Files
Bento4/Source/C++/Core/Ap4ContainerAtom.cpp
2017-09-09 16:58:47 -07:00

275 lines
10 KiB
C++

/*****************************************************************
|
| AP4 - Container Atoms
|
| Copyright 2002-2008 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL 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 2, or (at your option)
| any later version.
|
| Bento4|GPL 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 Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4Types.h"
#include "Ap4Atom.h"
#include "Ap4Utils.h"
#include "Ap4ContainerAtom.h"
#include "Ap4AtomFactory.h"
/*----------------------------------------------------------------------
| dynamic cast support
+---------------------------------------------------------------------*/
AP4_DEFINE_DYNAMIC_CAST_ANCHOR(AP4_ContainerAtom)
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom*
AP4_ContainerAtom::Create(Type type,
AP4_UI64 size,
bool is_full,
bool force_64,
AP4_ByteStream& stream,
AP4_AtomFactory& atom_factory)
{
if (is_full) {
AP4_UI08 version;
AP4_UI32 flags;
if (size < AP4_FULL_ATOM_HEADER_SIZE) return NULL;
if (AP4_FAILED(AP4_Atom::ReadFullHeader(stream, version, flags))) return NULL;
// special case for 'meta' atoms, because Apple sometimes creates them as
// regular (non-full) atoms. This is bogus, but we can try to detect it
if (type == AP4_ATOM_TYPE_META) {
AP4_UI32 phantom_size = (version<<24)|flags;
if (phantom_size >= 8 && size >= 16) {
// version+flags looks like a size. read the next 4 bytes just
// to be sure it is a hdlr atom
AP4_UI32 peek;
if (AP4_FAILED(stream.ReadUI32(peek))) return NULL;
if (peek == AP4_ATOM_TYPE_HDLR) {
// rewind the stream by 8 bytes
AP4_Position position;
stream.Tell(position);
stream.Seek(position-8);
// create a non-full container
return new AP4_ContainerAtom(type, size, force_64, stream, atom_factory);
} else {
// rewind the stream by 4 bytes
AP4_Position position;
stream.Tell(position);
stream.Seek(position-4);
}
}
}
return new AP4_ContainerAtom(type, size, force_64, version, flags, stream, atom_factory);
} else {
return new AP4_ContainerAtom(type, size, force_64, stream, atom_factory);
}
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom::AP4_ContainerAtom(Type type) :
AP4_Atom(type, AP4_ATOM_HEADER_SIZE)
{
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom::AP4_ContainerAtom(Type type, AP4_UI08 version, AP4_UI32 flags) :
AP4_Atom(type, AP4_FULL_ATOM_HEADER_SIZE, version, flags)
{
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom::AP4_ContainerAtom(Type type, AP4_UI64 size, bool force_64) :
AP4_Atom(type, size, force_64)
{
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom::AP4_ContainerAtom(Type type,
AP4_UI64 size,
bool force_64,
AP4_UI08 version,
AP4_UI32 flags) :
AP4_Atom(type, size, force_64, version, flags)
{
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom::AP4_ContainerAtom(Type type,
AP4_UI64 size,
bool force_64,
AP4_ByteStream& stream,
AP4_AtomFactory& atom_factory) :
AP4_Atom(type, size, force_64)
{
ReadChildren(atom_factory, stream, size-GetHeaderSize());
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::AP4_ContainerAtom
+---------------------------------------------------------------------*/
AP4_ContainerAtom::AP4_ContainerAtom(Type type,
AP4_UI64 size,
bool force_64,
AP4_UI08 version,
AP4_UI32 flags,
AP4_ByteStream& stream,
AP4_AtomFactory& atom_factory) :
AP4_Atom(type, size, force_64, version, flags)
{
ReadChildren(atom_factory, stream, size-GetHeaderSize());
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::Clone
+---------------------------------------------------------------------*/
AP4_Atom*
AP4_ContainerAtom::Clone()
{
AP4_ContainerAtom* clone;
if (m_IsFull) {
clone = new AP4_ContainerAtom(m_Type, m_Version, m_Flags);
} else {
clone = new AP4_ContainerAtom(m_Type);
}
AP4_List<AP4_Atom>::Item* child_item = m_Children.FirstItem();
while (child_item) {
AP4_Atom* child_clone = child_item->GetData()->Clone();
if (child_clone) clone->AddChild(child_clone);
child_item = child_item->GetNext();
}
return clone;
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::ReadChildren
+---------------------------------------------------------------------*/
void
AP4_ContainerAtom::ReadChildren(AP4_AtomFactory& atom_factory,
AP4_ByteStream& stream,
AP4_UI64 size)
{
AP4_Atom* atom;
AP4_LargeSize bytes_available = size;
// save and switch the factory's context
atom_factory.PushContext(m_Type);
while (AP4_SUCCEEDED(
atom_factory.CreateAtomFromStream(stream, bytes_available, atom))) {
atom->SetParent(this);
m_Children.Add(atom);
}
// restore the saved context
atom_factory.PopContext();
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::InspectFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_ContainerAtom::InspectFields(AP4_AtomInspector& inspector)
{
return InspectChildren(inspector);
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::InspectChildren
+---------------------------------------------------------------------*/
AP4_Result
AP4_ContainerAtom::InspectChildren(AP4_AtomInspector& inspector)
{
// inspect children
m_Children.Apply(AP4_AtomListInspector(inspector));
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::WriteFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_ContainerAtom::WriteFields(AP4_ByteStream& stream)
{
// write all children
return m_Children.Apply(AP4_AtomListWriter(stream));
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::OnChildChanged
+---------------------------------------------------------------------*/
void
AP4_ContainerAtom::OnChildChanged(AP4_Atom*)
{
// remcompute our size
AP4_UI64 size = GetHeaderSize();
m_Children.Apply(AP4_AtomSizeAdder(size));
SetSize(size);
// update our parent
if (m_Parent) m_Parent->OnChildChanged(this);
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::OnChildAdded
+---------------------------------------------------------------------*/
void
AP4_ContainerAtom::OnChildAdded(AP4_Atom* child)
{
// update our size
SetSize(GetSize()+child->GetSize());
// update our parent
if (m_Parent) m_Parent->OnChildChanged(this);
}
/*----------------------------------------------------------------------
| AP4_ContainerAtom::OnChildRemoved
+---------------------------------------------------------------------*/
void
AP4_ContainerAtom::OnChildRemoved(AP4_Atom* child)
{
// update our size
SetSize(GetSize()-child->GetSize());
// update our parent
if (m_Parent) m_Parent->OnChildChanged(this);
}