* Begin type names with capital letter * Remove typedefs for implementation type * Remove useless/obsolete comments * Simplify relevant code
247 lines
8.3 KiB
C++
247 lines
8.3 KiB
C++
#include "./mp4track.h"
|
|
#include "./mp4tag.h"
|
|
#include "./mp4atom.h"
|
|
#include "./mp4ids.h"
|
|
#include "./mp4container.h"
|
|
|
|
#include "../mediafileinfo.h"
|
|
#include "../exceptions.h"
|
|
|
|
#include <c++utilities/conversion/stringbuilder.h>
|
|
#include <c++utilities/io/binaryreader.h>
|
|
#include <c++utilities/io/binarywriter.h>
|
|
|
|
#include <sstream>
|
|
|
|
using namespace std;
|
|
using namespace IoUtilities;
|
|
using namespace ConversionUtilities;
|
|
|
|
namespace Media {
|
|
|
|
/*!
|
|
* \class Media::Mp4Atom
|
|
* \brief The Mp4Atom class helps to parse MP4 files.
|
|
*/
|
|
|
|
/*!
|
|
* \brief Constructs a new top level atom with the specified \a container at the specified \a startOffset.
|
|
*/
|
|
Mp4Atom::Mp4Atom(GenericFileElement::ContainerType &container, uint64 startOffset) :
|
|
GenericFileElement<Mp4Atom>(container, startOffset)
|
|
{}
|
|
|
|
/*!
|
|
* \brief Constructs a new top level atom with the specified \a container at the specified \a startOffset.
|
|
*/
|
|
Mp4Atom::Mp4Atom(GenericFileElement::ContainerType &container, uint64 startOffset, uint64 maxSize) :
|
|
GenericFileElement<Mp4Atom>(container, startOffset, maxSize)
|
|
{}
|
|
|
|
/*!
|
|
* \brief Constructs a new sub level atom with the specified \a parent at the specified \a startOffset.
|
|
*/
|
|
Mp4Atom::Mp4Atom(Mp4Atom &parent, uint64 startOffset) :
|
|
GenericFileElement<Mp4Atom>(parent, startOffset)
|
|
{}
|
|
|
|
/*!
|
|
* \brief Returns the parsing context.
|
|
*/
|
|
string Mp4Atom::parsingContext() const
|
|
{
|
|
return "parsing " % idToString() % " atom at " + startOffset();
|
|
}
|
|
|
|
/*!
|
|
* \brief Parses the MP4 atom.
|
|
*/
|
|
void Mp4Atom::internalParse()
|
|
{
|
|
invalidateStatus();
|
|
static const string context("parsing MP4 atom");
|
|
if(maxTotalSize() < minimumElementSize()) {
|
|
addNotification(NotificationType::Critical, "Atom is smaller than 8 byte and hence invalid. The remaining size within the parent atom is " % numberToString(maxTotalSize()) + ".", context);
|
|
throw TruncatedDataException();
|
|
}
|
|
stream().seekg(startOffset());
|
|
m_dataSize = reader().readUInt32BE();
|
|
if(m_dataSize == 0) {
|
|
// atom size extends to rest of the file/enclosing container
|
|
m_dataSize = maxTotalSize();
|
|
}
|
|
if(!m_dataSize) {
|
|
addNotification(NotificationType::Critical, "No data found (only null bytes).", context);
|
|
throw NoDataFoundException();
|
|
}
|
|
if(m_dataSize < 8 && m_dataSize != 1) {
|
|
addNotification(NotificationType::Critical, "Atom is smaller than 8 byte and hence invalid.", context);
|
|
throw TruncatedDataException();
|
|
}
|
|
m_id = reader().readUInt32BE();
|
|
m_idLength = 4;
|
|
if(m_dataSize == 1) { // atom denotes 64-bit size
|
|
m_dataSize = reader().readUInt64BE();
|
|
m_sizeLength = 12; // 4 bytes indicate long size denotation + 8 bytes for actual size denotation
|
|
if(dataSize() < 16 && m_dataSize != 1) {
|
|
addNotification(NotificationType::Critical, "Atom denoting 64-bit size is smaller than 16 byte and hence invalid.", parsingContext());
|
|
throw TruncatedDataException();
|
|
}
|
|
} else {
|
|
m_sizeLength = 4;
|
|
}
|
|
if(maxTotalSize() < m_dataSize) { // currently m_dataSize holds data size plus header size!
|
|
addNotification(NotificationType::Warning, "The atom seems to be truncated; unable to parse siblings of that ", parsingContext());
|
|
m_dataSize = maxTotalSize(); // using max size instead
|
|
}
|
|
// currently m_dataSize holds data size plus header size!
|
|
m_dataSize -= headerSize();
|
|
Mp4Atom *child = nullptr;
|
|
if(uint64 firstChildOffset = this->firstChildOffset()) {
|
|
if(firstChildOffset + minimumElementSize() <= totalSize()) {
|
|
child = new Mp4Atom(static_cast<Mp4Atom &>(*this), startOffset() + firstChildOffset);
|
|
}
|
|
}
|
|
m_firstChild.reset(child);
|
|
Mp4Atom *sibling = nullptr;
|
|
if(totalSize() < maxTotalSize()) {
|
|
if(parent()) {
|
|
sibling = new Mp4Atom(*(parent()), startOffset() + totalSize());
|
|
} else {
|
|
sibling = new Mp4Atom(container(), startOffset() + totalSize(), maxTotalSize() - totalSize());
|
|
}
|
|
}
|
|
m_nextSibling.reset(sibling);
|
|
}
|
|
|
|
/*!
|
|
* \brief This function helps to write the atom size after writing an atom to a stream.
|
|
* \param stream Specifies the stream.
|
|
* \param startOffset Specifies the start offset of the atom.
|
|
*
|
|
* This function seeks back to the start offset and writes the difference between the
|
|
* previous offset and the start offset as 32-bit unsigned integer to the \a stream.
|
|
* Then it seeks back to the previous offset.
|
|
*/
|
|
void Mp4Atom::seekBackAndWriteAtomSize(std::ostream &stream, const ostream::pos_type &startOffset)
|
|
{
|
|
ostream::pos_type currentOffset = stream.tellp();
|
|
stream.seekp(startOffset);
|
|
BinaryWriter writer(&stream);
|
|
writer.writeUInt32BE(currentOffset - startOffset);
|
|
stream.seekp(currentOffset);
|
|
}
|
|
|
|
/*!
|
|
* \brief This function helps to write the atom size after writing an atom to a stream.
|
|
* \param stream Specifies the stream.
|
|
* \param startOffset Specifies the start offset of the atom.
|
|
*
|
|
* This function seeks back to the start offset and writes the difference between the
|
|
* previous offset and the start offset as 64-bit unsigned integer to the \a stream.
|
|
* Then it seeks back to the previous offset.
|
|
*/
|
|
void Mp4Atom::seekBackAndWriteAtomSize64(std::ostream &stream, const ostream::pos_type &startOffset)
|
|
{
|
|
ostream::pos_type currentOffset = stream.tellp();
|
|
stream.seekp(startOffset);
|
|
BinaryWriter writer(&stream);
|
|
writer.writeUInt32BE(1);
|
|
stream.seekp(4, ios_base::cur);
|
|
writer.writeUInt64BE(currentOffset - startOffset);
|
|
stream.seekp(currentOffset);
|
|
}
|
|
|
|
/*!
|
|
* \brief Writes an MP4 atom header to the specified \a stream.
|
|
*/
|
|
void Mp4Atom::makeHeader(uint64 size, uint32 id, BinaryWriter &writer)
|
|
{
|
|
if(size < numeric_limits<uint32>::max()) {
|
|
writer.writeUInt32BE(static_cast<uint32>(size));
|
|
writer.writeUInt32BE(id);
|
|
} else {
|
|
writer.writeUInt32BE(1);
|
|
writer.writeUInt32BE(id);
|
|
writer.writeUInt64BE(size);
|
|
}
|
|
}
|
|
|
|
/*!
|
|
* \brief Returns an indication whether the atom is a parent element.
|
|
*
|
|
* \remarks This information is not read from the atom header. Some
|
|
* atoms are simply known to be parents whereas all other
|
|
* are considered as non-parents.
|
|
*/
|
|
bool Mp4Atom::isParent() const
|
|
{
|
|
using namespace Mp4AtomIds;
|
|
// some atom ids are known to be parents
|
|
switch(id()) {
|
|
case Movie: case Track: case Media: case MediaInformation: case DataInformation:
|
|
case SampleTable: case UserData: case Meta: case ItunesList: case MovieFragment:
|
|
case TrackFragment: case MovieExtends: case DataReference: case Mp4AtomIds::AvcConfiguration:
|
|
case FourccIds::Mpeg4Audio: case FourccIds::AmrNarrowband: case FourccIds::Amr:
|
|
case FourccIds::Drms: case FourccIds::Alac: case FourccIds::WindowsMediaAudio:
|
|
case FourccIds::Ac3: case FourccIds::EAc3: case FourccIds::DolbyMpl:
|
|
case FourccIds::Dts: case FourccIds::DtsH: case FourccIds::DtsE:
|
|
return true;
|
|
default:
|
|
if(parent()) {
|
|
// some atom ids are known to contain parents
|
|
switch(parent()->id()) {
|
|
case ItunesList:
|
|
return true;
|
|
default: ;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*!
|
|
* \brief Returns an indication whether the atom is a padding element.
|
|
*
|
|
* \remarks This information is not read from the atom header. Atoms with
|
|
* the IDs "free" and "skip" are considered as padding.
|
|
*/
|
|
bool Mp4Atom::isPadding() const
|
|
{
|
|
using namespace Mp4AtomIds;
|
|
switch(id()) {
|
|
case Free: case Skip:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/*!
|
|
* \brief Returns the offset of the first child (relative to the start offset of this atom).
|
|
*
|
|
* \remarks This information is not read from the atom header. The offsets are known
|
|
* for specific atoms.
|
|
* \remarks This method returns zero for non-parent atoms which have no childs.
|
|
* \remarks Childs with variable offset such as the "esds"-atom must be denoted!
|
|
*/
|
|
uint64 Mp4Atom::firstChildOffset() const
|
|
{
|
|
using namespace Mp4AtomIds;
|
|
using namespace FourccIds;
|
|
if(isParent()) {
|
|
switch(id()) {
|
|
case Meta: return headerSize() + 0x4u;
|
|
case DataReference: return headerSize() + 0x8u;
|
|
default: return headerSize();
|
|
}
|
|
} else {
|
|
switch(id()) {
|
|
case SampleDescription: return headerSize() + 0x08u;
|
|
default: return 0x00u;
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|