;
 753                 block->signal_to_connect = signal_idx;
 754                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR);  // Will be changed to deinterlaced at get_chain() time if needed.
 755                 return true;
 756 #ifdef HAVE_CEF
 757         } else if (luaL_testudata(L, idx, "HTMLInput")) {
 758                 CEFCapture *capture = *(CEFCapture **)luaL_checkudata(L, idx, "HTMLInput");
 759                 block->signal_type_to_connect = Block::CONNECT_CEF;
 760                 block->cef_to_connect = capture;
 761                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_BGRA);
 762                 assert(capture->get_current_pixel_format() == bmusb::PixelFormat_8BitBGRA);
 763                 return true;
 764 #endif
 765         } else if (luaL_testudata(L, idx, "VideoInput")) {
 766                 FFmpegCapture *capture = *(FFmpegCapture **)luaL_checkudata(L, idx, "VideoInput");
 767                 block->signal_type_to_connect = Block::CONNECT_VIDEO;
 768                 block->video_to_connect = capture;
 769                 if (capture->get_current_pixel_format() == bmusb::PixelFormat_8BitYCbCrPlanar) {
 770                         block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR_PLANAR);
 771                 } else {
 772                         assert(capture->get_current_pixel_format() == bmusb::PixelFormat_8BitBGRA);
 773                         block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_BGRA);
 774                 }
 775                 return true;
 776         } else if (luaL_testudata(L, idx, "ImageInput")) {
 777                 ImageInput *image = *(ImageInput **)luaL_checkudata(L, idx, "ImageInput");
 778                 block->signal_type_to_connect = Block::CONNECT_NONE;
 779                 block->currently_chosen_alternative = find_index_of(block, IMAGE_INPUT);
 780                 block->pathname = image->get_pathname();
 781                 return true;
 782         } else {
 783                 return false;
 784         }
 785 }
 786
 787 int Block_display(lua_State* L)
 788 {
 789         assert(lua_gettop(L) == 2);
 790         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 791         if (!block->is_input) {
 792                 luaL_error(L, "display() called on something that isn't an input");
 793         }
 794
 795         bool ok = display(block, L, 2);
 796         if (!ok) {
 797                 luaL_error(L, "display() called with something that's not a signal (a signal number, a HTML input, or a VideoInput)");
 798         }
 799
 800         if (block->currently_chosen_alternative == -1) {
 801                 luaL_error(L, "display() called on an input whose type was fixed at construction time, with a signal of different type");
 802         }
 803
 804         return 0;
 805 }
 806
 807 int Block_choose(lua_State* L)
 808 {
 809         assert(lua_gettop(L) == 2);
 810         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 811         int alternative_idx = -1;
 812         if (lua_isnumber(L, 2)) {
 813                 alternative_idx = luaL_checknumber(L, 2);
 814         } else if (lua_istable(L, 2)) {
 815                 // See if it's an Effect metatable (e.g. foo:choose(ResampleEffect))
 816                 lua_getfield(L, 2, "__effect_type_id");
 817                 if (lua_isnumber(L, -1)) {
 818                         EffectType effect_type = EffectType(luaL_checknumber(L, -1));
 819                         alternative_idx = find_index_of(block, effect_type);
 820                 }
 821                 lua_pop(L, 1);
 822         }
 823
 824         if (alternative_idx == -1) {
 825                 luaL_error(L, "choose() called with something that was not an index or an effect type (e.g. ResampleEffect) that was part of the alternatives");
 826         }
 827
 828         assert(alternative_idx >= 0);
 829         assert(size_t(alternative_idx) < block->alternatives.size());
 830         block->currently_chosen_alternative = alternative_idx;
 831
 832         return wrap_lua_existing_object_nonowned<EffectBlueprint>(L, "EffectBlueprint", block->alternatives[alternative_idx]);
 833 }
 834
 835 int Block_enable(lua_State *L)
 836 {
 837         assert(lua_gettop(L) == 1);
 838         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 839
 840         if (block->alternatives.size() != 2 ||
 841             block->alternatives[1]->effect_type != IDENTITY_EFFECT) {
 842                 luaL_error(L, "enable() called on something that wasn't added with add_optional_effect()");
 843         }
 844         block->currently_chosen_alternative = 0;  // The actual effect.
 845         return 0;
 846 }
 847
 848 int Block_enable_if(lua_State *L)
 849 {
 850         assert(lua_gettop(L) == 2);
 851         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 852
 853         if (block->alternatives.size() != 2 ||
 854             block->alternatives[1]->effect_type != IDENTITY_EFFECT) {
 855                 luaL_error(L, "enable_if() called on something that wasn't added with add_optional_effect()");
 856         }
 857         bool enabled = checkbool(L, 2);
 858         block->currently_chosen_alternative = enabled ? 0 : 1;
 859         return 0;
 860 }
 861
 862 int Block_disable(lua_State *L)
 863 {
 864         assert(lua_gettop(L) == 1);
 865         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 866
 867         block->currently_chosen_alternative = find_index_of(block, IDENTITY_EFFECT);
 868         if (block->currently_chosen_alternative == -1) {
 869                 luaL_error(L, "disable() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
 870         }
 871         assert(block->currently_chosen_alternative != -1);
 872         return 0;
 873 }
 874
 875 int Block_always_disable_if_disabled(lua_State *L)
 876 {
 877         assert(lua_gettop(L) == 2);
 878         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 879         Block *disabler_block = *(Block **)luaL_checkudata(L, 2, "Block");
 880
 881         int my_alternative = find_index_of(block, IDENTITY_EFFECT);
 882         int their_alternative = find_index_of(disabler_block, IDENTITY_EFFECT);
 883         if (my_alternative == -1) {
 884                 luaL_error(L, "always_disable_if_disabled() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
 885         }
 886         if (their_alternative == -1) {
 887                 luaL_error(L, "always_disable_if_disabled() with an argument that didn't have an IdentityEffect fallback (try add_optional_effect())");
 888         }
 889
 890         // The declaration point isn't actually used, but it's nice for completeness.
 891         block->disablers.push_back(Block::Disabler{ disabler_block->idx, Block::Disabler::DISABLE_IF_OTHER_DISABLED, get_declaration_point(L) });
 892
 893         lua_pop(L, 2);
 894         return 0;
 895 }
 896
 897 int Block_promise_to_disable_if_enabled(lua_State *L)
 898 {
 899         assert(lua_gettop(L) == 2);
 900         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 901         Block *disabler_block = *(Block **)luaL_checkudata(L, 2, "Block");
 902
 903         int my_alternative = find_index_of(block, IDENTITY_EFFECT);
 904         int their_alternative = find_index_of(disabler_block, IDENTITY_EFFECT);
 905         if (my_alternative == -1) {
 906                 luaL_error(L, "promise_to_disable_if_enabled() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
 907         }
 908         if (their_alternative == -1) {
 909                 luaL_error(L, "promise_to_disable_if_enabled() with an argument that didn't have an IdentityEffect fallback (try add_optional_effect())");
 910         }
 911
 912         block->disablers.push_back(Block::Disabler{ disabler_block->idx, Block::Disabler::DISABLE_IF_OTHER_ENABLED, get_declaration_point(L) });
 913
 914         lua_pop(L, 2);
 915         return 0;
 916 }
 917
 918 int Block_set_int(lua_State *L)
 919 {
 920         assert(lua_gettop(L) == 3);
 921         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 922         string key = checkstdstring(L, 2);
 923         float value = luaL_checknumber(L, 3);
 924
 925         // TODO: check validity already here, if possible?
 926         block->int_parameters[key] = value;
 927
 928         return 0;
 929 }
 930
 931 int Block_set_float(lua_State *L)
 932 {
 933         assert(lua_gettop(L) == 3);
 934         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 935         string key = checkstdstring(L, 2);
 936         float value = luaL_checknumber(L, 3);
 937
 938         // TODO: check validity already here, if possible?
 939         block->float_parameters[key] = value;
 940
 941         return 0;
 942 }
 943
 944 int Block_set_vec3(lua_State *L)
 945 {
 946         assert(lua_gettop(L) == 5);
 947         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 948         string key = checkstdstring(L, 2);
 949         array<float, 3> v;
 950         v[0] = luaL_checknumber(L, 3);
 951         v[1] = luaL_checknumber(L, 4);
 952         v[2] = luaL_checknumber(L, 5);
 953
 954         // TODO: check validity already here, if possible?
 955         block->vec3_parameters[key] = v;
 956
 957         return 0;
 958 }
 959
 960 int Block_set_vec4(lua_State *L)
 961 {
 962         assert(lua_gettop(L) == 6);
 963         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 964         string key = checkstdstring(L, 2);
 965         array<float, 4> v;
 966         v[0] = luaL_checknumber(L, 3);
 967         v[1] = luaL_checknumber(L, 4);
 968         v[2] = luaL_checknumber(L, 5);
 969         v[3] = luaL_checknumber(L, 6);
 970
 971         // TODO: check validity already here, if possible?
 972         block->vec4_parameters[key] = v;
 973
 974         return 0;
 975 }
 976