moved decodercache to base folder for shared usage

app/render/backend/decodercache.cpp

@@ -0,0 +1,21 @@
+#include "decodercache.h"
+
+DecoderCache::DecoderCache()
+{
+
+}
+
+void DecoderCache::Clear()
+{
+  decoders_.clear();
+}
+
+void DecoderCache::AddDecoder(Stream *stream, DecoderPtr shader)
+{
+  decoders_.insert(stream, shader);
+}
+
+DecoderPtr DecoderCache::GetDecoder(Stream *stream)
+{
+  return decoders_.value(stream);
+}

app/render/backend/decodercache.h

@@ -0,0 +1,26 @@
+#ifndef DECODERCACHE_H
+#define DECODERCACHE_H
+
+#include "decoder/decoder.h"
+#include "project/item/footage/stream.h"
+
+/**
+ * @brief Thread-safe cache of decoders
+ */
+class DecoderCache
+{
+public:
+  DecoderCache();
+
+  void Clear();
+
+  void AddDecoder(Stream* stream, DecoderPtr shader);
+
+  DecoderPtr GetDecoder(Stream* stream);
+
+private:
+  QMap<Stream*, DecoderPtr> decoders_;
+
+};
+
+#endif // DECODERCACHE_H