tagparser/matroska/ebmlelement.h

135 lines
4.3 KiB
C++

#ifndef EBMLELEMENT_H
#define EBMLELEMENT_H
#include "./ebmlid.h"
#include "./matroskaid.h"
#include "../statusprovider.h"
#include "../genericfileelement.h"
#include <c++utilities/conversion/types.h>
#include <c++utilities/conversion/stringbuilder.h>
#include <c++utilities/conversion/stringconversion.h>
#include <iostream>
#include <memory>
namespace Media {
class EbmlElement;
class MatroskaContainer;
/*!
* \brief Defines traits for the GenericFileElement implementation EbmlElement.
*/
template <>
class TAG_PARSER_EXPORT FileElementTraits<EbmlElement>
{
public:
typedef MatroskaContainer ContainerType;
typedef uint32 IdentifierType;
typedef uint64 DataSizeType;
};
class TAG_PARSER_EXPORT EbmlElement : public GenericFileElement<EbmlElement>
{
friend class GenericFileElement<EbmlElement>;
public:
EbmlElement(MatroskaContainer &container, uint64 startOffset);
std::string idToString() const;
bool isParent() const;
bool isPadding() const;
uint64 firstChildOffset() const;
std::string readString();
uint64 readUInteger();
float64 readFloat();
static byte calculateIdLength(IdentifierType id);
static byte calculateSizeDenotationLength(uint64 size);
static byte makeId(IdentifierType id, char *buff);
static byte makeSizeDenotation(uint64 size, char *buff);
static byte makeSizeDenotation(uint64 size, char *buff, byte minBytes);
static byte calculateUIntegerLength(uint64 integer);
static byte makeUInteger(uint64 value, char *buff);
static byte makeUInteger(uint64 value, char *buff, byte minBytes);
static void makeSimpleElement(std::ostream &stream, IdentifierType id, uint64 content);
static void makeSimpleElement(std::ostream &stream, IdentifierType id, const std::string &content);
static void makeSimpleElement(std::ostream &stream, IdentifierType id, const char *data, std::size_t dataSize);
static uint64 bytesToBeSkipped;
protected:
EbmlElement(EbmlElement &parent, uint64 startOffset);
EbmlElement(MatroskaContainer &container, uint64 startOffset, uint64 maxSize);
void internalParse();
private:
std::string parsingContext() const;
};
/*!
* \brief Converts the specified EBML \a ID to a printable string.
*/
inline std::string EbmlElement::idToString() const
{
using namespace ConversionUtilities;
const char *const name = matroskaIdName(id());
if(*name) {
return argsToString('0', 'x', numberToString(id(), 16), ' ', '\"', name, '\"');
} else {
return "0x" + numberToString(id(), 16);
}
}
/*!
* \brief Returns an indication whether the element is a parent element.
* \remarks This information is not read from the element header. Some
* elements are simply known to be parents whereas all other
* are considered as non-parents.
*/
inline bool EbmlElement::isParent() const
{
using namespace EbmlIds;
using namespace MatroskaIds;
switch(id()) {
case Header:
case SignatureSlot: case SignatureElements: case SignatureElementList:
case Segment: case SeekHead: case Seek:
case SegmentInfo: case ChapterTranslate:
case Cluster: case SilentTracks: case BlockGroup: case BlockAdditions: case BlockMore: case Slices: case TimeSlice: case ReferenceFrame:
case Tracks: case TrackEntry: case TrackTranslate: case TrackVideo: case TrackAudio: case TrackOperation: case TrackCombinePlanes: case TrackPlane: case TrackJoinBlocks:
case ContentEncodings: case ContentEncoding: case ContentCompression: case ContentEncryption:
case Cues: case CuePoint: case CueTrackPositions: case CueReference:
case Attachments: case AttachedFile:
case Chapters: case EditionEntry: case ChapterAtom: case ChapterTrack: case ChapterDisplay: case ChapProcess: case ChapProcessCommand:
case Tags: case MatroskaIds::Tag: case Targets: case SimpleTag:
return true;
default:
return false;
}
}
/*!
* \brief Returns an indication whether the element is considered as padding.
*/
inline bool EbmlElement::isPadding() const
{
return id() == EbmlIds::Void;
}
/*!
* \brief Returns the offset of the first child of the element.
* \remarks The returned offset is relative to the start offset if this element.
*/
inline uint64 EbmlElement::firstChildOffset() const
{
return isParent() ? (idLength() + sizeLength()) : 0;
}
}
#endif // EBMLELEMENT_H