VirtualDub2 cch_input

#ifndef mov_mp4_header
#define mov_mp4_header

#include "windows.h"
#include "inttypes.h"

struct MovAtom{
  __int64 sz;
  unsigned long t;
  __int64 pos;
  int hsize;
};

struct MovParser{
  const void* buf;
  int buf_size;

  const char* p;
  __int64 offset;
  __int64 fileSize;
  HANDLE hfile;

  MovParser(const void* buf, int buf_size, int64_t fileSize){
    this->buf = buf;
    this->buf_size = buf_size;
    this->fileSize = fileSize;
    p = (const char*)buf;
    offset = 0;
    hfile = 0;
  }

  MovParser(const wchar_t* name){
    buf = 0;
    buf_size = 0;
    p = 0;
    offset = 0;
    hfile = CreateFileW(name,GENERIC_READ,FILE_SHARE_READ,0,OPEN_EXISTING,0,0);
    LARGE_INTEGER s;
    GetFileSizeEx(hfile,&s);
    fileSize = s.QuadPart;
  }

  ~MovParser(){
    if(hfile) CloseHandle(hfile);
  }

  bool can_read(int64_t s){
    if(hfile){
      if(fileSize-offset<8) return false;
    } else {
      if(buf_size-offset<8) return false;
    }
    return true;
  }

  bool can_read(MovAtom& a){
    return offset<a.pos+a.sz;
  }

  void read(MovAtom& a, char*& buf, int& size, int extra=0){
    size = int(a.sz-a.hsize);
    buf = (char*)malloc(size+extra);
    memset(buf+size,0,extra);
    if(hfile){
      unsigned long w;
      ReadFile(hfile,buf,size,&w,0);
    } else {
      memcpy(buf,p,size); p+=size;
    }
    offset+=size;
  }

  void skip(MovAtom& a){
    __int64 d = a.pos+a.sz-offset;
    offset+=d;
    if(hfile){
      LARGE_INTEGER p;
      p.QuadPart = offset;
      SetFilePointerEx(hfile,p,0,FILE_BEGIN);
    } else {
      p+=d;
    }
  }

  unsigned long read4();
  __int64 read8();
  bool read(MovAtom& a);
};

#endif