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
  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 <nsIDOMBarProp.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         bool have_tweaked_page_;
 175         std::auto_ptr<temp_file> background_temp_;
 176         struct page_state;
 177         std::auto_ptr<page_state> page_state_;
 178         std::vector<boost::shared_ptr<temp_file> > page_temp_files_;
 179     };
 180
 181     WebDvdWindow::WebDvdWindow(
 182         const video::frame_params & frame_params,
 183         const std::string & main_page_uri,
 184         const std::string & output_dir)
 185             : frame_params_(frame_params),
 186               output_dir_(output_dir),
 187               stylesheet_(load_css("file://" WEBDVD_LIB_DIR "/webdvd.css")),
 188               pending_window_update_(false),
 189               pending_req_count_(0),
 190               have_tweaked_page_(false)
 191     {
 192         set_size_request(frame_params_.width, frame_params_.height);
 193         set_resizable(false);
 194
 195         add(browser_widget_);
 196         browser_widget_.show();
 197         browser_widget_.signal_net_state().connect(
 198             SigC::slot(*this, &WebDvdWindow::on_net_state_change));
 199
 200         add_page(main_page_uri);
 201         load_next_page();
 202     }
 203
 204     void WebDvdWindow::add_page(const std::string & uri)
 205     {
 206         if (resource_map_.insert(
 207                 std::make_pair(uri, ResourceEntry(page_resource, 0)))
 208             .second)
 209         {
 210             page_queue_.push(uri);
 211         }
 212     }
 213
 214     void WebDvdWindow::add_video(const std::string & uri)
 215     {
 216         if (resource_map_.insert(
 217                 std::make_pair(uri, ResourceEntry(video_resource,
 218                                                   video_paths_.size() + 1)))
 219             .second)
 220         {
 221             Glib::ustring hostname;
 222             video_paths_.push_back(Glib::filename_from_uri(uri, hostname));
 223             // FIXME: Should check the hostname
 224         }
 225     }
 226
 227     void WebDvdWindow::load_next_page()
 228     {
 229         assert(!page_queue_.empty());
 230         const std::string & uri = page_queue_.front();
 231         std::cout << "loading " << uri << std::endl;
 232
 233         std::size_t page_count = page_links_.size();
 234         resource_map_[uri].second = ++page_count;
 235         page_links_.resize(page_count);
 236
 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_IS_DOCUMENT
 256             && flags & GTK_MOZ_EMBED_FLAG_START)
 257         {
 258             pending_window_update_ = true;
 259             have_tweaked_page_ = false;
 260         }
 261
 262         if (flags & GTK_MOZ_EMBED_FLAG_IS_WINDOW
 263             && flags & GTK_MOZ_EMBED_FLAG_STOP)
 264         {
 265             // Check whether the load was successful, ignoring this
 266             // pseudo-error.
 267             if (status != NS_IMAGELIB_ERROR_LOAD_ABORTED)
 268                 check(status);
 269
 270             pending_window_update_ = false;
 271         }
 272
 273         if (pending_req_count_ == 0 && !pending_window_update_)
 274         {
 275             try
 276             {
 277                 if (!process_page())
 278                     Gtk::Main::quit();
 279             }
 280             catch (std::exception & e)
 281             {
 282                 std::cerr << "Fatal error";
 283                 if (!page_queue_.empty())
 284                     std::cerr << " while processing <" << page_queue_.front()
 285                               << ">";
 286                 std::cerr << ": " << e.what() << "\n";
 287                 Gtk::Main::quit();
 288             }
 289         }
 290     }
 291
 292     bool WebDvdWindow::process_page()
 293     {
 294         assert(!page_queue_.empty());
 295
 296         nsCOMPtr<nsIWebBrowser> browser(browser_widget_.get_browser());
 297         nsCOMPtr<nsIDocShell> doc_shell(do_GetInterface(browser));
 298         assert(doc_shell);
 299         nsCOMPtr<nsIPresShell> pres_shell;
 300         check(doc_shell->GetPresShell(getter_AddRefs(pres_shell)));
 301         nsCOMPtr<nsIPresContext> pres_context;
 302         check(doc_shell->GetPresContext(getter_AddRefs(pres_context)));
 303         nsCOMPtr<nsIDOMWindow> dom_window;
 304         check(browser->GetContentDOMWindow(getter_AddRefs(dom_window)));
 305
 306         // If we haven't done so already, apply the stylesheet and
 307         // disable scrollbars.
 308         if (!have_tweaked_page_)
 309         {
 310             apply_style_sheet(stylesheet_, pres_shell);
 311
 312             // This actually only needs to be done once.
 313             nsCOMPtr<nsIDOMBarProp> dom_bar_prop;
 314             check(dom_window->GetScrollbars(getter_AddRefs(dom_bar_prop)));
 315             check(dom_bar_prop->SetVisible(false));
 316
 317             have_tweaked_page_ = true;
 318
 319             // Might need to wait a while for things to load or more
 320             // likely for a re-layout.
 321             if (pending_req_count_ > 0)
 322                 return true;
 323         }
 324
 325         // All further work should only be done if we're not in preview mode.
 326         if (!output_dir_.empty())
 327         {
 328             // If we haven't already started work on this page, save a
 329             // screenshot of its normal appearance.
 330             if (!page_state_.get())
 331                 save_screenshot();
 332
 333             // Start or continue processing links.
 334             process_links(pres_shell, pres_context, dom_window);
 335
 336             // If we've finished work on the links, move on to the
 337             // next page, if any, or else generate the DVD filesystem.
 338             if (!page_state_.get())
 339             {
 340                 page_queue_.pop();
 341                 if (page_queue_.empty())
 342                 {
 343                     generate_dvd();
 344                     return false;
 345                 }
 346                 else
 347                 {
 348                     load_next_page();
 349                 }
 350             }
 351         }
 352
 353         return true;
 354     }
 355
 356     void WebDvdWindow::save_screenshot()
 357     {
 358         Glib::RefPtr<Gdk::Window> window(get_window());
 359         assert(window);
 360         window->process_updates(true);
 361
 362         background_temp_.reset(new temp_file("webdvd-back-"));
 363         background_temp_->close();
 364         std::cout << "saving " << background_temp_->get_name() << std::endl;
 365         Gdk::Pixbuf::create(Glib::RefPtr<Gdk::Drawable>(window),
 366                             window->get_colormap(),
 367                             0, 0, 0, 0,
 368                             frame_params_.width, frame_params_.height)
 369             ->save(background_temp_->get_name(), "png");
 370     }
 371
 372     struct WebDvdWindow::page_state
 373     {
 374         page_state(nsIDOMDocument * doc, int width, int height)
 375                 : diff_pixbuf(Gdk::Pixbuf::create(
 376                                   Gdk::COLORSPACE_RGB,
 377                                   true, 8, // has_alpha, bits_per_sample
 378                                   width, height)),
 379                   spumux_temp("webdvd-spumux-"),
 380                   links_temp("webdvd-links-"),
 381                   link_num(0),
 382                   links_it(doc),
 383                   link_changing(false)
 384             {
 385                 spumux_temp.close();
 386                 links_temp.close();
 387             }
 388
 389         Glib::RefPtr<Gdk::Pixbuf> diff_pixbuf;
 390
 391         temp_file spumux_temp;
 392         std::ofstream spumux_file;
 393
 394         temp_file links_temp;
 395
 396         int link_num;
 397         LinkIterator links_it, links_end;
 398
 399         rectangle link_rect;
 400         bool link_changing;
 401         Glib::RefPtr<Gdk::Pixbuf> norm_pixbuf;
 402     };
 403
 404     void WebDvdWindow::process_links(nsIPresShell * pres_shell,
 405                                      nsIPresContext * pres_context,
 406                                      nsIDOMWindow * dom_window)
 407     {
 408         Glib::RefPtr<Gdk::Window> window(get_window());
 409         assert(window);
 410
 411         nsCOMPtr<nsIDOMDocument> basic_doc;
 412         check(dom_window->GetDocument(getter_AddRefs(basic_doc)));
 413         nsCOMPtr<nsIDOMNSDocument> ns_doc(do_QueryInterface(basic_doc));
 414         assert(ns_doc);
 415         nsCOMPtr<nsIEventStateManager> event_state_man(
 416             pres_context->EventStateManager()); // does not AddRef
 417         assert(event_state_man);
 418         nsCOMPtr<nsIDOMDocumentEvent> event_factory(
 419             do_QueryInterface(basic_doc));
 420         assert(event_factory);
 421         nsCOMPtr<nsIDOMDocumentView> doc_view(do_QueryInterface(basic_doc));
 422         assert(doc_view);
 423         nsCOMPtr<nsIDOMAbstractView> view;
 424         check(doc_view->GetDefaultView(getter_AddRefs(view)));
 425
 426         // Set up or recover our iteration state.
 427         std::auto_ptr<page_state> state(page_state_);
 428         if (!state.get())
 429         {
 430             state.reset(
 431                 new page_state(
 432                     basic_doc, frame_params_.width, frame_params_.height));
 433
 434             state->spumux_file.open(state->spumux_temp.get_name().c_str());
 435             state->spumux_file <<
 436                 "<subpictures>\n"
 437                 "  <stream>\n"
 438                 "    <spu force='yes' start='00:00:00.00'\n"
 439                 "        highlight='" << state->links_temp.get_name() << "'\n"
 440                 "        select='" << state->links_temp.get_name() << "'>\n";
 441         }
 442
 443         rectangle window_rect = {
 444             0, 0, frame_params_.width, frame_params_.height
 445         };
 446
 447         for (/* no initialisation */;
 448              state->links_it != state->links_end;
 449              ++state->links_it)
 450         {
 451             nsCOMPtr<nsIDOMNode> node(*state->links_it);
 452
 453             // Find the link URI.
 454             nsCOMPtr<nsILink> link(do_QueryInterface(node));
 455             assert(link);
 456             nsCOMPtr<nsIURI> uri;
 457             check(link->GetHrefURI(getter_AddRefs(uri)));
 458             std::string uri_string;
 459             {
 460                 nsCString uri_ns_string;
 461                 check(uri->GetSpec(uri_ns_string));
 462                 uri_string.assign(uri_ns_string.BeginReading(),
 463                                   uri_ns_string.EndReading());
 464             }
 465             std::string uri_sans_fragment(uri_string, 0, uri_string.find('#'));
 466
 467             // Is this a new link?
 468             if (!state->link_changing)
 469             {
 470                 // Find a rectangle enclosing the link and clip it to the
 471                 // window.
 472                 nsCOMPtr<nsIDOMElement> elem(do_QueryInterface(node));
 473                 assert(elem);
 474                 state->link_rect = get_elem_rect(ns_doc, elem);
 475                 state->link_rect &= window_rect;
 476
 477                 if (state->link_rect.empty())
 478                 {
 479                     std::cerr << "Ignoring invisible link to "
 480                               << uri_string << "\n";
 481                     continue;
 482                 }
 483
 484                 ++state->link_num;
 485
 486                 if (state->link_num >= dvd::menu_buttons_max)
 487                 {
 488                     if (state->link_num == dvd::menu_buttons_max)
 489                         std::cerr << "No more than " << dvd::menu_buttons_max
 490                                   << " buttons can be placed on a page\n";
 491                     std::cerr << "Ignoring link to " << uri_string << "\n";
 492                     continue;
 493                 }
 494
 495                 // Check whether this is a link to a video or a page then
 496                 // add it to the known resources if not already seen.
 497                 nsCString path;
 498                 check(uri->GetPath(path));
 499                 // FIXME: This is a bit of a hack.  Perhaps we could decide
 500                 // later based on the MIME type determined by Mozilla?
 501                 if (path.Length() > 4
 502                     && std::strcmp(path.EndReading() - 4, ".vob") == 0)
 503                 {
 504                     PRBool is_file;
 505                     check(uri->SchemeIs("file", &is_file));
 506                     if (!is_file)
 507                     {
 508                         std::cerr << "Links to video must use the file:"
 509                                   << " scheme\n";
 510                         continue;
 511                     }
 512                     add_video(uri_sans_fragment);
 513                 }
 514                 else
 515                 {
 516                     add_page(uri_sans_fragment);
 517                 }
 518
 519                 nsCOMPtr<nsIContent> content(do_QueryInterface(node));
 520                 assert(content);
 521                 nsCOMPtr<nsIDOMEventTarget> event_target(
 522                     do_QueryInterface(node));
 523                 assert(event_target);
 524
 525                 state->norm_pixbuf = Gdk::Pixbuf::create(
 526                     Glib::RefPtr<Gdk::Drawable>(window),
 527                     window->get_colormap(),
 528                     state->link_rect.left,
 529                     state->link_rect.top,
 530                     0,
 531                     0,
 532                     state->link_rect.right - state->link_rect.left,
 533                     state->link_rect.bottom - state->link_rect.top);
 534
 535                 nsCOMPtr<nsIDOMEvent> event;
 536                 check(event_factory->CreateEvent(
 537                           NS_ConvertASCIItoUTF16("MouseEvents"),
 538                           getter_AddRefs(event)));
 539                 nsCOMPtr<nsIDOMMouseEvent> mouse_event(
 540                     do_QueryInterface(event));
 541                 assert(mouse_event);
 542                 check(mouse_event->InitMouseEvent(
 543                           NS_ConvertASCIItoUTF16("mouseover"),
 544                           true,  // can bubble
 545                           true,  // cancelable
 546                           view,
 547                           0,     // detail: mouse click count
 548                           state->link_rect.left, // screenX
 549                           state->link_rect.top,  // screenY
 550                           state->link_rect.left, // clientX
 551                           state->link_rect.top,  // clientY
 552                           false, false, false, false, // qualifiers
 553                           0,     // button: left (or primary)
 554                           0));   // related target
 555                 PRBool dummy;
 556                 check(event_target->DispatchEvent(mouse_event,
 557                                                   &dummy));
 558                 check(event_state_man->SetContentState(content,
 559                                                        NS_EVENT_STATE_HOVER));
 560
 561                 pres_shell->FlushPendingNotifications(true);
 562
 563                 // We may have to exit and wait for image loading
 564                 // to complete, at which point we will be called
 565                 // again.
 566                 if (pending_req_count_ > 0)
 567                 {
 568                     state->link_changing = true;
 569                     page_state_ = state;
 570                     return;
 571                 }
 572             }
 573
 574             window->process_updates(true);
 575
 576             Glib::RefPtr<Gdk::Pixbuf> changed_pixbuf(
 577                 Gdk::Pixbuf::create(
 578                     Glib::RefPtr<Gdk::Drawable>(window),
 579                     window->get_colormap(),
 580                     state->link_rect.left,
 581                     state->link_rect.top,
 582                     0,
 583                     0,
 584                     state->link_rect.right - state->link_rect.left,
 585                     state->link_rect.bottom - state->link_rect.top));
 586             diff_rgb_pixbufs(
 587                 state->norm_pixbuf,
 588                 changed_pixbuf,
 589                 state->diff_pixbuf,
 590                 state->link_rect.left,
 591                 state->link_rect.top,
 592                 state->link_rect.right - state->link_rect.left,
 593                 state->link_rect.bottom - state->link_rect.top);
 594
 595             state->spumux_file <<
 596                 "      <button x0='" << state->link_rect.left << "'"
 597                 " y0='" << state->link_rect.top << "'"
 598                 " x1='" << state->link_rect.right - 1 << "'"
 599                 " y1='" << state->link_rect.bottom - 1 << "'/>\n";
 600
 601             // Add to the page's links, ignoring any fragment (for now).
 602             page_links_.back().push_back(uri_sans_fragment);
 603         }
 604
 605         quantise_rgba_pixbuf(state->diff_pixbuf, dvd::button_n_colours);
 606
 607         std::cout << "saving " << state->links_temp.get_name()
 608                   << std::endl;
 609         state->diff_pixbuf->save(state->links_temp.get_name(), "png");
 610
 611         state->spumux_file <<
 612             "    </spu>\n"
 613             "  </stream>\n"
 614             "</subpictures>\n";
 615
 616         state->spumux_file.close();
 617
 618         // TODO: if (!state->spumux_file) throw ...
 619
 620         {
 621             boost::shared_ptr<temp_file> vob_temp(
 622                 new temp_file("webdvd-vob-"));
 623             std::ostringstream command_stream;
 624             command_stream << "pngtopnm "
 625                            << background_temp_->get_name()
 626                            << " | ppmtoy4m -v0 -n1 -F"
 627                            << frame_params_.rate_numer
 628                            << ":" << frame_params_.rate_denom
 629                            << " -A" << frame_params_.pixel_ratio_width
 630                            << ":" << frame_params_.pixel_ratio_height
 631                            << (" -Ip -S420_mpeg2"
 632                                " | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
 633                                " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
 634                                " | spumux -v0 -mdvd ")
 635                            << state->spumux_temp.get_name()
 636                            << " > " << vob_temp->get_name();
 637             std::string command(command_stream.str());
 638             const char * argv[] = {
 639                 "/bin/sh", "-c", command.c_str(), 0
 640             };
 641             std::cout << "running " << argv[2] << std::endl;
 642             int command_result;
 643             Glib::spawn_sync(".",
 644                              Glib::ArrayHandle<std::string>(
 645                                  argv, sizeof(argv)/sizeof(argv[0]),
 646                                  Glib::OWNERSHIP_NONE),
 647                              Glib::SPAWN_STDOUT_TO_DEV_NULL,
 648                              SigC::Slot0<void>(),
 649                              0, 0,
 650                              &command_result);
 651             if (command_result != 0)
 652                 throw std::runtime_error("spumux pipeline failed");
 653
 654             page_temp_files_.push_back(vob_temp);
 655         }
 656     }
 657
 658     void generate_page_dispatch(std::ostream &, int indent,
 659                                 int first_page, int last_page);
 660
 661     void WebDvdWindow::generate_dvd()
 662     {
 663         temp_file temp("webdvd-dvdauthor-");
 664         temp.close();
 665         std::ofstream file(temp.get_name().c_str());
 666
 667         // We generate code that uses registers in the following way:
 668         //
 669         // g0:     link destination (when jumping to menu 1), then scratch
 670         // g1:     current location
 671         // g2-g11: location history (g2 = most recent)
 672         // g12:    location that last linked to a video
 673         //
 674         // All locations are divided into two bitfields: the least
 675         // significant 10 bits are a page/menu number and the most
 676         // significant 6 bits are a link/button number.  This is
 677         // chosen for compatibility with the encoding of the s8
 678         // (button) register.
 679         //
 680         static const int link_mult = dvd::reg_s8_button_mult;
 681         static const int page_mask = link_mult - 1;
 682         static const int link_mask = (1 << dvd::reg_bits) - link_mult;
 683
 684         file <<
 685             "<dvdauthor>\n"
 686             "  <vmgm>\n"
 687             "    <menus>\n";
 688
 689         for (std::size_t page_num = 1;
 690              page_num <= page_links_.size();
 691              ++page_num)
 692         {
 693             std::vector<std::string> & page_links =
 694                 page_links_[page_num - 1];
 695
 696             if (page_num == 1)
 697             {
 698                 // This is the first page (root menu) which needs to
 699                 // include initialisation and dispatch code.
 700
 701                 file <<
 702                     "      <pgc entry='title'>\n"
 703                     "        <pre>\n"
 704                     // Has the location been set yet?
 705                     "          if (g1 eq 0)\n"
 706                     "          {\n"
 707                     // Initialise the current location to first link on
 708                     // this page.
 709                     "            g1 = " << 1 * link_mult + 1 << ";\n"
 710                     "          }\n"
 711                     "          else\n"
 712                     "          {\n"
 713                     // Has the user selected a link?
 714                     "            if (g0 ne 0)\n"
 715                     "            {\n"
 716                     // First update the history.
 717                     // Does link go to the last page in the history?
 718                     "              if (((g0 ^ g2) &amp; " << page_mask
 719                      << ") == 0)\n"
 720                     // It does; we treat this as going back and pop the old
 721                     // location off the history stack into the current
 722                     // location.  Clear the free stack slot.
 723                     "              {\n"
 724                     "                g1 = g2; g2 = g3; g3 = g4; g4 = g5;\n"
 725                     "                g5 = g6; g6 = g7; g7 = g8; g8 = g9;\n"
 726                     "                g9 = g10; g10 = g11; g11 = 0;\n"
 727                     "              }\n"
 728                     "              else\n"
 729                     // Link goes to some other page, so push current
 730                     // location onto the history stack and set the current
 731                     // location to be exactly the target location.
 732                     "              {\n"
 733                     "                g11 = g10; g10 = g9; g9 = g8; g8 = g7;\n"
 734                     "                g7 = g6; g6 = g5; g5 = g4; g4 = g3;\n"
 735                     "                g3 = g2; g2 = g1; g1 = g0;\n"
 736                     "              }\n"
 737                     "            }\n"
 738                     // Find the target page number.
 739                     "            g0 = g1 &amp; " << page_mask << ";\n";
 740                 // There seems to be no way to perform a computed jump,
 741                 // so we generate all possible jumps and a binary search
 742                 // to select the correct one.
 743                 generate_page_dispatch(file, 12, 1, page_links_.size());
 744                 file <<
 745                     "          }\n";
 746             }
 747             else // page_num != 1
 748             {
 749                 file <<
 750                     "      <pgc>\n"
 751                     "        <pre>\n";
 752             }
 753
 754             file <<
 755                 // Clear link indicator and highlight the
 756                 // appropriate link/button.
 757                 "          g0 = 0; s8 = g1 &amp; " << link_mask << ";\n"
 758                 "        </pre>\n"
 759                 "        <vob file='"
 760                  << page_temp_files_[page_num - 1]->get_name() << "'/>\n";
 761
 762             for (std::size_t link_num = 1;
 763                  link_num <= page_links.size();
 764                  ++link_num)
 765             {
 766                 file <<
 767                     "        <button>"
 768                     // Update current location.
 769                     " g1 = " << link_num * link_mult + page_num << ";";
 770
 771                 // Jump to appropriate resource.
 772                 const ResourceEntry & resource_loc =
 773                     resource_map_[page_links[link_num - 1]];
 774                 if (resource_loc.first == page_resource)
 775                     file <<
 776                         " g0 = " << 1 * link_mult + resource_loc.second << ";"
 777                         " jump menu 1;";
 778                 else if (resource_loc.first == video_resource)
 779                     file << " jump title " << resource_loc.second << ";";
 780
 781                 file <<  " </button>\n";
 782             }
 783
 784             file << "      </pgc>\n";
 785         }
 786
 787         file <<
 788             "    </menus>\n"
 789             "  </vmgm>\n";
 790
 791         // Generate a titleset for each video.  This appears to make
 792         // jumping to titles a whole lot simpler.
 793         for (std::size_t video_num = 1;
 794              video_num <= video_paths_.size();
 795              ++video_num)
 796         {
 797             file <<
 798                 "  <titleset>\n"
 799                 // Generate a dummy menu so that the menu button on the
 800                 // remote control will work.
 801                 "    <menus>\n"
 802                 "      <pgc entry='root'>\n"
 803                 "        <pre> jump vmgm menu; </pre>\n"
 804                 "      </pgc>\n"
 805                 "    </menus>\n"
 806                 "    <titles>\n"
 807                 "      <pgc>\n"
 808                 // Record calling page/menu.
 809                 "        <pre> g12 = g1; </pre>\n"
 810                 // FIXME: Should XML-escape the path
 811                 "        <vob file='" << video_paths_[video_num - 1]
 812                  << "'/>\n"
 813                 // If page/menu location has not been changed during the
 814                 // video, change the location to be the following
 815                 // link/button when returning to it.  In any case,
 816                 // return to a page/menu.
 817                 "        <post> if (g1 eq g12) g1 = g1 + " << link_mult
 818                  << "; call menu; </post>\n"
 819                 "      </pgc>\n"
 820                 "    </titles>\n"
 821                 "  </titleset>\n";
 822         }
 823
 824         file <<
 825             "</dvdauthor>\n";
 826
 827         file.close();
 828
 829         {
 830             const char * argv[] = {
 831                 "dvdauthor",
 832                 "-o", output_dir_.c_str(),
 833                 "-x", temp.get_name().c_str(),
 834                 0
 835             };
 836             int command_result;
 837             Glib::spawn_sync(".",
 838                              Glib::ArrayHandle<std::string>(
 839                                  argv, sizeof(argv)/sizeof(argv[0]),
 840                                  Glib::OWNERSHIP_NONE),
 841                              Glib::SPAWN_SEARCH_PATH
 842                              | Glib::SPAWN_STDOUT_TO_DEV_NULL,
 843                              SigC::Slot0<void>(),
 844                              0, 0,
 845                              &command_result);
 846             if (command_result != 0)
 847                 throw std::runtime_error("dvdauthor failed");
 848         }
 849     }
 850
 851     void generate_page_dispatch(std::ostream & file, int indent,
 852                                 int first_page, int last_page)
 853     {
 854         if (first_page == 1 && last_page == 1)
 855         {
 856             // The dispatch code is *on* page 1 so we must not dispatch to
 857             // page 1 since that would cause an infinite loop.  This case
 858             // should be unreachable if there is more than one page due
 859             // to the following case.
 860         }
 861         else if (first_page == 1 && last_page == 2)
 862         {
 863             // dvdauthor doesn't allow empty blocks or null statements so
 864             // when selecting between pages 1 and 2 we don't use an "else"
 865             // part.  We must use braces so that a following "else" will
 866             // match the right "if".
 867             file << std::setw(indent) << "" << "{\n"
 868                  << std::setw(indent) << "" << "if (g0 eq 2)\n"
 869                  << std::setw(indent + 2) << "" << "jump menu 2;\n"
 870                  << std::setw(indent) << "" << "}\n";
 871         }
 872         else if (first_page == last_page)
 873         {
 874             file << std::setw(indent) << ""
 875                  << "jump menu " << first_page << ";\n";
 876         }
 877         else
 878         {
 879             int middle = (first_page + last_page) / 2;
 880             file << std::setw(indent) << "" << "if (g0 le " << middle << ")\n";
 881             generate_page_dispatch(file, indent + 2, first_page, middle);
 882             file << std::setw(indent) << "" << "else\n";
 883             generate_page_dispatch(file, indent + 2, middle + 1, last_page);
 884         }
 885     }
 886
 887     const video::frame_params & lookup_frame_params(const char * str)
 888     {
 889         assert(str);
 890         static const struct { const char * str; bool is_ntsc; }
 891         known_strings[] = {
 892             { "NTSC",  true },
 893             { "ntsc",  true },
 894             { "PAL",   false },
 895             { "pal",   false },
 896             // For DVD purposes, SECAM can be treated identically to PAL.
 897             { "SECAM", false },
 898             { "secam", false }
 899         };
 900         for (std::size_t i = 0;
 901              i != sizeof(known_strings)/sizeof(known_strings[0]);
 902              ++i)
 903             if (std::strcmp(str, known_strings[i].str) == 0)
 904                 return known_strings[i].is_ntsc ?
 905                     video::ntsc_params : video::pal_params;
 906         throw std::runtime_error(
 907             std::string("Invalid video standard: ").append(str));
 908     }
 909
 910     void print_usage(std::ostream & stream, const char * command_name)
 911     {
 912         stream << "Usage: " << command_name
 913                << (" [gtk-options] [--video-std std-name]"
 914                    " [--preview] menu-url [output-dir]\n");
 915     }
 916
 917 } // namespace
 918
 919 int main(int argc, char ** argv)
 920 {
 921     try
 922     {
 923         video::frame_params frame_params = video::pal_params;
 924         bool preview_mode = false;
 925         std::string menu_url;
 926         std::string output_dir;
 927
 928         // Do initial option parsing.  We have to do this before
 929         // letting Gtk parse the arguments since we may need to spawn
 930         // Xvfb first.
 931         int argi = 1;
 932         while (argi != argc)
 933         {
 934             if (std::strcmp(argv[argi], "--") == 0)
 935             {
 936                 break;
 937             }
 938             else if (std::strcmp(argv[argi], "--help") == 0)
 939             {
 940                 print_usage(std::cout, argv[0]);
 941                 return EXIT_SUCCESS;
 942             }
 943             else if (std::strcmp(argv[argi], "--preview") == 0)
 944             {
 945                 preview_mode = true;
 946                 argi += 1;
 947             }
 948             else if (std::strcmp(argv[argi], "--video-std") == 0)
 949             {
 950                 if (argi + 1 == argc)
 951                 {
 952                     std::cerr << "Missing argument to --video-std\n";
 953                     print_usage(std::cerr, argv[0]);
 954                     return EXIT_FAILURE;
 955                 }
 956                 frame_params = lookup_frame_params(argv[argi + 1]);
 957                 argi += 2;
 958             }
 959             else
 960             {
 961                 argi += 1;
 962             }
 963         }
 964
 965         std::auto_ptr<FrameBuffer> fb;
 966         if (!preview_mode)
 967         {
 968             // Spawn Xvfb and set env variables so that Xlib will use it
 969             // Use 8 bits each for RGB components, which should translate into
 970             // "enough" bits for YUV components.
 971             fb.reset(new FrameBuffer(frame_params.width, frame_params.height,
 972                                      3 * 8));
 973             setenv("XAUTHORITY", fb->get_x_authority().c_str(), true);
 974             setenv("DISPLAY", fb->get_x_display().c_str(), true);
 975         }
 976
 977         // Initialise Gtk
 978         Gtk::Main kit(argc, argv);
 979
 980         // Complete option parsing with Gtk's options out of the way.
 981         argi = 1;
 982         while (argi != argc)
 983         {
 984             if (std::strcmp(argv[argi], "--") == 0)
 985             {
 986                 argi += 1;
 987                 break;
 988             }
 989             else if (std::strcmp(argv[argi], "--preview") == 0)
 990             {
 991                 argi += 1;
 992             }
 993             else if (std::strcmp(argv[argi], "--video-std") == 0)
 994             {
 995                 argi += 2;
 996             }
 997             else if (argv[argi][0] == '-')
 998             {
 999                 std::cerr << "Invalid option: " << argv[argi] << "\n";
1000                 print_usage(std::cerr, argv[0]);
1001                 return EXIT_FAILURE;
1002             }
1003             else
1004             {
1005                 break;
1006             }
1007         }
1008
1009         // Look for a starting URL or filename and (except in preview
1010         // mode) an output directory after the options.
1011         if (argc - argi != (preview_mode ? 1 : 2))
1012         {
1013             print_usage(std::cerr, argv[0]);
1014             return EXIT_FAILURE;
1015         }
1016         if (std::strstr(argv[argi], "://"))
1017         {
1018             // It appears to be an absolute URL, so use it as-is.
1019             menu_url = argv[argi];
1020         }
1021         else
1022         {
1023             // Assume it's a filename.  Resolve it to an absolute URL.
1024             std::string path(argv[argi]);
1025             if (!Glib::path_is_absolute(path))
1026                 path = Glib::build_filename(Glib::get_current_dir(), path);
1027             menu_url = Glib::filename_to_uri(path);
1028         }
1029         if (!preview_mode)
1030             output_dir = argv[argi + 1];
1031
1032         // Initialise Mozilla
1033         BrowserWidget::init();
1034
1035         // Run the browser/converter
1036         WebDvdWindow window(frame_params, menu_url, output_dir);
1037         Gtk::Main::run(window);
1038     }
1039     catch (std::exception & e)
1040     {
1041         std::cerr << "Fatal error: " << e.what() << "\n";
1042         return EXIT_FAILURE;
1043     }
1044
1045     return EXIT_SUCCESS;
1046 }