exiv2json.cpp

Extracts data from image in JSON format.

// ***************************************************************** -*- C++ -*-
// exiv2json.cpp
// Sample program to print metadata in JSON format
#include <exiv2/exiv2.hpp>
#include "Jzon.h"
#include <iostream>
#include <iomanip>
#include <cassert>
#include <string>
#include <map>
#include <vector>
#include <set>
#include <cstdlib>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#if defined(__MINGW32__) || defined(__MINGW64__)
# ifndef __MINGW__
# define __MINGW__
# endif
#endif
#if defined(_MSC_VER) || defined(__MINGW__)
#include <windows.h>
#ifndef PATH_MAX
# define PATH_MAX 512
#endif
const char* realpath(const char* file,char* path)
{
GetFullPathName(file,PATH_MAX,path,NULL);
return path;
}
#else
#include <unistd.h>
#endif
struct Token {
std::string n; // the name eg "History"
bool a; // name is an array eg History[]
int i; // index (indexed from 1) eg History[1]/stEvt:action
};
typedef std::vector<Token> Tokens;
// "XMP.xmp.MP.RegionInfo/MPRI:Regions[1]/MPReg:Rectangle"
bool getToken(std::string& in,Token& token,Exiv2::StringSet* pNS=NULL)
{
bool result = false;
bool ns = false;
token.n = "" ;
token.a = false ;
token.i = 0 ;
while ( !result && in.length() ) {
std::string c = in.substr(0,1);
char C = c[0];
in = in.substr(1,std::string::npos);
if ( in.length() == 0 && C != ']' ) token.n += c;
if ( C == '/' || C == '[' || C == ':' || C == '.' || C == ']' || in.length() == 0 ) {
ns |= C == '/' ;
token.a = C == '[' ;
if ( C == ']' ) token.i = std::atoi(token.n.c_str()); // encoded string first index == 1
result = token.n.length() > 0 ;
} else {
token.n += c;
}
}
if (ns && pNS) pNS->insert(token.n);
return result;
}
Jzon::Node& addToTree(Jzon::Node& r1,Token token)
{
Jzon::Object object ;
Jzon::Array array ;
std::string key = token.n ;
size_t index = token.i-1; // array Eg: "History[1]" indexed from 1. Jzon expects 0 based index.
Jzon::Node& empty = token.a ? (Jzon::Node&) array : (Jzon::Node&) object ;
if ( r1.IsObject() ) {
Jzon::Object& o1 = r1.AsObject();
if ( !o1.Has(key) ) o1.Add(key,empty);
return o1.Get(key);
} else if ( r1.IsArray() ) {
Jzon::Array& a1 = r1.AsArray();
while ( a1.GetCount() <= index ) a1.Add(empty);
return a1.Get(index);
}
return r1;
}
Jzon::Node& recursivelyBuildTree(Jzon::Node& root,Tokens& tokens,size_t k)
{
return addToTree( k==0 ? root : recursivelyBuildTree(root,tokens,k-1), tokens[k] );
}
// build the json tree for this key. return location and discover the name
Jzon::Node& objectForKey(const std::string& Key,Jzon::Object& root,std::string& name,Exiv2::StringSet* pNS=NULL)
{
// Parse the key
Tokens tokens ;
Token token ;
std::string input = Key ; // Example: "XMP.xmp.MP.RegionInfo/MPRI:Regions[1]/MPReg:Rectangle"
while ( getToken(input,token,pNS) ) tokens.push_back(token);
size_t l = tokens.size()-1; // leave leaf name to push()
name = tokens[l].n ;
// The second token. For example: XMP.dc is a namespace
if ( pNS && tokens.size() > 1 ) pNS->insert(tokens[1].n);
return recursivelyBuildTree(root,tokens,l-1);
#if 0
// recursivelyBuildTree:
// Go to the root. Climb out adding objects or arrays to create the tree
// The leaf is pushed on the top by the caller of objectForKey()
// The recursion could be expressed by these if statements:
if ( l == 1 ) return addToTree(root,tokens[0]);
if ( l == 2 ) return addToTree(addToTree(root,tokens[0]),tokens[1]);
if ( l == 3 ) return addToTree(addToTree(addToTree(root,tokens[0]),tokens[1]),tokens[2]);
if ( l == 4 ) return addToTree(addToTree(addToTree(addToTree(root,tokens[0]),tokens[1]),tokens[2]),tokens[3]);
...
#endif
}
bool isObject(std::string& value)
{
return !value.compare(std::string("type=\"Struct\""));
}
bool isArray(std::string& value)
{
return !value.compare(std::string("type=\"Seq\""))
|| !value.compare(std::string("type=\"Bag\""))
|| !value.compare(std::string("type=\"Alt\""))
;
}
#define STORE(node,key,value) \
if (node.IsObject()) node.AsObject().Add(key,value);\
else node.AsArray() .Add( value)
template <class T>
void push(Jzon::Node& node,const std::string& key,T i)
{
#define ABORT_IF_I_EMTPY \
if (i->value().size() == 0) { \
return; \
}
std::string value = i->value().toString();
switch ( i->typeId() ) {
if ( ::isObject(value) ) {
Jzon::Object v;
STORE(node,key,v);
} else if ( ::isArray(value) ) {
Jzon::Array v;
STORE(node,key,v);
} else {
STORE(node,key,value);
}
break;
STORE(node,key,std::atoi(value.c_str()) );
break;
STORE(node,key,std::atof(value.c_str()) );
break;
ABORT_IF_I_EMTPY
Jzon::Array arr;
Exiv2::Rational rat = i->value().toRational();
arr.Add(rat.first );
arr.Add(rat.second);
STORE(node,key,arr);
} break;
ABORT_IF_I_EMTPY
Jzon::Object l ;
const Exiv2::LangAltValue& langs = dynamic_cast<const Exiv2::LangAltValue&>(i->value());
for ( Exiv2::LangAltValue::ValueType::const_iterator lang = langs.value_.begin()
; lang != langs.value_.end()
; lang++
) {
l.Add(lang->first,lang->second);
}
Jzon::Object o ;
o.Add("lang",l);
STORE(node,key,o);
}
break;
default:
// http://dev.exiv2.org/boards/3/topics/1367#message-1373
if ( key == "UserComment" ) {
size_t pos = value.find('\0') ;
if ( pos != std::string::npos )
value = value.substr(0,pos);
}
if ( key == "MakerNote") return;
STORE(node,key,value);
break;
}
}
void fileSystemPush(const char* path,Jzon::Node& nfs)
{
Jzon::Object& fs = (Jzon::Object&) nfs;
fs.Add("path",path);
char resolved_path[2000]; // PATH_MAX];
fs.Add("realpath",realpath(path,resolved_path));
struct stat buf;
memset(&buf,0,sizeof(buf));
stat(path,&buf);
fs.Add("st_dev" ,(int) buf.st_dev ); /* ID of device containing file */
fs.Add("st_ino" ,(int) buf.st_ino ); /* inode number */
fs.Add("st_mode" ,(int) buf.st_mode ); /* protection */
fs.Add("st_nlink" ,(int) buf.st_nlink ); /* number of hard links */
fs.Add("st_uid" ,(int) buf.st_uid ); /* user ID of owner */
fs.Add("st_gid" ,(int) buf.st_gid ); /* group ID of owner */
fs.Add("st_rdev" ,(int) buf.st_rdev ); /* device ID (if special file) */
fs.Add("st_size" ,(int) buf.st_size ); /* total size, in bytes */
fs.Add("st_atime" ,(int) buf.st_atime ); /* time of last access */
fs.Add("st_mtime" ,(int) buf.st_mtime ); /* time of last modification */
fs.Add("st_ctime" ,(int) buf.st_ctime ); /* time of last status change */
#if defined(_MSC_VER) || defined(__MINGW__)
size_t blksize = 1024;
size_t blocks = (buf.st_size+blksize-1)/blksize;
#else
size_t blksize = buf.st_blksize;
size_t blocks = buf.st_blocks ;
#endif
fs.Add("st_blksize",(int) blksize ); /* blocksize for file system I/O */
fs.Add("st_blocks" ,(int) blocks ); /* number of 512B blocks allocated */
}
int main(int argc, char* const argv[])
{
try {
if (argc < 2 || argc > 3) {
std::cout << "Usage: " << argv[0] << " [-option] file" << std::endl;
std::cout << "Option: all | exif | iptc | xmp | filesystem" << std::endl;
return 1;
}
const char* path = argv[argc-1];
const char* opt = argc == 3 ? argv[1] : "-all" ;
while (opt[0] == '-') opt++ ; // skip past leading -'s
char option = opt[0];
assert(image.get() != 0);
image->readMetadata();
Jzon::Object root;
if ( option == 'f' ) { // only report filesystem when requested
const char* FS="FS";
Jzon::Object fs ;
root.Add(FS,fs) ;
fileSystemPush(path,root.Get(FS));
}
if ( option == 'a' || option == 'e' ) {
Exiv2::ExifData &exifData = image->exifData();
for ( Exiv2::ExifData::const_iterator i = exifData.begin(); i != exifData.end() ; ++i ) {
std::string name ;
Jzon::Node& object = objectForKey(i->key(),root,name);
push(object,name,i);
}
}
if ( option == 'a' || option == 'i' ) {
Exiv2::IptcData &iptcData = image->iptcData();
for (Exiv2::IptcData::const_iterator i = iptcData.begin(); i != iptcData.end(); ++i) {
std::string name ;
Jzon::Node& object = objectForKey(i->key(),root,name);
push(object,name,i);
}
}
#ifdef EXV_HAVE_XMP_TOOLKIT
if ( option == 'a' || option == 'x' ) {
Exiv2::XmpData &xmpData = image->xmpData();
if ( !xmpData.empty() ) {
// get the xmpData and recursively parse into a Jzon Object
Exiv2::StringSet namespaces;
for (Exiv2::XmpData::const_iterator i = xmpData.begin(); i != xmpData.end(); ++i) {
std::string name ;
Jzon::Node& object = objectForKey(i->key(),root,name,&namespaces);
push(object,name,i);
}
// get the namespace dictionary from XMP
// create and populate a Jzon::Object for the namespaces
Jzon::Object xmlns;
for ( Exiv2::StringSet_i it = namespaces.begin() ; it != namespaces.end() ; it++ ) {
std::string ns = *it ;
std::string uri = nsDict[ns];
xmlns.Add(ns,uri);
}
// add xmlns as Xmp.xmlns
root.Get("Xmp").AsObject().Add("xmlns",xmlns);
}
}
#endif
Jzon::Writer writer(root, Jzon::StandardFormat);
writer.Write();
std::cout << writer.GetResult() << std::endl;
return 0;
}
catch (Exiv2::Error& e) {
std::cout << "Caught Exiv2 exception '" << e.what() << "'\n";
return -1;
}
}