diff --git a/app/common/timerange.cpp b/app/common/timerange.cpp
index 83d65e9f7..a9cbad326 100644
--- a/app/common/timerange.cpp
+++ b/app/common/timerange.cpp
@@ -296,6 +296,68 @@ uint qHash(const TimeRange &r, uint seed)
   return qHash(r.in(), seed) ^ qHash(r.out(), seed);
 }
 
+TimeRangeListFrameIterator::TimeRangeListFrameIterator(const TimeRangeList &list, const rational &timebase) :
+  list_(list),
+  timebase_(timebase),
+  index_(-1),
+  size_(-1)
+{
+  UpdateIndexIfNecessary();
+}
+
+bool TimeRangeListFrameIterator::GetNext(rational *out)
+{
+  if (index_ == list_.size()) {
+    return false;
+  }
+
+  // Output current value
+  *out = current_;
+
+  // Determine next value by adding timebase
+  current_ += timebase_;
+
+  // If this time is outside the current range, jump to the next one
+  UpdateIndexIfNecessary();
+
+  return true;
+}
+
+int TimeRangeListFrameIterator::size()
+{
+  if (size_ == -1) {
+    // Size isn't calculated automatically for optimization, so we'll calculate it now
+    size_ = 0;
+
+    foreach (const TimeRange &range, list_) {
+      rational start = Timecode::snap_time_to_timebase(range.in(), timebase_, Timecode::kCeil);
+      rational end = Timecode::snap_time_to_timebase(range.out(), timebase_, Timecode::kFloor);
+
+      if (end == range.out()) {
+        end -= timebase_;
+      }
+
+      int64_t start_ts = Timecode::time_to_timestamp(start, timebase_);
+      int64_t end_ts = Timecode::time_to_timestamp(end, timebase_);
+
+      size_ += 1 + (end_ts - start_ts);
+    }
+  }
+
+  return size_;
+}
+
+void TimeRangeListFrameIterator::UpdateIndexIfNecessary()
+{
+  while (index_ < list_.size() && (index_ == -1 || current_ >= list_.at(index_).out())) {
+    index_++;
+
+    if (index_ < list_.size()) {
+      current_ = Timecode::snap_time_to_timebase(list_.at(index_).in(), timebase_, Timecode::kCeil);
+    }
+  }
+}
+
 }
 
 QDebug operator<<(QDebug debug, const olive::TimeRange &r)
diff --git a/app/common/timerange.h b/app/common/timerange.h
index 28913f6df..78c95d8db 100644
--- a/app/common/timerange.h
+++ b/app/common/timerange.h
@@ -22,6 +22,7 @@
 #define TIMERANGE_H
 
 #include "rational.h"
+#include "timecodefunctions.h"
 
 namespace olive {
 
@@ -127,16 +128,61 @@ public:
     return array_.last();
   }
 
+  const TimeRange& at(int index) const
+  {
+    return array_.at(index);
+  }
+
   const QVector<TimeRange>& internal_array() const
   {
     return array_;
   }
 
+  bool operator==(const TimeRangeList &rhs) const
+  {
+    return array_ == rhs.array_;
+  }
+
 private:
   QVector<TimeRange> array_;
 
 };
 
+class TimeRangeListFrameIterator
+{
+public:
+  TimeRangeListFrameIterator(const TimeRangeList &list, const rational &timebase);
+
+  bool GetNext(rational *out);
+
+  QVector<rational> ToVector() const
+  {
+    TimeRangeListFrameIterator copy(list_, timebase_);
+    QVector<rational> times;
+    rational r;
+    while (copy.GetNext(&r)) {
+      times.append(r);
+    }
+    return times;
+  }
+
+  int size();
+
+private:
+  void UpdateIndexIfNecessary();
+
+  TimeRangeList list_;
+
+  rational timebase_;
+
+  rational current_;
+
+  int index_;
+
+  int size_;
+
+};
+
 uint qHash(const TimeRange& r, uint seed = 0);
 
 }
diff --git a/app/render/framehashcache.cpp b/app/render/framehashcache.cpp
index 84857614d..52e6028f2 100644
--- a/app/render/framehashcache.cpp
+++ b/app/render/framehashcache.cpp
@@ -114,77 +114,6 @@ void FrameHashCache::ValidateFramesWithHash(const QByteArray &hash)
   }
 }
 
-QList<rational> FrameHashCache::GetFramesWithHash(const QByteArray &hash)
-{
-  QList<rational> times;
-
-  for (int64_t i=0; i<GetMapSize(); i++) {
-    if (time_hash_map_.at(i) == hash) {
-      times.append(ToTime(i));
-    }
-  }
-
-  return times;
-}
-
-QList<rational> FrameHashCache::TakeFramesWithHash(const QByteArray &hash)
-{
-  TimeRangeList range_to_invalidate;
-  QList<rational> times;
-
-  for (int64_t i=0; i<GetMapSize(); i++) {
-    if (time_hash_map_.at(i) == hash) {
-      time_hash_map_[i].clear();
-
-      rational time = ToTime(i);
-      times.append(time);
-      range_to_invalidate.insert(TimeRange(time, time + timebase_));
-    }
-  }
-
-  foreach (const TimeRange& r, range_to_invalidate) {
-    // We apply a 0 job time because the graph hasn't changed to get here, so any renderer should
-    // be up to date already
-    Invalidate(r, 0);
-  }
-
-  return times;
-}
-
-QVector<rational> FrameHashCache::GetFrameListFromTimeRange(TimeRangeList range_list, const rational &timebase)
-{
-  // If timebase is null, this will be an infinite loop
-  Q_ASSERT(!timebase.isNull());
-
-  QVector<rational> times;
-
-  foreach (const TimeRange &range, range_list) {
-    rational frame = Timecode::snap_time_to_timebase(range.in(), timebase, Timecode::kCeil);
-
-    while (frame < range.out()) {
-      times.append(frame);
-      frame += timebase;
-    }
-  }
-
-  return times;
-}
-
-QVector<rational> FrameHashCache::GetFrameListFromTimeRange(const TimeRangeList &range)
-{
-  return GetFrameListFromTimeRange(range, timebase_);
-}
-
-QVector<rational> FrameHashCache::GetInvalidatedFrames()
-{
-  return GetFrameListFromTimeRange(GetInvalidatedRanges());
-}
-
-QVector<rational> FrameHashCache::GetInvalidatedFrames(const TimeRange &intersecting)
-{
-  return GetFrameListFromTimeRange(GetInvalidatedRanges().Intersects(intersecting));
-}
-
 bool FrameHashCache::SaveCacheFrame(const QByteArray& hash,
                                     char* data,
                                     const VideoParams& vparam,
diff --git a/app/render/framehashcache.h b/app/render/framehashcache.h
index 56753c199..b6904ec51 100644
--- a/app/render/framehashcache.h
+++ b/app/render/framehashcache.h
@@ -50,16 +50,6 @@ public:
 
   void ValidateFramesWithHash(const QByteArray& hash);
 
-  /**
-   * @brief Returns a list of frames that use a particular hash
-   */
-  QList<rational> GetFramesWithHash(const QByteArray& hash);
-
-  /**
-   * @brief Same as FramesWithHash() but also removes these frames from the map
-   */
-  QList<rational> TakeFramesWithHash(const QByteArray& hash);
-
   QMap<rational, QByteArray> time_hash_map();
 
   /**
@@ -77,11 +67,6 @@ public:
   FramePtr LoadCacheFrame(const QByteArray& hash) const;
   static FramePtr LoadCacheFrame(const QString& fn);
 
-  static QVector<rational> GetFrameListFromTimeRange(TimeRangeList range_list, const rational& timebase);
-  QVector<rational> GetFrameListFromTimeRange(const TimeRangeList &range);
-  QVector<rational> GetInvalidatedFrames();
-  QVector<rational> GetInvalidatedFrames(const TimeRange& intersecting);
-
 public slots:
   void SetHash(const olive::rational &time, const QByteArray& hash, const qint64 &job_time, bool frame_exists);
 
diff --git a/app/render/previewautocacher.cpp b/app/render/previewautocacher.cpp
index 916be3318..5c2f70ac2 100644
--- a/app/render/previewautocacher.cpp
+++ b/app/render/previewautocacher.cpp
@@ -91,8 +91,10 @@ void GenerateHashesInternal(ViewerOutput *viewer, FrameHashCache* cache, const Q
   }
 }
 
-void PreviewAutoCacher::GenerateHashes(ViewerOutput *viewer, FrameHashCache* cache, const QVector<rational> &times, qint64 job_time)
+void PreviewAutoCacher::GenerateHashes(ViewerOutput *viewer, FrameHashCache* cache, TimeRangeListFrameIterator iterator, qint64 job_time)
 {
+  QVector<rational> times = iterator.ToVector();
+
   // Ensure number of threads doesn't exceed idealThreadCount for maximum concurrency
   int hashes_per_thread = times.size() / qMax(1, QThread::idealThreadCount()-1);
 
@@ -493,7 +495,7 @@ void PreviewAutoCacher::TryRender()
 
   // If we're here, we must be able to render
   if (!invalidated_video_.isEmpty()) {
-    QVector<rational> frames = viewer_node_->video_frame_cache()->GetFrameListFromTimeRange(invalidated_video_);
+    TimeRangeListFrameIterator frames(invalidated_video_, viewer_node_->video_frame_cache()->GetTimebase());
 
     QFutureWatcher<void>* watcher = new QFutureWatcher<void>();
     hash_tasks_.append(watcher);
@@ -578,9 +580,11 @@ void PreviewAutoCacher::RequeueFrames()
       using_range = cache_range_;
     }
 
-    QVector<rational> invalidated_ranges = viewer_node_->video_frame_cache()->GetInvalidatedFrames(using_range);
+    TimeRangeList invalidated = viewer_node_->video_frame_cache()->GetInvalidatedRanges().Intersects(using_range);
+    TimeRangeListFrameIterator invalidated_ranges(invalidated, viewer_node_->video_frame_cache()->GetTimebase());
 
-    foreach (const rational& t, invalidated_ranges) {
+    rational t;
+    while (invalidated_ranges.GetNext(&t)) {
       const QByteArray& hash = viewer_node_->video_frame_cache()->GetHash(t);
 
       RenderTicketWatcher* render_task = video_tasks_.key(hash);
diff --git a/app/render/previewautocacher.h b/app/render/previewautocacher.h
index 6d0bd4f44..2c40ba7dc 100644
--- a/app/render/previewautocacher.h
+++ b/app/render/previewautocacher.h
@@ -80,7 +80,7 @@ public:
   void ClearVideoDownloadQueue(bool wait = false);
 
 private:
-  static void GenerateHashes(ViewerOutput *viewer, FrameHashCache *cache, const QVector<rational>& times, qint64 job_time);
+  static void GenerateHashes(ViewerOutput *viewer, FrameHashCache *cache, TimeRangeListFrameIterator times, qint64 job_time);
 
   void TryRender();
 
diff --git a/app/task/render/render.cpp b/app/task/render/render.cpp
index ee559fe2c..2254477a5 100644
--- a/app/task/render/render.cpp
+++ b/app/task/render/render.cpp
@@ -84,16 +84,19 @@ bool RenderTask::Render(ColorManager* manager,
 
   if (!video_range.isEmpty()) {
     // Get list of discrete frames from range
-    QVector<rational> times = FrameHashCache::GetFrameListFromTimeRange(video_range, video_params().frame_rate_as_time_base());
-    QVector<QByteArray> hashes(times.size());
+    TimeRangeListFrameIterator iterator(video_range, video_params().frame_rate_as_time_base());
+    QVector<rational> times(iterator.size());
+    QVector<QByteArray> hashes(iterator.size());
 
     // Generate hashes
-    for (int i=0; i<times.size(); i++) {
+    rational r;
+    for (int i=0; iterator.GetNext(&r); i++) {
       if (IsCancelled()) {
         return true;
       }
 
-      hashes[i] = RenderManager::instance()->Hash(viewer()->GetConnectedTextureOutput(), video_params_, times.at(i));
+      times[i] = r;
+      hashes[i] = RenderManager::instance()->Hash(viewer()->GetConnectedTextureOutput(), video_params_, r);
     }
 
     // Filter out duplicates
diff --git a/tests/general/CMakeLists.txt b/tests/general/CMakeLists.txt
index 11f3472ed..7f87c6302 100644
--- a/tests/general/CMakeLists.txt
+++ b/tests/general/CMakeLists.txt
@@ -16,3 +16,4 @@
 
 olive_add_test(General common-tests common-tests.cpp)
 olive_add_test(General rational-tests rational-tests.cpp)
+olive_add_test(General timerange-tests timerange-tests.cpp)
diff --git a/tests/testutil.h b/tests/testutil.h
index 9f916c2d0..3cfd6845d 100644
--- a/tests/testutil.h
+++ b/tests/testutil.h
@@ -21,6 +21,7 @@
 #include <iostream>
 
 #define OLIVE_ASSERT(x) if (!(x)) return false
+#define OLIVE_ASSERT_EQUAL(x, y) if (x != y) {std::cout << " - Equal assert failed on line " << __LINE__ << ": " << x << " != " << y; return false;}void()
 #define OLIVE_TEST_END return true
 
 #define OLIVE_ADD_TEST(x) bool Test##x()