Ticket #4515: 4515-bradley-v1.patch

libs/libmythtv/dvbrecorder.cpp

@@ -491 +491 @@
         _buffer_packets = !FindMPEG2Keyframes(&tspacket);
     }
 
-    return ProcessTSPacket(tspacket);
+    return ProcessAVTSPacket(tspacket);
 }
 
 bool DVBRecorder::ProcessAudioTSPacket(const TSPacket &tspacket)
 {
     _buffer_packets = !FindAudioKeyframes(&tspacket);
-    return ProcessTSPacket(tspacket);
+    return ProcessAVTSPacket(tspacket);
 }
 
-bool DVBRecorder::ProcessTSPacket(const TSPacket &tspacket)
+/// Common code for processing both audio and video packets
+bool DVBRecorder::ProcessAVTSPacket(const TSPacket &tspacket)
 {
     const uint pid = tspacket.PID();
 
@@ -513 +514 @@
     }
 
     // Sync recording start to first keyframe
+    // (Delay's until first GOP to avoid decoder crash on res change)
     if (_wait_for_keyframe_option && _first_keyframe < 0)
         return true;
 
@@ -529 +531 @@
         _pid_status[pid] |= kPayloadStartSeen;
     }
 
+    return ProcessTSPacketCommon(tspacket);
+}
+
+bool DVBRecorder::ProcessTSPacket(const TSPacket &tspacket)
+{
+    _buffer_packets = !FindOtherKeyframes(&tspacket);
+    return ProcessTSPacketCommon(tspacket);
+}
+
+bool DVBRecorder::ProcessTSPacketCommon(const TSPacket &tspacket)
+{
+    // Care must be taken to make sure that the packet actually gets written
+    // as the decision to actually write it has already been made
+    const uint pid = tspacket.PID();
+
+    // Check continuity counter
+    if ((pid != 0x1fff) && !CheckCC(pid, tspacket.ContinuityCounter()))
+    {
+        VERBOSE(VB_RECORD, LOC +
+                QString("PID 0x%1 discontinuity detected").arg(pid,0,16));
+        _continuity_error_count++;
+    }
+
     BufferedWrite(tspacket);
 
     return true;
 }
+
+void DVBRecorder::BufferedWrite(const TSPacket &tspacket)
+{
+    // Care must be taken to make sure that the packet actually gets written
+    // as the decision to actually write it has already been made
+
+    // Do we have to buffer the packet for exact keyframe detection?
+    if (_buffer_packets)
+    {
+        int idx = _payload_buffer.size();
+        _payload_buffer.resize(idx + TSPacket::SIZE);
+        memcpy(&_payload_buffer[idx], tspacket.data(), TSPacket::SIZE);
+        return;
+    }
+
+    // We are free to write the packet, but if we have buffered packet[s]
+    // we have to write them first...
+    if (!_payload_buffer.empty())
+    {
+        if (ringBuffer)
+            ringBuffer->Write(&_payload_buffer[0], _payload_buffer.size());
+        _payload_buffer.clear();
+    }
+
+    if (ringBuffer)
+        ringBuffer->Write(tspacket.data(), TSPacket::SIZE);
+}

libs/libmythtv/dvbrecorder.h

@@ -64 +64 @@
     bool IsOpen(void) const { return _stream_fd >= 0; }
     void Close(void);
 
+    // Methods to handle MHEG, when there are no A/V streams
+    bool ProcessAVTSPacket(const TSPacket &tspacket);
+    bool ProcessTSPacketCommon(const TSPacket &tspacket);
+    void BufferedWrite(const TSPacket &tspacket);
+
+    // MPEG Stream Listener
     void HandlePAT(const ProgramAssociationTable*);
     void HandleCAT(const ConditionalAccessTable*) {}
     void HandlePMT(uint pid, const ProgramMapTable*);

libs/libmythtv/dtvrecorder.h

@@ -65 +65 @@
     bool FindH264Keyframes(const TSPacket* tspacket);
     void HandleH264Keyframe(void);
 
+    // MHEG no A/V support
+    bool FindOtherKeyframes(const TSPacket *tspacket);
+
     // file handle for stream
     int _stream_fd;
 
@@ -77 +80 @@
     unsigned long long _last_gop_seen;
     unsigned long long _last_seq_seen;
     unsigned long long _last_keyframe_seen;
+    bool               _has_written_mheg_keyframe;
 
     // H.264 support
     bool _pes_synced;

libs/libmythtv/dtvrecorder.cpp

@@ -38 +38 @@
     // used for scanning pes headers for keyframes
     _start_code(0xffffffff),        _first_keyframe(-1),
     _last_gop_seen(0),              _last_seq_seen(0),
-    _last_keyframe_seen(0),
+    _last_keyframe_seen(0),         _has_written_mheg_keyframe(false),
     // H.264 support
     _pes_synced(false),
     _seen_sps(false),
@@ -146 +146 @@
 
     //_start_code
     _first_keyframe             =-1;
+    _has_written_mheg_keyframe  = false;
     _last_keyframe_seen         = 0;
     _last_gop_seen              = 0;
     _last_seq_seen              = 0;
@@ -344 +345 @@
     return hasKeyFrame;
 }
 
+/** \brief This creates a fake keyframe for MHEG only streams.
+ *
+ *   This is for MHEG streams which contain no audio or video streams
+ *   We write just one key-frame at the start so that the frontend
+ *   can jump to the start of the stream.
+ */
+bool DTVRecorder::FindOtherKeyframes(const TSPacket *tspacket)
+{
+    if (_has_written_mheg_keyframe)
+        return true;
+
+    _frames_seen_count++;
+    _frames_written_count++;
+    _last_keyframe_seen = _frames_seen_count;
+    HandleKeyframe();
+
+    _has_written_mheg_keyframe = true;
+
+    return true;
+}
+
 // documented in recorderbase.h
 void DTVRecorder::SetNextRecording(const ProgramInfo *progInf, RingBuffer *rb)
 {