DVD startup fixes.

- re-implement the dvdnav_first_play method that Stanley Skamithi added
some time ago and I removed some time later...

- minor tidy up of the CloseDVD method.

- use the dvdnav_first_play call when 're-starting' the dvd following
the codec scan.

Closes #9143

mythtv/libs/libmythdvdnav/dvdnav/dvdnav.h

@@ -261,6 +261,11 @@ dvdnav_status_t dvdnav_stop(dvdnav_t *self);
  * title/part navigation                                             *
  *********************************************************************/
 
+/*
+ * Play DVD from the Beginning
+ */
+void dvdnav_first_play(dvdnav_t *self);
+
 /*
  * Returns the number of titles on the disk.
  */

mythtv/libs/libmythdvdnav/dvdnav/navigation.c

@@ -169,6 +169,14 @@ dvdnav_status_t dvdnav_current_title_program(dvdnav_t *this, int32_t *title, int
   return DVDNAV_STATUS_ERR;
 }
 
+void dvdnav_first_play(dvdnav_t *this) {
+  pthread_mutex_lock(&this->vm_lock);
+  this->started = 0;
+  vm_start(this->vm);
+  this->started = 1;
+  pthread_mutex_unlock(&this->vm_lock);
+}
+
 dvdnav_status_t dvdnav_title_play(dvdnav_t *this, int32_t title) {
   return dvdnav_part_play(this, title, 1);
 }

mythtv/libs/libmythtv/dvdringbuffer.cpp

@@ -141,6 +141,8 @@ void DVDRingBuffer::CloseDVD(void)
         dvdnav_close(m_dvdnav);
         m_dvdnav = NULL;
     }
+    m_gotStop = false;
+    m_audioStreamsChanged = true;
 }
 
 void DVDRingBuffer::ClearChapterCache(void)
@@ -299,10 +301,7 @@ bool DVDRingBuffer::OpenFile(const QString &lfilename, uint retry_ms)
     rwlock.lockForWrite();
 
     if (m_dvdnav)
-    {
-        dvdnav_close(m_dvdnav);
-        m_dvdnav = NULL;
-    }
+        CloseDVD();
 
     filename = lfilename;
     QByteArray fname = filename.toLocal8Bit();
@@ -412,9 +411,6 @@ bool DVDRingBuffer::OpenFile(const QString &lfilename, uint retry_ms)
 
 bool DVDRingBuffer::StartFromBeginning(void)
 {
-    if (!m_dvdnav)
-        return false;
-
     VERBOSE(VB_IMPORTANT, LOC + "Resetting DVD device.");
 
     // if a DVDNAV_STOP event has been emitted, dvdnav_reset does not
@@ -424,20 +420,19 @@ bool DVDRingBuffer::StartFromBeginning(void)
         VERBOSE(VB_IMPORTANT, LOC +
                 "DVD errored after initial scan - trying again");
         CloseDVD();
-        m_gotStop = false;
         OpenFile(filename);
         if (!m_dvdnav)
-        {
             VERBOSE(VB_IMPORTANT, LOC + "Failed to re-open DVD.");
-            return false;
-        }
     }
 
-    QMutexLocker lock(&m_seekLock);
-    dvdnav_reset(m_dvdnav);
-    dvdnav_title_play(m_dvdnav, 0);
-    m_audioStreamsChanged = true;
-    return true;
+    if (m_dvdnav)
+    {
+        QMutexLocker lock(&m_seekLock);
+        dvdnav_first_play(m_dvdnav);
+        m_audioStreamsChanged = true;
+    }
+
+    return m_dvdnav;
 }
 
 void DVDRingBuffer::GetChapterTimes(QList<long long> &times)