decoder: began implementation of a frame pool

app/codec/framepool.cpp

@@ -0,0 +1,97 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
+#include "framepool.h"
+
+OLIVE_NAMESPACE_ENTER
+
+FramePool::FramePool()
+{
+  data_ = nullptr;
+}
+
+bool FramePool::Allocate(int width, int height, PixelFormat::Format format, int nb_elements)
+{
+  delete [] data_;
+
+  element_sz_ = width * height * PixelFormat::BytesPerPixel(format);
+
+  if ((data_ = new char[element_sz_ * nb_elements])) {
+    // Only allocate available array if data allocation succeeded
+    available_.resize(nb_elements);
+    available_.fill(true);
+
+    return true;
+  } else {
+    available_.clear();
+
+    return false;
+  }
+}
+
+void FramePool::Destroy()
+{
+  delete [] data_;
+  available_.clear();
+}
+
+FramePool::~FramePool()
+{
+  delete [] data_;
+}
+
+FramePool::ElementPtr FramePool::Get()
+{
+  for (int i=0;i<available_.size();i++) {
+    if (available_.at(i)) {
+      // This buffer is available
+      available_.replace(i, false);
+      return std::make_shared<Element>(this, data_ + i * element_sz_);
+    }
+  }
+
+  return nullptr;
+}
+
+void FramePool::Release(FramePool::Element *e)
+{
+  quintptr offs = reinterpret_cast<quintptr>(e->data());
+  quintptr start = reinterpret_cast<quintptr>(data_);
+
+  quintptr diff = offs - start;
+
+  int index = diff / element_sz_;
+
+  available_.replace(index, true);
+}
+
+FramePool::Element::Element(FramePool *parent, char *data)
+{
+  parent_ = parent;
+  data_ = data;
+  accessed_ = QDateTime::currentMSecsSinceEpoch();
+}
+
+FramePool::Element::~Element()
+{
+  parent_->Release(this);
+}
+
+OLIVE_NAMESPACE_EXIT