1 files changed, 100 insertions, 0 deletions
diff --git a/dom/media/mp4/Box.h b/dom/media/mp4/Box.h
new file mode 100644
index 0000000000..e63bfbcc90
--- /dev/null
+++ b/dom/media/mp4/Box.h
@@ -0,0 +1,100 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BOX_H_
+#define BOX_H_
+
+#include <stdint.h>
+#include "nsTArray.h"
+#include "MediaResource.h"
+#include "mozilla/EndianUtils.h"
+#include "AtomType.h"
+#include "BufferReader.h"
+
+namespace mozilla {
+class ByteStream;
+
+class BumpAllocator {
+ public:
+  uint8_t* Allocate(size_t aNumBytes);
+
+ private:
+  nsTArray<nsTArray<uint8_t>> mBuffers;
+};
+
+class BoxContext {
+ public:
+  BoxContext(ByteStream* aSource, const MediaByteRangeSet& aByteRanges)
+      : mSource(aSource), mByteRanges(aByteRanges) {}
+
+  RefPtr<ByteStream> mSource;
+  const MediaByteRangeSet& mByteRanges;
+  BumpAllocator mAllocator;
+};
+
+struct ByteSlice {
+  const uint8_t* mBytes;
+  size_t mSize;
+};
+
+class Box {
+ public:
+  Box(BoxContext* aContext, uint64_t aOffset, const Box* aParent = nullptr);
+  Box();
+
+  bool IsAvailable() const { return !mRange.IsEmpty(); }
+  uint64_t Offset() const { return mRange.mStart; }
+  uint64_t Length() const { return mRange.mEnd - mRange.mStart; }
+  uint64_t NextOffset() const { return mRange.mEnd; }
+  const MediaByteRange& Range() const { return mRange; }
+  const Box* Parent() const { return mParent; }
+  bool IsType(const char* aType) const { return mType == AtomType(aType); }
+
+  Box Next() const;
+  Box FirstChild() const;
+  // Reads the box contents, excluding the header.
+  nsTArray<uint8_t> Read() const;
+
+  // Reads the complete box; its header and body.
+  nsTArray<uint8_t> ReadCompleteBox() const;
+
+  // Reads from the content of the box, excluding header.
+  bool Read(nsTArray<uint8_t>* aDest, const MediaByteRange& aRange) const;
+
+  static const uint64_t kMAX_BOX_READ;
+
+  // Returns a slice, pointing to the data of this box. The lifetime of
+  // the memory this slice points to matches the box's context's lifetime.
+  ByteSlice ReadAsSlice();
+
+ private:
+  bool Contains(MediaByteRange aRange) const;
+  BoxContext* mContext;
+  mozilla::MediaByteRange mRange;
+  uint64_t mBodyOffset;
+  uint64_t mChildOffset;
+  AtomType mType;
+  const Box* mParent;
+};
+
+// BoxReader serves box data through an AutoByteReader. The box data is
+// stored either in the box's context's bump allocator, or in the ByteStream
+// itself if the ByteStream implements the Access() method.
+// NOTE: The data the BoxReader reads may be stored in the Box's BoxContext.
+// Ensure that the BoxReader doesn't outlive the BoxContext!
+class MOZ_RAII BoxReader {
+ public:
+  explicit BoxReader(Box& aBox)
+      : mData(aBox.ReadAsSlice()), mReader(mData.mBytes, mData.mSize) {}
+  BufferReader* operator->() { return &mReader; }
+
+ private:
+  ByteSlice mData;
+  BufferReader mReader;
+};
+}  // namespace mozilla
+
+#endif