CGII/framework/include/cgv/media/riff.h
2018-05-17 15:50:03 +02:00

68 lines
No EOL
2.4 KiB
C++

#pragma once
#include <string>
#include <stdio.h>
#include <iostream>
#include "lib_begin.h"
namespace cgv {
namespace media {
/// represents fourcc ids as used in the riff format to identify chunks
struct CGV_API fourcc
{
static unsigned make_id(const std::string& ascii);
/// store fourcc as 32 bit integer
unsigned id;
/// construct from unsigned integer
fourcc(unsigned _id = 0) : id(_id) {}
/// construct from string
fourcc(const std::string& s) : id(make_id(s)) {}
/// convert to string
std::string to_string() const;
/// compare with string
bool operator == (const std::string& s) const;
/// compare with string
bool operator != (const std::string& s) const;
};
/// stream out fourcc structure
extern CGV_API std::ostream& operator << (std::ostream& os, const fourcc& f);
/// callback handler passed to riff reader
struct CGV_API riff_handler
{
/// this is called when riff or list chunk is started, return whether to process list elements (default return is true)
virtual bool begin_list_chunk(fourcc id, unsigned size, fourcc hdr);
//! this is called before data of chunk is read, return whether to process chunk data (default return is true)
/*! If the chunk data should be stored in memory allocated by the handler, set \c data_ptr to this memory block
that must provide space for \c size bytes. If \c data_ptr is not set, the reader automatically allocates
a new data block, which is also deallocated by the reader after the corresponding call to \c process_chunk_data. */
virtual bool process_chunk_header(fourcc id, unsigned size, void*& data_ptr);
/// if \c process_chunk_header returned \c true, this callback is called to process chunk data
virtual void process_chunk_data(fourcc id, unsigned size, void* data_ptr);
/// called to mark the end of a list chunk
virtual void end_list_chunk(fourcc id, unsigned size, fourcc hdr);
};
/// reader class for riff files such as .ani or .avi
class CGV_API riff_reader
{
protected:
FILE* fp;
riff_handler* rh;
bool read_chunk_info(fourcc& f, unsigned& size);
bool read_chunk_list(unsigned size);
void close();
public:
/// construct from riff_handler
riff_reader(riff_handler* _rh);
/// read given file and generate callbacks to the riff_handler, return whether read was successful
bool read(const std::string& file_name);
};
}
}
#include <cgv/config/lib_end.h>