Backport r27213 from trunk to release-0-24-fixes

Teletext fixes.

    * add a TryLockOSD method to MythPlayer which will wait 50ms for the
lock and use this in the teletext decoder.

    * Only decode teletext data if teletext based captions are enabled. 

The latter will introduce a certain amount of delay between enabling
teletext items and their display on screen as the teletext data is no
longer continuously cached.


git-svn-id: http://svn.mythtv.org/svn/branches/release-0-24-fixes@27220 7dbf422c-18fa-0310-86e9-fd20926502f2

Author: Mark Kendall

mythtv/libs/libmythtv/mythplayer.h

@@ -297,8 +297,9 @@ class MPUBLIC MythPlayer
                        QMap<long long, long long> &posMap);
 
     // OSD locking for TV class
-    void LockOSD(void)   { osdLock.lock();   }
-    void UnlockOSD(void) { osdLock.unlock(); }
+    bool TryLockOSD(void) { return osdLock.tryLock(50); }
+    void LockOSD(void)    { osdLock.lock();   }
+    void UnlockOSD(void)  { osdLock.unlock(); }
 
   protected:
     // Initialization

mythtv/libs/libmythtv/teletextdecoder.cpp

@@ -53,7 +53,19 @@ void TeletextDecoder::Decode(const unsigned char *buf, int vbimode)
     if (!m_player)
         return;
 
-    m_player->LockOSD();
+    int mode = m_player->GetCaptionMode();
+    if (!((mode == kDisplayNUVTeletextCaptions) ||
+          (mode == kDisplayTeletextCaptions) ||
+          (mode == kDisplayTeletextMenu)))
+    {
+        return;
+    }
+
+    if (!m_player->TryLockOSD())
+    {
+        VERBOSE(VB_PLAYBACK, "TeletextDecoder: Failed to get OSD lock.");
+        return;
+    }
 
     if (!m_teletextviewer && m_player)
     {

mythtv/libs/libmythtv/teletextscreen.cpp

@@ -469,6 +469,9 @@ void TeletextScreen::AddPageHeader(int page, int subpage,
                                     const uint8_t * buf,
                                     int vbimode, int lang, int flags)
 {
+    if (!m_displaying)
+        return;
+
     QMutexLocker locker(&m_lock);
 
     int magazine = MAGAZINE(page);
@@ -547,6 +550,9 @@ void TeletextScreen::AddPageHeader(int page, int subpage,
 void TeletextScreen::AddTeletextData(int magazine, int row,
                                       const uint8_t * buf, int vbimode)
 {
+    if (!m_displaying)
+        return;
+
     QMutexLocker locker(&m_lock);
 
     int b1, b2, b3, err = 0;