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             std::string filename(Glib::filename_from_uri(uri, hostname));
 223             // FIXME: Should check the hostname
 224             if (!Glib::file_test(filename, Glib::FILE_TEST_IS_REGULAR))
 225                 throw std::runtime_error(
 226                     filename + " is missing or not a regular file");
 227             video_paths_.push_back(filename);
 228         }
 229     }
 230
 231     void WebDvdWindow::load_next_page()
 232     {
 233         assert(!page_queue_.empty());
 234         const std::string & uri = page_queue_.front();
 235         std::cout << "loading " << uri << std::endl;
 236
 237         std::size_t page_count = page_links_.size();
 238         resource_map_[uri].second = ++page_count;
 239         page_links_.resize(page_count);
 240
 241         browser_widget_.load_uri(uri);
 242     }
 243
 244     void WebDvdWindow::on_net_state_change(const char * uri,
 245                                            gint flags, guint status)
 246     {
 247 #       ifdef DEBUG_ON_NET_STATE_CHANGE
 248         std::cout << "WebDvdWindow::on_net_state_change(";
 249         if (uri)
 250             std::cout << '"' << uri << '"';
 251         else
 252             std::cout << "NULL";
 253         std::cout << ", ";
 254         {
 255             gint flags_left = flags;
 256             static const struct {
 257                 gint value;
 258                 const char * name;
 259             } flag_names[] = {
 260                 { GTK_MOZ_EMBED_FLAG_START, "STATE_START" },
 261                 { GTK_MOZ_EMBED_FLAG_REDIRECTING, "STATE_REDIRECTING" },
 262                 { GTK_MOZ_EMBED_FLAG_TRANSFERRING, "STATE_TRANSFERRING" },
 263                 { GTK_MOZ_EMBED_FLAG_NEGOTIATING, "STATE_NEGOTIATING" },
 264                 { GTK_MOZ_EMBED_FLAG_STOP, "STATE_STOP" },
 265                 { GTK_MOZ_EMBED_FLAG_IS_REQUEST, "STATE_IS_REQUEST" },
 266                 { GTK_MOZ_EMBED_FLAG_IS_DOCUMENT, "STATE_IS_DOCUMENT" },
 267                 { GTK_MOZ_EMBED_FLAG_IS_NETWORK, "STATE_IS_NETWORK" },
 268                 { GTK_MOZ_EMBED_FLAG_IS_WINDOW, "STATE_IS_WINDOW" }
 269             };
 270             for (int i = 0; i != sizeof(flag_names)/sizeof(flag_names[0]); ++i)
 271             {
 272                 if (flags & flag_names[i].value)
 273                 {
 274                     std::cout << flag_names[i].name;
 275                     flags_left -= flag_names[i].value;
 276                     if (flags_left)
 277                         std::cout << " | ";
 278                 }
 279             }
 280             if (flags_left)
 281                 std::cout << "0x" << std::setbase(16) << flags_left;
 282         }
 283         std::cout << ", " << "0x" << std::setbase(16) << status << ")\n";
 284 #       endif // DEBUG_ON_NET_STATE_CHANGE
 285
 286         if (flags & GTK_MOZ_EMBED_FLAG_IS_REQUEST)
 287         {
 288             if (flags & GTK_MOZ_EMBED_FLAG_START)
 289                 ++pending_req_count_;
 290
 291             if (flags & GTK_MOZ_EMBED_FLAG_STOP)
 292             {
 293                 assert(pending_req_count_ != 0);
 294                 --pending_req_count_;
 295             }
 296         }
 297
 298         if (flags & GTK_MOZ_EMBED_FLAG_IS_DOCUMENT
 299             && flags & GTK_MOZ_EMBED_FLAG_START)
 300         {
 301             pending_window_update_ = true;
 302             have_tweaked_page_ = false;
 303         }
 304
 305         if (flags & GTK_MOZ_EMBED_FLAG_IS_WINDOW
 306             && flags & GTK_MOZ_EMBED_FLAG_STOP)
 307         {
 308             // Check whether the load was successful, ignoring this
 309             // pseudo-error.
 310             if (status != NS_IMAGELIB_ERROR_LOAD_ABORTED)
 311                 check(status);
 312
 313             pending_window_update_ = false;
 314         }
 315
 316         if (pending_req_count_ == 0 && !pending_window_update_)
 317         {
 318             try
 319             {
 320                 if (!process_page())
 321                     Gtk::Main::quit();
 322             }
 323             catch (std::exception & e)
 324             {
 325                 std::cerr << "Fatal error";
 326                 if (!page_queue_.empty())
 327                     std::cerr << " while processing <" << page_queue_.front()
 328                               << ">";
 329                 std::cerr << ": " << e.what() << "\n";
 330                 Gtk::Main::quit();
 331             }
 332         }
 333     }
 334
 335     bool WebDvdWindow::process_page()
 336     {
 337         assert(!page_queue_.empty());
 338
 339         nsCOMPtr<nsIWebBrowser> browser(browser_widget_.get_browser());
 340         nsCOMPtr<nsIDocShell> doc_shell(do_GetInterface(browser));
 341         assert(doc_shell);
 342         nsCOMPtr<nsIPresShell> pres_shell;
 343         check(doc_shell->GetPresShell(getter_AddRefs(pres_shell)));
 344         nsCOMPtr<nsIPresContext> pres_context;
 345         check(doc_shell->GetPresContext(getter_AddRefs(pres_context)));
 346         nsCOMPtr<nsIDOMWindow> dom_window;
 347         check(browser->GetContentDOMWindow(getter_AddRefs(dom_window)));
 348
 349         // If we haven't done so already, apply the stylesheet and
 350         // disable scrollbars.
 351         if (!have_tweaked_page_)
 352         {
 353             apply_style_sheet(stylesheet_, pres_shell);
 354
 355             // This actually only needs to be done once.
 356             nsCOMPtr<nsIDOMBarProp> dom_bar_prop;
 357             check(dom_window->GetScrollbars(getter_AddRefs(dom_bar_prop)));
 358             check(dom_bar_prop->SetVisible(false));
 359
 360             have_tweaked_page_ = true;
 361
 362             // Might need to wait a while for things to load or more
 363             // likely for a re-layout.
 364             if (pending_req_count_ > 0)
 365                 return true;
 366         }
 367
 368         // All further work should only be done if we're not in preview mode.
 369         if (!output_dir_.empty())
 370         {
 371             // If we haven't already started work on this page, save a
 372             // screenshot of its normal appearance.
 373             if (!page_state_.get())
 374                 save_screenshot();
 375
 376             // Start or continue processing links.
 377             process_links(pres_shell, pres_context, dom_window);
 378
 379             // If we've finished work on the links, move on to the
 380             // next page, if any, or else generate the DVD filesystem.
 381             if (!page_state_.get())
 382             {
 383                 page_queue_.pop();
 384                 if (page_queue_.empty())
 385                 {
 386                     generate_dvd();
 387                     return false;
 388                 }
 389                 else
 390                 {
 391                     load_next_page();
 392                 }
 393             }
 394         }
 395
 396         return true;
 397     }
 398
 399     void WebDvdWindow::save_screenshot()
 400     {
 401         Glib::RefPtr<Gdk::Window> window(get_window());
 402         assert(window);
 403         window->process_updates(true);
 404
 405         background_temp_.reset(new temp_file("webdvd-back-"));
 406         background_temp_->close();
 407         std::cout << "saving " << background_temp_->get_name() << std::endl;
 408         Gdk::Pixbuf::create(Glib::RefPtr<Gdk::Drawable>(window),
 409                             window->get_colormap(),
 410                             0, 0, 0, 0,
 411                             frame_params_.width, frame_params_.height)
 412             ->save(background_temp_->get_name(), "png");
 413     }
 414
 415     struct WebDvdWindow::page_state
 416     {
 417         page_state(nsIDOMDocument * doc, int width, int height)
 418                 : diff_pixbuf(Gdk::Pixbuf::create(
 419                                   Gdk::COLORSPACE_RGB,
 420                                   true, 8, // has_alpha, bits_per_sample
 421                                   width, height)),
 422                   spumux_temp("webdvd-spumux-"),
 423                   links_temp("webdvd-links-"),
 424                   link_num(0),
 425                   links_it(doc),
 426                   link_changing(false)
 427             {
 428                 spumux_temp.close();
 429                 links_temp.close();
 430             }
 431
 432         Glib::RefPtr<Gdk::Pixbuf> diff_pixbuf;
 433
 434         temp_file spumux_temp;
 435         std::ofstream spumux_file;
 436
 437         temp_file links_temp;
 438
 439         int link_num;
 440         LinkIterator links_it, links_end;
 441
 442         rectangle link_rect;
 443         bool link_changing;
 444         Glib::RefPtr<Gdk::Pixbuf> norm_pixbuf;
 445     };
 446
 447     void WebDvdWindow::process_links(nsIPresShell * pres_shell,
 448                                      nsIPresContext * pres_context,
 449                                      nsIDOMWindow * dom_window)
 450     {
 451         Glib::RefPtr<Gdk::Window> window(get_window());
 452         assert(window);
 453
 454         nsCOMPtr<nsIDOMDocument> basic_doc;
 455         check(dom_window->GetDocument(getter_AddRefs(basic_doc)));
 456         nsCOMPtr<nsIDOMNSDocument> ns_doc(do_QueryInterface(basic_doc));
 457         assert(ns_doc);
 458         nsCOMPtr<nsIEventStateManager> event_state_man(
 459             pres_context->EventStateManager()); // does not AddRef
 460         assert(event_state_man);
 461         nsCOMPtr<nsIDOMDocumentEvent> event_factory(
 462             do_QueryInterface(basic_doc));
 463         assert(event_factory);
 464         nsCOMPtr<nsIDOMDocumentView> doc_view(do_QueryInterface(basic_doc));
 465         assert(doc_view);
 466         nsCOMPtr<nsIDOMAbstractView> view;
 467         check(doc_view->GetDefaultView(getter_AddRefs(view)));
 468
 469         // Set up or recover our iteration state.
 470         std::auto_ptr<page_state> state(page_state_);
 471         if (!state.get())
 472         {
 473             state.reset(
 474                 new page_state(
 475                     basic_doc, frame_params_.width, frame_params_.height));
 476
 477             state->spumux_file.open(state->spumux_temp.get_name().c_str());
 478             state->spumux_file <<
 479                 "<subpictures>\n"
 480                 "  <stream>\n"
 481                 "    <spu force='yes' start='00:00:00.00'\n"
 482                 "        highlight='" << state->links_temp.get_name() << "'\n"
 483                 "        select='" << state->links_temp.get_name() << "'>\n";
 484         }
 485
 486         rectangle window_rect = {
 487             0, 0, frame_params_.width, frame_params_.height
 488         };
 489
 490         for (/* no initialisation */;
 491              state->links_it != state->links_end;
 492              ++state->links_it)
 493         {
 494             nsCOMPtr<nsIDOMNode> node(*state->links_it);
 495
 496             // Find the link URI.
 497             nsCOMPtr<nsILink> link(do_QueryInterface(node));
 498             assert(link);
 499             nsCOMPtr<nsIURI> uri;
 500             check(link->GetHrefURI(getter_AddRefs(uri)));
 501             std::string uri_string;
 502             {
 503                 nsCString uri_ns_string;
 504                 check(uri->GetSpec(uri_ns_string));
 505                 uri_string.assign(uri_ns_string.BeginReading(),
 506                                   uri_ns_string.EndReading());
 507             }
 508             std::string uri_sans_fragment(uri_string, 0, uri_string.find('#'));
 509
 510             // Is this a new link?
 511             if (!state->link_changing)
 512             {
 513                 // Find a rectangle enclosing the link and clip it to the
 514                 // window.
 515                 nsCOMPtr<nsIDOMElement> elem(do_QueryInterface(node));
 516                 assert(elem);
 517                 state->link_rect = get_elem_rect(ns_doc, elem);
 518                 state->link_rect &= window_rect;
 519
 520                 if (state->link_rect.empty())
 521                 {
 522                     std::cerr << "Ignoring invisible link to "
 523                               << uri_string << "\n";
 524                     continue;
 525                 }
 526
 527                 ++state->link_num;
 528
 529                 if (state->link_num >= dvd::menu_buttons_max)
 530                 {
 531                     if (state->link_num == dvd::menu_buttons_max)
 532                         std::cerr << "No more than " << dvd::menu_buttons_max
 533                                   << " buttons can be placed on a page\n";
 534                     std::cerr << "Ignoring link to " << uri_string << "\n";
 535                     continue;
 536                 }
 537
 538                 // Check whether this is a link to a video or a page then
 539                 // add it to the known resources if not already seen.
 540                 nsCString path;
 541                 check(uri->GetPath(path));
 542                 // FIXME: This is a bit of a hack.  Perhaps we could decide
 543                 // later based on the MIME type determined by Mozilla?
 544                 if ((path.Length() > 4
 545                      && std::strcmp(path.EndReading() - 4, ".vob") == 0)
 546                     || (path.Length() > 8
 547                         && std::strcmp(path.EndReading() - 8, ".voblist")
 548                            == 0))
 549                 {
 550                     PRBool is_file;
 551                     check(uri->SchemeIs("file", &is_file));
 552                     if (!is_file)
 553                     {
 554                         std::cerr << "Links to video must use the file:"
 555                                   << " scheme\n";
 556                         continue;
 557                     }
 558                     add_video(uri_sans_fragment);
 559                 }
 560                 else
 561                 {
 562                     add_page(uri_sans_fragment);
 563                 }
 564
 565                 nsCOMPtr<nsIContent> content(do_QueryInterface(node));
 566                 assert(content);
 567                 nsCOMPtr<nsIDOMEventTarget> event_target(
 568                     do_QueryInterface(node));
 569                 assert(event_target);
 570
 571                 state->norm_pixbuf = Gdk::Pixbuf::create(
 572                     Glib::RefPtr<Gdk::Drawable>(window),
 573                     window->get_colormap(),
 574                     state->link_rect.left,
 575                     state->link_rect.top,
 576                     0,
 577                     0,
 578                     state->link_rect.right - state->link_rect.left,
 579                     state->link_rect.bottom - state->link_rect.top);
 580
 581                 nsCOMPtr<nsIDOMEvent> event;
 582                 check(event_factory->CreateEvent(
 583                           NS_ConvertASCIItoUTF16("MouseEvents"),
 584                           getter_AddRefs(event)));
 585                 nsCOMPtr<nsIDOMMouseEvent> mouse_event(
 586                     do_QueryInterface(event));
 587                 assert(mouse_event);
 588                 check(mouse_event->InitMouseEvent(
 589                           NS_ConvertASCIItoUTF16("mouseover"),
 590                           true,  // can bubble
 591                           true,  // cancelable
 592                           view,
 593                           0,     // detail: mouse click count
 594                           state->link_rect.left, // screenX
 595                           state->link_rect.top,  // screenY
 596                           state->link_rect.left, // clientX
 597                           state->link_rect.top,  // clientY
 598                           false, false, false, false, // qualifiers
 599                           0,     // button: left (or primary)
 600                           0));   // related target
 601                 PRBool dummy;
 602                 check(event_target->DispatchEvent(mouse_event,
 603                                                   &dummy));
 604                 check(event_state_man->SetContentState(content,
 605                                                        NS_EVENT_STATE_HOVER));
 606
 607                 pres_shell->FlushPendingNotifications(true);
 608
 609                 // We may have to exit and wait for image loading
 610                 // to complete, at which point we will be called
 611                 // again.
 612                 if (pending_req_count_ > 0)
 613                 {
 614                     state->link_changing = true;
 615                     page_state_ = state;
 616                     return;
 617                 }
 618             }
 619
 620             window->process_updates(true);
 621
 622             Glib::RefPtr<Gdk::Pixbuf> changed_pixbuf(
 623                 Gdk::Pixbuf::create(
 624                     Glib::RefPtr<Gdk::Drawable>(window),
 625                     window->get_colormap(),
 626                     state->link_rect.left,
 627                     state->link_rect.top,
 628                     0,
 629                     0,
 630                     state->link_rect.right - state->link_rect.left,
 631                     state->link_rect.bottom - state->link_rect.top));
 632             diff_rgb_pixbufs(
 633                 state->norm_pixbuf,
 634                 changed_pixbuf,
 635                 state->diff_pixbuf,
 636                 state->link_rect.left,
 637                 state->link_rect.top,
 638                 state->link_rect.right - state->link_rect.left,
 639                 state->link_rect.bottom - state->link_rect.top);
 640
 641             state->spumux_file <<
 642                 "      <button x0='" << state->link_rect.left << "'"
 643                 " y0='" << state->link_rect.top << "'"
 644                 " x1='" << state->link_rect.right - 1 << "'"
 645                 " y1='" << state->link_rect.bottom - 1 << "'/>\n";
 646
 647             // Add to the page's links, ignoring any fragment (for now).
 648             page_links_.back().push_back(uri_sans_fragment);
 649         }
 650
 651         quantise_rgba_pixbuf(state->diff_pixbuf, dvd::button_n_colours);
 652
 653         std::cout << "saving " << state->links_temp.get_name()
 654                   << std::endl;
 655         state->diff_pixbuf->save(state->links_temp.get_name(), "png");
 656
 657         state->spumux_file <<
 658             "    </spu>\n"
 659             "  </stream>\n"
 660             "</subpictures>\n";
 661
 662         state->spumux_file.close();
 663
 664         // TODO: if (!state->spumux_file) throw ...
 665
 666         {
 667             boost::shared_ptr<temp_file> vob_temp(
 668                 new temp_file("webdvd-vob-"));
 669             std::ostringstream command_stream;
 670             command_stream << "pngtopnm "
 671                            << background_temp_->get_name()
 672                            << " | ppmtoy4m -v0 -n1 -F"
 673                            << frame_params_.rate_numer
 674                            << ":" << frame_params_.rate_denom
 675                            << " -A" << frame_params_.pixel_ratio_width
 676                            << ":" << frame_params_.pixel_ratio_height
 677                            << (" -Ip -S420_mpeg2"
 678                                " | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
 679                                " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
 680                                " | spumux -v0 -mdvd ")
 681                            << state->spumux_temp.get_name()
 682                            << " > " << vob_temp->get_name();
 683             std::string command(command_stream.str());
 684             const char * argv[] = {
 685                 "/bin/sh", "-c", command.c_str(), 0
 686             };
 687             std::cout << "running " << argv[2] << std::endl;
 688             int command_result;
 689             Glib::spawn_sync(".",
 690                              Glib::ArrayHandle<std::string>(
 691                                  argv, sizeof(argv)/sizeof(argv[0]),
 692                                  Glib::OWNERSHIP_NONE),
 693                              Glib::SPAWN_STDOUT_TO_DEV_NULL,
 694                              SigC::Slot0<void>(),
 695                              0, 0,
 696                              &command_result);
 697             if (command_result != 0)
 698                 throw std::runtime_error("spumux pipeline failed");
 699
 700             page_temp_files_.push_back(vob_temp);
 701         }
 702     }
 703
 704     void generate_page_dispatch(std::ostream &, int indent,
 705                                 int first_page, int last_page);
 706
 707     void WebDvdWindow::generate_dvd()
 708     {
 709         temp_file temp("webdvd-dvdauthor-");
 710         temp.close();
 711         std::ofstream file(temp.get_name().c_str());
 712
 713         // We generate code that uses registers in the following way:
 714         //
 715         // g0:     link destination (when jumping to menu 1), then scratch
 716         // g1:     current location
 717         // g2-g11: location history (g2 = most recent)
 718         // g12:    location that last linked to a video
 719         //
 720         // All locations are divided into two bitfields: the least
 721         // significant 10 bits are a page/menu number and the most
 722         // significant 6 bits are a link/button number.  This is
 723         // chosen for compatibility with the encoding of the s8
 724         // (button) register.
 725         //
 726         static const int link_mult = dvd::reg_s8_button_mult;
 727         static const int page_mask = link_mult - 1;
 728         static const int link_mask = (1 << dvd::reg_bits) - link_mult;
 729
 730         file <<
 731             "<dvdauthor>\n"
 732             "  <vmgm>\n"
 733             "    <menus>\n";
 734
 735         for (std::size_t page_num = 1;
 736              page_num <= page_links_.size();
 737              ++page_num)
 738         {
 739             std::vector<std::string> & page_links =
 740                 page_links_[page_num - 1];
 741
 742             if (page_num == 1)
 743             {
 744                 // This is the first page (root menu) which needs to
 745                 // include initialisation and dispatch code.
 746
 747                 file <<
 748                     "      <pgc entry='title'>\n"
 749                     "        <pre>\n"
 750                     // Has the location been set yet?
 751                     "          if (g1 eq 0)\n"
 752                     "          {\n"
 753                     // Initialise the current location to first link on
 754                     // this page.
 755                     "            g1 = " << 1 * link_mult + 1 << ";\n"
 756                     "          }\n"
 757                     "          else\n"
 758                     "          {\n"
 759                     // Has the user selected a link?
 760                     "            if (g0 ne 0)\n"
 761                     "            {\n"
 762                     // First update the history.
 763                     // Does link go to the last page in the history?
 764                     "              if (((g0 ^ g2) &amp; " << page_mask
 765                      << ") == 0)\n"
 766                     // It does; we treat this as going back and pop the old
 767                     // location off the history stack into the current
 768                     // location.  Clear the free stack slot.
 769                     "              {\n"
 770                     "                g1 = g2; g2 = g3; g3 = g4; g4 = g5;\n"
 771                     "                g5 = g6; g6 = g7; g7 = g8; g8 = g9;\n"
 772                     "                g9 = g10; g10 = g11; g11 = 0;\n"
 773                     "              }\n"
 774                     "              else\n"
 775                     // Link goes to some other page, so push current
 776                     // location onto the history stack and set the current
 777                     // location to be exactly the target location.
 778                     "              {\n"
 779                     "                g11 = g10; g10 = g9; g9 = g8; g8 = g7;\n"
 780                     "                g7 = g6; g6 = g5; g5 = g4; g4 = g3;\n"
 781                     "                g3 = g2; g2 = g1; g1 = g0;\n"
 782                     "              }\n"
 783                     "            }\n"
 784                     // Find the target page number.
 785                     "            g0 = g1 &amp; " << page_mask << ";\n";
 786                 // There seems to be no way to perform a computed jump,
 787                 // so we generate all possible jumps and a binary search
 788                 // to select the correct one.
 789                 generate_page_dispatch(file, 12, 1, page_links_.size());
 790                 file <<
 791                     "          }\n";
 792             }
 793             else // page_num != 1
 794             {
 795                 file <<
 796                     "      <pgc>\n"
 797                     "        <pre>\n";
 798             }
 799
 800             file <<
 801                 // Clear link indicator and highlight the
 802                 // appropriate link/button.
 803                 "          g0 = 0; s8 = g1 &amp; " << link_mask << ";\n"
 804                 "        </pre>\n"
 805                 "        <vob file='"
 806                  << page_temp_files_[page_num - 1]->get_name() << "'/>\n";
 807
 808             for (std::size_t link_num = 1;
 809                  link_num <= page_links.size();
 810                  ++link_num)
 811             {
 812                 file <<
 813                     "        <button>"
 814                     // Update current location.
 815                     " g1 = " << link_num * link_mult + page_num << ";";
 816
 817                 // Jump to appropriate resource.
 818                 const ResourceEntry & resource_loc =
 819                     resource_map_[page_links[link_num - 1]];
 820                 if (resource_loc.first == page_resource)
 821                     file <<
 822                         " g0 = " << 1 * link_mult + resource_loc.second << ";"
 823                         " jump menu 1;";
 824                 else if (resource_loc.first == video_resource)
 825                     file << " jump title " << resource_loc.second << ";";
 826
 827                 file <<  " </button>\n";
 828             }
 829
 830             file << "      </pgc>\n";
 831         }
 832
 833         file <<
 834             "    </menus>\n"
 835             "  </vmgm>\n";
 836
 837         // Generate a titleset for each video.  This appears to make
 838         // jumping to titles a whole lot simpler.
 839         for (std::size_t video_num = 1;
 840              video_num <= video_paths_.size();
 841              ++video_num)
 842         {
 843             file <<
 844                 "  <titleset>\n"
 845                 // Generate a dummy menu so that the menu button on the
 846                 // remote control will work.
 847                 "    <menus>\n"
 848                 "      <pgc entry='root'>\n"
 849                 "        <pre> jump vmgm menu; </pre>\n"
 850                 "      </pgc>\n"
 851                 "    </menus>\n"
 852                 "    <titles>\n"
 853                 "      <pgc>\n"
 854                 // Record calling page/menu.
 855                 "        <pre> g12 = g1; </pre>\n";
 856
 857             // Write a reference to a linked VOB file, or the contents
 858             // of a linked VOB list file.
 859             const std::string & video_path = video_paths_[video_num - 1];
 860             if (video_path.compare(video_path.size() - 4, 4, ".vob") == 0)
 861             {
 862                 // FIXME: Should XML-escape the path
 863                 file << "        <vob file='" << video_path << "'/>\n";
 864             }
 865             else
 866             {
 867                 assert(video_path.compare(video_path.size() - 8, 8,
 868                                           ".voblist") == 0);
 869                 // TODO: Validate the file contents;
 870                 file << Glib::file_get_contents(video_path);
 871             }
 872
 873             file <<
 874                 // If page/menu location has not been changed during the
 875                 // video, change the location to be the following
 876                 // link/button when returning to it.  In any case,
 877                 // return to a page/menu.
 878                 "        <post> if (g1 eq g12) g1 = g1 + " << link_mult
 879                  << "; call menu; </post>\n"
 880                 "      </pgc>\n"
 881                 "    </titles>\n"
 882                 "  </titleset>\n";
 883         }
 884
 885         file <<
 886             "</dvdauthor>\n";
 887
 888         file.close();
 889
 890         {
 891             const char * argv[] = {
 892                 "dvdauthor",
 893                 "-o", output_dir_.c_str(),
 894                 "-x", temp.get_name().c_str(),
 895                 0
 896             };
 897             int command_result;
 898             Glib::spawn_sync(".",
 899                              Glib::ArrayHandle<std::string>(
 900                                  argv, sizeof(argv)/sizeof(argv[0]),
 901                                  Glib::OWNERSHIP_NONE),
 902                              Glib::SPAWN_SEARCH_PATH
 903                              | Glib::SPAWN_STDOUT_TO_DEV_NULL,
 904                              SigC::Slot0<void>(),
 905                              0, 0,
 906                              &command_result);
 907             if (command_result != 0)
 908                 throw std::runtime_error("dvdauthor failed");
 909         }
 910     }
 911
 912     void generate_page_dispatch(std::ostream & file, int indent,
 913                                 int first_page, int last_page)
 914     {
 915         if (first_page == 1 && last_page == 1)
 916         {
 917             // The dispatch code is *on* page 1 so we must not dispatch to
 918             // page 1 since that would cause an infinite loop.  This case
 919             // should be unreachable if there is more than one page due
 920             // to the following case.
 921         }
 922         else if (first_page == 1 && last_page == 2)
 923         {
 924             // dvdauthor doesn't allow empty blocks or null statements so
 925             // when selecting between pages 1 and 2 we don't use an "else"
 926             // part.  We must use braces so that a following "else" will
 927             // match the right "if".
 928             file << std::setw(indent) << "" << "{\n"
 929                  << std::setw(indent) << "" << "if (g0 eq 2)\n"
 930                  << std::setw(indent + 2) << "" << "jump menu 2;\n"
 931                  << std::setw(indent) << "" << "}\n";
 932         }
 933         else if (first_page == last_page)
 934         {
 935             file << std::setw(indent) << ""
 936                  << "jump menu " << first_page << ";\n";
 937         }
 938         else
 939         {
 940             int middle = (first_page + last_page) / 2;
 941             file << std::setw(indent) << "" << "if (g0 le " << middle << ")\n";
 942             generate_page_dispatch(file, indent + 2, first_page, middle);
 943             file << std::setw(indent) << "" << "else\n";
 944             generate_page_dispatch(file, indent + 2, middle + 1, last_page);
 945         }
 946     }
 947
 948     const video::frame_params & lookup_frame_params(const char * str)
 949     {
 950         assert(str);
 951         static const struct { const char * str; bool is_ntsc; }
 952         known_strings[] = {
 953             { "NTSC",  true },
 954             { "ntsc",  true },
 955             { "PAL",   false },
 956             { "pal",   false },
 957             // For DVD purposes, SECAM can be treated identically to PAL.
 958             { "SECAM", false },
 959             { "secam", false }
 960         };
 961         for (std::size_t i = 0;
 962              i != sizeof(known_strings)/sizeof(known_strings[0]);
 963              ++i)
 964             if (std::strcmp(str, known_strings[i].str) == 0)
 965                 return known_strings[i].is_ntsc ?
 966                     video::ntsc_params : video::pal_params;
 967         throw std::runtime_error(
 968             std::string("Invalid video standard: ").append(str));
 969     }
 970
 971     void print_usage(std::ostream & stream, const char * command_name)
 972     {
 973         stream << "Usage: " << command_name
 974                << (" [gtk-options] [--video-std std-name]"
 975                    " [--preview] menu-url [output-dir]\n");
 976     }
 977
 978 } // namespace
 979
 980 int main(int argc, char ** argv)
 981 {
 982     try
 983     {
 984         video::frame_params frame_params = video::pal_params;
 985         bool preview_mode = false;
 986         std::string menu_url;
 987         std::string output_dir;
 988
 989         // Do initial option parsing.  We have to do this before
 990         // letting Gtk parse the arguments since we may need to spawn
 991         // Xvfb first.
 992         int argi = 1;
 993         while (argi != argc)
 994         {
 995             if (std::strcmp(argv[argi], "--") == 0)
 996             {
 997                 break;
 998             }
 999             else if (std::strcmp(argv[argi], "--help") == 0)
1000             {
1001                 print_usage(std::cout, argv[0]);
1002                 return EXIT_SUCCESS;
1003             }
1004             else if (std::strcmp(argv[argi], "--preview") == 0)
1005             {
1006                 preview_mode = true;
1007                 argi += 1;
1008             }
1009             else if (std::strcmp(argv[argi], "--video-std") == 0)
1010             {
1011                 if (argi + 1 == argc)
1012                 {
1013                     std::cerr << "Missing argument to --video-std\n";
1014                     print_usage(std::cerr, argv[0]);
1015                     return EXIT_FAILURE;
1016                 }
1017                 frame_params = lookup_frame_params(argv[argi + 1]);
1018                 argi += 2;
1019             }
1020             else
1021             {
1022                 argi += 1;
1023             }
1024         }
1025
1026         std::auto_ptr<FrameBuffer> fb;
1027         if (!preview_mode)
1028         {
1029             // Spawn Xvfb and set env variables so that Xlib will use it
1030             // Use 8 bits each for RGB components, which should translate into
1031             // "enough" bits for YUV components.
1032             fb.reset(new FrameBuffer(frame_params.width, frame_params.height,
1033                                      3 * 8));
1034             setenv("XAUTHORITY", fb->get_x_authority().c_str(), true);
1035             setenv("DISPLAY", fb->get_x_display().c_str(), true);
1036         }
1037
1038         // Initialise Gtk
1039         Gtk::Main kit(argc, argv);
1040
1041         // Complete option parsing with Gtk's options out of the way.
1042         argi = 1;
1043         while (argi != argc)
1044         {
1045             if (std::strcmp(argv[argi], "--") == 0)
1046             {
1047                 argi += 1;
1048                 break;
1049             }
1050             else if (std::strcmp(argv[argi], "--preview") == 0)
1051             {
1052                 argi += 1;
1053             }
1054             else if (std::strcmp(argv[argi], "--video-std") == 0)
1055             {
1056                 argi += 2;
1057             }
1058             else if (argv[argi][0] == '-')
1059             {
1060                 std::cerr << "Invalid option: " << argv[argi] << "\n";
1061                 print_usage(std::cerr, argv[0]);
1062                 return EXIT_FAILURE;
1063             }
1064             else
1065             {
1066                 break;
1067             }
1068         }
1069
1070         // Look for a starting URL or filename and (except in preview
1071         // mode) an output directory after the options.
1072         if (argc - argi != (preview_mode ? 1 : 2))
1073         {
1074             print_usage(std::cerr, argv[0]);
1075             return EXIT_FAILURE;
1076         }
1077         if (std::strstr(argv[argi], "://"))
1078         {
1079             // It appears to be an absolute URL, so use it as-is.
1080             menu_url = argv[argi];
1081         }
1082         else
1083         {
1084             // Assume it's a filename.  Resolve it to an absolute URL.
1085             std::string path(argv[argi]);
1086             if (!Glib::path_is_absolute(path))
1087                 path = Glib::build_filename(Glib::get_current_dir(), path);
1088             menu_url = Glib::filename_to_uri(path);
1089         }
1090         if (!preview_mode)
1091             output_dir = argv[argi + 1];
1092
1093         // Initialise Mozilla
1094         BrowserWidget::init();
1095
1096         // Run the browser/converter
1097         WebDvdWindow window(frame_params, menu_url, output_dir);
1098         Gtk::Main::run(window);
1099     }
1100     catch (std::exception & e)
1101     {
1102         std::cerr << "Fatal error: " << e.what() << "\n";
1103         return EXIT_FAILURE;
1104     }
1105
1106     return EXIT_SUCCESS;
1107 }