webdvd.cpp

   1 // Copyright 2005 Ben Hutchings <ben@decadentplace.org.uk>.
   2 // See the file "COPYING" for licence details.
   3
   4 #include <cassert>
   5 #include <exception>
   6 #include <fstream>
   7 #include <iomanip>
   8 #include <iostream>
   9 #include <memory>
  10 #include <queue>
  11 #include <set>
  12 #include <sstream>
  13 #include <string>
  14
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17
  18 #include <boost/shared_ptr.hpp>
  19
  20 #include <gdkmm/pixbuf.h>
  21 #include <glibmm/convert.h>
  22 #include <glibmm/spawn.h>
  23 #include <gtkmm/main.h>
  24 #include <gtkmm/window.h>
  25
  26 #include <imglib2/ImageErrors.h>
  27 #include <nsGUIEvent.h>
  28 #include <nsIBoxObject.h>
  29 #include <nsIContent.h>
  30 #include <nsIDocShell.h>
  31 #include <nsIDOMAbstractView.h>
  32 #include <nsIDOMDocumentEvent.h>
  33 #include <nsIDOMDocumentView.h>
  34 #include <nsIDOMElement.h>
  35 #include <nsIDOMEventTarget.h>
  36 #include <nsIDOMHTMLDocument.h>
  37 #include <nsIDOMMouseEvent.h>
  38 #include <nsIDOMNSDocument.h>
  39 #include <nsIDOMWindow.h>
  40 #include <nsIEventStateManager.h>
  41 #include <nsIInterfaceRequestorUtils.h>
  42 #include <nsIURI.h> // required before nsILink.h
  43 #include <nsILink.h>
  44 #include <nsIPresContext.h>
  45 #include <nsIPresShell.h>
  46 #include <nsIWebBrowser.h>
  47 #include <nsString.h>
  48
  49 #include "browserwidget.hpp"
  50 #include "childiterator.hpp"
  51 #include "dvd.hpp"
  52 #include "framebuffer.hpp"
  53 #include "linkiterator.hpp"
  54 #include "pixbufs.hpp"
  55 #include "stylesheets.hpp"
  56 #include "temp_file.hpp"
  57 #include "video.hpp"
  58 #include "xpcom_support.hpp"
  59
  60 using xpcom_support::check;
  61
  62 namespace
  63 {
  64     struct rectangle
  65     {
  66         int left, top;     // inclusive
  67         int right, bottom; // exclusive
  68
  69         rectangle operator|=(const rectangle & other)
  70             {
  71                 if (other.empty())
  72                 {
  73                     // use current extents unchanged
  74                 }
  75                 else if (empty())
  76                 {
  77                     // use other extents
  78                     *this = other;
  79                 }
  80                 else
  81                 {
  82                     // find rectangle enclosing both extents
  83                     left = std::min(left, other.left);
  84                     top = std::min(top, other.top);
  85                     right = std::max(right, other.right);
  86                     bottom = std::max(bottom, other.bottom);
  87                 }
  88
  89                 return *this;
  90             }
  91
  92         rectangle operator&=(const rectangle & other)
  93             {
  94                 // find rectangle enclosed in both extents
  95                 left = std::max(left, other.left);
  96                 top = std::max(top, other.top);
  97                 right = std::max(left, std::min(right, other.right));
  98                 bottom = std::max(top, std::min(bottom, other.bottom));
  99                 return *this;
 100             }
 101
 102         bool empty() const
 103             {
 104                 return left == right || bottom == top;
 105             }
 106     };
 107
 108     rectangle get_elem_rect(nsIDOMNSDocument * ns_doc,
 109                             nsIDOMElement * elem)
 110     {
 111         rectangle result;
 112
 113         // Start with this element's bounding box
 114         nsCOMPtr<nsIBoxObject> box;
 115         check(ns_doc->GetBoxObjectFor(elem, getter_AddRefs(box)));
 116         int width, height;
 117         check(box->GetScreenX(&result.left));
 118         check(box->GetScreenY(&result.top));
 119         check(box->GetWidth(&width));
 120         check(box->GetHeight(&height));
 121         result.right = result.left + width;
 122         result.bottom = result.top + height;
 123
 124         // Merge bounding boxes of all child elements
 125         for (ChildIterator it = ChildIterator(elem), end; it != end; ++it)
 126         {
 127             nsCOMPtr<nsIDOMNode> child_node(*it);
 128             PRUint16 child_type;
 129             if (check(child_node->GetNodeType(&child_type)),
 130                 child_type == nsIDOMNode::ELEMENT_NODE)
 131             {
 132                 nsCOMPtr<nsIDOMElement> child_elem(
 133                     do_QueryInterface(child_node));
 134                 result |= get_elem_rect(ns_doc, child_elem);
 135             }
 136         }
 137
 138         return result;
 139     }
 140
 141     class WebDvdWindow : public Gtk::Window
 142     {
 143     public:
 144         WebDvdWindow(
 145             const video::frame_params & frame_params,
 146             const std::string & main_page_uri,
 147             const std::string & output_dir);
 148
 149     private:
 150         void add_page(const std::string & uri);
 151         void add_video(const std::string & uri);
 152         void load_next_page();
 153         void on_net_state_change(const char * uri, gint flags, guint status);
 154         bool process_page();
 155         void save_screenshot();
 156         void process_links(nsIPresShell * pres_shell,
 157                            nsIPresContext * pres_context,
 158                            nsIDOMWindow * dom_window);
 159         void generate_dvd();
 160
 161         enum ResourceType { page_resource, video_resource };
 162         typedef std::pair<ResourceType, int> ResourceEntry;
 163         video::frame_params frame_params_;
 164         std::string output_dir_;
 165         BrowserWidget browser_widget_;
 166         nsCOMPtr<nsIStyleSheet> stylesheet_;
 167         std::queue<std::string> page_queue_;
 168         std::map<std::string, ResourceEntry> resource_map_;
 169         std::vector<std::vector<std::string> > page_links_;
 170         std::vector<std::string> video_paths_;
 171         bool pending_window_update_;
 172         int pending_req_count_;
 173         std::auto_ptr<temp_file> background_temp_;
 174         struct page_state;
 175         std::auto_ptr<page_state> page_state_;
 176         std::vector<boost::shared_ptr<temp_file> > page_temp_files_;
 177     };
 178
 179     WebDvdWindow::WebDvdWindow(
 180         const video::frame_params & frame_params,
 181         const std::string & main_page_uri,
 182         const std::string & output_dir)
 183             : frame_params_(frame_params),
 184               output_dir_(output_dir),
 185               stylesheet_(load_css("file://" WEBDVD_LIB_DIR "/webdvd.css")),
 186               pending_window_update_(false),
 187               pending_req_count_(0)
 188     {
 189         set_size_request(frame_params_.width, frame_params_.height);
 190         set_resizable(false);
 191
 192         add(browser_widget_);
 193         browser_widget_.show();
 194         browser_widget_.signal_net_state().connect(
 195             SigC::slot(*this, &WebDvdWindow::on_net_state_change));
 196
 197         add_page(main_page_uri);
 198         load_next_page();
 199     }
 200
 201     void WebDvdWindow::add_page(const std::string & uri)
 202     {
 203         if (resource_map_.insert(
 204                 std::make_pair(uri, ResourceEntry(page_resource, 0)))
 205             .second)
 206         {
 207             page_queue_.push(uri);
 208         }
 209     }
 210
 211     void WebDvdWindow::add_video(const std::string & uri)
 212     {
 213         if (resource_map_.insert(
 214                 std::make_pair(uri, ResourceEntry(video_resource,
 215                                                   video_paths_.size() + 1)))
 216             .second)
 217         {
 218             // FIXME: Should accept some slightly different URI prefixes
 219             // (e.g. file://localhost/) and decode any URI-escaped
 220             // characters in the path.
 221             assert(uri.compare(0, 8, "file:///") == 0);
 222             video_paths_.push_back(uri.substr(7));
 223         }
 224     }
 225
 226     void WebDvdWindow::load_next_page()
 227     {
 228         assert(!page_queue_.empty());
 229         const std::string & uri = page_queue_.front();
 230         std::cout << "loading " << uri << std::endl;
 231
 232         std::size_t page_count = page_links_.size();
 233         resource_map_[uri].second = ++page_count;
 234         page_links_.resize(page_count);
 235
 236         pending_window_update_ = true;
 237         browser_widget_.load_uri(uri);
 238     }
 239
 240     void WebDvdWindow::on_net_state_change(const char * uri,
 241                                            gint flags, guint status)
 242     {
 243         if (flags & GTK_MOZ_EMBED_FLAG_IS_REQUEST)
 244         {
 245             if (flags & GTK_MOZ_EMBED_FLAG_START)
 246                 ++pending_req_count_;
 247
 248             if (flags & GTK_MOZ_EMBED_FLAG_STOP)
 249             {
 250                 assert(pending_req_count_ != 0);
 251                 --pending_req_count_;
 252             }
 253         }
 254
 255         if (flags & GTK_MOZ_EMBED_FLAG_STOP
 256             && flags & GTK_MOZ_EMBED_FLAG_IS_WINDOW)
 257         {
 258             // Check whether the load was successful, ignoring this
 259             // pseudo-error.
 260             if (status != NS_IMAGELIB_ERROR_LOAD_ABORTED)
 261                 check(status);
 262
 263             pending_window_update_ = false;
 264         }
 265
 266         if (pending_req_count_ == 0 && !pending_window_update_)
 267         {
 268             try
 269             {
 270                 if (!process_page())
 271                     Gtk::Main::quit();
 272             }
 273             catch (std::exception & e)
 274             {
 275                 std::cerr << "Fatal error";
 276                 if (!page_queue_.empty())
 277                     std::cerr << " while processing <" << page_queue_.front()
 278                               << ">";
 279                 std::cerr << ": " << e.what() << "\n";
 280                 Gtk::Main::quit();
 281             }
 282         }
 283     }
 284
 285     bool WebDvdWindow::process_page()
 286     {
 287         assert(!page_queue_.empty());
 288
 289         nsCOMPtr<nsIWebBrowser> browser(browser_widget_.get_browser());
 290         nsCOMPtr<nsIDocShell> doc_shell(do_GetInterface(browser));
 291         assert(doc_shell);
 292         nsCOMPtr<nsIPresShell> pres_shell;
 293         check(doc_shell->GetPresShell(getter_AddRefs(pres_shell)));
 294         nsCOMPtr<nsIPresContext> pres_context;
 295         check(doc_shell->GetPresContext(getter_AddRefs(pres_context)));
 296         nsCOMPtr<nsIDOMWindow> dom_window;
 297         check(browser->GetContentDOMWindow(getter_AddRefs(dom_window)));
 298
 299         if (output_dir_.empty())
 300         {
 301             // In preview mode, just apply the stylesheet and let the
 302             // user select links.
 303             apply_style_sheet(stylesheet_, pres_shell);
 304         }
 305         else
 306         {
 307             // If we haven't already started work on this page, apply
 308             // the stylesheet and save a screenshot of its normal
 309             // appearance.
 310             if (!page_state_.get())
 311             {
 312                 apply_style_sheet(stylesheet_, pres_shell);
 313                 save_screenshot();
 314             }
 315
 316             // Start or continue processing links.
 317             process_links(pres_shell, pres_context, dom_window);
 318
 319             // If we've finished work on the links, move on to the
 320             // next page, if any, or else generate the DVD filesystem.
 321             if (!page_state_.get())
 322             {
 323                 page_queue_.pop();
 324                 if (page_queue_.empty())
 325                 {
 326                     generate_dvd();
 327                     return false;
 328                 }
 329                 else
 330                 {
 331                     load_next_page();
 332                 }
 333             }
 334         }
 335
 336         return true;
 337     }
 338
 339     void WebDvdWindow::save_screenshot()
 340     {
 341         Glib::RefPtr<Gdk::Window> window(get_window());
 342         assert(window);
 343         window->process_updates(true);
 344
 345         background_temp_.reset(new temp_file("webdvd-back-"));
 346         background_temp_->close();
 347         std::cout << "saving " << background_temp_->get_name() << std::endl;
 348         Gdk::Pixbuf::create(Glib::RefPtr<Gdk::Drawable>(window),
 349                             window->get_colormap(),
 350                             0, 0, 0, 0,
 351                             frame_params_.width, frame_params_.height)
 352             ->save(background_temp_->get_name(), "png");
 353     }
 354
 355     struct WebDvdWindow::page_state
 356     {
 357         page_state(nsIDOMDocument * doc, int width, int height)
 358                 : diff_pixbuf(Gdk::Pixbuf::create(
 359                                   Gdk::COLORSPACE_RGB,
 360                                   true, 8, // has_alpha, bits_per_sample
 361                                   width, height)),
 362                   spumux_temp("webdvd-spumux-"),
 363                   links_temp("webdvd-links-"),
 364                   link_num(0),
 365                   links_it(doc),
 366                   link_changing(false)
 367             {
 368                 spumux_temp.close();
 369                 links_temp.close();
 370             }
 371
 372         Glib::RefPtr<Gdk::Pixbuf> diff_pixbuf;
 373
 374         temp_file spumux_temp;
 375         std::ofstream spumux_file;
 376
 377         temp_file links_temp;
 378
 379         int link_num;
 380         LinkIterator links_it, links_end;
 381
 382         rectangle link_rect;
 383         bool link_changing;
 384         Glib::RefPtr<Gdk::Pixbuf> norm_pixbuf;
 385     };
 386
 387     void WebDvdWindow::process_links(nsIPresShell * pres_shell,
 388                                      nsIPresContext * pres_context,
 389                                      nsIDOMWindow * dom_window)
 390     {
 391         Glib::RefPtr<Gdk::Window> window(get_window());
 392         assert(window);
 393
 394         nsCOMPtr<nsIDOMDocument> basic_doc;
 395         check(dom_window->GetDocument(getter_AddRefs(basic_doc)));
 396         nsCOMPtr<nsIDOMNSDocument> ns_doc(do_QueryInterface(basic_doc));
 397         assert(ns_doc);
 398         nsCOMPtr<nsIEventStateManager> event_state_man(
 399             pres_context->EventStateManager()); // does not AddRef
 400         assert(event_state_man);
 401         nsCOMPtr<nsIDOMDocumentEvent> event_factory(
 402             do_QueryInterface(basic_doc));
 403         assert(event_factory);
 404         nsCOMPtr<nsIDOMDocumentView> doc_view(do_QueryInterface(basic_doc));
 405         assert(doc_view);
 406         nsCOMPtr<nsIDOMAbstractView> view;
 407         check(doc_view->GetDefaultView(getter_AddRefs(view)));
 408
 409         // Set up or recover our iteration state.
 410         std::auto_ptr<page_state> state(page_state_);
 411         if (!state.get())
 412         {
 413             state.reset(
 414                 new page_state(
 415                     basic_doc, frame_params_.width, frame_params_.height));
 416
 417             state->spumux_file.open(state->spumux_temp.get_name().c_str());
 418             state->spumux_file <<
 419                 "<subpictures>\n"
 420                 "  <stream>\n"
 421                 "    <spu force='yes' start='00:00:00.00'\n"
 422                 "        highlight='" << state->links_temp.get_name() << "'\n"
 423                 "        select='" << state->links_temp.get_name() << "'>\n";
 424         }
 425
 426         rectangle window_rect = {
 427             0, 0, frame_params_.width, frame_params_.height
 428         };
 429
 430         for (/* no initialisation */;
 431              state->links_it != state->links_end;
 432              ++state->links_it)
 433         {
 434             nsCOMPtr<nsIDOMNode> node(*state->links_it);
 435
 436             // Find the link URI.
 437             nsCOMPtr<nsILink> link(do_QueryInterface(node));
 438             assert(link);
 439             nsCOMPtr<nsIURI> uri;
 440             check(link->GetHrefURI(getter_AddRefs(uri)));
 441             std::string uri_string;
 442             {
 443                 nsCString uri_ns_string;
 444                 check(uri->GetSpec(uri_ns_string));
 445                 uri_string.assign(uri_ns_string.BeginReading(),
 446                                   uri_ns_string.EndReading());
 447             }
 448             std::string uri_sans_fragment(uri_string, 0, uri_string.find('#'));
 449
 450             // Is this a new link?
 451             if (!state->link_changing)
 452             {
 453                 // Find a rectangle enclosing the link and clip it to the
 454                 // window.
 455                 nsCOMPtr<nsIDOMElement> elem(do_QueryInterface(node));
 456                 assert(elem);
 457                 state->link_rect = get_elem_rect(ns_doc, elem);
 458                 state->link_rect &= window_rect;
 459
 460                 if (state->link_rect.empty())
 461                 {
 462                     std::cerr << "Ignoring invisible link to "
 463                               << uri_string << "\n";
 464                     continue;
 465                 }
 466
 467                 ++state->link_num;
 468
 469                 if (state->link_num >= dvd::menu_buttons_max)
 470                 {
 471                     if (state->link_num == dvd::menu_buttons_max)
 472                         std::cerr << "No more than " << dvd::menu_buttons_max
 473                                   << " buttons can be placed on a page\n";
 474                     std::cerr << "Ignoring link to " << uri_string << "\n";
 475                     continue;
 476                 }
 477
 478                 // Check whether this is a link to a video or a page then
 479                 // add it to the known resources if not already seen.
 480                 nsCString path;
 481                 check(uri->GetPath(path));
 482                 // FIXME: This is a bit of a hack.  Perhaps we could decide
 483                 // later based on the MIME type determined by Mozilla?
 484                 if (path.Length() > 4
 485                     && std::strcmp(path.EndReading() - 4, ".vob") == 0)
 486                 {
 487                     PRBool is_file;
 488                     check(uri->SchemeIs("file", &is_file));
 489                     if (!is_file)
 490                     {
 491                         std::cerr << "Links to video must use the file:"
 492                                   << " scheme\n";
 493                         continue;
 494                     }
 495                     add_video(uri_sans_fragment);
 496                 }
 497                 else
 498                 {
 499                     add_page(uri_sans_fragment);
 500                 }
 501
 502                 nsCOMPtr<nsIContent> content(do_QueryInterface(node));
 503                 assert(content);
 504                 nsCOMPtr<nsIDOMEventTarget> event_target(
 505                     do_QueryInterface(node));
 506                 assert(event_target);
 507
 508                 state->norm_pixbuf = Gdk::Pixbuf::create(
 509                     Glib::RefPtr<Gdk::Drawable>(window),
 510                     window->get_colormap(),
 511                     state->link_rect.left,
 512                     state->link_rect.top,
 513                     0,
 514                     0,
 515                     state->link_rect.right - state->link_rect.left,
 516                     state->link_rect.bottom - state->link_rect.top);
 517
 518                 nsCOMPtr<nsIDOMEvent> event;
 519                 check(event_factory->CreateEvent(
 520                           NS_ConvertASCIItoUTF16("MouseEvents"),
 521                           getter_AddRefs(event)));
 522                 nsCOMPtr<nsIDOMMouseEvent> mouse_event(
 523                     do_QueryInterface(event));
 524                 assert(mouse_event);
 525                 check(mouse_event->InitMouseEvent(
 526                           NS_ConvertASCIItoUTF16("mouseover"),
 527                           true,  // can bubble
 528                           true,  // cancelable
 529                           view,
 530                           0,     // detail: mouse click count
 531                           state->link_rect.left, // screenX
 532                           state->link_rect.top,  // screenY
 533                           state->link_rect.left, // clientX
 534                           state->link_rect.top,  // clientY
 535                           false, false, false, false, // qualifiers
 536                           0,     // button: left (or primary)
 537                           0));   // related target
 538                 PRBool dummy;
 539                 check(event_target->DispatchEvent(mouse_event,
 540                                                   &dummy));
 541                 check(event_state_man->SetContentState(content,
 542                                                        NS_EVENT_STATE_HOVER));
 543
 544                 pres_shell->FlushPendingNotifications(true);
 545
 546                 // We may have to exit and wait for image loading
 547                 // to complete, at which point we will be called
 548                 // again.
 549                 if (pending_req_count_ > 0)
 550                 {
 551                     state->link_changing = true;
 552                     page_state_ = state;
 553                     return;
 554                 }
 555             }
 556
 557             window->process_updates(true);
 558
 559             Glib::RefPtr<Gdk::Pixbuf> changed_pixbuf(
 560                 Gdk::Pixbuf::create(
 561                     Glib::RefPtr<Gdk::Drawable>(window),
 562                     window->get_colormap(),
 563                     state->link_rect.left,
 564                     state->link_rect.top,
 565                     0,
 566                     0,
 567                     state->link_rect.right - state->link_rect.left,
 568                     state->link_rect.bottom - state->link_rect.top));
 569             diff_rgb_pixbufs(
 570                 state->norm_pixbuf,
 571                 changed_pixbuf,
 572                 state->diff_pixbuf,
 573                 state->link_rect.left,
 574                 state->link_rect.top,
 575                 state->link_rect.right - state->link_rect.left,
 576                 state->link_rect.bottom - state->link_rect.top);
 577
 578             state->spumux_file <<
 579                 "      <button x0='" << state->link_rect.left << "'"
 580                 " y0='" << state->link_rect.top << "'"
 581                 " x1='" << state->link_rect.right - 1 << "'"
 582                 " y1='" << state->link_rect.bottom - 1 << "'/>\n";
 583
 584             // Add to the page's links, ignoring any fragment (for now).
 585             page_links_.back().push_back(uri_sans_fragment);
 586         }
 587
 588         quantise_rgba_pixbuf(state->diff_pixbuf, dvd::button_n_colours);
 589
 590         std::cout << "saving " << state->links_temp.get_name()
 591                   << std::endl;
 592         state->diff_pixbuf->save(state->links_temp.get_name(), "png");
 593
 594         state->spumux_file <<
 595             "    </spu>\n"
 596             "  </stream>\n"
 597             "</subpictures>\n";
 598
 599         state->spumux_file.close();
 600
 601         // TODO: if (!state->spumux_file) throw ...
 602
 603         {
 604             boost::shared_ptr<temp_file> vob_temp(
 605                 new temp_file("webdvd-vob-"));
 606             std::ostringstream command_stream;
 607             command_stream << "pngtopnm "
 608                            << background_temp_->get_name()
 609                            << " | ppmtoy4m -v0 -n1 -F"
 610                            << frame_params_.rate_numer
 611                            << ":" << frame_params_.rate_denom
 612                            << " -A" << frame_params_.pixel_ratio_width
 613                            << ":" << frame_params_.pixel_ratio_height
 614                            << (" -Ip -S420_mpeg2"
 615                                " | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
 616                                " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
 617                                " | spumux -v0 -mdvd ")
 618                            << state->spumux_temp.get_name()
 619                            << " > " << vob_temp->get_name();
 620             std::string command(command_stream.str());
 621             const char * argv[] = {
 622                 "/bin/sh", "-c", command.c_str(), 0
 623             };
 624             std::cout << "running " << argv[2] << std::endl;
 625             int command_result;
 626             Glib::spawn_sync(".",
 627                              Glib::ArrayHandle<std::string>(
 628                                  argv, sizeof(argv)/sizeof(argv[0]),
 629                                  Glib::OWNERSHIP_NONE),
 630                              Glib::SPAWN_STDOUT_TO_DEV_NULL,
 631                              SigC::Slot0<void>(),
 632                              0, 0,
 633                              &command_result);
 634             if (command_result != 0)
 635                 throw std::runtime_error("spumux pipeline failed");
 636
 637             page_temp_files_.push_back(vob_temp);
 638         }
 639     }
 640
 641     void generate_page_dispatch(std::ostream &, int indent,
 642                                 int first_page, int last_page);
 643
 644     void WebDvdWindow::generate_dvd()
 645     {
 646         temp_file temp("webdvd-dvdauthor-");
 647         temp.close();
 648         std::ofstream file(temp.get_name().c_str());
 649
 650         // We generate code that uses registers in the following way:
 651         //
 652         // g0:     link destination (when jumping to menu 1), then scratch
 653         // g1:     current location
 654         // g2-g11: location history (g2 = most recent)
 655         // g12:    location that last linked to a video
 656         //
 657         // All locations are divided into two bitfields: the least
 658         // significant 10 bits are a page/menu number and the most
 659         // significant 6 bits are a link/button number.  This is
 660         // chosen for compatibility with the encoding of the s8
 661         // (button) register.
 662         //
 663         static const int link_mult = dvd::reg_s8_button_mult;
 664         static const int page_mask = link_mult - 1;
 665         static const int link_mask = (1 << dvd::reg_bits) - link_mult;
 666
 667         file <<
 668             "<dvdauthor>\n"
 669             "  <vmgm>\n"
 670             "    <menus>\n";
 671
 672         for (std::size_t page_num = 1;
 673              page_num <= page_links_.size();
 674              ++page_num)
 675         {
 676             std::vector<std::string> & page_links =
 677                 page_links_[page_num - 1];
 678
 679             if (page_num == 1)
 680             {
 681                 // This is the first page (root menu) which needs to
 682                 // include initialisation and dispatch code.
 683
 684                 file <<
 685                     "      <pgc entry='title'>\n"
 686                     "        <pre>\n"
 687                     // Has the location been set yet?
 688                     "          if (g1 eq 0)\n"
 689                     "          {\n"
 690                     // Initialise the current location to first link on
 691                     // this page.
 692                     "            g1 = " << 1 * link_mult + 1 << ";\n"
 693                     "          }\n"
 694                     "          else\n"
 695                     "          {\n"
 696                     // Has the user selected a link?
 697                     "            if (g0 ne 0)\n"
 698                     "            {\n"
 699                     // First update the history.
 700                     // Does link go to the last page in the history?
 701                     "              if (((g0 ^ g2) &amp; " << page_mask
 702                      << ") == 0)\n"
 703                     // It does; we treat this as going back and pop the old
 704                     // location off the history stack into the current
 705                     // location.  Clear the free stack slot.
 706                     "              {\n"
 707                     "                g1 = g2; g2 = g3; g3 = g4; g4 = g5;\n"
 708                     "                g5 = g6; g6 = g7; g7 = g8; g8 = g9;\n"
 709                     "                g9 = g10; g10 = g11; g11 = 0;\n"
 710                     "              }\n"
 711                     "              else\n"
 712                     // Link goes to some other page, so push current
 713                     // location onto the history stack and set the current
 714                     // location to be exactly the target location.
 715                     "              {\n"
 716                     "                g11 = g10; g10 = g9; g9 = g8; g8 = g7;\n"
 717                     "                g7 = g6; g6 = g5; g5 = g4; g4 = g3;\n"
 718                     "                g3 = g2; g2 = g1; g1 = g0;\n"
 719                     "              }\n"
 720                     "            }\n"
 721                     // Find the target page number.
 722                     "            g0 = g1 &amp; " << page_mask << ";\n";
 723                 // There seems to be no way to perform a computed jump,
 724                 // so we generate all possible jumps and a binary search
 725                 // to select the correct one.
 726                 generate_page_dispatch(file, 12, 1, page_links_.size());
 727                 file <<
 728                     "          }\n";
 729             }
 730             else // page_num != 1
 731             {
 732                 file <<
 733                     "      <pgc>\n"
 734                     "        <pre>\n";
 735             }
 736
 737             file <<
 738                 // Clear link indicator and highlight the
 739                 // appropriate link/button.
 740                 "          g0 = 0; s8 = g1 &amp; " << link_mask << ";\n"
 741                 "        </pre>\n"
 742                 "        <vob file='"
 743                  << page_temp_files_[page_num - 1]->get_name() << "'/>\n";
 744
 745             for (std::size_t link_num = 1;
 746                  link_num <= page_links.size();
 747                  ++link_num)
 748             {
 749                 file <<
 750                     "        <button>"
 751                     // Update current location.
 752                     " g1 = " << link_num * link_mult + page_num << ";";
 753
 754                 // Jump to appropriate resource.
 755                 const ResourceEntry & resource_loc =
 756                     resource_map_[page_links[link_num - 1]];
 757                 if (resource_loc.first == page_resource)
 758                     file <<
 759                         " g0 = " << 1 * link_mult + resource_loc.second << ";"
 760                         " jump menu 1;";
 761                 else if (resource_loc.first == video_resource)
 762                     file << " jump title " << resource_loc.second << ";";
 763
 764                 file <<  " </button>\n";
 765             }
 766
 767             file << "      </pgc>\n";
 768         }
 769
 770         file <<
 771             "    </menus>\n"
 772             "  </vmgm>\n";
 773
 774         // Generate a titleset for each video.  This appears to make
 775         // jumping to titles a whole lot simpler.
 776         for (std::size_t video_num = 1;
 777              video_num <= video_paths_.size();
 778              ++video_num)
 779         {
 780             file <<
 781                 "  <titleset>\n"
 782                 // Generate a dummy menu so that the menu button on the
 783                 // remote control will work.
 784                 "    <menus>\n"
 785                 "      <pgc entry='root'>\n"
 786                 "        <pre> jump vmgm menu; </pre>\n"
 787                 "      </pgc>\n"
 788                 "    </menus>\n"
 789                 "    <titles>\n"
 790                 "      <pgc>\n"
 791                 // Record calling page/menu.
 792                 "        <pre> g12 = g1; </pre>\n"
 793                 // FIXME: Should XML-escape the path
 794                 "        <vob file='" << video_paths_[video_num - 1]
 795                  << "'/>\n"
 796                 // If page/menu location has not been changed during the
 797                 // video, change the location to be the following
 798                 // link/button when returning to it.  In any case,
 799                 // return to a page/menu.
 800                 "        <post> if (g1 eq g12) g1 = g1 + " << link_mult
 801                  << "; call menu; </post>\n"
 802                 "      </pgc>\n"
 803                 "    </titles>\n"
 804                 "  </titleset>\n";
 805         }
 806
 807         file <<
 808             "</dvdauthor>\n";
 809
 810         file.close();
 811
 812         {
 813             const char * argv[] = {
 814                 "dvdauthor",
 815                 "-o", output_dir_.c_str(),
 816                 "-x", temp.get_name().c_str(),
 817                 0
 818             };
 819             int command_result;
 820             Glib::spawn_sync(".",
 821                              Glib::ArrayHandle<std::string>(
 822                                  argv, sizeof(argv)/sizeof(argv[0]),
 823                                  Glib::OWNERSHIP_NONE),
 824                              Glib::SPAWN_SEARCH_PATH
 825                              | Glib::SPAWN_STDOUT_TO_DEV_NULL,
 826                              SigC::Slot0<void>(),
 827                              0, 0,
 828                              &command_result);
 829             if (command_result != 0)
 830                 throw std::runtime_error("dvdauthor failed");
 831         }
 832     }
 833
 834     void generate_page_dispatch(std::ostream & file, int indent,
 835                                 int first_page, int last_page)
 836     {
 837         if (first_page == 1 && last_page == 1)
 838         {
 839             // The dispatch code is *on* page 1 so we must not dispatch to
 840             // page 1 since that would cause an infinite loop.  This case
 841             // should be unreachable if there is more than one page due
 842             // to the following case.
 843         }
 844         else if (first_page == 1 && last_page == 2)
 845         {
 846             // dvdauthor doesn't allow empty blocks or null statements so
 847             // when selecting between pages 1 and 2 we don't use an "else"
 848             // part.  We must use braces so that a following "else" will
 849             // match the right "if".
 850             file << std::setw(indent) << "" << "{\n"
 851                  << std::setw(indent) << "" << "if (g0 eq 2)\n"
 852                  << std::setw(indent + 2) << "" << "jump menu 2;\n"
 853                  << std::setw(indent) << "" << "}\n";
 854         }
 855         else if (first_page == last_page)
 856         {
 857             file << std::setw(indent) << ""
 858                  << "jump menu " << first_page << ";\n";
 859         }
 860         else
 861         {
 862             int middle = (first_page + last_page) / 2;
 863             file << std::setw(indent) << "" << "if (g0 le " << middle << ")\n";
 864             generate_page_dispatch(file, indent + 2, first_page, middle);
 865             file << std::setw(indent) << "" << "else\n";
 866             generate_page_dispatch(file, indent + 2, middle + 1, last_page);
 867         }
 868     }
 869
 870     const video::frame_params & lookup_frame_params(const char * str)
 871     {
 872         assert(str);
 873         static const struct { const char * str; bool is_ntsc; }
 874         known_strings[] = {
 875             { "NTSC",  true },
 876             { "ntsc",  true },
 877             { "PAL",   false },
 878             { "pal",   false },
 879             // For DVD purposes, SECAM can be treated identically to PAL.
 880             { "SECAM", false },
 881             { "secam", false }
 882         };
 883         for (std::size_t i = 0;
 884              i != sizeof(known_strings)/sizeof(known_strings[0]);
 885              ++i)
 886             if (std::strcmp(str, known_strings[i].str) == 0)
 887                 return known_strings[i].is_ntsc ?
 888                     video::ntsc_params : video::pal_params;
 889         throw std::runtime_error(
 890             std::string("Invalid video standard: ").append(str));
 891     }
 892
 893     void print_usage(std::ostream & stream, const char * command_name)
 894     {
 895         stream << "Usage: " << command_name
 896                << (" [gtk-options] [--video-std std-name]"
 897                    " [--preview] menu-url [output-dir]\n");
 898     }
 899
 900 } // namespace
 901
 902 int main(int argc, char ** argv)
 903 {
 904     try
 905     {
 906         video::frame_params frame_params = video::pal_params;
 907         bool preview_mode = false;
 908
 909         // Do initial argument parsing.  We have to do this before
 910         // letting Gtk parse the arguments since we may need to spawn
 911         // Xvfb first.
 912         int argi = 1;
 913         while (argi != argc)
 914         {
 915             if (std::strcmp(argv[argi], "--") == 0)
 916             {
 917                 break;
 918             }
 919             else if (std::strcmp(argv[argi], "--help") == 0)
 920             {
 921                 print_usage(std::cout, argv[0]);
 922                 return EXIT_SUCCESS;
 923             }
 924             else if (std::strcmp(argv[argi], "--preview") == 0)
 925             {
 926                 preview_mode = true;
 927                 argi += 1;
 928             }
 929             else if (std::strcmp(argv[argi], "--video-std") == 0)
 930             {
 931                 if (argi + 1 == argc)
 932                 {
 933                     std::cerr << "Missing argument to --video-std\n";
 934                     print_usage(std::cerr, argv[0]);
 935                     return EXIT_FAILURE;
 936                 }
 937                 frame_params = lookup_frame_params(argv[argi + 1]);
 938                 argi += 2;
 939             }
 940             else
 941             {
 942                 argi += 1;
 943             }
 944         }
 945
 946         std::auto_ptr<FrameBuffer> fb;
 947         if (!preview_mode)
 948         {
 949             // Spawn Xvfb and set env variables so that Xlib will use it
 950             // Use 8 bits each for RGB components, which should translate into
 951             // "enough" bits for YUV components.
 952             fb.reset(new FrameBuffer(frame_params.width, frame_params.height,
 953                                      3 * 8));
 954             setenv("XAUTHORITY", fb->get_x_authority().c_str(), true);
 955             setenv("DISPLAY", fb->get_x_display().c_str(), true);
 956         }
 957
 958         // Initialise Gtk
 959         Gtk::Main kit(argc, argv);
 960
 961         // Complete argument parsing with Gtk's options out of the way.
 962         argi = 1;
 963         while (argi != argc)
 964         {
 965             if (std::strcmp(argv[argi], "--") == 0)
 966             {
 967                 argi += 1;
 968                 break;
 969             }
 970             else if (std::strcmp(argv[argi], "--preview") == 0)
 971             {
 972                 argi += 1;
 973             }
 974             else if (std::strcmp(argv[argi], "--video-std") == 0)
 975             {
 976                 argi += 2;
 977             }
 978             else if (argv[argi][0] == '-')
 979             {
 980                 std::cerr << "Invalid option: " << argv[argi] << "\n";
 981                 print_usage(std::cerr, argv[0]);
 982                 return EXIT_FAILURE;
 983             }
 984             else
 985             {
 986                 break;
 987             }
 988         }
 989         if (argc - argi != (preview_mode ? 1 : 2))
 990         {
 991             print_usage(std::cerr, argv[0]);
 992             return EXIT_FAILURE;
 993         }
 994
 995         // Initialise Mozilla
 996         BrowserWidget::init();
 997
 998         WebDvdWindow window(frame_params,
 999                             argv[argi],
1000                             preview_mode ? "" : argv[argi + 1]);
1001         Gtk::Main::run(window);
1002     }
1003     catch (std::exception & e)
1004     {
1005         std::cerr << "Fatal error: " << e.what() << "\n";
1006         return EXIT_FAILURE;
1007     }
1008
1009     return EXIT_SUCCESS;
1010 }