git.sesse.net Git - casparcg/blob - core/producer/framerate/framerate_producer.cpp

   1 /*
   2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
   3 *
   4 * This file is part of CasparCG (www.casparcg.com).
   5 *
   6 * CasparCG is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 3 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * CasparCG is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
  18 *
  19 * Author: Helge Norberg, helge.norberg@svt.se
  20 */
  21
  22 #include "../../StdAfx.h"
  23
  24 #include "framerate_producer.h"
  25
  26 #include "../frame_producer.h"
  27 #include "../../frame/audio_channel_layout.h"
  28 #include "../../frame/draw_frame.h"
  29 #include "../../frame/frame.h"
  30 #include "../../frame/frame_transform.h"
  31 #include "../../frame/pixel_format.h"
  32 #include "../../monitor/monitor.h"
  33 #include "../../help/help_sink.h"
  34
  35 #include <common/future.h>
  36 #include <common/tweener.h>
  37
  38 #include <functional>
  39 #include <queue>
  40 #include <future>
  41 #include <stack>
  42
  43 namespace caspar { namespace core {
  44
  45 draw_frame drop_and_skip(const draw_frame& source, const draw_frame&, const boost::rational<int64_t>&)
  46 {
  47         return source;
  48 }
  49
  50 // Blends next frame with current frame when the distance is not 0.
  51 // Completely sharp when distance is 0 but blurry when in between.
  52 draw_frame blend2(const draw_frame& source, const draw_frame& destination, const boost::rational<int64_t>& distance)
  53 {
  54         if (destination == draw_frame::empty())
  55                 return source;
  56
  57         auto under                                      = source;
  58         auto over                                       = destination;
  59         double float_distance           = boost::rational_cast<double>(distance);
  60
  61         under.transform().image_transform.is_mix        = true;
  62         under.transform().image_transform.opacity       = 1 - float_distance;
  63         over.transform().image_transform.is_mix         = true;
  64         over.transform().image_transform.opacity        = float_distance;
  65
  66         return draw_frame::over(under, over);
  67 }
  68
  69 // Blends a moving window with a width of 1 frame duration.
  70 // * A distance of 0.0 gives 50% previous, 50% current and 0% next.
  71 // * A distance of 0.5 gives 25% previous, 50% current and 25% next.
  72 // * A distance of 0.75 gives 12.5% previous, 50% current and 37.5% next.
  73 // This is blurrier than blend2, but gives a more even bluriness, instead of sharp, blurry, sharp, blurry.
  74 struct blend3
  75 {
  76         draw_frame previous_frame       = draw_frame::empty();
  77         draw_frame last_source          = draw_frame::empty();
  78         draw_frame last_destination     = draw_frame::empty();
  79
  80         draw_frame operator()(const draw_frame& source, const draw_frame& destination, const boost::rational<int64_t>& distance)
  81         {
  82                 if (last_source != draw_frame::empty() && last_source != source)
  83                 {
  84                         if (last_destination == source)
  85                                 previous_frame = last_source;
  86                         else // A two frame jump
  87                                 previous_frame = last_destination;
  88                 }
  89
  90                 last_source                     = source;
  91                 last_destination        = destination;
  92
  93                 bool has_previous = previous_frame != draw_frame::empty();
  94
  95                 if (!has_previous)
  96                         return blend2(source, destination, distance);
  97
  98                 auto middle                                                                                     = last_source;
  99                 auto next_frame                                                                         = destination;
 100                 previous_frame.transform().image_transform.is_mix       = true;
 101                 middle.transform().image_transform.is_mix                       = true;
 102                 next_frame.transform().image_transform.is_mix           = true;
 103
 104                 double float_distance                                                           = boost::rational_cast<double>(distance);
 105                 previous_frame.transform().image_transform.opacity      = std::max(0.0, 0.5 - float_distance * 0.5);
 106                 middle.transform().image_transform.opacity                      = 0.5;
 107                 next_frame.transform().image_transform.opacity          = 1.0 - previous_frame.transform().image_transform.opacity - middle.transform().image_transform.opacity;
 108
 109                 std::vector<draw_frame> combination { previous_frame, middle, next_frame };
 110
 111                 return draw_frame(std::move(combination));
 112         }
 113 };
 114
 115 class audio_extractor : public frame_visitor
 116 {
 117         std::stack<core::audio_transform>                               transform_stack_;
 118         std::function<void(const const_frame& frame)>   on_frame_;
 119 public:
 120         audio_extractor(std::function<void(const const_frame& frame)> on_frame)
 121                 : on_frame_(std::move(on_frame))
 122         {
 123                 transform_stack_.push(audio_transform());
 124         }
 125
 126         void push(const frame_transform& transform) override
 127         {
 128                 transform_stack_.push(transform_stack_.top() * transform.audio_transform);
 129         }
 130
 131         void pop() override
 132         {
 133                 transform_stack_.pop();
 134         }
 135
 136         void visit(const const_frame& frame) override
 137         {
 138                 if (!frame.audio_data().empty() && !transform_stack_.top().is_still)
 139                         on_frame_(frame);
 140         }
 141 };
 142
 143 // Like tweened_transform but for framerates
 144 class speed_tweener
 145 {
 146         boost::rational<int64_t>        source_         = 1LL;
 147         boost::rational<int64_t>        dest_           = 1LL;
 148         int                                                     duration_       = 0;
 149         int                                                     time_           = 0;
 150         tweener                                         tweener_;
 151 public:
 152         speed_tweener() = default;
 153         speed_tweener(
 154                         const boost::rational<int64_t>& source,
 155                         const boost::rational<int64_t>& dest,
 156                         int duration,
 157                         const tweener& tween)
 158                 : source_(source)
 159                 , dest_(dest)
 160                 , duration_(duration)
 161                 , time_(0)
 162                 , tweener_(tween)
 163         {
 164         }
 165
 166         const boost::rational<int64_t>& dest() const
 167         {
 168                 return dest_;
 169         }
 170
 171         boost::rational<int64_t> fetch() const
 172         {
 173                 if (time_ == duration_)
 174                         return dest_;
 175
 176                 double source   = boost::rational_cast<double>(source_);
 177                 double delta    = boost::rational_cast<double>(dest_) - source;
 178                 double result   = tweener_(time_, source, delta, duration_);
 179
 180                 return boost::rational<int64_t>(static_cast<int64_t>(result * 1000000.0), 1000000);
 181         }
 182
 183         boost::rational<int64_t> fetch_and_tick()
 184         {
 185                 time_ = std::min(time_ + 1, duration_);
 186                 return fetch();
 187         }
 188 };
 189
 190 class framerate_producer : public frame_producer_base
 191 {
 192         spl::shared_ptr<frame_producer>                                         source_;
 193         std::function<boost::rational<int>()>                           get_source_framerate_;
 194         boost::rational<int>                                                            source_framerate_                               = -1;
 195         audio_channel_layout                                                            source_channel_layout_                  = audio_channel_layout::invalid();
 196         boost::rational<int>                                                            original_destination_framerate_;
 197         field_mode                                                                                      original_destination_fieldmode_;
 198         field_mode                                                                                      destination_fieldmode_                  = field_mode::empty;
 199         std::vector<int>                                                                        destination_audio_cadence_;
 200         boost::rational<std::int64_t>                                           speed_;
 201         speed_tweener                                                                           user_speed_;
 202         std::function<draw_frame (
 203                         const draw_frame& source,
 204                         const draw_frame& destination,
 205                         const boost::rational<int64_t>& distance)>      interpolator_                                   = drop_and_skip;
 206
 207         boost::rational<std::int64_t>                                           current_frame_number_                   = 0;
 208         draw_frame                                                                                      previous_frame_                                 = draw_frame::empty();
 209         draw_frame                                                                                      next_frame_                                             = draw_frame::empty();
 210         mutable_audio_buffer                                                            audio_samples_;
 211
 212         unsigned int                                                                            output_repeat_                                  = 0;
 213         unsigned int                                                                            output_frame_                                   = 0;
 214         draw_frame                                                                                      last_frame_                                             = draw_frame::empty();
 215 public:
 216         framerate_producer(
 217                         spl::shared_ptr<frame_producer> source,
 218                         std::function<boost::rational<int> ()> get_source_framerate,
 219                         boost::rational<int> destination_framerate,
 220                         field_mode destination_fieldmode,
 221                         std::vector<int> destination_audio_cadence)
 222                 : source_(std::move(source))
 223                 , get_source_framerate_(std::move(get_source_framerate))
 224                 , original_destination_framerate_(std::move(destination_framerate))
 225                 , original_destination_fieldmode_(destination_fieldmode)
 226                 , destination_audio_cadence_(std::move(destination_audio_cadence))
 227         {
 228                 // Note: Uses 1 step rotated cadence for 1001 modes (1602, 1602, 1601, 1602, 1601)
 229                 // This cadence fills the audio mixer most optimally.
 230                 boost::range::rotate(destination_audio_cadence_, std::end(destination_audio_cadence_) - 1);
 231         }
 232
 233         draw_frame receive_impl() override
 234         {
 235                 // destination field mode initially unknown but known after the first update_source_framerate().
 236                 auto field1 = do_render_progressive_frame(true);
 237
 238                 if (destination_fieldmode_ == field_mode::progressive)
 239                 {
 240
 241                         return field1;
 242                 }
 243                 else
 244                 {
 245                         auto field2 = do_render_progressive_frame(false);
 246
 247                         return draw_frame::interlace(field1, field2, destination_fieldmode_);
 248                 }
 249         }
 250
 251         std::future<std::wstring> call(const std::vector<std::wstring>& params) override
 252         {
 253                 if (!boost::iequals(params.at(0), L"framerate"))
 254                         return source_->call(params);
 255
 256                 if (boost::iequals(params.at(1), L"speed"))
 257                 {
 258                         auto destination_user_speed = boost::rational<std::int64_t>(
 259                                         static_cast<std::int64_t>(boost::lexical_cast<double>(params.at(2)) * 1000000.0),
 260                                         1000000);
 261                         auto frames = params.size() > 3 ? boost::lexical_cast<int>(params.at(3)) : 0;
 262                         auto easing = params.size() > 4 ? params.at(4) : L"linear";
 263
 264                         user_speed_ = speed_tweener(user_speed_.fetch(), destination_user_speed, frames, tweener(easing));
 265                 }
 266                 else if (boost::iequals(params.at(1), L"interpolation"))
 267                 {
 268                         if (boost::iequals(params.at(2), L"blend2"))
 269                                 interpolator_ = &blend2;
 270                         else if (boost::iequals(params.at(2), L"blend3"))
 271                                 interpolator_ = blend3();
 272                         else if (boost::iequals(params.at(2), L"drop_and_skip"))
 273                                 interpolator_ = &drop_and_skip;
 274                         else
 275                                 CASPAR_THROW_EXCEPTION(user_error() << msg_info("Valid interpolations are DROP_AND_SKIP, BLEND2 and BLEND3"));
 276                 }
 277                 else if (boost::iequals(params.at(1), L"output_repeat")) // Only for debugging purposes
 278                 {
 279                         output_repeat_ = boost::lexical_cast<unsigned int>(params.at(2));
 280                 }
 281
 282                 return make_ready_future<std::wstring>(L"");
 283         }
 284
 285         monitor::subject& monitor_output() override
 286         {
 287                 return source_->monitor_output();
 288         }
 289
 290         std::wstring print() const override
 291         {
 292                 return source_->print();
 293         }
 294
 295         std::wstring name() const override
 296         {
 297                 return source_->name();
 298         }
 299
 300         boost::property_tree::wptree info() const override
 301         {
 302                 auto info = source_->info();
 303
 304                 auto incorrect_frame_number = info.get_child_optional(L"frame-number");
 305                 if (incorrect_frame_number)
 306                         incorrect_frame_number->put_value(frame_number());
 307
 308                 auto incorrect_nb_frames = info.get_child_optional(L"nb-frames");
 309                 if (incorrect_nb_frames)
 310                         incorrect_nb_frames->put_value(nb_frames());
 311
 312                 return info;
 313         }
 314
 315         uint32_t nb_frames() const override
 316         {
 317                 auto source_nb_frames = source_->nb_frames();
 318                 auto multiple = boost::rational_cast<double>(1 / get_speed() * (output_repeat_ != 0 ? 2 : 1));
 319
 320                 return static_cast<uint32_t>(source_nb_frames * multiple);
 321         }
 322
 323         uint32_t frame_number() const override
 324         {
 325                 auto source_frame_number = source_->frame_number() - 1; // next frame already received
 326                 auto multiple = boost::rational_cast<double>(1 / get_speed() * (output_repeat_ != 0 ? 2 : 1));
 327
 328                 return static_cast<uint32_t>(source_frame_number * multiple);
 329         }
 330
 331         constraints& pixel_constraints() override
 332         {
 333                 return source_->pixel_constraints();
 334         }
 335 private:
 336         draw_frame do_render_progressive_frame(bool sound)
 337         {
 338                 user_speed_.fetch_and_tick();
 339
 340                 if (output_repeat_ && output_frame_++ % output_repeat_)
 341                 {
 342                         auto frame = last_frame_;
 343
 344                         frame.transform().audio_transform.volume = 0.0;
 345
 346                         return attach_sound(frame);
 347                 }
 348
 349                 if (previous_frame_ == draw_frame::empty())
 350                         previous_frame_ = pop_frame_from_source();
 351
 352                 auto current_frame_number       = current_frame_number_;
 353                 auto distance                           = current_frame_number_ - boost::rational_cast<int64_t>(current_frame_number_);
 354                 bool needs_next                         = distance > 0 || !enough_sound();
 355
 356                 if (needs_next && next_frame_ == draw_frame::empty())
 357                         next_frame_ = pop_frame_from_source();
 358
 359                 auto result = interpolator_(previous_frame_, next_frame_, distance);
 360
 361                 auto next_frame_number          = current_frame_number_ += get_speed();
 362                 auto integer_current_frame      = boost::rational_cast<std::int64_t>(current_frame_number);
 363                 auto integer_next_frame         = boost::rational_cast<std::int64_t>(next_frame_number);
 364
 365                 fast_forward_integer_frames(integer_next_frame - integer_current_frame);
 366
 367                 last_frame_ = result;
 368
 369                 if (sound)
 370                         return attach_sound(result);
 371                 else
 372                         return result;
 373         }
 374
 375         void fast_forward_integer_frames(std::int64_t num_frames)
 376         {
 377                 if (num_frames == 0)
 378                         return;
 379
 380                 for (std::int64_t i = 0; i < num_frames; ++i)
 381                 {
 382                         if (next_frame_ == draw_frame::empty())
 383                                 previous_frame_ = pop_frame_from_source();
 384                         else
 385                         {
 386                                 previous_frame_ = std::move(next_frame_);
 387
 388                                 next_frame_ = pop_frame_from_source();
 389                         }
 390                 }
 391         }
 392
 393         boost::rational<std::int64_t> get_speed() const
 394         {
 395                 return speed_ * user_speed_.fetch();
 396         }
 397
 398         draw_frame pop_frame_from_source()
 399         {
 400                 auto frame = source_->receive();
 401                 update_source_framerate();
 402
 403                 if (user_speed_.fetch() == 1)
 404                 {
 405                         audio_extractor extractor([this](const const_frame& frame)
 406                         {
 407                                 if (source_channel_layout_ != frame.audio_channel_layout())
 408                                 {
 409                                         source_channel_layout_ = frame.audio_channel_layout();
 410
 411                                         // Insert silence samples so that the audio mixer is guaranteed to be filled.
 412                                         auto min_num_samples_per_frame  = *boost::min_element(destination_audio_cadence_);
 413                                         auto max_num_samples_per_frame  = *boost::max_element(destination_audio_cadence_);
 414                                         auto cadence_safety_samples             = max_num_samples_per_frame - min_num_samples_per_frame;
 415                                         audio_samples_.resize(source_channel_layout_.num_channels * cadence_safety_samples, 0);
 416                                 }
 417
 418                                 auto& buffer = frame.audio_data();
 419                                 audio_samples_.insert(audio_samples_.end(), buffer.begin(), buffer.end());
 420                         });
 421
 422                         frame.accept(extractor);
 423                 }
 424                 else
 425                 {
 426                         source_channel_layout_ = audio_channel_layout::invalid();
 427                         audio_samples_.clear();
 428                 }
 429
 430                 frame.transform().audio_transform.volume = 0.0;
 431
 432                 return frame;
 433         }
 434
 435         draw_frame attach_sound(draw_frame frame)
 436         {
 437                 if (user_speed_.fetch() != 1 || source_channel_layout_ == audio_channel_layout::invalid())
 438                         return frame;
 439
 440                 mutable_audio_buffer buffer;
 441
 442                 if (destination_audio_cadence_.front() * source_channel_layout_.num_channels == audio_samples_.size())
 443                 {
 444                         buffer.swap(audio_samples_);
 445                 }
 446                 else if (audio_samples_.size() >= destination_audio_cadence_.front() * source_channel_layout_.num_channels)
 447                 {
 448                         auto begin      = audio_samples_.begin();
 449                         auto end        = begin + destination_audio_cadence_.front() * source_channel_layout_.num_channels;
 450
 451                         buffer.insert(buffer.begin(), begin, end);
 452                         audio_samples_.erase(begin, end);
 453                 }
 454                 else
 455                 {
 456                         auto needed = destination_audio_cadence_.front();
 457                         auto got = audio_samples_.size() / source_channel_layout_.num_channels;
 458                         if (got != 0) // If at end of stream we don't care
 459                                 CASPAR_LOG(debug) << print() << L" Too few audio samples. Needed " << needed << L" but got " << got;
 460                         buffer.swap(audio_samples_);
 461                         buffer.resize(needed * source_channel_layout_.num_channels, 0);
 462                 }
 463
 464                 boost::range::rotate(destination_audio_cadence_, std::begin(destination_audio_cadence_) + 1);
 465
 466                 auto audio_frame = mutable_frame(
 467                                 {},
 468                                 std::move(buffer),
 469                                 this,
 470                                 pixel_format_desc(),
 471                                 source_channel_layout_);
 472                 return draw_frame::over(frame, draw_frame(std::move(audio_frame)));
 473         }
 474
 475         bool enough_sound() const
 476         {
 477                 return source_channel_layout_ == core::audio_channel_layout::invalid()
 478                                 || user_speed_.fetch() != 1
 479                                 || audio_samples_.size() / source_channel_layout_.num_channels >= destination_audio_cadence_.at(0);
 480         }
 481
 482         void update_source_framerate()
 483         {
 484                 auto source_framerate = get_source_framerate_();
 485
 486                 if (source_framerate_ == source_framerate)
 487                         return;
 488
 489                 source_framerate_                       = source_framerate;
 490                 auto destination_framerate      = original_destination_framerate_;
 491                 destination_fieldmode_          = original_destination_fieldmode_;
 492
 493                 // Coarse adjustment to correct fps family (23.98 - 30 vs 47.95 - 60)
 494                 if (destination_fieldmode_ != field_mode::progressive)  // Interlaced output
 495                 {
 496                         auto diff_double        = boost::abs(source_framerate_ - destination_framerate * 2);
 497                         auto diff_keep          = boost::abs(source_framerate_ - destination_framerate);
 498
 499                         if (diff_double < diff_keep)                                            // Double rate interlaced
 500                         {
 501                                 destination_framerate *= 2;
 502                         }
 503                         else                                                                                            // Progressive non interlaced
 504                         {
 505                                 destination_fieldmode_ = field_mode::progressive;
 506                         }
 507                 }
 508                 else                                                                                                    // Progressive
 509                 {
 510                         auto diff_halve = boost::abs(source_framerate_ * 2      - destination_framerate);
 511                         auto diff_keep  = boost::abs(source_framerate_          - destination_framerate);
 512
 513                         if (diff_halve < diff_keep)                                                     // Repeat every frame two times
 514                         {
 515                                 destination_framerate   /= 2;
 516                                 output_repeat_                  = 2;
 517                         }
 518                 }
 519
 520                 speed_ = boost::rational<int64_t>(source_framerate_ / destination_framerate);
 521
 522                 // drop_and_skip will only be used by default for exact framerate multiples (half, same and double)
 523                 // for all other framerates a frame interpolator will be chosen.
 524                 if (speed_ != 1 && speed_ * 2 != 1 && speed_ != 2)
 525                 {
 526                         auto high_source_framerate              = source_framerate_ > 47;
 527                         auto high_destination_framerate = destination_framerate > 47
 528                                         || destination_fieldmode_ != field_mode::progressive;
 529
 530                         if (high_source_framerate && high_destination_framerate)        // The bluriness of blend3 is acceptable on high framerates.
 531                                 interpolator_   = blend3();
 532                         else                                                                                                            // blend3 is mostly too blurry on low framerates. blend2 provides a compromise.
 533                                 interpolator_   = &blend2;
 534
 535                         CASPAR_LOG(warning) << source_->print() << L" Frame blending frame rate conversion required to conform to channel frame rate.";
 536                 }
 537                 else
 538                         interpolator_           = &drop_and_skip;
 539         }
 540 };
 541
 542 void describe_framerate_producer(help_sink& sink)
 543 {
 544         sink.para()->text(L"Framerate conversion control / Slow motion examples:");
 545         sink.example(L">> CALL 1-10 FRAMERATE INTERPOLATION BLEND2", L"enables 2 frame blend interpolation.");
 546         sink.example(L">> CALL 1-10 FRAMERATE INTERPOLATION BLEND3", L"enables 3 frame blend interpolation.");
 547         sink.example(L">> CALL 1-10 FRAMERATE INTERPOLATION DROP_AND_SKIP", L"disables frame interpolation.");
 548         sink.example(L">> CALL 1-10 FRAMERATE SPEED 0.25", L"immediately changes the speed to 25%. Sound will be disabled.");
 549         sink.example(L">> CALL 1-10 FRAMERATE SPEED 0.25 50", L"changes the speed to 25% linearly over 50 frames. Sound will be disabled.");
 550         sink.example(L">> CALL 1-10 FRAMERATE SPEED 0.25 50 easeinoutsine", L"changes the speed to 25% over 50 frames using specified easing curve. Sound will be disabled.");
 551         sink.example(L">> CALL 1-10 FRAMERATE SPEED 1 50", L"changes the speed to 100% linearly over 50 frames. Sound will be enabled when the destination speed of 100% has been reached.");
 552 }
 553
 554 spl::shared_ptr<frame_producer> create_framerate_producer(
 555                 spl::shared_ptr<frame_producer> source,
 556                 std::function<boost::rational<int> ()> get_source_framerate,
 557                 boost::rational<int> destination_framerate,
 558                 field_mode destination_fieldmode,
 559                 std::vector<int> destination_audio_cadence)
 560 {
 561         return spl::make_shared<framerate_producer>(
 562                         std::move(source),
 563                         std::move(get_source_framerate),
 564                         std::move(destination_framerate),
 565                         destination_fieldmode,
 566                         std::move(destination_audio_cadence));
 567 }
 568
 569 }}