Add a new DVDInfo class.

This is a simple DVD helper that simply opens the device and retrieves
the name and serial number of the disc. A complete DVD device, as
implemented in DVDRingBuffer, can be expensive to fully create and open
and when performing the initial DVD bookmark check, we need nothing more
than the basics.

For remote, storage group based playback this can knock up to 5 seconds
off the time taken to start a disc.

mythtv/libs/libmythtv/dvdringbuffer.cpp

@@ -33,6 +33,49 @@ static const char *dvdnav_menu_table[] =
     "Part",
 };
 
+DVDInfo::DVDInfo(const QString &filename)
+  : m_nav(NULL), m_name(NULL), m_serialnumber(NULL)
+{
+    QString name = filename;
+    if (name.left(6) == "dvd://")
+        name.remove(0,5);
+    else if (name.left(5) == "dvd:/")
+        name.remove(0,4);
+    else if (name.left(4) == "dvd:")
+        name.remove(0,4);
+
+    QByteArray fname = name.toLocal8Bit();
+    dvdnav_status_t res = dvdnav_open(&m_nav, fname.constData());
+    if (res == DVDNAV_STATUS_ERR)
+    {
+        VERBOSE(VB_IMPORTANT, QString("DVDInfo: Failed to open device at %1")
+                .arg(fname.constData()));
+        return;
+    }
+
+    res = dvdnav_get_title_string(m_nav, &m_name);
+    if (res == DVDNAV_STATUS_ERR)
+        VERBOSE(VB_IMPORTANT, QString("DVDInfo: Failed to get name."));
+    res = dvdnav_get_serial_string(m_nav, &m_serialnumber);
+    if (res == DVDNAV_STATUS_ERR)
+        VERBOSE(VB_IMPORTANT, QString("DVDInfo: Failed to get serial number."));
+}
+
+DVDInfo::~DVDInfo(void)
+{
+    if (m_nav)
+        dvdnav_close(m_nav);
+}
+
+bool DVDInfo::GetNameAndSerialNum(QString &name, QString &serial)
+{
+    name   = QString(m_name);
+    serial = QString(m_serialnumber);
+    if (name.isEmpty() && serial.isEmpty())
+        return false;
+    return true;
+}
+
 DVDRingBuffer::DVDRingBuffer(const QString &lfilename) :
     m_dvdnav(NULL),     m_dvdBlockReadBuf(NULL),
     m_dvdBlockRPos(0),  m_dvdBlockWPos(0),

mythtv/libs/libmythtv/dvdringbuffer.h

@@ -27,6 +27,20 @@ extern "C" {
 
 class MythDVDPlayer;
 
+class MTV_PUBLIC DVDInfo
+{
+  public:
+    DVDInfo(const QString &filename);
+   ~DVDInfo(void);
+    bool IsValid(void) { return m_nav != NULL; }
+    bool GetNameAndSerialNum(QString &name, QString &serialnum);
+
+  protected:
+    dvdnav_t   *m_nav;
+    const char *m_name;
+    const char *m_serialnumber;
+};
+
 class MTV_PUBLIC DVDRingBuffer : public RingBuffer
 {
   public:

mythtv/programs/mythfrontend/main.cpp

@@ -804,26 +804,29 @@ static int internal_play_media(const QString &mrl, const QString &plot,
 
     if (pginfo->IsVideoDVD())
     {
-        RingBuffer *tmprbuf = RingBuffer::Create(pginfo->GetPathname(), false);
-
-        if (!tmprbuf)
-        {
-            delete pginfo;
-            return res;
-        }
-        QString name;
-        QString serialid;
-        if (tmprbuf->IsDVD() &&
-            tmprbuf->DVD()->GetNameAndSerialNum(name, serialid))
+        DVDInfo *dvd = new DVDInfo(pginfo->GetPathname());
+        if (dvd && dvd->IsValid())
         {
-            QStringList fields = pginfo->QueryDVDBookmark(serialid);
-            if (!fields.empty())
+            QString name;
+            QString serialid;
+            if (dvd->GetNameAndSerialNum(name, serialid))
             {
-                QStringList::Iterator it = fields.begin();
-                pos = (int64_t)((*++it).toLongLong() & 0xffffffffLL);
+                QStringList fields = pginfo->QueryDVDBookmark(serialid);
+                if (!fields.empty())
+                {
+                    QStringList::Iterator it = fields.begin();
+                    pos = (int64_t)((*++it).toLongLong() & 0xffffffffLL);
+                }
             }
         }
-        delete tmprbuf;
+        else
+        {
+            if (dvd)
+                delete dvd;
+            delete pginfo;
+            return res;
+        }
+        delete dvd;
     }
     else if (pginfo->IsVideo())
         pos = pginfo->QueryBookmark();