Ticket #7521: t7521_avseek_fixes_rev3.diff

libs/libmythtv/decoderbase.h

@@ -91 +91 @@
                          int testbufsize = kDecoderProbeBufferSize) = 0;
 
     void setExactSeeks(bool exact) { exactseeks = exact; }
+    bool getExactSeeks(void) { return exactseeks; }
     void setLiveTVMode(bool live) { livetv = live; }
 
     // Must be done while player is paused.

libs/libmythtv/avformatdecoder.cpp

@@ -589 +589 @@
     if (recordingHasPositionMap || livetv)
         return DecoderBase::DoRewind(desiredFrame, discardFrames);
 
+    dorewind = true;
+
     // avformat-based seeking
     return DoFastForward(desiredFrame, discardFrames);
 }
@@ -619 +621 @@
     if (!st)
         return false;
 
+    int seekDelta = desiredFrame - framesPlayed;
+
+    // avoid using av_frame_seek if we want to advance forward < 1 second
+    if (seekDelta >= 0 && seekDelta < (int)(fps + 1.0f) && !dorewind)
+    {
+        SeekReset(framesPlayed, seekDelta, false, true);
+        GetNVP()->SetFramesPlayed(framesPlayed + 1);
+        GetNVP()->getVideoOutput()->SetFramesPlayed(framesPlayed + 1);
+
+        return true;
+    }
+
     int64_t frameseekadjust = 0;
     AVCodecContext *context = st->codec;
 
@@ -633 +647 @@
     long double diff = (max(desiredFrame - frameseekadjust, 0LL)) * AV_TIME_BASE / fps;
     ts += (long long)diff;
 
-    if (av_seek_frame(ic, -1, ts, AVSEEK_FLAG_BACKWARD) < 0)
+    bool exactseeks = DecoderBase::getExactSeeks();
+
+    int flags = 0;
+    if (dorewind || exactseeks)
+        flags |= AVSEEK_FLAG_BACKWARD;
+
+    if (av_seek_frame(ic, -1, ts, flags) < 0)
     {
         VERBOSE(VB_IMPORTANT, LOC_ERR
                 <<"av_seek_frame(ic, -1, "<<ts<<", 0) -- error");
@@ -672 +692 @@
         framesPlayed = lastKey;
         framesRead = lastKey;
 
-        normalframes = desiredFrame - framesPlayed;
+        normalframes = (exactseeks) ? desiredFrame - framesPlayed : 0;
         normalframes = max(normalframes, 0);
         no_dts_hack = false;
     }
@@ -685 +705 @@
         normalframes = 0;
     }
 
-    SeekReset(lastKey, normalframes, discardFrames, discardFrames);
+    SeekReset(lastKey, normalframes, true, discardFrames);
 
     if (discardFrames)
     {
@@ -693 +713 @@
         GetNVP()->getVideoOutput()->SetFramesPlayed(framesPlayed + 1);
     }
 
+    dorewind = false;
+
     getrawframes = oldrawstate;
 
     return true;

libs/libmythtv/avformatdecoder.h

@@ -220 +220 @@
     bool drawband;
 
     bool no_dts_hack;
+    bool dorewind;
 
     bool gopset;
     /// A flag to indicate that we've seen a GOP frame.  Used in junction with seq_count.