DVB: Improve encryption detection by only checking the CA encryption …

…bits for Audio and Video. This prevents cases where some channels are mistakenly discarded as encrypted in DVB systems. This should help to improve the accuracy of scans. Patch from eallaud, minor cleanup and verification against the specs by me, secondary code review by Stuart A. Thanks! Fixes #8645.
MythTV · Jun 9, 2011 · 19a2cc7 · 19a2cc7
1 parent c0a27a6
commit 19a2cc7
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Showing 4 changed files with 15 additions and 10 deletions.
diff --git a/mythtv/libs/libmythtv/channelscan/channelscan_sm.cpp b/mythtv/libs/libmythtv/channelscan/channelscan_sm.cpp
@@ -370,7 +370,7 @@ void ChannelScanSM::HandlePMT(uint, const ProgramMapTable *pmt)
             QString("Got a Program Map Table for %1")
             .arg((*current).FriendlyName) + "\n" + pmt->toString());
 
-    if (!currentTestingDecryption && pmt->IsEncrypted())
+    if (!currentTestingDecryption && pmt->IsEncrypted(GetDTVChannel()->GetSIStandard()))
         currentEncryptionStatus[pmt->ProgramNumber()] = kEncUnknown;
 }
 
@@ -1184,7 +1184,7 @@ ChannelScanSM::GetChannelList(transport_scan_items_it_t trans_info,
                 info.is_opencable = true;
         }
 
-        info.is_encrypted |= pmt->IsEncrypted();
+        info.is_encrypted |= pmt->IsEncrypted(GetDTVChannel()->GetSIStandard());
         info.in_pmt = true;
     }
 

diff --git a/mythtv/libs/libmythtv/dtvsignalmonitor.cpp b/mythtv/libs/libmythtv/dtvsignalmonitor.cpp
@@ -329,8 +329,10 @@ void DTVSignalMonitor::HandlePMT(uint, const ProgramMapTable *pmt)
         return; // Not the PMT we are looking for...
     }
 
-    if (pmt->IsEncrypted())
+    if (pmt->IsEncrypted(GetDTVChannel()->GetSIStandard())) {
+        VERBOSE(VB_IMPORTANT,QString("PMT says program %1 is encrypted").arg(programNumber));
         GetStreamData()->TestDecryption(pmt);
+    }
 
     // if PMT contains audio and/or video stream set as matching.
     uint hasAudio = 0;
@@ -345,7 +347,7 @@ void DTVSignalMonitor::HandlePMT(uint, const ProgramMapTable *pmt)
     if ((hasVideo >= GetStreamData()->GetVideoStreamsRequired()) &&
         (hasAudio >= GetStreamData()->GetAudioStreamsRequired()))
     {
-        if (pmt->IsEncrypted() && !ignore_encrypted)
+        if (pmt->IsEncrypted(GetDTVChannel()->GetSIStandard()) && !ignore_encrypted)
             AddFlags(kDTVSigMon_WaitForCrypt);
 
         AddFlags(kDTVSigMon_PMTMatch);

diff --git a/mythtv/libs/libmythtv/mpeg/mpegtables.cpp b/mythtv/libs/libmythtv/mpeg/mpegtables.cpp
@@ -467,15 +467,18 @@ bool ProgramMapTable::IsAudio(uint i, QString sistandard) const
     return StreamID::IsAudio(stream_id);
 }
 
-/** \fn ProgramMapTable::IsEncrypted(void) const
- *  \brief Returns true iff PMT contains CA descriptor.
+/** \fn ProgramMapTable::IsEncrypted(QString sistandard) const
+ *  \brief Returns true iff PMT contains CA descriptor for a vid/aud stream.
  */
-bool ProgramMapTable::IsEncrypted(void) const
+bool ProgramMapTable::IsEncrypted(QString sistandard) const
 {
     bool encrypted = IsProgramEncrypted();
 
-    for (uint i = 0; !encrypted && i < StreamCount(); i++)
-        encrypted |= IsStreamEncrypted(i);
+    for (uint i = 0; !encrypted && i < StreamCount(); i++) {
+    /* Only check audio/video streams */
+        if (IsAudio(i,sistandard) || IsVideo(i,sistandard))
+            encrypted |= IsStreamEncrypted(i);
+    }
 
     return encrypted;
 }

diff --git a/mythtv/libs/libmythtv/mpeg/mpegtables.h b/mythtv/libs/libmythtv/mpeg/mpegtables.h
@@ -605,7 +605,7 @@ class ProgramMapTable : public PSIPTable
     // helper methods
     bool IsVideo(uint i, QString sistandard) const;
     bool IsAudio(uint i, QString sistandard) const;
-    bool IsEncrypted(void) const;
+    bool IsEncrypted(QString sistandard) const;
     bool IsProgramEncrypted(void) const;
     bool IsStreamEncrypted(uint pid) const;
     /// Returns true iff PMT contains a still-picture video stream