Ticket #2984: dvbrecorder.audio_scan_code2.diff

libs/libmythtv/dvbrecorder.cpp

@@ -64 +64 @@
 #include "cardutil.h"
 #include "tv_rec.h"
 
+extern "C" {
+// from libavcodec
+extern const uint8_t *ff_find_start_code(const uint8_t * restrict p, const uint8_t *end, uint32_t * restrict state);
+}
+
 // MythTV DVB includes
 #include "dvbtypes.h"
 #include "dvbchannel.h"
@@ -1192 +1197 @@
 void DVBRecorder::GetTimeStamp(const TSPacket& tspacket)
 {
     const uint pid = tspacket.PID();
-    if (pid != _audio_pid)
+    if (pid != _audio_pid || tspacket.PayloadStart())
+    {
         _audio_header_pos = 0;
+        _audio_start_code = 0xffffffff;
+    }
 
-    // Find the current audio time stamp.  This code is based on
-    // DTVRecorder::FindMPEG2Keyframes.
-    if (tspacket.PayloadStart())
-        _audio_header_pos = 0;
-    for (uint i = tspacket.AFCOffset(); i < TSPacket::SIZE; i++)
+    const uint8_t *bufptr = tspacket.data() + tspacket.AFCOffset();
+    const uint8_t *bufend = tspacket.data() + TSPacket::SIZE;
+    
+    while (bufptr < bufend)
     {
-        const unsigned char k = tspacket.data()[i];
+        if (!_audio_header_pos)
+            bufptr = ff_find_start_code(bufptr, bufend, &_audio_start_code);
+
+        if ((_audio_start_code & 0xffffff00) != 0x00000100)
+        {
+            _audio_header_pos = 0;
+            continue;
+        }
+        else
+        {
+            _audio_header_pos = _audio_header_pos ? _audio_header_pos : 3;
+            bufptr++;
+        }
+
+        const unsigned char k = *(bufptr - 2);
+
         switch (_audio_header_pos)
         {
-            case 0:
-                _audio_header_pos = (k == 0x00) ? 1 : 0;
-                break;
-            case 1:
-                _audio_header_pos = (k == 0x00) ? 2 : 0;
-                break;
-            case 2:
-                _audio_header_pos = (k == 0x00) ? 2 : ((k == 0x01) ? 3 : 0);
-                break;
             case 3:
                 if ((k >= PESStreamID::MPEGAudioStreamBegin) &&
                     (k <= PESStreamID::MPEGAudioStreamEnd))

libs/libmythtv/dvbrecorder.h

@@ -170 +170 @@
     int             _ts_packets_until_psip_sync;
 
     // Fake video for streams without video
+    uint32_t        _audio_start_code;
     uint            _audio_header_pos;
     uint            _video_header_pos;
     uint            _audio_pid;