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 <cstring>
   6 #include <exception>
   7 #include <fstream>
   8 #include <iomanip>
   9 #include <iostream>
  10 #include <memory>
  11 #include <queue>
  12 #include <set>
  13 #include <sstream>
  14 #include <string>
  15
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18
  19 #include <boost/shared_ptr.hpp>
  20
  21 #include <gdkmm/pixbuf.h>
  22 #include <glibmm/convert.h>
  23 #include <glibmm/spawn.h>
  24 #include <gtkmm/main.h>
  25 #include <gtkmm/window.h>
  26
  27 #include <imglib2/ImageErrors.h>
  28 #include <nsGUIEvent.h>
  29 #include <nsIBoxObject.h>
  30 #include <nsIContent.h>
  31 #include <nsIDocShell.h>
  32 #include <nsIDOMAbstractView.h>
  33 #include <nsIDOMDocumentEvent.h>
  34 #include <nsIDOMDocumentView.h>
  35 #include <nsIDOMElement.h>
  36 #include <nsIDOMEventTarget.h>
  37 #include <nsIDOMHTMLDocument.h>
  38 #include <nsIDOMMouseEvent.h>
  39 #include <nsIDOMNSDocument.h>
  40 #include <nsIDOMWindow.h>
  41 #include <nsIEventStateManager.h>
  42 #include <nsIInterfaceRequestorUtils.h>
  43 #include <nsIURI.h> // required before nsILink.h
  44 #include <nsILink.h>
  45 #include <nsIPresContext.h>
  46 #include <nsIPresShell.h>
  47 #include <nsIWebBrowser.h>
  48 #include <nsString.h>
  49
  50 #include "browserwidget.hpp"
  51 #include "childiterator.hpp"
  52 #include "dvd.hpp"
  53 #include "framebuffer.hpp"
  54 #include "linkiterator.hpp"
  55 #include "pixbufs.hpp"
  56 #include "stylesheets.hpp"
  57 #include "temp_file.hpp"
  58 #include "video.hpp"
  59 #include "xpcom_support.hpp"
  60
  61 using xpcom_support::check;
  62
  63 namespace
  64 {
  65     struct rectangle
  66     {
  67         int left, top;     // inclusive
  68         int right, bottom; // exclusive
  69
  70         rectangle operator|=(const rectangle & other)
  71             {
  72                 if (other.empty())
  73                 {
  74                     // use current extents unchanged
  75                 }
  76                 else if (empty())
  77                 {
  78                     // use other extents
  79                     *this = other;
  80                 }
  81                 else
  82                 {
  83                     // find rectangle enclosing both extents
  84                     left = std::min(left, other.left);
  85                     top = std::min(top, other.top);
  86                     right = std::max(right, other.right);
  87                     bottom = std::max(bottom, other.bottom);
  88                 }
  89
  90                 return *this;
  91             }
  92
  93         rectangle operator&=(const rectangle & other)
  94             {
  95                 // find rectangle enclosed in both extents
  96                 left = std::max(left, other.left);
  97                 top = std::max(top, other.top);
  98                 right = std::max(left, std::min(right, other.right));
  99                 bottom = std::max(top, std::min(bottom, other.bottom));
 100                 return *this;
 101             }
 102
 103         bool empty() const
 104             {
 105                 return left == right || bottom == top;
 106             }
 107     };
 108
 109     rectangle get_elem_rect(nsIDOMNSDocument * ns_doc,
 110                             nsIDOMElement * elem)
 111     {
 112         rectangle result;
 113
 114         // Start with this element's bounding box
 115         nsCOMPtr<nsIBoxObject> box;
 116         check(ns_doc->GetBoxObjectFor(elem, getter_AddRefs(box)));
 117         int width, height;
 118         check(box->GetScreenX(&result.left));
 119         check(box->GetScreenY(&result.top));
 120         check(box->GetWidth(&width));
 121         check(box->GetHeight(&height));
 122         result.right = result.left + width;
 123         result.bottom = result.top + height;
 124
 125         // Merge bounding boxes of all child elements
 126         for (ChildIterator it = ChildIterator(elem), end; it != end; ++it)
 127         {
 128             nsCOMPtr<nsIDOMNode> child_node(*it);
 129             PRUint16 child_type;
 130             if (check(child_node->GetNodeType(&child_type)),
 131                 child_type == nsIDOMNode::ELEMENT_NODE)
 132             {
 133                 nsCOMPtr<nsIDOMElement> child_elem(
 134                     do_QueryInterface(child_node));
 135                 result |= get_elem_rect(ns_doc, child_elem);
 136             }
 137         }
 138
 139         return result;
 140     }
 141
 142     class WebDvdWindow : public Gtk::Window
 143     {
 144     public:
 145         WebDvdWindow(
 146             const video::frame_params & frame_params,
 147             const std::string & main_page_uri,
 148             const std::string & output_dir);
 149
 150     private:
 151         void add_page(const std::string & uri);
 152         void add_video(const std::string & uri);
 153         void load_next_page();
 154         void on_net_state_change(const char * uri, gint flags, guint status);
 155         bool process_page();
 156         void save_screenshot();
 157         void process_links(nsIPresShell * pres_shell,
 158                            nsIPresContext * pres_context,
 159                            nsIDOMWindow * dom_window);
 160         void generate_dvd();
 161
 162         enum ResourceType { page_resource, video_resource };
 163         typedef std::pair<ResourceType, int> ResourceEntry;
 164         video::frame_params frame_params_;
 165         std::string output_dir_;
 166         BrowserWidget browser_widget_;
 167         nsCOMPtr<nsIStyleSheet> stylesheet_;
 168         std::queue<std::string> page_queue_;
 169         std::map<std::string, ResourceEntry> resource_map_;
 170         std::vector<std::vector<std::string> > page_links_;
 171         std::vector<std::string> video_paths_;
 172         bool pending_window_update_;
 173         int pending_req_count_;
 174         std::auto_ptr<temp_file> background_temp_;
 175         struct page_state;
 176         std::auto_ptr<page_state> page_state_;
 177         std::vector<boost::shared_ptr<temp_file> > page_temp_files_;
 178     };
 179
 180     WebDvdWindow::WebDvdWindow(
 181         const video::frame_params & frame_params,
 182         const std::string & main_page_uri,
 183         const std::string & output_dir)
 184             : frame_params_(frame_params),
 185               output_dir_(output_dir),
 186               stylesheet_(load_css("file://" WEBDVD_LIB_DIR "/webdvd.css")),
 187               pending_window_update_(false),
 188               pending_req_count_(0)
 189     {
 190         set_size_request(frame_params_.width, frame_params_.height);
 191         set_resizable(false);
 192
 193         add(browser_widget_);
 194         browser_widget_.show();
 195         browser_widget_.signal_net_state().connect(
 196             SigC::slot(*this, &WebDvdWindow::on_net_state_change));
 197
 198         add_page(main_page_uri);
 199         load_next_page();
 200     }
 201
 202     void WebDvdWindow::add_page(const std::string & uri)
 203     {
 204         if (resource_map_.insert(
 205                 std::make_pair(uri, ResourceEntry(page_resource, 0)))
 206             .second)
 207         {
 208             page_queue_.push(uri);
 209         }
 210     }
 211
 212     void WebDvdWindow::add_video(const std::string & uri)
 213     {
 214         if (resource_map_.insert(
 215                 std::make_pair(uri, ResourceEntry(video_resource,
 216                                                   video_paths_.size() + 1)))
 217             .second)
 218         {
 219             Glib::ustring hostname;
 220             video_paths_.push_back(Glib::filename_from_uri(uri, hostname));
 221             // FIXME: Should check the hostname
 222         }
 223     }
 224
 225     void WebDvdWindow::load_next_page()
 226     {
 227         assert(!page_queue_.empty());
 228         const std::string & uri = page_queue_.front();
 229         std::cout << "loading " << uri << std::endl;
 230
 231         std::size_t page_count = page_links_.size();
 232         resource_map_[uri].second = ++page_count;
 233         page_links_.resize(page_count);
 234
 235         pending_window_update_ = true;
 236         browser_widget_.load_uri(uri);
 237     }
 238
 239     void WebDvdWindow::on_net_state_change(const char * uri,
 240                                            gint flags, guint status)
 241     {
 242         if (flags & GTK_MOZ_EMBED_FLAG_IS_REQUEST)
 243         {
 244             if (flags & GTK_MOZ_EMBED_FLAG_START)
 245                 ++pending_req_count_;
 246
 247             if (flags & GTK_MOZ_EMBED_FLAG_STOP)
 248             {
 249                 assert(pending_req_count_ != 0);
 250                 --pending_req_count_;
 251             }
 252         }
 253
 254         if (flags & GTK_MOZ_EMBED_FLAG_STOP
 255             && flags & GTK_MOZ_EMBED_FLAG_IS_WINDOW)
 256         {
 257             // Check whether the load was successful, ignoring this
 258             // pseudo-error.
 259             if (status != NS_IMAGELIB_ERROR_LOAD_ABORTED)
 260                 check(status);
 261
 262             pending_window_update_ = false;
 263         }
 264
 265         if (pending_req_count_ == 0 && !pending_window_update_)
 266         {
 267             try
 268             {
 269                 if (!process_page())
 270                     Gtk::Main::quit();
 271             }
 272             catch (std::exception & e)
 273             {
 274                 std::cerr << "Fatal error";
 275                 if (!page_queue_.empty())
 276                     std::cerr << " while processing <" << page_queue_.front()
 277                               << ">";
 278                 std::cerr << ": " << e.what() << "\n";
 279                 Gtk::Main::quit();
 280             }
 281         }
 282     }
 283
 284     bool WebDvdWindow::process_page()
 285     {
 286         assert(!page_queue_.empty());
 287
 288         nsCOMPtr<nsIWebBrowser> browser(browser_widget_.get_browser());
 289         nsCOMPtr<nsIDocShell> doc_shell(do_GetInterface(browser));
 290         assert(doc_shell);
 291         nsCOMPtr<nsIPresShell> pres_shell;
 292         check(doc_shell->GetPresShell(getter_AddRefs(pres_shell)));
 293         nsCOMPtr<nsIPresContext> pres_context;
 294         check(doc_shell->GetPresContext(getter_AddRefs(pres_context)));
 295         nsCOMPtr<nsIDOMWindow> dom_window;
 296         check(browser->GetContentDOMWindow(getter_AddRefs(dom_window)));
 297
 298         if (output_dir_.empty())
 299         {
 300             // In preview mode, just apply the stylesheet and let the
 301             // user select links.
 302             apply_style_sheet(stylesheet_, pres_shell);
 303         }
 304         else
 305         {
 306             // If we haven't already started work on this page, apply
 307             // the stylesheet and save a screenshot of its normal
 308             // appearance.
 309             if (!page_state_.get())
 310             {
 311                 apply_style_sheet(stylesheet_, pres_shell);
 312                 save_screenshot();
 313             }
 314
 315             // Start or continue processing links.
 316             process_links(pres_shell, pres_context, dom_window);
 317
 318             // If we've finished work on the links, move on to the
 319             // next page, if any, or else generate the DVD filesystem.
 320             if (!page_state_.get())
 321             {
 322                 page_queue_.pop();
 323                 if (page_queue_.empty())
 324                 {
 325                     generate_dvd();
 326                     return false;
 327                 }
 328                 else
 329                 {
 330                     load_next_page();
 331                 }
 332             }
 333         }
 334
 335         return true;
 336     }
 337
 338     void WebDvdWindow::save_screenshot()
 339     {
 340         Glib::RefPtr<Gdk::Window> window(get_window());
 341         assert(window);
 342         window->process_updates(true);
 343
 344         background_temp_.reset(new temp_file("webdvd-back-"));
 345         background_temp_->close();
 346         std::cout << "saving " << background_temp_->get_name() << std::endl;
 347         Gdk::Pixbuf::create(Glib::RefPtr<Gdk::Drawable>(window),
 348                             window->get_colormap(),
 349                             0, 0, 0, 0,
 350                             frame_params_.width, frame_params_.height)
 351             ->save(background_temp_->get_name(), "png");
 352     }
 353
 354     struct WebDvdWindow::page_state
 355     {
 356         page_state(nsIDOMDocument * doc, int width, int height)
 357                 : diff_pixbuf(Gdk::Pixbuf::create(
 358                                   Gdk::COLORSPACE_RGB,
 359                                   true, 8, // has_alpha, bits_per_sample
 360                                   width, height)),
 361                   spumux_temp("webdvd-spumux-"),
 362                   links_temp("webdvd-links-"),
 363                   link_num(0),
 364                   links_it(doc),
 365                   link_changing(false)
 366             {
 367                 spumux_temp.close();
 368                 links_temp.close();
 369             }
 370
 371         Glib::RefPtr<Gdk::Pixbuf> diff_pixbuf;
 372
 373         temp_file spumux_temp;
 374         std::ofstream spumux_file;
 375
 376         temp_file links_temp;
 377
 378         int link_num;
 379         LinkIterator links_it, links_end;
 380
 381         rectangle link_rect;
 382         bool link_changing;
 383         Glib::RefPtr<Gdk::Pixbuf> norm_pixbuf;
 384     };
 385
 386     void WebDvdWindow::process_links(nsIPresShell * pres_shell,
 387                                      nsIPresContext * pres_context,
 388                                      nsIDOMWindow * dom_window)
 389     {
 390         Glib::RefPtr<Gdk::Window> window(get_window());
 391         assert(window);
 392
 393         nsCOMPtr<nsIDOMDocument> basic_doc;
 394         check(dom_window->GetDocument(getter_AddRefs(basic_doc)));
 395         nsCOMPtr<nsIDOMNSDocument> ns_doc(do_QueryInterface(basic_doc));
 396         assert(ns_doc);
 397         nsCOMPtr<nsIEventStateManager> event_state_man(
 398             pres_context->EventStateManager()); // does not AddRef
 399         assert(event_state_man);
 400         nsCOMPtr<nsIDOMDocumentEvent> event_factory(
 401             do_QueryInterface(basic_doc));
 402         assert(event_factory);
 403         nsCOMPtr<nsIDOMDocumentView> doc_view(do_QueryInterface(basic_doc));
 404         assert(doc_view);
 405         nsCOMPtr<nsIDOMAbstractView> view;
 406         check(doc_view->GetDefaultView(getter_AddRefs(view)));
 407
 408         // Set up or recover our iteration state.
 409         std::auto_ptr<page_state> state(page_state_);
 410         if (!state.get())
 411         {
 412             state.reset(
 413                 new page_state(
 414                     basic_doc, frame_params_.width, frame_params_.height));
 415
 416             state->spumux_file.open(state->spumux_temp.get_name().c_str());
 417             state->spumux_file <<
 418                 "<subpictures>\n"
 419                 "  <stream>\n"
 420                 "    <spu force='yes' start='00:00:00.00'\n"
 421                 "        highlight='" << state->links_temp.get_name() << "'\n"
 422                 "        select='" << state->links_temp.get_name() << "'>\n";
 423         }
 424
 425         rectangle window_rect = {
 426             0, 0, frame_params_.width, frame_params_.height
 427         };
 428
 429         for (/* no initialisation */;
 430              state->links_it != state->links_end;
 431              ++state->links_it)
 432         {
 433             nsCOMPtr<nsIDOMNode> node(*state->links_it);
 434
 435             // Find the link URI.
 436             nsCOMPtr<nsILink> link(do_QueryInterface(node));
 437             assert(link);
 438             nsCOMPtr<nsIURI> uri;
 439             check(link->GetHrefURI(getter_AddRefs(uri)));
 440             std::string uri_string;
 441             {
 442                 nsCString uri_ns_string;
 443                 check(uri->GetSpec(uri_ns_string));
 444                 uri_string.assign(uri_ns_string.BeginReading(),
 445                                   uri_ns_string.EndReading());
 446             }
 447             std::string uri_sans_fragment(uri_string, 0, uri_string.find('#'));
 448
 449             // Is this a new link?
 450             if (!state->link_changing)
 451             {
 452                 // Find a rectangle enclosing the link and clip it to the
 453                 // window.
 454                 nsCOMPtr<nsIDOMElement> elem(do_QueryInterface(node));
 455                 assert(elem);
 456                 state->link_rect = get_elem_rect(ns_doc, elem);
 457                 state->link_rect &= window_rect;
 458
 459                 if (state->link_rect.empty())
 460                 {
 461                     std::cerr << "Ignoring invisible link to "
 462                               << uri_string << "\n";
 463                     continue;
 464                 }
 465
 466                 ++state->link_num;
 467
 468                 if (state->link_num >= dvd::menu_buttons_max)
 469                 {
 470                     if (state->link_num == dvd::menu_buttons_max)
 471                         std::cerr << "No more than " << dvd::menu_buttons_max
 472                                   << " buttons can be placed on a page\n";
 473                     std::cerr << "Ignoring link to " << uri_string << "\n";
 474                     continue;
 475                 }
 476
 477                 // Check whether this is a link to a video or a page then
 478                 // add it to the known resources if not already seen.
 479                 nsCString path;
 480                 check(uri->GetPath(path));
 481                 // FIXME: This is a bit of a hack.  Perhaps we could decide
 482                 // later based on the MIME type determined by Mozilla?
 483                 if (path.Length() > 4
 484                     && std::strcmp(path.EndReading() - 4, ".vob") == 0)
 485                 {
 486                     PRBool is_file;
 487                     check(uri->SchemeIs("file", &is_file));
 488                     if (!is_file)
 489                     {
 490                         std::cerr << "Links to video must use the file:"
 491                                   << " scheme\n";
 492                         continue;
 493                     }
 494                     add_video(uri_sans_fragment);
 495                 }
 496                 else
 497                 {
 498                     add_page(uri_sans_fragment);
 499                 }
 500
 501                 nsCOMPtr<nsIContent> content(do_QueryInterface(node));
 502                 assert(content);
 503                 nsCOMPtr<nsIDOMEventTarget> event_target(
 504                     do_QueryInterface(node));
 505                 assert(event_target);
 506
 507                 state->norm_pixbuf = Gdk::Pixbuf::create(
 508                     Glib::RefPtr<Gdk::Drawable>(window),
 509                     window->get_colormap(),
 510                     state->link_rect.left,
 511                     state->link_rect.top,
 512                     0,
 513                     0,
 514                     state->link_rect.right - state->link_rect.left,
 515                     state->link_rect.bottom - state->link_rect.top);
 516
 517                 nsCOMPtr<nsIDOMEvent> event;
 518                 check(event_factory->CreateEvent(
 519                           NS_ConvertASCIItoUTF16("MouseEvents"),
 520                           getter_AddRefs(event)));
 521                 nsCOMPtr<nsIDOMMouseEvent> mouse_event(
 522                     do_QueryInterface(event));
 523                 assert(mouse_event);
 524                 check(mouse_event->InitMouseEvent(
 525                           NS_ConvertASCIItoUTF16("mouseover"),
 526                           true,  // can bubble
 527                           true,  // cancelable
 528                           view,
 529                           0,     // detail: mouse click count
 530                           state->link_rect.left, // screenX
 531                           state->link_rect.top,  // screenY
 532                           state->link_rect.left, // clientX
 533                           state->link_rect.top,  // clientY
 534                           false, false, false, false, // qualifiers
 535                           0,     // button: left (or primary)
 536                           0));   // related target
 537                 PRBool dummy;
 538                 check(event_target->DispatchEvent(mouse_event,
 539                                                   &dummy));
 540                 check(event_state_man->SetContentState(content,
 541                                                        NS_EVENT_STATE_HOVER));
 542
 543                 pres_shell->FlushPendingNotifications(true);
 544
 545                 // We may have to exit and wait for image loading
 546                 // to complete, at which point we will be called
 547                 // again.
 548                 if (pending_req_count_ > 0)
 549                 {
 550                     state->link_changing = true;
 551                     page_state_ = state;
 552                     return;
 553                 }
 554             }
 555
 556             window->process_updates(true);
 557
 558             Glib::RefPtr<Gdk::Pixbuf> changed_pixbuf(
 559                 Gdk::Pixbuf::create(
 560                     Glib::RefPtr<Gdk::Drawable>(window),
 561                     window->get_colormap(),
 562                     state->link_rect.left,
 563                     state->link_rect.top,
 564                     0,
 565                     0,
 566                     state->link_rect.right - state->link_rect.left,
 567                     state->link_rect.bottom - state->link_rect.top));
 568             diff_rgb_pixbufs(
 569                 state->norm_pixbuf,
 570                 changed_pixbuf,
 571                 state->diff_pixbuf,
 572                 state->link_rect.left,
 573                 state->link_rect.top,
 574                 state->link_rect.right - state->link_rect.left,
 575                 state->link_rect.bottom - state->link_rect.top);
 576
 577             state->spumux_file <<
 578                 "      <button x0='" << state->link_rect.left << "'"
 579                 " y0='" << state->link_rect.top << "'"
 580                 " x1='" << state->link_rect.right - 1 << "'"
 581                 " y1='" << state->link_rect.bottom - 1 << "'/>\n";
 582
 583             // Add to the page's links, ignoring any fragment (for now).
 584             page_links_.back().push_back(uri_sans_fragment);
 585         }
 586
 587         quantise_rgba_pixbuf(state->diff_pixbuf, dvd::button_n_colours);
 588
 589         std::cout << "saving " << state->links_temp.get_name()
 590                   << std::endl;
 591         state->diff_pixbuf->save(state->links_temp.get_name(), "png");
 592
 593         state->spumux_file <<
 594             "    </spu>\n"
 595             "  </stream>\n"
 596             "</subpictures>\n";
 597
 598         state->spumux_file.close();
 599
 600         // TODO: if (!state->spumux_file) throw ...
 601
 602         {
 603             boost::shared_ptr<temp_file> vob_temp(
 604                 new temp_file("webdvd-vob-"));
 605             std::ostringstream command_stream;
 606             command_stream << "pngtopnm "
 607                            << background_temp_->get_name()
 608                            << " | ppmtoy4m -v0 -n1 -F"
 609                            << frame_params_.rate_numer
 610                            << ":" << frame_params_.rate_denom
 611                            << " -A" << frame_params_.pixel_ratio_width
 612                            << ":" << frame_params_.pixel_ratio_height
 613                            << (" -Ip -S420_mpeg2"
 614                                " | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
 615                                " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
 616                                " | spumux -v0 -mdvd ")
 617                            << state->spumux_temp.get_name()
 618                            << " > " << vob_temp->get_name();
 619             std::string command(command_stream.str());
 620             const char * argv[] = {
 621                 "/bin/sh", "-c", command.c_str(), 0
 622             };
 623             std::cout << "running " << argv[2] << std::endl;
 624             int command_result;
 625             Glib::spawn_sync(".",
 626                              Glib::ArrayHandle<std::string>(
 627                                  argv, sizeof(argv)/sizeof(argv[0]),
 628                                  Glib::OWNERSHIP_NONE),
 629                              Glib::SPAWN_STDOUT_TO_DEV_NULL,
 630                              SigC::Slot0<void>(),
 631                              0, 0,
 632                              &command_result);
 633             if (command_result != 0)
 634                 throw std::runtime_error("spumux pipeline failed");
 635
 636             page_temp_files_.push_back(vob_temp);
 637         }
 638     }
 639
 640     void generate_page_dispatch(std::ostream &, int indent,
 641                                 int first_page, int last_page);
 642
 643     void WebDvdWindow::generate_dvd()
 644     {
 645         temp_file temp("webdvd-dvdauthor-");
 646         temp.close();
 647         std::ofstream file(temp.get_name().c_str());
 648
 649         // We generate code that uses registers in the following way:
 650         //
 651         // g0:     link destination (when jumping to menu 1), then scratch
 652         // g1:     current location
 653         // g2-g11: location history (g2 = most recent)
 654         // g12:    location that last linked to a video
 655         //
 656         // All locations are divided into two bitfields: the least
 657         // significant 10 bits are a page/menu number and the most
 658         // significant 6 bits are a link/button number.  This is
 659         // chosen for compatibility with the encoding of the s8
 660         // (button) register.
 661         //
 662         static const int link_mult = dvd::reg_s8_button_mult;
 663         static const int page_mask = link_mult - 1;
 664         static const int link_mask = (1 << dvd::reg_bits) - link_mult;
 665
 666         file <<
 667             "<dvdauthor>\n"
 668             "  <vmgm>\n"
 669             "    <menus>\n";
 670
 671         for (std::size_t page_num = 1;
 672              page_num <= page_links_.size();
 673              ++page_num)
 674         {
 675             std::vector<std::string> & page_links =
 676                 page_links_[page_num - 1];
 677
 678             if (page_num == 1)
 679             {
 680                 // This is the first page (root menu) which needs to
 681                 // include initialisation and dispatch code.
 682
 683                 file <<
 684                     "      <pgc entry='title'>\n"
 685                     "        <pre>\n"
 686                     // Has the location been set yet?
 687                     "          if (g1 eq 0)\n"
 688                     "          {\n"
 689                     // Initialise the current location to first link on
 690                     // this page.
 691                     "            g1 = " << 1 * link_mult + 1 << ";\n"
 692                     "          }\n"
 693                     "          else\n"
 694                     "          {\n"
 695                     // Has the user selected a link?
 696                     "            if (g0 ne 0)\n"
 697                     "            {\n"
 698                     // First update the history.
 699                     // Does link go to the last page in the history?
 700                     "              if (((g0 ^ g2) &amp; " << page_mask
 701                      << ") == 0)\n"
 702                     // It does; we treat this as going back and pop the old
 703                     // location off the history stack into the current
 704                     // location.  Clear the free stack slot.
 705                     "              {\n"
 706                     "                g1 = g2; g2 = g3; g3 = g4; g4 = g5;\n"
 707                     "                g5 = g6; g6 = g7; g7 = g8; g8 = g9;\n"
 708                     "                g9 = g10; g10 = g11; g11 = 0;\n"
 709                     "              }\n"
 710                     "              else\n"
 711                     // Link goes to some other page, so push current
 712                     // location onto the history stack and set the current
 713                     // location to be exactly the target location.
 714                     "              {\n"
 715                     "                g11 = g10; g10 = g9; g9 = g8; g8 = g7;\n"
 716                     "                g7 = g6; g6 = g5; g5 = g4; g4 = g3;\n"
 717                     "                g3 = g2; g2 = g1; g1 = g0;\n"
 718                     "              }\n"
 719                     "            }\n"
 720                     // Find the target page number.
 721                     "            g0 = g1 &amp; " << page_mask << ";\n";
 722                 // There seems to be no way to perform a computed jump,
 723                 // so we generate all possible jumps and a binary search
 724                 // to select the correct one.
 725                 generate_page_dispatch(file, 12, 1, page_links_.size());
 726                 file <<
 727                     "          }\n";
 728             }
 729             else // page_num != 1
 730             {
 731                 file <<
 732                     "      <pgc>\n"
 733                     "        <pre>\n";
 734             }
 735
 736             file <<
 737                 // Clear link indicator and highlight the
 738                 // appropriate link/button.
 739                 "          g0 = 0; s8 = g1 &amp; " << link_mask << ";\n"
 740                 "        </pre>\n"
 741                 "        <vob file='"
 742                  << page_temp_files_[page_num - 1]->get_name() << "'/>\n";
 743
 744             for (std::size_t link_num = 1;
 745                  link_num <= page_links.size();
 746                  ++link_num)
 747             {
 748                 file <<
 749                     "        <button>"
 750                     // Update current location.
 751                     " g1 = " << link_num * link_mult + page_num << ";";
 752
 753                 // Jump to appropriate resource.
 754                 const ResourceEntry & resource_loc =
 755                     resource_map_[page_links[link_num - 1]];
 756                 if (resource_loc.first == page_resource)
 757                     file <<
 758                         " g0 = " << 1 * link_mult + resource_loc.second << ";"
 759                         " jump menu 1;";
 760                 else if (resource_loc.first == video_resource)
 761                     file << " jump title " << resource_loc.second << ";";
 762
 763                 file <<  " </button>\n";
 764             }
 765
 766             file << "      </pgc>\n";
 767         }
 768
 769         file <<
 770             "    </menus>\n"
 771             "  </vmgm>\n";
 772
 773         // Generate a titleset for each video.  This appears to make
 774         // jumping to titles a whole lot simpler.
 775         for (std::size_t video_num = 1;
 776              video_num <= video_paths_.size();
 777              ++video_num)
 778         {
 779             file <<
 780                 "  <titleset>\n"
 781                 // Generate a dummy menu so that the menu button on the
 782                 // remote control will work.
 783                 "    <menus>\n"
 784                 "      <pgc entry='root'>\n"
 785                 "        <pre> jump vmgm menu; </pre>\n"
 786                 "      </pgc>\n"
 787                 "    </menus>\n"
 788                 "    <titles>\n"
 789                 "      <pgc>\n"
 790                 // Record calling page/menu.
 791                 "        <pre> g12 = g1; </pre>\n"
 792                 // FIXME: Should XML-escape the path
 793                 "        <vob file='" << video_paths_[video_num - 1]
 794                  << "'/>\n"
 795                 // If page/menu location has not been changed during the
 796                 // video, change the location to be the following
 797                 // link/button when returning to it.  In any case,
 798                 // return to a page/menu.
 799                 "        <post> if (g1 eq g12) g1 = g1 + " << link_mult
 800                  << "; call menu; </post>\n"
 801                 "      </pgc>\n"
 802                 "    </titles>\n"
 803                 "  </titleset>\n";
 804         }
 805
 806         file <<
 807             "</dvdauthor>\n";
 808
 809         file.close();
 810
 811         {
 812             const char * argv[] = {
 813                 "dvdauthor",
 814                 "-o", output_dir_.c_str(),
 815                 "-x", temp.get_name().c_str(),
 816                 0
 817             };
 818             int command_result;
 819             Glib::spawn_sync(".",
 820                              Glib::ArrayHandle<std::string>(
 821                                  argv, sizeof(argv)/sizeof(argv[0]),
 822                                  Glib::OWNERSHIP_NONE),
 823                              Glib::SPAWN_SEARCH_PATH
 824                              | Glib::SPAWN_STDOUT_TO_DEV_NULL,
 825                              SigC::Slot0<void>(),
 826                              0, 0,
 827                              &command_result);
 828             if (command_result != 0)
 829                 throw std::runtime_error("dvdauthor failed");
 830         }
 831     }
 832
 833     void generate_page_dispatch(std::ostream & file, int indent,
 834                                 int first_page, int last_page)
 835     {
 836         if (first_page == 1 && last_page == 1)
 837         {
 838             // The dispatch code is *on* page 1 so we must not dispatch to
 839             // page 1 since that would cause an infinite loop.  This case
 840             // should be unreachable if there is more than one page due
 841             // to the following case.
 842         }
 843         else if (first_page == 1 && last_page == 2)
 844         {
 845             // dvdauthor doesn't allow empty blocks or null statements so
 846             // when selecting between pages 1 and 2 we don't use an "else"
 847             // part.  We must use braces so that a following "else" will
 848             // match the right "if".
 849             file << std::setw(indent) << "" << "{\n"
 850                  << std::setw(indent) << "" << "if (g0 eq 2)\n"
 851                  << std::setw(indent + 2) << "" << "jump menu 2;\n"
 852                  << std::setw(indent) << "" << "}\n";
 853         }
 854         else if (first_page == last_page)
 855         {
 856             file << std::setw(indent) << ""
 857                  << "jump menu " << first_page << ";\n";
 858         }
 859         else
 860         {
 861             int middle = (first_page + last_page) / 2;
 862             file << std::setw(indent) << "" << "if (g0 le " << middle << ")\n";
 863             generate_page_dispatch(file, indent + 2, first_page, middle);
 864             file << std::setw(indent) << "" << "else\n";
 865             generate_page_dispatch(file, indent + 2, middle + 1, last_page);
 866         }
 867     }
 868
 869     const video::frame_params & lookup_frame_params(const char * str)
 870     {
 871         assert(str);
 872         static const struct { const char * str; bool is_ntsc; }
 873         known_strings[] = {
 874             { "NTSC",  true },
 875             { "ntsc",  true },
 876             { "PAL",   false },
 877             { "pal",   false },
 878             // For DVD purposes, SECAM can be treated identically to PAL.
 879             { "SECAM", false },
 880             { "secam", false }
 881         };
 882         for (std::size_t i = 0;
 883              i != sizeof(known_strings)/sizeof(known_strings[0]);
 884              ++i)
 885             if (std::strcmp(str, known_strings[i].str) == 0)
 886                 return known_strings[i].is_ntsc ?
 887                     video::ntsc_params : video::pal_params;
 888         throw std::runtime_error(
 889             std::string("Invalid video standard: ").append(str));
 890     }
 891
 892     void print_usage(std::ostream & stream, const char * command_name)
 893     {
 894         stream << "Usage: " << command_name
 895                << (" [gtk-options] [--video-std std-name]"
 896                    " [--preview] menu-url [output-dir]\n");
 897     }
 898
 899 } // namespace
 900
 901 int main(int argc, char ** argv)
 902 {
 903     try
 904     {
 905         video::frame_params frame_params = video::pal_params;
 906         bool preview_mode = false;
 907         std::string menu_url;
 908         std::string output_dir;
 909
 910         // Do initial option parsing.  We have to do this before
 911         // letting Gtk parse the arguments since we may need to spawn
 912         // Xvfb first.
 913         int argi = 1;
 914         while (argi != argc)
 915         {
 916             if (std::strcmp(argv[argi], "--") == 0)
 917             {
 918                 break;
 919             }
 920             else if (std::strcmp(argv[argi], "--help") == 0)
 921             {
 922                 print_usage(std::cout, argv[0]);
 923                 return EXIT_SUCCESS;
 924             }
 925             else if (std::strcmp(argv[argi], "--preview") == 0)
 926             {
 927                 preview_mode = true;
 928                 argi += 1;
 929             }
 930             else if (std::strcmp(argv[argi], "--video-std") == 0)
 931             {
 932                 if (argi + 1 == argc)
 933                 {
 934                     std::cerr << "Missing argument to --video-std\n";
 935                     print_usage(std::cerr, argv[0]);
 936                     return EXIT_FAILURE;
 937                 }
 938                 frame_params = lookup_frame_params(argv[argi + 1]);
 939                 argi += 2;
 940             }
 941             else
 942             {
 943                 argi += 1;
 944             }
 945         }
 946
 947         std::auto_ptr<FrameBuffer> fb;
 948         if (!preview_mode)
 949         {
 950             // Spawn Xvfb and set env variables so that Xlib will use it
 951             // Use 8 bits each for RGB components, which should translate into
 952             // "enough" bits for YUV components.
 953             fb.reset(new FrameBuffer(frame_params.width, frame_params.height,
 954                                      3 * 8));
 955             setenv("XAUTHORITY", fb->get_x_authority().c_str(), true);
 956             setenv("DISPLAY", fb->get_x_display().c_str(), true);
 957         }
 958
 959         // Initialise Gtk
 960         Gtk::Main kit(argc, argv);
 961
 962         // Complete option parsing with Gtk's options out of the way.
 963         argi = 1;
 964         while (argi != argc)
 965         {
 966             if (std::strcmp(argv[argi], "--") == 0)
 967             {
 968                 argi += 1;
 969                 break;
 970             }
 971             else if (std::strcmp(argv[argi], "--preview") == 0)
 972             {
 973                 argi += 1;
 974             }
 975             else if (std::strcmp(argv[argi], "--video-std") == 0)
 976             {
 977                 argi += 2;
 978             }
 979             else if (argv[argi][0] == '-')
 980             {
 981                 std::cerr << "Invalid option: " << argv[argi] << "\n";
 982                 print_usage(std::cerr, argv[0]);
 983                 return EXIT_FAILURE;
 984             }
 985             else
 986             {
 987                 break;
 988             }
 989         }
 990
 991         // Look for a starting URL or filename and (except in preview
 992         // mode) an output directory after the options.
 993         if (argc - argi != (preview_mode ? 1 : 2))
 994         {
 995             print_usage(std::cerr, argv[0]);
 996             return EXIT_FAILURE;
 997         }
 998         if (std::strstr(argv[argi], "://"))
 999         {
1000             // It appears to be an absolute URL, so use it as-is.
1001             menu_url = argv[argi];
1002         }
1003         else
1004         {
1005             // Assume it's a filename.  Resolve it to an absolute URL.
1006             std::string path(argv[argi]);
1007             if (!Glib::path_is_absolute(path))
1008                 path = Glib::build_filename(Glib::get_current_dir(), path);
1009             menu_url = Glib::filename_to_uri(path);
1010         }
1011         if (!preview_mode)
1012             output_dir = argv[argi + 1];
1013
1014         // Initialise Mozilla
1015         BrowserWidget::init();
1016
1017         // Run the browser/converter
1018         WebDvdWindow window(frame_params, menu_url, output_dir);
1019         Gtk::Main::run(window);
1020     }
1021     catch (std::exception & e)
1022     {
1023         std::cerr << "Fatal error: " << e.what() << "\n";
1024         return EXIT_FAILURE;
1025     }
1026
1027     return EXIT_SUCCESS;
1028 }