diff --git a/audio.c b/audio.c
index e9d72883..6e749eee 100644
--- a/audio.c
+++ b/audio.c
@@ -769,7 +769,6 @@ static int AlsaPlayRingbuffer(void)
 	    Error("audio/alsa: bytes lost -> out of sync");
 	}
 #endif
-
 	for (;;) {
 	    pthread_mutex_lock(&ReadAdvance_mutex);
 	    if (AlsaUseMmap) {
@@ -779,12 +778,13 @@ static int AlsaPlayRingbuffer(void)
 	    }
 	    if (err != frames) {
 		if (err < 0) {
-		    pthread_mutex_unlock(&ReadAdvance_mutex);
 		    if (err == -EAGAIN) {
+			pthread_mutex_unlock(&ReadAdvance_mutex);
 			continue;
 		    }
 		    Error("audio/alsa: writei underrun error? '%s'", snd_strerror(err));
 		    err = snd_pcm_recover(AlsaPCMHandle, err, 0);
+		    pthread_mutex_unlock(&ReadAdvance_mutex);
 		    if (err >= 0) {
 			return 0;
 		    }
@@ -1361,8 +1361,8 @@ static int AudioNextRing(void)
     if (remain <= AUDIO_MIN_BUFFER_FREE) {
 	Debug5("audio: force start");
     }
-    if (remain <= AUDIO_MIN_BUFFER_FREE || ((AudioVideoIsReady || !SoftIsPlayingVideo)
-	    && AudioStartThreshold < used)) {
+    if (AudioStartThreshold * 4 < used || remain <= AUDIO_MIN_BUFFER_FREE || ((AudioVideoIsReady
+		|| !SoftIsPlayingVideo) && AudioStartThreshold < used)) {
 	return 0;
     }
     return 1;
@@ -1613,8 +1613,8 @@ void AudioEnqueue(const void *samples, int count)
 	if (remain <= AUDIO_MIN_BUFFER_FREE) {
 	    Debug5("audio: force start");
 	}
-	if (remain <= AUDIO_MIN_BUFFER_FREE || ((AudioVideoIsReady || !SoftIsPlayingVideo)
-		&& AudioStartThreshold < n)) {
+	if (AudioStartThreshold * 4 < n || remain <= AUDIO_MIN_BUFFER_FREE || ((AudioVideoIsReady
+		    || !SoftIsPlayingVideo) && AudioStartThreshold < n)) {
 	    // restart play-back
 	    // no lock needed, can wakeup next time
 	    AudioRunning = 1;
diff --git a/codec.c b/codec.c
index 063e8854..09c80352 100644
--- a/codec.c
+++ b/codec.c
@@ -450,7 +450,7 @@ void CodecVideoFlushBuffers(VideoDecoder * decoder)
 **
 **	@param decoder	video decoder data
 */
-const char* CodecVideoGetCodecName(VideoDecoder * decoder)
+const char *CodecVideoGetCodecName(VideoDecoder * decoder)
 {
     if (decoder && decoder->VideoCodec)
 	return avcodec_get_name(decoder->VideoCodec->id);
@@ -458,7 +458,6 @@ const char* CodecVideoGetCodecName(VideoDecoder * decoder)
     return avcodec_get_name(AV_CODEC_ID_NONE);
 }
 
-
 //----------------------------------------------------------------------------
 //  Audio
 //----------------------------------------------------------------------------
@@ -567,7 +566,7 @@ void CodecAudioOpen(AudioDecoder * audio_decoder, int codec_id_old)
     switch (device_get_atype()) {
 	case 0:
 	    break;
-	case 0x3:	/* FALLTHRU */
+	case 0x3:		       /* FALLTHRU */
 	case 0x4:
 	    codec_id = AV_CODEC_ID_MP2;
 	    break;
@@ -600,7 +599,7 @@ void CodecAudioOpen(AudioDecoder * audio_decoder, int codec_id_old)
 	audio_decoder->AudioFmtCtx->audio_codec_id = codec_id;
 
     av_dict_set_int(&options, "analyzeduration", 500, 0);
-    av_dict_set_int(&options, "probesize", alloc_size / 2 , 0);
+    av_dict_set_int(&options, "probesize", alloc_size / 2, 0);
 
     input_format = av_find_input_format("mpeg");
     if (!input_format) {
@@ -622,18 +621,14 @@ void CodecAudioOpen(AudioDecoder * audio_decoder, int codec_id_old)
 	Error("codec: failed to add audio stream to context");
 	goto error_avformat_new_stream;
     }
-
-#if 1
     audio_decoder->AudioFmtCtx->streams[0]->codecpar->codec_id = codec_id;
     audio_decoder->AudioFmtCtx->streams[0]->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
-#endif
-#if 1
+
     ret = avformat_find_stream_info(audio_decoder->AudioFmtCtx, NULL);
     if (ret < 0) {
 	Error("codec: can't find audio stream info: %s", av_err2str(ret));
 	goto error_avformat_find_stream_info;
     }
-#endif
 
     av_dump_format(audio_decoder->AudioFmtCtx, 0, "vaapidevice audio", 0);
 #if 0
@@ -704,7 +699,9 @@ void CodecAudioOpen(AudioDecoder * audio_decoder, int codec_id_old)
   error_avcodec_alloc_context3:
   error_avcodec_find_decoder:
   error_avformat_new_stream:
+#if 0
   error_avformat_find_best_stream:
+#endif
   error_avformat_find_stream_info:
   error_avformat_open_input:
     av_freep(avio_ctx);
diff --git a/codec.h b/codec.h
index 3e0ada47..b4a9276e 100644
--- a/codec.h
+++ b/codec.h
@@ -75,7 +75,7 @@ extern void CodecVideoDecode(VideoDecoder *);
 extern void CodecVideoFlushBuffers(VideoDecoder *);
 
     /// Get video decoder name.
-extern const char* CodecVideoGetCodecName(VideoDecoder *);
+extern const char *CodecVideoGetCodecName(VideoDecoder *);
 
     /// Allocate a new audio decoder context.
 extern AudioDecoder *CodecAudioNewDecoder(void);
diff --git a/vaapidev.c b/vaapidev.c
index 4dbda95f..5331989c 100644
--- a/vaapidev.c
+++ b/vaapidev.c
@@ -36,7 +36,6 @@
 #include "video.h"
 #include "codec.h"
 
-
 //////////////////////////////////////////////////////////////////////////////
 //  Variables
 //////////////////////////////////////////////////////////////////////////////
@@ -1613,6 +1612,7 @@ char *GetVideoStats(void)
 char *GetVideoInfo(void)
 {
     const char *codec = CodecVideoGetCodecName(MyVideoStream->Decoder);
+
     return MyVideoStream->HwDecoder ? VideoGetInfo(MyVideoStream->HwDecoder, codec) : NULL;
 }
 
diff --git a/vaapidevice.cpp b/vaapidevice.cpp
index 7c0733cf..97c9e38d 100644
--- a/vaapidevice.cpp
+++ b/vaapidevice.cpp
@@ -1985,6 +1985,7 @@ void cVaapiDevice::GetOsdSize(int &width, int &height, double &pixel_aspect)
 int cVaapiDevice::PlayAudio(const uchar * data, int length, uchar id)
 {
     const int ringBufferSize = KILOBYTE(512);
+
     if (length > ringBufferSize) {
 	Error("Audio PES packet size (%d) too large for frame ringbuffer", length);
 	return 0;
@@ -1999,6 +2000,7 @@ int cVaapiDevice::PlayAudio(const uchar * data, int length, uchar id)
     if (audioEof || !audioBuffer->Put(packet)) {
 	// If this happens often enough vdr will start asking for a clear of device
 	delete packet;
+
 	return 0;
     }
     // TODO: remove vaapidev code
@@ -2046,6 +2048,7 @@ void cVaapiDevice::SetVolumeDevice(int volume)
 int cVaapiDevice::PlayVideo(const uchar * data, int length)
 {
     const int ringBufferSize = MEGABYTE(1);
+
     if (length > ringBufferSize) {
 	Error("Video PES packet size (%d) too large for frame ringbuffer", length);
 	return 0;
@@ -2060,6 +2063,7 @@ int cVaapiDevice::PlayVideo(const uchar * data, int length)
     if (videoEof || !videoBuffer->Put(packet)) {
 	// If this happens often enough vdr will start asking for a clear of device
 	delete packet;
+
 	return 0;
     }
 
@@ -2124,10 +2128,9 @@ int cVaapiDevice::DeviceGetAtype()
     eTrackType track = GetCurrentAudioTrack();
 
     if (IS_AUDIO_TRACK(track)) {
-	return PatPmtParser()->Atype(int(track - ttAudioFirst));
-    }
-    else if (IS_DOLBY_TRACK(track)) {
-	return PatPmtParser()->Dtype(int(track - ttDolbyFirst));
+	return PatPmtParser()->Atype(int (track - ttAudioFirst));
+    } else if (IS_DOLBY_TRACK(track)) {
+	return PatPmtParser()->Dtype(int (track - ttDolbyFirst));
     }
 
     return -1;
@@ -2209,7 +2212,6 @@ int cVaapiDevice::DeviceAudioReadCallback(uchar * data, int size)
 
     } while (!packet && ffmpegMode == 0 && retries++ < 3);
 
-
     if (!packet) {
 	return ffmpegMode ? 0 : AVERROR_EOF;
     }
diff --git a/video.c b/video.c
index 3e6cbc69..7f6f4f49 100644
--- a/video.c
+++ b/video.c
@@ -74,6 +74,9 @@
 #define TO_VAAPI_DEVICE_CTX(x) ((AVVAAPIDeviceContext*)TO_AVHW_DEVICE_CTX(x)->hwctx)
 #define TO_VAAPI_FRAMES_CTX(x) ((AVVAAPIFramesContext*)TO_AVHW_FRAMES_CTX(x)->hwctx)
 
+// PTS Filter-Elements of 1, 2, 4, 8, 16, ..
+#define LP_FILTER_CNT 2
+
 //----------------------------------------------------------------------------
 //  Declarations
 //----------------------------------------------------------------------------
@@ -830,7 +833,11 @@ struct _vaapi_decoder_
     int SyncOnAudio;			///< flag sync to audio
     int64_t PTS;			///< video PTS clock
 
-    int LastAVDiff;			///< last audio - video difference
+    int64_t AvPtsDiffFilter;		///< AV-PTS-Diff Delay element – 64 bits
+    int AvPtsDiffFilterInit;		///< Filter Init Done
+    int64_t LastVideoPTS;		///< Video-PTS Rollover Test
+    int64_t LastAudioPTS;		///< Audio-PTS Rollover Test
+
     int SyncCounter;			///< counter to sync frames
     int StartCounter;			///< counter for video start
     int FramesDuped;			///< number of frames duplicated
@@ -1343,6 +1350,13 @@ static VaapiDecoder *VaapiNewHwDecoder(VideoStream * stream)
 
     decoder->GetPutImage = 1;
 
+    decoder->AvPtsDiffFilterInit = 1;
+    decoder->AvPtsDiffFilter = 0;
+    decoder->LastVideoPTS = 0;
+    decoder->LastAudioPTS = 0;
+    decoder->SyncCounter = 0;
+    decoder->StartCounter = 0;
+
     VaapiDecoders[VaapiDecoderN++] = decoder;
 
     return decoder;
@@ -3603,7 +3617,8 @@ char *VaapiGetStats(VaapiDecoder * decoder)
     if (snprintf(&buffer[0], sizeof(buffer),
 	    " Frames: missed(%d) duped(%d) dropped(%d) total(%d) PTS(%s) drift(%" PRId64 ") audio(%" PRId64 ") video(%"
 	    PRId64 ")", decoder->FramesMissed, decoder->FramesDuped, decoder->FramesDropped, decoder->FrameCounter,
-	    Timestamp2String(video_clock), (video_clock - audio_clock) / 90, AudioGetDelay() / 90, VideoDeltaPTS / 90)) {
+	    Timestamp2String(video_clock), (video_clock - audio_clock) / 90, AudioGetDelay() / 90,
+	    VideoDeltaPTS / 90)) {
 	return strdup(buffer);
     }
 
@@ -3654,6 +3669,11 @@ static void VaapiSyncDecoder(VaapiDecoder * decoder)
     int filled;
     int64_t audio_clock;
     int64_t video_clock;
+    int64_t diff;
+
+    if (decoder == NULL) {
+	return;
+    }
 
     err = 0;
     mutex_start_time = GetMsTicks();
@@ -3675,7 +3695,7 @@ static void VaapiSyncDecoder(VaapiDecoder * decoder)
 	    goto out;
 	}
 	// both clocks are known
-	if (audio_clock + VideoAudioDelay <= video_clock + 25 * 90) {
+	if (audio_clock + (int64_t) VideoAudioDelay <= video_clock + (int64_t) 25 * 90) {
 	    goto out;
 	}
 	// out of sync: audio before video
@@ -3705,35 +3725,48 @@ static void VaapiSyncDecoder(VaapiDecoder * decoder)
 
     if (audio_clock != (int64_t) AV_NOPTS_VALUE && video_clock != (int64_t) AV_NOPTS_VALUE) {
 	// both clocks are known
-	int diff;
-	int lower_limit;
-
-	diff = video_clock - audio_clock - VideoAudioDelay;
-	lower_limit = !IsReplay()? -25 : 32;
-	if (!IsReplay()) {
-	    diff = (decoder->LastAVDiff + diff) / 2;
-	    decoder->LastAVDiff = diff;
+	// FIXME: "diff" doesn't checks frametype (i - Top/Bottom, p - Full)
+	diff = video_clock - audio_clock - (int64_t) VideoAudioDelay;
+
+	// AV-Diff greater than 1:00:00.000 should be a PTS-Rollover,
+	// but observable is: audio_clock jumps to negative values...
+	if ((audio_clock < 0) || (video_clock < 0) || (abs(diff) > (int64_t) 60 * 60 * 90000)) {
+	    // Set Bit 34 of video_clock if below 1:00:00.000
+	    if (video_clock < (int64_t) 60 * 60 * 90000)
+		video_clock = video_clock + (int64_t) 0x200000000;
+	    // Set Bit 34 of audio_clock if below 1:00:00.000
+	    if (audio_clock < (int64_t) 60 * 60 * 90000)
+		audio_clock = audio_clock + (int64_t) 0x200000000;
+
+	    // Calc correct diff
+	    err = VaapiMessage(1, "AV-PTS Rollover, correcting AV-PTS Difference");
+	    diff = (video_clock - audio_clock - (int64_t) VideoAudioDelay);
+	}
+	// Low-Pass Filter AV-PTS-Diff, if in Sync-Range of +/- 250 ms
+	if (abs(diff) < (int64_t) 250 * 90) {
+	    // Filter-Init done?
+	    if (decoder->AvPtsDiffFilterInit) {
+		// No.
+		decoder->AvPtsDiffFilterInit = 0;
+		decoder->AvPtsDiffFilter = diff * LP_FILTER_CNT;
+	    }
+	    decoder->AvPtsDiffFilter = decoder->AvPtsDiffFilter - (decoder->AvPtsDiffFilter / LP_FILTER_CNT) + diff;
+	    diff = decoder->AvPtsDiffFilter / LP_FILTER_CNT;
 	}
 
-	if (abs(diff) > 5000 * 90) {	// more than 5s
+	if (abs(diff) > (int64_t) 5000 * 90) {	// more than 5s
 	    err = VaapiMessage(2, "video: audio/video difference too big");
-	} else if (diff > 100 * 90) {
-	    // FIXME: this quicker sync step, did not work with new code!
-	    err = VaapiMessage(2, "video: slow down video, duping frame");
-	    ++decoder->FramesDuped;
-	    if (VideoSoftStartSync) {
-		decoder->SyncCounter = 1;
-		goto out;
-	    }
-	} else if (diff > 55 * 90) {
-	    err = VaapiMessage(2, "video: slow down video, duping frame");
+	} else if (diff > (int64_t) 40 * 90) {
+	    Debug("video: slow down video, duping frame (/\\=%.2f ms, vClk %s - aClk %s)", diff * 1000 / (double)90000,
+		Timestamp2String(video_clock), Timestamp2String(audio_clock));
 	    ++decoder->FramesDuped;
 	    if (VideoSoftStartSync) {
 		decoder->SyncCounter = 1;
 		goto out;
 	    }
-	} else if (diff < lower_limit * 90 && filled > 1 + 2 * decoder->Interlaced) {
-	    err = VaapiMessage(2, "video: speed up video, droping frame");
+	} else if ((diff < (int64_t) - 20 * 90) && (filled > 1 + 2 * decoder->Interlaced)) {
+	    Debug("video: speed up video, droping frame (/\\=%.2f ms, vClk %s - aClk %s)", diff * 1000 / (double)90000,
+		Timestamp2String(video_clock), Timestamp2String(audio_clock));
 	    ++decoder->FramesDropped;
 	    VaapiAdvanceDecoderFrame(decoder);
 	    if (VideoSoftStartSync) {
@@ -3780,9 +3813,9 @@ static void VaapiSyncDecoder(VaapiDecoder * decoder)
 	}
 	Info("video: %s%+5" PRId64 " %4" PRId64 " %3d/\\ms %3d%+d v-buf", Timestamp2String(video_clock),
 	    (video_clock - audio_clock) / 90, AudioGetDelay() / 90, (int)VideoDeltaPTS / 90,
-	    VideoGetBuffers(decoder->Stream), decoder->Interlaced ?
-	    (2 * atomic_read(&decoder->SurfacesFilled) - decoder->SurfaceField) :
-	    atomic_read(&decoder->SurfacesFilled));
+	    VideoGetBuffers(decoder->Stream),
+	    decoder->Interlaced ? (2 * atomic_read(&decoder->SurfacesFilled) -
+		decoder->SurfaceField) : atomic_read(&decoder->SurfacesFilled));
 	if (!(decoder->FramesDisplayed % (5 * 60 * 60))) {
 	    VaapiPrintFrames(decoder);
 	}