diff --git a/app/codec/decoder.h b/app/codec/decoder.h
index 061378be0..99fa74428 100644
--- a/app/codec/decoder.h
+++ b/app/codec/decoder.h
@@ -34,6 +34,7 @@ extern "C" {
 #include "codec/frame.h"
 #include "codec/samplebuffer.h"
 #include "common/rational.h"
+#include "node/block/block.h"
 #include "node/project/footage/footage.h"
 #include "node/project/footage/footagedescription.h"
 #include "task/task.h"
@@ -85,13 +86,15 @@ public:
   {
   public:
     CodecStream() :
-      stream_(-1)
+      stream_(-1),
+      block_(nullptr)
     {
     }
 
-    CodecStream(const QString& filename, int stream) :
+    CodecStream(const QString& filename, int stream, Block *block) :
       filename_(filename),
-      stream_(stream)
+      stream_(stream),
+      block_(block)
     {
     }
 
@@ -125,11 +128,18 @@ public:
       return stream_;
     }
 
+    Block *block() const
+    {
+      return block_;
+    }
+
   private:
     QString filename_;
 
     int stream_;
 
+    Block *block_;
+
   };
 
   /**
diff --git a/app/codec/ffmpeg/ffmpegdecoder.cpp b/app/codec/ffmpeg/ffmpegdecoder.cpp
index 977f1c251..a2ebad125 100644
--- a/app/codec/ffmpeg/ffmpegdecoder.cpp
+++ b/app/codec/ffmpeg/ffmpegdecoder.cpp
@@ -63,7 +63,6 @@ FFmpegDecoder::FFmpegDecoder() :
   native_output_pix_fmt_(VideoParams::kFormatInvalid),
   working_frame_(nullptr),
   working_packet_(nullptr),
-  is_working_(false),
   cache_at_zero_(false),
   cache_at_eof_(false)
 {
@@ -750,7 +749,7 @@ AVFramePtr FFmpegDecoder::RetrieveFrame(const rational& time, const QAtomicInt *
   int64_t target_ts = GetTimeInTimebaseUnits(time, instance_.avstream()->time_base, instance_.avstream()->start_time);
 
   const int64_t min_seek = -instance_.avstream()->start_time;
-  int64_t seek_ts = target_ts;
+  int64_t seek_ts = std::max(min_seek, target_ts - MaximumQueueSize());
   bool still_seeking = false;
 
   if (time != kAnyTimecode) {
@@ -839,7 +838,7 @@ AVFramePtr FFmpegDecoder::RetrieveFrame(const rational& time, const QAtomicInt *
     } else {
 
       // Cut down to thread count - 1 before we acquire a new frame
-      if (cached_frames_.size() == size_t(QThread::idealThreadCount())) {
+      if (cached_frames_.size() == size_t(MaximumQueueSize())) {
         RemoveFirstFrame();
       }
 
@@ -1040,6 +1039,11 @@ void FFmpegDecoder::RemoveFirstFrame()
   cache_at_zero_ = false;
 }
 
+int FFmpegDecoder::MaximumQueueSize()
+{
+  return QThread::idealThreadCount();
+}
+
 FFmpegDecoder::Instance::Instance() :
   fmt_ctx_(nullptr),
   codec_ctx_(nullptr),
diff --git a/app/codec/ffmpeg/ffmpegdecoder.h b/app/codec/ffmpeg/ffmpegdecoder.h
index 80c46fb1f..4e51f496f 100644
--- a/app/codec/ffmpeg/ffmpegdecoder.h
+++ b/app/codec/ffmpeg/ffmpegdecoder.h
@@ -155,6 +155,8 @@ private:
 
   void RemoveFirstFrame();
 
+  static int MaximumQueueSize();
+
   RetrieveVideoParams filter_params_;
   AVFilterGraph* filter_graph_;
   AVFilterContext* buffersrc_ctx_;
@@ -171,9 +173,6 @@ private:
 
   std::list<AVFramePtr> cached_frames_;
 
-  bool is_working_;
-  QMutex is_working_mutex_;
-
   bool cache_at_zero_;
   bool cache_at_eof_;
 
diff --git a/app/render/rendercache.h b/app/render/rendercache.h
index 114244fb8..77a56780d 100644
--- a/app/render/rendercache.h
+++ b/app/render/rendercache.h
@@ -39,15 +39,10 @@ private:
 
 };
 
-struct DecoderPair {
-  DecoderPair()
-  {
-    decoder = nullptr;
-    last_modified = 0;
-  }
-
-  DecoderPtr decoder;
-  qint64 last_modified;
+struct DecoderPair
+{
+  DecoderPtr decoder = nullptr;
+  qint64 last_modified = 0;
 };
 
 using DecoderCache = RenderCache<Decoder::CodecStream, DecoderPair>;
diff --git a/app/render/renderer.cpp b/app/render/renderer.cpp
index 80683c285..b66fd6ca8 100644
--- a/app/render/renderer.cpp
+++ b/app/render/renderer.cpp
@@ -72,8 +72,21 @@ TexturePtr Renderer::InterlaceTexture(TexturePtr top, TexturePtr bottom, const V
   return output;
 }
 
+QVariant Renderer::GetDefaultShader()
+{
+  if (default_shader_.isNull()) {
+    default_shader_ = CreateNativeShader(ShaderCode(QString(), QString()));
+  }
+
+  return default_shader_;
+}
+
 void Renderer::Destroy()
 {
+  if (!default_shader_.isNull()) {
+    DestroyNativeShader(default_shader_);
+  }
+
   color_cache_.clear();
 
   if (!interlace_texture_.isNull()) {
diff --git a/app/render/renderer.h b/app/render/renderer.h
index 749d777cf..839be32cf 100644
--- a/app/render/renderer.h
+++ b/app/render/renderer.h
@@ -76,6 +76,8 @@ public:
 
   TexturePtr InterlaceTexture(TexturePtr top, TexturePtr bottom, const VideoParams &params);
 
+  QVariant GetDefaultShader();
+
   void Destroy();
 
   virtual void PostDestroy() = 0;
@@ -134,6 +136,8 @@ private:
 
   QMutex color_cache_mutex_;
 
+  QVariant default_shader_;
+
   QVariant interlace_texture_;
 
 };
diff --git a/app/render/rendermanager.cpp b/app/render/rendermanager.cpp
index c34b050d8..9710aa626 100644
--- a/app/render/rendermanager.cpp
+++ b/app/render/rendermanager.cpp
@@ -54,7 +54,6 @@ RenderManager::RenderManager(QObject *parent) :
 
     decoder_cache_ = new DecoderCache();
     shader_cache_ = new ShaderCache();
-    default_shader_ = context_->CreateNativeShader(ShaderCode(QString(), QString()));
   } else {
     qCritical() << "Tried to initialize unknown graphics backend";
     context_ = nullptr;
@@ -65,8 +64,6 @@ RenderManager::RenderManager(QObject *parent) :
 RenderManager::~RenderManager()
 {
   if (context_) {
-    context_->DestroyNativeShader(default_shader_);
-
     delete shader_cache_;
     delete decoder_cache_;
 
@@ -157,7 +154,7 @@ void RenderManager::RunTicket(RenderTicketPtr ticket) const
     return;
   }
 
-  RenderProcessor::Process(ticket, context_, decoder_cache_, shader_cache_, default_shader_);
+  RenderProcessor::Process(ticket, context_, decoder_cache_, shader_cache_);
 }
 
 }
diff --git a/app/render/rendermanager.h b/app/render/rendermanager.h
index 8753f7c90..2cf6b22a7 100644
--- a/app/render/rendermanager.h
+++ b/app/render/rendermanager.h
@@ -130,8 +130,6 @@ private:
 
   ShaderCache* shader_cache_;
 
-  QVariant default_shader_;
-
 };
 
 }
diff --git a/app/render/renderprocessor.cpp b/app/render/renderprocessor.cpp
index 37e11a66a..31fc78ec6 100644
--- a/app/render/renderprocessor.cpp
+++ b/app/render/renderprocessor.cpp
@@ -35,12 +35,11 @@ namespace olive {
 
 #define super NodeTraverser
 
-RenderProcessor::RenderProcessor(RenderTicketPtr ticket, Renderer *render_ctx, DecoderCache* decoder_cache, ShaderCache *shader_cache, QVariant default_shader) :
+RenderProcessor::RenderProcessor(RenderTicketPtr ticket, Renderer *render_ctx, DecoderCache* decoder_cache, ShaderCache *shader_cache) :
   ticket_(ticket),
   render_ctx_(render_ctx),
   decoder_cache_(decoder_cache),
-  shader_cache_(shader_cache),
-  default_shader_(default_shader)
+  shader_cache_(shader_cache)
 {
 }
 
@@ -115,7 +114,7 @@ FramePtr RenderProcessor::GenerateFrame(TexturePtr texture, const rational& time
         job.Insert(QStringLiteral("ove_maintex"), NodeValue(NodeValue::kTexture, QVariant::fromValue(texture)));
         job.Insert(QStringLiteral("ove_mvpmat"), NodeValue(NodeValue::kMatrix, matrix));
 
-        render_ctx_->BlitToTexture(default_shader_, job, blit_tex.get());
+        render_ctx_->BlitToTexture(render_ctx_->GetDefaultShader(), job, blit_tex.get());
       }
 
       // Replace texture that we're going to download in the next step
@@ -269,9 +268,9 @@ DecoderPtr RenderProcessor::ResolveDecoderFromInput(const QString& decoder_id, c
   return decoder.decoder;
 }
 
-void RenderProcessor::Process(RenderTicketPtr ticket, Renderer *render_ctx, DecoderCache *decoder_cache, ShaderCache *shader_cache, QVariant default_shader)
+void RenderProcessor::Process(RenderTicketPtr ticket, Renderer *render_ctx, DecoderCache *decoder_cache, ShaderCache *shader_cache)
 {
-  RenderProcessor p(ticket, render_ctx, decoder_cache, shader_cache, default_shader);
+  RenderProcessor p(ticket, render_ctx, decoder_cache, shader_cache);
   p.Run();
 }
 
diff --git a/app/render/renderprocessor.h b/app/render/renderprocessor.h
index 1fb6ea23f..f0ef31227 100644
--- a/app/render/renderprocessor.h
+++ b/app/render/renderprocessor.h
@@ -32,7 +32,7 @@ namespace olive {
 class RenderProcessor : public NodeTraverser
 {
 public:
-  static void Process(RenderTicketPtr ticket, Renderer* render_ctx, DecoderCache* decoder_cache, ShaderCache* shader_cache, QVariant default_shader);
+  static void Process(RenderTicketPtr ticket, Renderer* render_ctx, DecoderCache* decoder_cache, ShaderCache* shader_cache);
 
   struct RenderedWaveform {
     const ClipBlock* block;
@@ -71,7 +71,7 @@ protected:
   virtual void ConvertToReferenceSpace(TexturePtr destination, TexturePtr source, const QString &input_cs) override;
 
 private:
-  RenderProcessor(RenderTicketPtr ticket, Renderer* render_ctx, DecoderCache* decoder_cache, ShaderCache* shader_cache, QVariant default_shader);
+  RenderProcessor(RenderTicketPtr ticket, Renderer* render_ctx, DecoderCache* decoder_cache, ShaderCache* shader_cache);
 
   TexturePtr GenerateTexture(const rational& time, const rational& frame_length);
 
@@ -89,8 +89,6 @@ private:
 
   ShaderCache* shader_cache_;
 
-  QVariant default_shader_;
-
 };
 
 }
diff --git a/app/widget/viewer/viewer.cpp b/app/widget/viewer/viewer.cpp
index 35eb765d0..b5726864c 100644
--- a/app/widget/viewer/viewer.cpp
+++ b/app/widget/viewer/viewer.cpp
@@ -709,7 +709,7 @@ void ViewerWidget::UpdateTextureFromNode()
       ClearVideoAutoCacherQueue();
     }
 
-    watcher->SetTicket(GetFrame(time, RenderTicketPriority::kHigh));
+    watcher->SetTicket(GetFrame(time, RenderTicketPriority::kNormal));
   } else {
     // There is definitely no frame here, we can immediately flip to showing nothing
     nonqueue_watchers_.clear();
@@ -762,7 +762,7 @@ void ViewerWidget::PlayInternal(int speed, bool in_to_out_only)
   playback_speed_ = speed;
   play_in_to_out_only_ = in_to_out_only;
 
-  playback_queue_next_frame_ = GetTimestamp();
+  playback_queue_next_frame_ = GetTimestamp() + playback_speed_;
 
   controls_->ShowPauseButton();
 
@@ -776,18 +776,10 @@ void ViewerWidget::PlayInternal(int speed, bool in_to_out_only)
       prequeuing_video_ = true;
       prequeue_count_ = 0;
 
-      // We "prioritize" the frames, which means they're pushed to the top of the render queue,
-      // we queue in reverse so that they're still queued in order
-
-      playback_queue_next_frame_ += playback_speed_ * prequeue_length_;
-      int64_t temp = playback_queue_next_frame_;
-
       for (int i=0; i<prequeue_length_; i++) {
-        playback_queue_next_frame_ -= playback_speed_;
-        RequestNextFrameForQueue(RenderTicketPriority::kHigh, false);
+        RequestNextFrameForQueue(RenderTicketPriority::kNormal, false);
+        playback_queue_next_frame_ += playback_speed_;
       }
-
-      playback_queue_next_frame_ = temp;
     }
   }