mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-21 09:15:35 +00:00
51415ba462
A lot of the overhead in MoofParser::RebuildFragmentedIndex(BoxContext&) is copying data into the BoxReader's storage. In the MSE case the underlying data being read is actually buffered in memory, so we may be able to just read the in-memory data directly, avoiding the copy. Note that the data may not be stored in a single contiguous ResourceItem in the SourceBufferResource's ResourQueue. If so, it's not as straightforward to hand out a uint8_t* to the underlying data. So we just copy it in that case for simplicity. In most cases, the data in a single MP4 box would be appended in a single append, and so is likely to be in a single ResourceItem. Differential Revision: https://phabricator.services.mozilla.com/D33877 --HG-- extra : moz-landing-system : lando
101 lines
2.9 KiB
C++
101 lines
2.9 KiB
C++
/* -*- 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
|