X-Git-Url: https://git.decadent.org.uk/gitweb/?p=videolink.git;a=blobdiff_plain;f=generate_dvd.cpp;h=2fa3388d6bb1e5c6b6e1e8d3c1835ba4d095b0cc;hp=64079d28ad6c406e6579cc452bb7f1ae1e364ded;hb=fcc6457245904ddccbeef52a3fc38c18efedf8ac;hpb=07a027ef87333662b3709215025838646ee3d6be diff --git a/generate_dvd.cpp b/generate_dvd.cpp index 64079d2..2fa3388 100644 --- a/generate_dvd.cpp +++ b/generate_dvd.cpp @@ -88,9 +88,34 @@ namespace double menu_duration_seconds(const video::frame_params & params) { return double(menu_duration_frames(params)) - * double(params.rate_numer) - / double(params.rate_denom); + / double(params.rate_numer) + * double(params.rate_denom); } + + void throw_length_error(const char * limit_type, std::size_t limit) + { + std::ostringstream oss; + oss << "exceeded DVD limit: " << limit_type << " > " << limit; + throw std::length_error(oss.str()); + } + + // dvdauthor uses some menu numbers to represent entry points - + // distinct from the actual numbers of the menus assigned as those + // entry points - resulting in a practical limit of 119 per + // domain. This seems to be an oddity of the parser that could be + // fixed, but for now we'll have to work with it. + const unsigned dvdauthor_anonymous_menus_max = dvd::domain_pgcs_max - 8; + + // The current navigation code packs menu and button number into a + // single register, so the number of menus is limited to + // dvd::reg_s8_button_mult - 1 == 1023. However temp_file_name() + // is limited to 999 numbered files and it seems pointless to + // change it to get another 24. + // If people really need more we could use separate menu and + // button number registers, possibly allowing up to 11900 menus + // (the size of the indirect jump tables might become a problem + // though). + const unsigned menus_max = 999; } dvd_generator::dvd_generator(const video::frame_params & frame_params, @@ -104,13 +129,8 @@ dvd_generator::pgc_ref dvd_generator::add_menu() { pgc_ref next_menu(menu_pgc, menus_.size()); - // Check against maximum number of menus. It appears that no more - // than 128 menus are reachable through LinkPGCN instructions, and - // dvdauthor uses some menu numbers for special purposes, resulting - // in a practical limit of 119 per domain. We can work around this - // later by spreading some menus across titlesets. - if (next_menu.index == 119) - throw std::runtime_error("No more than 119 menus can be used"); + if (next_menu.index == menus_max) + throw_length_error("number of menus", menus_max); menus_.resize(next_menu.index + 1); return next_menu; @@ -123,6 +143,10 @@ void dvd_generator::add_menu_entry(unsigned index, assert(index < menus_.size()); assert(target.type == menu_pgc && target.index < menus_.size() || target.type == title_pgc && target.index < titles_.size()); + + if (menus_[index].entries.size() == dvd::menu_buttons_max) + throw_length_error("number of buttons", dvd::menu_buttons_max); + menu_entry new_entry = { area, target }; menus_[index].entries.push_back(new_entry); } @@ -276,8 +300,8 @@ dvd_generator::pgc_ref dvd_generator::add_title(vob_list & content) pgc_ref next_title(title_pgc, titles_.size()); // Check against maximum number of titles. - if (next_title.index == 99) - throw std::runtime_error("No more than 99 titles can be used"); + if (next_title.index == dvd::titles_max) + throw_length_error("number of titles", dvd::titles_max); titles_.resize(next_title.index + 1); titles_[next_title.index].swap(content); @@ -286,257 +310,387 @@ dvd_generator::pgc_ref dvd_generator::add_title(vob_list & content) void dvd_generator::generate(const std::string & output_dir) const { + // This function uses a mixture of 0-based and 1-based numbering, + // due to the differing conventions of the language and the DVD + // format. Variable names ending in "_index" indicate 0-based + // indices and variable names ending in "_num" indicate 1-based + // numbers. + std::string name(temp_file_name(temp_dir_, "videolink.dvdauthor")); std::ofstream file(name.c_str()); + file << "\n"; // We generate code that uses registers in the following way: // - // g0: scratch - // g1: target menu location - // g2: source/return menu location for title - // g3: target chapter number - // - // 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 << - "\n" - " \n" - " \n"; - - for (unsigned menu_index = 0; menu_index != menus_.size(); ++menu_index) + // g0: Scratch. + // g1: Target location when jumping between menus. Top 6 bits are + // the button number (like s8) and bottom 10 bits are the menu + // number. This is used for selecting the appropriate button + // when entering a menu, for completing indirect jumps between + // domains, and for jumping to the correct menu after exiting a + // title. This is set to 0 in the pre-routine of the target + // menu. + // g2: Current location in menus. This is used for jumping to the + // correct menu when the player exits a title. + // g3: Target chapter number plus 1 when jumping to a title. + // This is used to jump to the correct chapter and to + // distinguish between indirect jumps to menus and titles. + // This is set to 0 in the pre-routine of the target title. + // g4: Source menu location used to jump to a title. This is + // compared with g2 to determine whether to increment the + // button number if the title is played to the end. + + static const unsigned button_mult = dvd::reg_s8_button_mult; + static const unsigned menu_mask = button_mult - 1; + static const unsigned button_mask = (1U << dvd::reg_bits) - button_mult; + + // Iterate over VMGM and titlesets. For these purposes, we + // consider the VMGM to be titleset 0. + + // We need a titleset for each title, and we may also need titlesets to + // hold extra menus if we have too many for the VMGM. + // Also, we need at least one titleset. + const unsigned titleset_end = std::max( + 1U + std::max(1U, titles_.size()), + (menus_.size() + dvdauthor_anonymous_menus_max - 1) + / dvdauthor_anonymous_menus_max); + + for (unsigned titleset_num = 0; + titleset_num != titleset_end; + ++titleset_num) { - const menu & this_menu = menus_[menu_index]; - - if (menu_index == 0) - { - // This is the first (title) menu, displayed when the - // disc is first played. - file << - " \n" - " 
\n"
-		// Set a default target location if none is set.
-		// This covers first play and use of the "top menu"
-		// button.
-		"          if (g1 eq 0)\n"
-		"            g1 = " << 1 + button_mult << ";\n";
-	}
-	else
+	const char * const outer_element_name =
+	    titleset_num == 0 ? "vmgm" : "titleset";
+	const bool have_real_title =
+	    titleset_num != 0 && titleset_num <= titles_.size();
+	const bool have_real_menus =
+	    titleset_num * dvdauthor_anonymous_menus_max < menus_.size();
+
+	file << "  <" << outer_element_name << ">\n"
+	     << "    \n";
+
+	const unsigned menu_begin = titleset_num * dvdauthor_anonymous_menus_max;
+	const unsigned menu_end =
+	    have_real_menus
+	    ? std::min((titleset_num + 1) * dvdauthor_anonymous_menus_max,
+		       menus_.size())
+	    : menu_begin + 1;
+
+	for (unsigned menu_index = menu_begin;
+	     menu_index != menu_end;
+	     ++menu_index)
 	{
-	    file <<
-		"      \n"
-		"        
\n";
-	}
+	    // There are various cases in which menus may be called:
+	    //
+	    // 1. The user follows a direct link to the menu.
+	    // 2. The user follows an indirect link to some other menu
+	    //    and that goes via this menu.  This is distinguished
+            //    from case 1 by the value of g1.  We must jump to or
+	    //    at least toward the other menu.
+	    // 3. The title menu is called when the disc is first
+	    //    played or the user presses the "top menu" button.
+	    //    This is distinguished from cases 2 and 3 by g1 == 0.
+	    //    We make this look like case 1.
+	    // 4. The root menu of a titleset is called when the user
+	    //    follows an indirect link to the title.  This is
+	    //    distinguished from all other cases by g3 != 0.  We
+	    //    must jump to the title.
+	    // 5. The root menu of a titleset is called when the title
+	    //    ends or the user presses the "menu" button during
+	    //    the title.  This is distinguished from cases 1, 2
+	    //    and 4 by g1 == 0 and g3 == 0.  We must jump to the
+	    //    latest menu (which can turn into case 1 or 2).
+	    //
+	    // Cases 3 and 5 do not apply to the same menus so they
+	    // do not need to be distinguished.
+
+	    if (menu_index == 0)
+	    {
+		// Title menu.
+		file <<
+		    "      \n"
+		    "        
\n"
+		    "          if (g1 eq 0)\n" // case 3
+		    "            g1 = " << 1 + button_mult << ";\n";
+	    }
+	    else if (menu_index == titleset_num * dvdauthor_anonymous_menus_max)
+	    {
+		// Root menu.
+ 		file <<
+		    "      \n"
+		    "        
\n";
+		if (have_real_title)
+		{
+		    file <<
+			"          if (g3 ne 0)\n" // case 4
+			"            jump title 1;\n"
+			"          if (g1 eq 0) {\n" // case 5
+			"            g1 = g2;\n"
+			"            jump vmgm menu entry title;\n"
+			"          }\n";
+		}
+	    }
+	    else
+	    {
+		// Some other menu.
+		file <<
+		    "      \n"
+		    "        
\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 
 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_index + menu_incr < menus_.size()
-		&& (menu_index & (menu_incr * 2 - 1)) == 0)
+	    if (!have_real_menus)
 	    {
+		// This is a root menu only reachable from the title.
 		file <<
-		    "          if (g0 ge " << 1 + menu_index + menu_incr
-					   << ")\n"
-		    "            jump menu " << 1 + menu_index + menu_incr
-					   << ";\n";
+		    "        
\n"
+		    "      \n";
+		continue;
 	    }
-	}
 
-	file <<
+	    const menu & this_menu = menus_[menu_index];
+
+	    // Detect and handle case 2.
+	    //
+	    // There is a limit of 128 VM instructions in each PGC.
+	    // Also, we can't jump to an arbitrary menu in another
+	    // domain.  Finally, we can't do computed jumps.
+	    // Therefore we statically expand and distribute a binary
+	    // search across the menus, resulting in a code size of
+	    // O(log(menu_count)) in each menu.  In practice there are
+	    // at most 11 conditional jumps needed in any menu.
+	    //
+	    // The initial bounds of the binary search are strange
+	    // because we must ensure that any jump between titlesets
+	    // is to the first menu of the titleset, marked as the
+	    // root entry.
+
+	    // Mask target location to get the target menu.
+	    file << "          g0 = g1 & " << menu_mask << ";\n";
+
+	    for (unsigned
+		     bottom = 0,
+		     top = 16 * dvdauthor_anonymous_menus_max;
+		 top - bottom > 1;)
+	    {
+		unsigned middle = (bottom + top) / 2;
+		if (menu_index == bottom && middle < menus_.size())
+		{
+		    file << "          if (g0 ge " << 1 + middle << ")\n"
+			 << "            jump ";
+		    unsigned target_titleset_num =
+			middle / dvdauthor_anonymous_menus_max;
+		    if (target_titleset_num != titleset_num)
+		    {
+			assert(middle % dvdauthor_anonymous_menus_max == 0);
+			file << "titleset " << target_titleset_num
+			     << " menu entry root";
+		    }
+		    else
+		    {
+			file << "menu "
+			     << 1 + middle % dvdauthor_anonymous_menus_max;
+		    }
+		    file << ";\n";
+		}
+		if (menu_index >= middle)
+		    bottom = middle;
+		else
+		    top = middle;
+	    }
+
+	    // Case 1.
+
 	    // Highlight the appropriate button.
-	    "          s8 = g1 & " << button_mask << ";\n"
-	    // Forget the link target.  If we don't do this, pressing
-	    // the "top menu" button will result in jumping back to
-	    // this same menu!
-	    "          g1 = 0;\n"
-	    "        
\n"
-	    "        \n"
-	    // Define a cell covering the whole menu and set a still
-	    // time at the end of that, since it seems all players
-	    // support that but some ignore a still time set on a PGC.
-	    "          \n"
-	    "        \n";
-
-	for (unsigned button_index = 0;
-	     button_index != this_menu.entries.size();
-	     ++button_index)
-	{
-	    const pgc_ref & target = this_menu.entries[button_index].target;
+	    file << "          s8 = g1 & " << button_mask << ";\n";
 
-	    file << "        
\n"
+		"        \n"
+		// Define a cell covering the whole menu and set a still
+		// time at the end of that, since it seems all players
+		// support that but some ignore a still time set on a PGC.
+		"          \n"
+		"        \n";
+
+	    for (unsigned button_index = 0;
+		 button_index != this_menu.entries.size();
+		 ++button_index)
 	    {
-		unsigned target_button_num;
+		const pgc_ref & target =
+		    this_menu.entries[button_index].target;
 
-		if (target.sub_index)
+		file << "        \n";
 	    }
 
-	    file <<  "\n";
+	    file <<
+		"      \n";
 	}
 
-	file <<
-	    "      \n";
-    }
+	file << "    \n";
 
-    file <<
-	"    \n"
- 	"  \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 (unsigned title_index = 0;
- 	 title_index != titles_.size();
- 	 ++title_index)
-    {
- 	file <<
-	    "  \n"
-	    // Generate a dummy menu so that the "menu" button will
-	    // work.  This returns to the source menu via the title
-	    // menu.
-	    "    \n"
-	    "      \n"
-	    "        
 g1 = g2; jump vmgm menu; 
\n"
-	    "      \n"
-	    "    \n"
-	    "    \n"
-	    "      \n"
-	    "        
\n";
-
-	// Count chapters in the title.
-	unsigned n_chapters = 0;
-	for (vob_list::const_iterator
-		 it = titles_[title_index].begin(),
-		 end = titles_[title_index].end();
-	     it != end;
-	     ++it)
+	if (have_real_title)
 	{
-	    // Chapter start times may be specified in the "chapters"
-	    // attribute as a comma-separated list.  If this is not
-	    // specified then the beginning of each file starts a new
-	    // chapter.  Thus the number of chapters in each file is
-	    // the number of commas in the chapter attribute, plus 1.
-	    ++n_chapters;
-	    std::size_t pos = 0;
-	    while ((pos = it->chapters.find(',', pos)) != std::string::npos)
+	    file <<
+		"    \n"
+		"      \n";
+
+	    file << "        
\n";
+
+	    // Count chapters in the title.
+	    unsigned n_chapters = 0;
+	    for (vob_list::const_iterator
+		     it = titles_[titleset_num - 1].begin(),
+		     end = titles_[titleset_num - 1].end();
+		 it != end;
+		 ++it)
 	    {
+		// Chapter start times may be specified in the "chapters"
+		// attribute as a comma-separated list.  If this is not
+		// specified then the beginning of each file starts a new
+		// chapter.  Thus the number of chapters in each file is
+		// the number of commas in the chapter attribute, plus 1.
 		++n_chapters;
-		++pos;
+		std::size_t pos = 0;
+		while ((pos = it->chapters.find(',', pos)) != std::string::npos)
+		{
+		    ++n_chapters;
+		    ++pos;
+		}
 	    }
-	}
 
-	// Generate jump "table" for chapters.
-	for (unsigned chapter_num = 1;
-	     chapter_num <= n_chapters;
-	     ++chapter_num)
-	    file <<
-		"          if (g3 == " << chapter_num << ")\n"
-		"            jump chapter " << chapter_num << ";\n";
+	    // Move the chapter number to scratch so the root menu can
+	    // distinguish cases 4 and 5.
+	    file << "          g0 = g3; g3 = 0;\n";
 
-	file <<
-	    "        
\n";
+	    // Copy the latest menu location for use by the post-routine.
+	    file << "          g4 = g2;\n";
 
-	for (vob_list::const_iterator
-		 it = titles_[title_index].begin(),
-		 end = titles_[title_index].end();
-	     it != end;
-	     ++it)
+	    // Jump to the correct chapter.
+	    for (unsigned chapter_num = 1;
+		 chapter_num <= n_chapters;
+		 ++chapter_num)
+		file <<
+		    "          if (g0 eq " << 1 + chapter_num << ")\n"
+		    "            jump chapter " << chapter_num << ";\n";
+
+	    file << "        
\n";
+
+	    for (vob_list::const_iterator
+		     it = titles_[titleset_num - 1].begin(),
+		     end = titles_[titleset_num - 1].end();
+		 it != end;
+		 ++it)
+	    {
+		file << "        chapters.empty())
+		    file << " chapters='" << xml_escape(it->chapters) << "'";
+		if (!it->pause.empty())
+		    file << " pause='" << xml_escape(it->pause) << "'";
+		file << "/>\n";
+	    }
+
+	    // If the user has not exited to the menus and then
+	    // resumed the title, set the latest menu location to be
+	    // the button after the one that linked to this title.
+	    // In any case, return to the (root) menu which will
+	    // then jump to the correct menu.
+	    file <<
+		"        \n"
+		"          if (g2 eq g4)\n"
+		"            g2 = g2 + " << button_mult << ";\n"
+		"          call menu;\n"
+		"        \n"
+		"      \n"
+		"    \n";
+	}
+	else if (titleset_num != 0) // && !have_real_title
 	{
-	    file << "        chapters.empty())
-		file << " chapters='" << xml_escape(it->chapters) << "'";
-	    if (!it->pause.empty())
-		file << " pause='" << xml_escape(it->pause) << "'";
-	    file << "/>\n";
+	    file << "    \n";
 	}
 
-	file <<
-	    "        \n"
-	    // Return to the source menu, but highlight the next button.
-	    "          g2 = g2 + " << button_mult << ";\n"
-	    "          call menu;\n"
-	    "        \n"
-	    "      \n"
-	    "    \n"
-	    "  \n";
+	file << "  \n";
     }
 
-    file <<
-	"\n";
-
+    file << "\n";
     file.close();
 
     {