bool isXmpType(BasicIo& iIo, bool advance)
{
/*
Check if the file starts with an optional XML declaration followed by
either an XMP header (<?xpacket ... ?>) or an <x:xmpmeta> element.
In addition, in order for empty XmpSidecar objects as created by
Exiv2 to pass the test, just an XML header is also considered ok.
*/
const int32_t len = 80;
byte buf[len];
iIo.read(buf, xmlHdrCnt + 1);
if ( iIo.eof()
&& 0 == strncmp(reinterpret_cast<const char*>(buf), xmlHeader, xmlHdrCnt)) {
return true;
}
if (iIo.error() || iIo.eof()) {
return false;
}
iIo.read(buf + xmlHdrCnt + 1, len - xmlHdrCnt - 1);
if (iIo.error() || iIo.eof()) {
return false;
}
// Skip leading BOM
int32_t start = 0;
if (0 == strncmp(reinterpret_cast<const char*>(buf), "\xef\xbb\xbf", 3)) {
start = 3;
}
bool rc = false;
std::string head(reinterpret_cast<const char*>(buf + start), len - start);
if (head.substr(0, 5) == "<?xml") {
// Forward to the next tag
for (unsigned i = 5; i < head.size(); ++i) {
if (head[i] == '<') {
head = head.substr(i);
break;
}
}
}
if ( head.size() > 9
&& ( head.substr(0, 9) == "<?xpacket"
|| head.substr(0, 10) == "<x:xmpmeta")) {
rc = true;
}
if (!advance || !rc) {
iIo.seek(-(len - start), BasicIo::cur); // Swallow the BOM
}
return rc;
}
bool isTgaType(BasicIo& iIo, bool /*advance*/)
{
// not all TARGA files have a signature string, so first just try to match the file name extension
std::string path = iIo.path();
if(path.rfind(".tga") != std::string::npos || path.rfind(".TGA") != std::string::npos)
{
return true;
}
byte buf[26];
long curPos = iIo.tell();
iIo.seek(-26, BasicIo::end);
if (iIo.error() || iIo.eof())
{
return false;
}
iIo.read(buf, sizeof(buf));
if (iIo.error())
{
return false;
}
// some TARGA files, but not all, have a signature string at the end
bool matched = (memcmp(buf + 8, "TRUEVISION-XFILE", 16) == 0);
iIo.seek(curPos, BasicIo::beg);
return matched;
}
bool isXmpType(BasicIo& iIo, bool advance)
{
/*
Make sure the file starts with and (optional) XML declaration,
followed by an XMP header (<?xpacket ... ?>) or an <x:xmpmeta>
element. That doesn't cover all cases, since also x:xmpmeta is
optional, but let's wait and see.
*/
// Todo: Proper implementation
const int32_t len = 10;
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof()) {
return false;
}
bool rc = false;
const std::string head(reinterpret_cast<const char*>(buf), len);
if ( head.substr(0, 5) == "<?xml"
|| head.substr(0, 9) == "<?xpacket"
|| head.substr(0, 10) == "<x:xmpmeta") {
rc = true;
}
if (!advance || !rc) {
iIo.seek(-len, BasicIo::cur);
}
return rc;
}
bool isJpegType(BasicIo& iIo, bool advance)
{
bool result = true;
byte tmpBuf[2];
iIo.read(tmpBuf, 2);
if (iIo.error() || iIo.eof()) return false;
if (0xff != tmpBuf[0] || JpegImage::soi_ != tmpBuf[1]) {
result = false;
}
if (!advance || !result ) iIo.seek(-2, BasicIo::cur);
return result;
}
bool isMrwType(BasicIo& iIo, bool advance)
{
const int32_t len = 4;
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof()) {
return false;
}
int rc = memcmp(buf, "\0MRM", 4);
if (!advance || rc != 0) {
iIo.seek(-len, BasicIo::cur);
}
return rc == 0;
}
bool isExvType(BasicIo& iIo, bool advance)
{
bool result = true;
byte tmpBuf[7];
iIo.read(tmpBuf, 7);
if (iIo.error() || iIo.eof()) return false;
if ( 0xff != tmpBuf[0] || 0x01 != tmpBuf[1]
|| memcmp(tmpBuf + 2, ExvImage::exiv2Id_, 5) != 0) {
result = false;
}
if (!advance || !result) iIo.seek(-7, BasicIo::cur);
return result;
}
bool isOrfType(BasicIo& iIo, bool advance)
{
const int32_t len = 8;
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof()) {
return false;
}
OrfHeader orfHeader;
bool rc = orfHeader.read(buf, len);
if (!advance || !rc) {
iIo.seek(-len, BasicIo::cur);
}
return rc;
}
bool isJp2Type(BasicIo& iIo, bool advance)
{
const int32_t len = 12;
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof())
{
return false;
}
bool matched = (memcmp(buf, Jp2Signature, len) == 0);
if (!advance || !matched)
{
iIo.seek(-len, BasicIo::cur);
}
return matched;
}
bool isPgfType(BasicIo& iIo, bool advance)
{
const int32_t len = 3;
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof())
{
return false;
}
int rc = memcmp(buf, pgfSignature, 3);
if (!advance || rc != 0)
{
iIo.seek(-len, BasicIo::cur);
}
return rc == 0;
}
bool isBmpType(BasicIo& iIo, bool advance)
{
const int32_t len = 2;
const unsigned char BmpImageId[2] = { 'B', 'M' };
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof())
{
return false;
}
bool matched = (memcmp(buf, BmpImageId, len) == 0);
if (!advance || !matched)
{
iIo.seek(-len, BasicIo::cur);
}
return matched;
}
bool isAsfType(BasicIo& iIo, bool advance)
{
const int32_t len = 16;
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof()) {
return false;
}
bool matched = isASFType(buf);
if (!advance || !matched) {
iIo.seek(0, BasicIo::beg);
}
return matched;
}
bool isPsdType(BasicIo& iIo, bool advance)
{
const int32_t len = 6;
const unsigned char PsdHeader[6] = { '8', 'B', 'P', 'S', 0, 1 };
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof())
{
return false;
}
bool matched = (memcmp(buf, PsdHeader, len) == 0);
if (!advance || !matched)
{
iIo.seek(-len, BasicIo::cur);
}
return matched;
}
bool isCrwType(BasicIo& iIo, bool advance)
{
bool result = true;
byte tmpBuf[14];
iIo.read(tmpBuf, 14);
if (iIo.error() || iIo.eof()) {
return false;
}
if (!( ('I' == tmpBuf[0] && 'I' == tmpBuf[1])
|| ('M' == tmpBuf[0] && 'M' == tmpBuf[1]))) {
result = false;
}
if ( true == result
&& std::memcmp(tmpBuf + 6, CiffHeader::signature_, 8) != 0) {
result = false;
}
if (!advance || !result) iIo.seek(-14, BasicIo::cur);
return result;
}
bool isGifType(BasicIo& iIo, bool advance)
{
const int32_t len = 6;
const unsigned char Gif87aId[8] = { 'G', 'I', 'F', '8', '7', 'a' };
const unsigned char Gif89aId[8] = { 'G', 'I', 'F', '8', '9', 'a' };
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof())
{
return false;
}
bool matched = (memcmp(buf, Gif87aId, len) == 0)
|| (memcmp(buf, Gif89aId, len) == 0);
if (!advance || !matched)
{
iIo.seek(-len, BasicIo::cur);
}
return matched;
}
