Ticket #7964: timestretch-predictive-frame-skip.patch

libs/libmythtv/NuppelVideoPlayer.cpp

@@ -255 +255 @@
     text_size = 8 * (sizeof(teletextsubtitle) + VT_WIDTH);
     for (int i = 0; i < MAXTBUFFER; i++)
         txtbuffers[i].buffer = new unsigned char[text_size + 1];
+
+    m_skip_frame_idx = m_skip_frame_extra_idx = 0;
+    m_skip_frame = m_skip_frame_extra = 0;
 }
 
 NuppelVideoPlayer::~NuppelVideoPlayer(void)
@@ -500 +503 @@
     audio_lock.lock();
     if (audioOutput && unpauseaudio)
         audio_paused = false;
-    
+
     audio_lock.unlock();
     if (player_ctx->buffer)
         player_ctx->buffer->Unpause();
@@ -534 +537 @@
 void NuppelVideoPlayer::PauseVideo(bool wait)
 {
     QMutexLocker locker(&pauseUnpauseLock);
-    
+
     if (wait)
         video_actually_paused = false;
     pausevideo = true;
-    
+
     for (uint i = 0; wait && !video_actually_paused; i++)
     {
         videoThreadPaused.wait(&pauseUnpauseLock, 250);
@@ -1023 +1026 @@
     m_scan_locked  = false;
 }
 
+void NuppelVideoPlayer::PredictFrameSkip(FrameScanType scan)
+{
+    if (play_speed > 1.0)
+    {
+        float skip_frame, extra_skip;
+        skip_frame = (video_frame_rate /
+                      ((play_speed * video_frame_rate) -
+                       video_frame_rate));
+        VERBOSE(VB_PLAYBACK, "skip_frame " << skip_frame);
+        if (kScan_Progressive != scan)
+            skip_frame *= 2;
+        VERBOSE(VB_IMPORTANT, QString("kScan = %1, scan = %2")
+                .arg(kScan_Progressive).arg(scan));
+        VERBOSE(VB_PLAYBACK, "skip_frame " << skip_frame);
+        m_skip_frame = skip_frame;
+        VERBOSE(VB_PLAYBACK, "m_skip_frame " << m_skip_frame);
+        VERBOSE(VB_PLAYBACK, " diff " << skip_frame - m_skip_frame);
+        if (skip_frame - (float)m_skip_frame < 0.0001)
+        {
+            m_skip_frame_extra = 0;
+            m_skip_frame_extra_idx = 0;
+        }
+        else
+        {
+            m_skip_frame_extra = (1.0 /
+                                  (skip_frame - (float)m_skip_frame))
+                                 * (float)m_skip_frame;
+            --m_skip_frame_extra; // Seems better to skip to often, than not often enough
+            VERBOSE(VB_PLAYBACK, "m_skip_frame_extra " << m_skip_frame_extra);
+            m_skip_frame_extra_idx = -2;
+        }
+
+        m_skip_frame_idx = 0;
+        ++m_skip_frame;
+        VERBOSE(VB_PLAYBACK, "m_skip_frame " << m_skip_frame);
+
+        VERBOSE(VB_PLAYBACK, LOC + QString("Adjusted play speed %1,  "
+                                           "skip frame %2 & %3 "
+                                           "(rate %4)")
+                .arg(play_speed).arg(m_skip_frame)
+                .arg(m_skip_frame_extra).arg(video_frame_rate));
+    }
+    else
+    {
+        m_skip_frame_idx = m_skip_frame_extra_idx = 0;
+        m_skip_frame = m_skip_frame_extra = 0;
+    }
+}
+
 void NuppelVideoPlayer::SetScanType(FrameScanType scan)
 {
     QMutexLocker locker(&videofiltersLock);
@@ -1046 +1098 @@
     {
         m_scan = scan;
         videosync->SetFrameInterval(frame_interval, false);
+        PredictFrameSkip(scan);
         return;
     }
 
@@ -1089 +1142 @@
     if (osd)
     {
         osd->SetFrameInterval(
-            (m_double_framerate && m_double_process) ?
-            (frame_interval>>1) : frame_interval);
+                              (m_double_framerate && m_double_process) ?
+                              (frame_interval>>1) : frame_interval);
     }
 
+    if (m_scan != scan)
+        PredictFrameSkip(scan);
+
     m_scan = scan;
 }
 
@@ -1150 +1206 @@
     isDummy = true;
 
     float displayAspect =
-        gContext->GetFloatSettingOnHost("XineramaMonitorAspectRatio", 
+        gContext->GetFloatSettingOnHost("XineramaMonitorAspectRatio",
                                         gContext->GetHostName(), 1.3333);
 
     if (!videoOutput)
@@ -2406 +2462 @@
     if (kScan_Detect == m_scan || kScan_Ignore == m_scan)
         ps = kScan_Progressive;
 
-    if (diverge < -MAXDIVERGE)
+    if (m_skip_frame_extra && ++m_skip_frame_extra_idx == m_skip_frame_extra)
+    {
+        m_skip_frame_extra_idx = 0;
+
+        /* Copied from (diverge < -MAXDIVERGE), below.  Can it be optimized? */
+        // Reset A/V Sync
+        lastsync = true;
+
+        if (buffer && !using_null_videoout &&
+            videoOutput->hasHWAcceleration() &&
+           !videoOutput->IsSyncLocked())
+        {
+            // If we are using certain hardware decoders, so we've already done
+            // the decoding; display the frame, but don't wait for A/V Sync.
+            // Excludes HW decoder/render methods that are locked to
+            // the vertical sync (e.g. VDPAU)
+            videoOutput->PrepareFrame(buffer, kScan_Intr2ndField);
+            videoOutput->Show(kScan_Intr2ndField);
+            VERBOSE(VB_PLAYBACK, LOC + "skipping A/V wait.");
+        }
+    }
+    if (m_skip_frame && ++m_skip_frame_idx == m_skip_frame)
+    {
+        m_skip_frame_idx = 0;
+
+        /* Copied from (diverge < -MAXDIVERGE), below.  Can it be optimized? */
+        // Reset A/V Sync
+        lastsync = true;
+
+        if (buffer && !using_null_videoout &&
+            videoOutput->hasHWAcceleration() &&
+           !videoOutput->IsSyncLocked())
+        {
+            // If we are using certain hardware decoders, so we've already done
+            // the decoding; display the frame, but don't wait for A/V Sync.
+            // Excludes HW decoder/render methods that are locked to
+            // the vertical sync (e.g. VDPAU)
+            videoOutput->PrepareFrame(buffer, kScan_Intr2ndField);
+            videoOutput->Show(kScan_Intr2ndField);
+            VERBOSE(VB_PLAYBACK, LOC + "skipping A/V wait.");
+        }
+    }
+    else if (diverge < -MAXDIVERGE)
     {
         // If video is way behind of audio, adjust for it...
         QString dbg = QString("Video is %1 frames behind audio (too slow), ")
@@ -2414 +2512 @@
 
         // Reset A/V Sync
         lastsync = true;
+        m_skip_frame_idx = 0;
+        m_skip_frame_extra_idx = -2;
 
         if (buffer && !using_null_videoout &&
             videoOutput->hasHWAcceleration() &&
@@ -2524 +2624 @@
         VERBOSE(VB_PLAYBACK, LOC +
                 QString("Video is %1 frames ahead of audio,\n"
                         "\t\t\tdoubling video frame interval to slow down.").arg(diverge));
+        m_skip_frame_idx = 0;
+        m_skip_frame_extra_idx = -2;
     }
 
     audio_lock.lock();
@@ -2593 +2695 @@
             avsync_avg = 0;
             avsync_oldavg = 0;
         }
-    } 
+    }
     else
         audio_lock.unlock();
 }
@@ -3595 +3697 @@
 
             play_speed = next_play_speed;
             normal_speed = next_normal_speed;
+
             VERBOSE(VB_PLAYBACK, LOC + "Changing speed to " << play_speed);
 
+            PredictFrameSkip(m_scan);
+
             if (play_speed == 0.0)
             {
                 DoPause();
@@ -4442 +4547 @@
         audio_lock.unlock();
     }
 
+
     VERBOSE(VB_PLAYBACK, LOC + "DoPlay() -- setting unpaused");
     paused = actuallypaused = false;
 }
@@ -6861 +6967 @@
         if (decoder)
         {
             msg = decoder->GetTrackDesc(type, GetTrack(type));
-            
+
             if (player_ctx->buffer->isDVD())
                 player_ctx->buffer->DVD()->SetTrack(type, trackNo);
         }
@@ -7592 +7698 @@
 {
     if (!player_ctx->buffer->isDVD())
         return false;
-    
+
     textDisplayMode = kDisplayNone;
     bool ret = player_ctx->buffer->DVD()->GoToMenu(str);
-    
+
     if (!ret)
     {
         if (osd)
@@ -7603 +7709 @@
         VERBOSE(VB_GENERAL, "No DVD Menu available.");
         return false;
     }
-    
+
     return true;
 }
 
@@ -8056 +8162 @@
 }
 
 /* vim: set expandtab tabstop=4 shiftwidth=4: */
+

libs/libmythtv/NuppelVideoPlayer.h

@@ -151 +151 @@
     void ClearBookmark(void);
     void SetForcedAspectRatio(int mpeg2_aspect_value, int letterbox_permission);
 
+    void PredictFrameSkip(FrameScanType scan);
+
     void NextScanType(void)
         { SetScanType((FrameScanType)(((int)m_scan + 1) & 0x3)); }
     void SetScanType(FrameScanType);
@@ -803 +805 @@
     bool       decode_extra_audio;
     float      m_stored_audio_stretchfactor;
     bool       audio_paused;
+    int        m_skip_frame_idx;
+    int        m_skip_frame;
+    int        m_skip_frame_extra;
+    int        m_skip_frame_extra_idx;
 
     // Audio warping stuff
     bool       usevideotimebase;