overhauled render classes to support video AND audio

Major refactoring work to try sharing as much code as possible between the
video renderers and audio renderers, as well as make them as
platform-independent as possible.

app/render/backend/audiorenderbackend.cpp

@@ -1,11 +1,13 @@
 #include "audiorenderbackend.h"
 
+#include <QDir>
 #include <QtMath>
 
+#include "common/filefunctions.h"
+
 AudioRenderBackend::AudioRenderBackend(QObject *parent) :
   RenderBackend(parent)
 {
-
 }
 
 void AudioRenderBackend::SetParameters(const AudioRenderingParams &params)
@@ -23,8 +25,17 @@ void AudioRenderBackend::SetParameters(const AudioRenderingParams &params)
 
 void AudioRenderBackend::InvalidateCache(const rational &start_range, const rational &end_range)
 {
+  rational start_range_adj = qMax(rational(0), start_range);
+  rational end_range_adj = qMin(viewer_node()->Length(), end_range);
+
+  // Truncate to length if necessary
+  int max_length_in_bytes = params().time_to_bytes(viewer_node()->Length());
+  if (pcm_data_.size() > max_length_in_bytes) {
+    pcm_data_.resize(max_length_in_bytes);
+  }
+
   // Add the range to the list
-  cache_queue_.append(TimeRange(start_range, end_range));
+  cache_queue_.append(TimeRange(start_range_adj, end_range_adj));
 
   // Remove any overlaps so we don't render the same thing twice
   ValidateRanges();
@@ -37,7 +48,7 @@ void AudioRenderBackend::ViewerNodeChangedEvent(ViewerOutput *node)
 {
   if (node != nullptr) {
     // FIXME: Hardcoded format
-    SetParameters(AudioRenderingParams(node->audio_params(), olive::SAMPLE_FMT_FLT));
+    SetParameters(AudioRenderingParams(node->audio_params(), SAMPLE_FMT_FLT));
   }
 }
 
@@ -55,6 +66,16 @@ bool AudioRenderBackend::GenerateCacheIDInternal(QCryptographicHash &hash)
   return true;
 }
 
+const AudioRenderingParams &AudioRenderBackend::params()
+{
+  return params_;
+}
+
+NodeInput *AudioRenderBackend::GetDependentInput()
+{
+  return viewer_node()->samples_input();
+}
+
 void AudioRenderBackend::ValidateRanges()
 {
   for (int i=0;i<cache_queue_.size();i++) {
@@ -75,6 +96,14 @@ void AudioRenderBackend::ValidateRanges()
   }
 }
 
+QString AudioRenderBackend::CachePathName()
+{
+  QDir this_cache_dir = QDir(GetMediaCacheLocation()).filePath(cache_id());
+  this_cache_dir.mkpath(".");
+
+  return this_cache_dir.filePath(QStringLiteral("pcm"));
+}
+
 TimeRange AudioRenderBackend::CombineRange(const TimeRange &a, const TimeRange &b)
 {
   return TimeRange(qMin(a.in(), b.in()),
@@ -83,5 +112,5 @@ TimeRange AudioRenderBackend::CombineRange(const TimeRange &a, const TimeRange &
 
 bool AudioRenderBackend::RangesOverlap(const TimeRange &a, const TimeRange &b)
 {
-  return (a.out() < b.in() && a.in() > b.out());
+  return !(a.out() < b.in() || a.in() > b.out());
 }