- void webdvd_window::generate_dvd()
- {
- temp_file temp("webdvd-dvdauthor-");
- temp.close();
- std::ofstream file(temp.get_name().c_str());
-
- // We generate code that uses registers in the following way:
- //
- // g0: scratch
- // g1: current location
- // g12: location that last jumped to a video
- //
- // All locations are divided into two bitfields: the least
- // significant 10 bits are a page/menu number and the most
- // significant 6 bits are a link/button number, and numbering
- // starts at 1, not 0. This is done for compatibility with
- // the encoding of the s8 (button) register.
- //
- static const int button_mult = dvd::reg_s8_button_mult;
- static const int menu_mask = button_mult - 1;
- static const int button_mask = (1 << dvd::reg_bits) - button_mult;
-
- file <<
- "<dvdauthor>\n"
- " <vmgm>\n"
- " <menus>\n";
-
- for (std::size_t menu_num = 0;
- menu_num != contents_.menus.size();
- ++menu_num)
- {
- dvd_contents::menu & menu = contents_.menus[menu_num];
-
- if (menu_num == 0)
- {
- // This is the first (title) menu, displayed when the
- // disc is first played.
- file <<
- " <pgc entry='title'>\n"
- " <pre>\n"
- // Initialise the current location if it is not set
- // (all general registers are initially 0).
- " if (g1 eq 0)\n"
- " g1 = " << 1 + button_mult << ";\n";
- }
- else
- {
- file <<
- " <pgc>\n"
- " <pre>\n";
- }
-
- // When a title finishes or the user presses the menu
- // button, this always jumps to the titleset's root menu.
- // We want to return the user to the last menu they used.
- // So we arrange for each titleset's root menu to return
- // to the vmgm title menu and then dispatch from there to
- // whatever the correct menu is. We determine the correct
- // menu by looking at the menu part of g1.
-
- file << " g0 = g1 & " << menu_mask << ";\n";
-
- // There is a limit of 128 VM instructions in each PGC.
- // Therefore in each menu's <pre> section we generate
- // jumps to menus with numbers greater by 512, 256, 128,
- // ..., 1 where (a) such a menu exists, (b) this menu
- // number is divisible by twice that increment and (c) the
- // correct menu is that or a later menu. Thus each menu
- // has at most 10 such conditional jumps and is reachable
- // by at most 10 jumps from the title menu. This chain of
- // jumps might take too long on some players; this has yet
- // to be investigated.
-
- for (std::size_t menu_incr = (menu_mask + 1) / 2;
- menu_incr != 0;
- menu_incr /= 2)
- {
- if (menu_num + menu_incr < contents_.menus.size()
- && (menu_num & (menu_incr * 2 - 1)) == 0)
- {
- file <<
- " if (g0 ge " << 1 + menu_num + menu_incr
- << ")\n"
- " jump menu " << 1 + menu_num + menu_incr
- << ";\n";
- }
- }
-
- file <<
- // Highlight the appropriate button.
- " s8 = g1 & " << button_mask << ";\n"
- " </pre>\n"
- " <vob file='" << menu.vob_temp->get_name() << "'/>\n";
-
- for (std::size_t button_num = 0;
- button_num != menu.entries.size();
- ++button_num)
- {
- file << " <button> ";
-
- if (menu.entries[button_num].first == dvd_contents::menu_pgc)
- {
- int dest_menu_num = menu.entries[button_num].second;
-
- // Look for a button on the new menu that links
- // back to this one. If there is one, set that to
- // be the highlighted button; otherwise, use the
- // first button.
- const std::vector<dvd_contents::pgc_ref> &
- dest_menu_entries =
- contents_.menus[dest_menu_num].entries;
- dvd_contents::pgc_ref this_pgc(
- dvd_contents::menu_pgc, menu_num);
- std::size_t dest_button_num = dest_menu_entries.size();
- while (dest_button_num != 0
- && dest_menu_entries[--dest_button_num] != this_pgc)
- ;
-
- file << "g1 = "
- << (1 + dest_menu_num
- + (1 + dest_button_num) * button_mult)
- << "; jump menu " << 1 + dest_menu_num << ";";
- }
- else
- {
- assert(menu.entries[button_num].first
- == dvd_contents::title_pgc);
-
- file << "g1 = "
- << 1 + menu_num + (1 + button_num) * button_mult
- << "; jump title "
- << 1 + menu.entries[button_num].second << ";";
- }
-
- file << " </button>\n";
- }
-
- file << " </pgc>\n";
- }
-
- file <<
- " </menus>\n"
- " </vmgm>\n";
-
- // Generate a titleset for each title. This appears to make
- // jumping to titles a whole lot simpler (but limits us to 99
- // titles).
- for (std::size_t title_num = 0;
- title_num != contents_.titles.size();
- ++title_num)
- {
- file <<
- " <titleset>\n"
- // Generate a dummy menu so that the menu button on the
- // remote control will work.
- " <menus>\n"
- " <pgc entry='root'>\n"
- " <pre> jump vmgm menu; </pre>\n"
- " </pgc>\n"
- " </menus>\n"
- " <titles>\n"
- " <pgc>\n"
- // Record calling location.
- " <pre> g12 = g1; </pre>\n"
- << contents_.titles[title_num].vob_list <<
- // If the menu location has not been changed during
- // the title, set the location to be the following
- // button in the menu. In any case, return to some
- // menu.
- " <post> if (g1 eq g12) g1 = g1 + " << button_mult
- << "; call menu; </post>\n"
- " </pgc>\n"
- " </titles>\n"
- " </titleset>\n";
- }
-
- file <<
- "</dvdauthor>\n";
-
- file.close();
-
- {
- const char * argv[] = {
- "dvdauthor",
- "-o", output_dir_.c_str(),
- "-x", temp.get_name().c_str(),
- 0
- };
- int command_result;
- Glib::spawn_sync(".",
- Glib::ArrayHandle<std::string>(
- argv, sizeof(argv)/sizeof(argv[0]),
- Glib::OWNERSHIP_NONE),
- Glib::SPAWN_SEARCH_PATH
- | Glib::SPAWN_STDOUT_TO_DEV_NULL,
- SigC::Slot0<void>(),
- 0, 0,
- &command_result);
- if (command_result != 0)
- throw std::runtime_error("dvdauthor failed");
- }
- }
-