]> git.decadent.org.uk Git - videolink.git/blobdiff - webdvd.cpp
Use ffmpeg by default since it seems to work if we use pause correctly.
[videolink.git] / webdvd.cpp
index e80996874157ce339063dd7a5fd5ab30b42aaa4f..f8e44005f204f24bcd80a7196e126dad7ff97c6b 100644 (file)
@@ -1,4 +1,4 @@
-// Copyright 2005 Ben Hutchings <ben@decadentplace.org.uk>.
+// Copyright 2005-6 Ben Hutchings <ben@decadentplace.org.uk>.
 // See the file "COPYING" for licence details.
 
 #include <cassert>
 #include "browser_widget.hpp"
 #include "child_iterator.hpp"
 #include "dvd.hpp"
+#include "generate_dvd.hpp"
 #include "link_iterator.hpp"
+#include "null_prompt_service.hpp"
 #include "pixbufs.hpp"
 #include "style_sheets.hpp"
 #include "temp_file.hpp"
 #include "video.hpp"
 #include "x_frame_buffer.hpp"
+#include "xml_utils.hpp"
 #include "xpcom_support.hpp"
 
 using xpcom_support::check;
 
 namespace
 {
+    // We can try using any of these encoders to convert PNG to MPEG.
+    enum mpeg_encoder
+    {
+       mpeg_encoder_ffmpeg,         // ffmpeg
+       mpeg_encoder_mjpegtools_old, // mjpegtools before version 1.8
+       mpeg_encoder_mjpegtools_new  // mjpegtools from version 1.8
+    };
+
     struct rectangle
     {
        int left, top;     // inclusive
@@ -143,75 +154,16 @@ namespace
     }
 
 
-    std::string xml_escape(const std::string & str)
-    {
-       std::string result;
-       std::size_t begin = 0;
-
-       for (;;)
-       {
-           std::size_t end = str.find_first_of("\"&'<>", begin);
-           result.append(str, begin, end - begin);
-           if (end == std::string::npos)
-               return result;
-
-           const char * entity = NULL;
-           switch (str[end])
-           {
-           case '"':  entity = "&quot;"; break;
-           case '&':  entity = "&amp;";  break;
-           case '\'': entity = "&apos;"; break;
-           case '<':  entity = "&lt;";   break;
-           case '>':  entity = "&gt;";   break;
-           }
-           assert(entity);
-           result.append(entity);
-
-           begin = end + 1;
-       }
-    }
-
-    
-    struct dvd_contents
-    {
-       enum pgc_type { menu_pgc, title_pgc };
-       typedef std::pair<pgc_type, int> pgc_ref;
-
-       struct menu
-       {
-           menu()
-                   : vob_temp(new temp_file("webdvd-vob-"))
-               {
-                   vob_temp->close();
-               }
-
-           boost::shared_ptr<temp_file> vob_temp;
-           std::vector<pgc_ref> entries;
-       };
-
-       struct title
-       {
-           explicit title(const std::string & vob_list)
-                   : vob_list(vob_list)
-               {}
-
-           std::string vob_list;
-       };
-
-       std::vector<menu> menus;
-       std::vector<title> titles;
-    };
-
-    void generate_dvd(const dvd_contents & contents,
-                     const std::string & output_dir);
-
     class webdvd_window : public Gtk::Window
     {
     public:
        webdvd_window(
            const video::frame_params & frame_params,
            const std::string & main_page_uri,
-           const std::string & output_dir);
+           const std::string & output_dir,
+           mpeg_encoder encoder);
+
+       bool is_finished() const;
 
     private:
        dvd_contents::pgc_ref add_menu(const std::string & uri);
@@ -230,6 +182,7 @@ namespace
 
        video::frame_params frame_params_;
        std::string output_dir_;
+       mpeg_encoder encoder_;
        browser_widget browser_widget_;
        nsCOMPtr<nsIStyleSheet> stylesheet_;
 
@@ -244,18 +197,23 @@ namespace
        std::auto_ptr<temp_file> background_temp_;
        struct page_state;
        std::auto_ptr<page_state> page_state_;
+
+       bool finished_;
     };
 
     webdvd_window::webdvd_window(
        const video::frame_params & frame_params,
        const std::string & main_page_uri,
-       const std::string & output_dir)
+       const std::string & output_dir,
+       mpeg_encoder encoder)
            : frame_params_(frame_params),
              output_dir_(output_dir),
+             encoder_(encoder),
              stylesheet_(load_css("file://" WEBDVD_LIB_DIR "/webdvd.css")),
              pending_window_update_(false),
              pending_req_count_(0),
-             have_tweaked_page_(false)
+             have_tweaked_page_(false),
+             finished_(false)
     {
        set_size_request(frame_params_.width, frame_params_.height);
        set_resizable(false);
@@ -269,6 +227,11 @@ namespace
        load_next_page();
     }
 
+    bool webdvd_window::is_finished() const
+    {
+       return finished_;
+    }
+
     dvd_contents::pgc_ref webdvd_window::add_menu(const std::string & uri)
     {
        dvd_contents::pgc_ref next_menu(dvd_contents::menu_pgc,
@@ -302,32 +265,30 @@ namespace
        else
        {
            Glib::ustring hostname;
-           std::string filename(Glib::filename_from_uri(uri, hostname));
+           std::string path(Glib::filename_from_uri(uri, hostname));
            // FIXME: Should check the hostname
 
-           std::string vob_list;
+           vob_list list;
 
            // Store a reference to a linked VOB file, or the contents
            // of a linked VOB list file.
-           if (filename.compare(filename.size() - 4, 4, ".vob") == 0)
+           if (path.compare(path.size() - 4, 4, ".vob") == 0)
            {
-               if (!Glib::file_test(filename, Glib::FILE_TEST_IS_REGULAR))
+               if (!Glib::file_test(path, Glib::FILE_TEST_IS_REGULAR))
                    throw std::runtime_error(
-                       filename + " is missing or not a regular file");
-               vob_list
-                   .append("<vob file='")
-                   .append(xml_escape(filename))
-                   .append("'/>\n");
+                       path + " is missing or not a regular file");
+               vob_ref ref;
+               ref.file = path;
+               list.push_back(ref);
            }
            else
            {
-               assert(filename.compare(filename.size() - 8, 8, ".voblist")
-                      == 0);
-               // TODO: Validate the file contents
-               vob_list.assign(Glib::file_get_contents(filename));
+               assert(path.compare(path.size() - 8, 8, ".voblist") == 0);
+               read_vob_list(path).swap(list);
            }
 
-           contents_.titles.push_back(dvd_contents::title(vob_list));
+           contents_.titles.resize(contents_.titles.size() + 1);
+           contents_.titles.back().swap(list);
            return next_title;
        }
     }
@@ -418,7 +379,10 @@ namespace
            try
            {
                if (!process_page())
+               {
+                   finished_ = true;
                    Gtk::Main::quit();
+               }
            }
            catch (std::exception & e)
            {
@@ -429,6 +393,15 @@ namespace
                std::cerr << ": " << e.what() << "\n";
                Gtk::Main::quit();
            }
+           catch (Glib::Exception & e)
+           {
+               std::cerr << "Fatal error";
+               if (!page_queue_.empty())
+                   std::cerr << " while processing <" << page_queue_.front()
+                             << ">";
+               std::cerr << ": " << e.what() << "\n";
+               Gtk::Main::quit();
+           }
        }
     }
 
@@ -536,7 +509,7 @@ namespace
 
        temp_file links_temp;
 
-       int link_num;
+       unsigned link_num;
        link_iterator links_it, links_end;
 
        rectangle link_rect;
@@ -587,7 +560,7 @@ namespace
            0, 0, frame_params_.width, frame_params_.height
        };
 
-       int menu_num = resource_map_[page_queue_.front()].second;
+       unsigned menu_num = resource_map_[page_queue_.front()].index;
 
        for (/* no initialisation */;
             state->links_it != state->links_end;
@@ -595,19 +568,24 @@ namespace
        {
            nsCOMPtr<nsIDOMNode> node(*state->links_it);
 
-           // Find the link URI.
+           // Find the link URI and separate any fragment from it.
            nsCOMPtr<nsILink> link(do_QueryInterface(node));
            assert(link);
-           nsCOMPtr<nsIURI> uri;
-           check(link->GetHrefURI(getter_AddRefs(uri)));
-           std::string uri_string;
+           nsCOMPtr<nsIURI> uri_iface;
+           check(link->GetHrefURI(getter_AddRefs(uri_iface)));
+           std::string uri_and_fragment, uri, fragment;
            {
-               nsCString uri_ns_string;
-               check(uri->GetSpec(uri_ns_string));
-               uri_string.assign(uri_ns_string.BeginReading(),
-                                 uri_ns_string.EndReading());
+               nsCString uri_and_fragment_ns;
+               check(uri_iface->GetSpec(uri_and_fragment_ns));
+               uri_and_fragment.assign(uri_and_fragment_ns.BeginReading(),
+                                       uri_and_fragment_ns.EndReading());
+
+               std::size_t hash_pos = uri_and_fragment.find('#');
+               uri.assign(uri_and_fragment, 0, hash_pos);
+               if (hash_pos != std::string::npos)
+                   fragment.assign(uri_and_fragment,
+                                   hash_pos + 1, std::string::npos);
            }
-           std::string uri_sans_fragment(uri_string, 0, uri_string.find('#'));
 
            // Is this a new link?
            if (!state->link_changing)
@@ -622,18 +600,19 @@ namespace
                if (state->link_rect.empty())
                {
                    std::cerr << "Ignoring invisible link to "
-                             << uri_string << "\n";
+                             << uri_and_fragment << "\n";
                    continue;
                }
 
                ++state->link_num;
 
-               if (state->link_num >= dvd::menu_buttons_max)
+               if (state->link_num >= unsigned(dvd::menu_buttons_max))
                {
-                   if (state->link_num == dvd::menu_buttons_max)
+                   if (state->link_num == unsigned(dvd::menu_buttons_max))
                        std::cerr << "No more than " << dvd::menu_buttons_max
                                  << " buttons can be placed on a menu\n";
-                   std::cerr << "Ignoring link to " << uri_string << "\n";
+                   std::cerr << "Ignoring link to " << uri_and_fragment
+                             << "\n";
                    continue;
                }
 
@@ -646,32 +625,33 @@ namespace
                // Check whether this is a link to a video or a page then
                // add it to the known resources if not already seen; then
                // add it to the menu entries.
-               nsCString path;
-               check(uri->GetPath(path));
-               dvd_contents::pgc_ref dest_pgc;
+               dvd_contents::pgc_ref target;
                // FIXME: This is a bit of a hack.  Perhaps we could decide
                // later based on the MIME type determined by Mozilla?
-               if ((path.Length() > 4
-                    && std::strcmp(path.EndReading() - 4, ".vob") == 0)
-                   || (path.Length() > 8
-                       && std::strcmp(path.EndReading() - 8, ".voblist")
-                          == 0))
+               if ((uri.size() > 4
+                    && uri.compare(uri.size() - 4, 4, ".vob") == 0)
+                   || (uri.size() > 8
+                       && uri.compare(uri.size() - 8, 8, ".voblist") == 0))
                {
                    PRBool is_file;
-                   check(uri->SchemeIs("file", &is_file));
+                   check(uri_iface->SchemeIs("file", &is_file));
                    if (!is_file)
                    {
                        std::cerr << "Links to video must use the file:"
                                  << " scheme\n";
                        continue;
                    }
-                   dest_pgc = add_title(uri_sans_fragment);
+                   target = add_title(uri);
+                   target.sub_index =
+                       std::strtoul(fragment.c_str(), NULL, 10);
                }
                else
                {
-                   dest_pgc = add_menu(uri_sans_fragment);
+                   target = add_menu(uri);
+                   // TODO: If there's a fragment, work out which button
+                   // is closest and set target.sub_index.
                }
-               contents_.menus[menu_num].entries.push_back(dest_pgc);
+               contents_.menus[menu_num].entries.push_back(target);
 
                nsCOMPtr<nsIContent> content(do_QueryInterface(node));
                assert(content);
@@ -767,271 +747,92 @@ namespace
 
        {
            std::ostringstream command_stream;
-           command_stream << "pngtopnm "
-                          << background_temp_->get_name()
-                          << " | ppmtoy4m -v0 -n1 -F"
-                          << frame_params_.rate_numer
-                          << ":" << frame_params_.rate_denom
-                          << " -A" << frame_params_.pixel_ratio_width
-                          << ":" << frame_params_.pixel_ratio_height
-                          << (" -Ip -S420_mpeg2"
-                              " | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
-                              " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
-                              " | spumux -v0 -mdvd ")
-                          << state->spumux_temp.get_name()
-                          << " > "
-                          << contents_.menus[menu_num].vob_temp->get_name();
-           std::string command(command_stream.str());
-           const char * argv[] = {
-               "/bin/sh", "-c", command.c_str(), 0
-           };
-           std::cout << "running " << argv[2] << std::endl;
-           int command_result;
-           Glib::spawn_sync(".",
-                            Glib::ArrayHandle<std::string>(
-                                argv, sizeof(argv)/sizeof(argv[0]),
-                                Glib::OWNERSHIP_NONE),
-                            Glib::SPAWN_STDOUT_TO_DEV_NULL,
-                            SigC::Slot0<void>(),
-                            0, 0,
-                            &command_result);
-           if (command_result != 0)
-               throw std::runtime_error("spumux pipeline failed");
-       }
-    }
-
-    void generate_dvd(const dvd_contents & contents,
-                     const std::string & output_dir)
-    {
-       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)
-       {
-           const dvd_contents::menu & menu = contents.menus[menu_num];
-
-           if (menu_num == 0)
+           if (encoder_ == mpeg_encoder_ffmpeg)
            {
-               // 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";
+               command_stream
+                   << "ffmpeg"
+                   << " -f image2 -vcodec png -i "
+                   << background_temp_->get_name()
+                   << " -target " << frame_params_.ffmpeg_name <<  "-dvd"
+                   << " -vcodec mpeg2video -an -y /dev/stdout"
+                   << " | spumux -v0 -mdvd " << state->spumux_temp.get_name()
+                   << " > " << contents_.menus[menu_num].vob_temp->get_name();
            }
            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 &amp; " << 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 &amp; " << 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 << ";";
-               }
+               assert(encoder_ == mpeg_encoder_mjpegtools_old
+                      || encoder_ == mpeg_encoder_mjpegtools_new);
+               command_stream
+                   << "pngtopnm "
+                   << background_temp_->get_name()
+                   << " | ppmtoy4m -v0 -n1 -F"
+                   << frame_params_.rate_numer
+                   << ":" << frame_params_.rate_denom
+                   << " -A" << frame_params_.pixel_ratio_width
+                   << ":" << frame_params_.pixel_ratio_height
+                   << " -Ip ";
+               // The chroma subsampling keywords changed between
+               // versions 1.6.2 and 1.8 of mjpegtools.  There is no
+               // keyword that works with both.
+               if (encoder_ == mpeg_encoder_mjpegtools_old)
+                   command_stream << "-S420_mpeg2";
                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";
+                   command_stream << "-S420mpeg2";
+               command_stream
+                   << (" | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
+                       " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
+                       " | spumux -v0 -mdvd ")
+                   << state->spumux_temp.get_name()
+                   << " > "
+                   << contents_.menus[menu_num].vob_temp->get_name();
            }
-
-           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();
-
-       {
+           std::string command(command_stream.str());
            const char * argv[] = {
-               "dvdauthor",
-               "-o", output_dir.c_str(),
-               "-x", temp.get_name().c_str(),
-               0
+               "/bin/sh", "-c", command.c_str(), 0
            };
+           std::cout << "running " << argv[2] << std::endl;
            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,
+                            Glib::SPAWN_STDOUT_TO_DEV_NULL,
                             SigC::Slot0<void>(),
                             0, 0,
                             &command_result);
            if (command_result != 0)
-               throw std::runtime_error("dvdauthor failed");
+               throw std::runtime_error("spumux pipeline failed");
        }
     }
 
     const video::frame_params & lookup_frame_params(const char * str)
     {
        assert(str);
-       static const struct { const char * str; bool is_ntsc; }
-       known_strings[] = {
-           { "NTSC",  true },
-           { "ntsc",  true },
-           { "PAL",   false },
-           { "pal",   false },
-           // For DVD purposes, SECAM can be treated identically to PAL.
-           { "SECAM", false },
-           { "secam", false }
+       static const char * const known_strings[] = {
+           "525",    "625",
+           "525/60", "625/50",
+           "NTSC",   "PAL",
+           "ntsc",   "pal"
        };
        for (std::size_t i = 0;
             i != sizeof(known_strings)/sizeof(known_strings[0]);
             ++i)
-           if (std::strcmp(str, known_strings[i].str) == 0)
-               return known_strings[i].is_ntsc ?
-                   video::ntsc_params : video::pal_params;
+           if (std::strcmp(str, known_strings[i]) == 0)
+               return (i & 1)
+                   ? video::frame_params_625
+                   : video::frame_params_525;
        throw std::runtime_error(
            std::string("Invalid video standard: ").append(str));
     }
 
     void print_usage(std::ostream & stream, const char * command_name)
     {
-       stream << "Usage: " << command_name
-              << (" [gtk-options] [--video-std std-name]"
-                  " [--preview] menu-url [output-dir]\n");
+       stream <<
+           "Usage: " << command_name << " [gtk-options] [--preview]\n"
+           "           [--video-std {525|525/60|NTSC|ntsc"
+           " | 625|625/50|PAL|pal}]\n"
+           "           [--encoder {mjpegtools|mjpegtools-old}]\n"
+           "           menu-url [output-dir]\n";
     }
     
     void set_browser_preferences()
@@ -1069,14 +870,21 @@ namespace
 
 } // namespace
 
+void fatal_error(const std::string & message)
+{
+    std::cerr << "Fatal error: " << message << "\n";
+    Gtk::Main::quit();
+}
+
 int main(int argc, char ** argv)
 {
     try
     {
-       video::frame_params frame_params = video::pal_params;
+       video::frame_params frame_params = video::frame_params_625;
        bool preview_mode = false;
        std::string menu_url;
        std::string output_dir;
+       mpeg_encoder encoder = mpeg_encoder_ffmpeg;
 
        // Do initial option parsing.  We have to do this before
        // letting Gtk parse the arguments since we may need to spawn
@@ -1148,6 +956,40 @@ int main(int argc, char ** argv)
            {
                argi += 2;
            }
+           else if (std::strcmp(argv[argi], "--save-temps") == 0)
+           {
+               temp_file::keep_all(true);
+               argi += 1;
+           }
+           else if (std::strcmp(argv[argi], "--encoder") == 0)
+           {
+               if (argi + 1 == argc)
+               {
+                   std::cerr << "Missing argument to --encoder\n";
+                   print_usage(std::cerr, argv[0]);
+                   return EXIT_FAILURE;
+               }
+               if (std::strcmp(argv[argi + 1], "ffmpeg") == 0)
+               {
+                   encoder = mpeg_encoder_ffmpeg;
+               }
+               else if (std::strcmp(argv[argi + 1], "mjpegtools-old") == 0)
+               {
+                   encoder = mpeg_encoder_mjpegtools_old;
+               }
+               else if (std::strcmp(argv[argi + 1], "mjpegtools") == 0
+                        || std::strcmp(argv[argi + 1], "mjpegtools-new") == 0)
+               {
+                   encoder = mpeg_encoder_mjpegtools_new;
+               }
+               else
+               {
+                   std::cerr << "Invalid argument to --encoder\n";
+                   print_usage(std::cerr, argv[0]);
+                   return EXIT_FAILURE;
+               }
+               argi += 2;
+           }
            else if (argv[argi][0] == '-')
            {
                std::cerr << "Invalid option: " << argv[argi] << "\n";
@@ -1186,16 +1028,20 @@ int main(int argc, char ** argv)
        // Initialise Mozilla
        browser_widget::initialiser browser_init;
        set_browser_preferences();
+       if (!preview_mode)
+           null_prompt_service::install();
 
        // Run the browser/converter
-       webdvd_window window(frame_params, menu_url, output_dir);
+       webdvd_window window(frame_params, menu_url, output_dir, encoder);
        Gtk::Main::run(window);
+
+       return ((preview_mode || window.is_finished())
+               ? EXIT_SUCCESS
+               : EXIT_FAILURE);
     }
     catch (std::exception & e)
     {
        std::cerr << "Fatal error: " << e.what() << "\n";
        return EXIT_FAILURE;
     }
-
-    return EXIT_SUCCESS;
 }