/* Examine the metadata tags on the image and update the EXIF block.
*/
int
vips__exif_update( VipsImage *image )
{
unsigned char *data;
size_t length;
unsigned int idl;
ExifData *ed;
/* Either parse from the embedded EXIF, or if there's none, make
* some fresh EXIF we can write the resolution to.
*/
if( vips_image_get_typeof( image, VIPS_META_EXIF_NAME ) ) {
if( vips_image_get_blob( image, VIPS_META_EXIF_NAME,
(void *) &data, &length ) )
return( -1 );
if( !(ed = exif_data_new_from_data( data, length )) )
return( -1 );
}
else {
ed = exif_data_new();
exif_data_set_option( ed,
EXIF_DATA_OPTION_FOLLOW_SPECIFICATION );
exif_data_set_data_type( ed, EXIF_DATA_TYPE_COMPRESSED );
exif_data_set_byte_order( ed, EXIF_BYTE_ORDER_INTEL );
/* Create the mandatory EXIF fields with default data.
*/
exif_data_fix( ed );
}
/* Update EXIF tags from the image metadata.
*/
vips_exif_update( ed, image );
/* Update EXIF resolution from the vips image header.
*/
if( vips_exif_resolution_from_image( ed, image ) ) {
exif_data_free( ed );
return( -1 );
}
/* Update EXIF image dimensions from the vips image header.
*/
if( vips_exif_set_dimensions( ed, image ) ) {
exif_data_free( ed );
return( -1 );
}
/* Update EXIF orientation from the vips image header.
*/
if( vips_exif_set_orientation( ed, image ) ) {
exif_data_free( ed );
return( -1 );
}
/* Update the thumbnail.
*/
if( vips_exif_set_thumbnail( ed, image ) ) {
exif_data_free( ed );
return( -1 );
}
/* Reserialise and write. exif_data_save_data() returns an int for some
* reason.
*/
exif_data_save_data( ed, &data, &idl );
if( !idl ) {
vips_error( "exif", "%s", _( "error saving EXIF" ) );
exif_data_free( ed );
return( -1 );
}
length = idl;
#ifdef DEBUG
printf( "vips__exif_update: generated %zd bytes of EXIF\n", length );
#endif /*DEBUG*/
vips_image_set_blob( image, VIPS_META_EXIF_NAME,
(VipsCallbackFn) vips_free, data, length );
exif_data_free( ed );
return( 0 );
}
static int
write_exif( Write *write )
{
#ifdef HAVE_EXIF
unsigned char *data;
size_t data_length;
unsigned int idl;
ExifData *ed;
/* Either parse from the embedded EXIF, or if there's none, make
* some fresh EXIF we can write the resolution to.
*/
if( vips_image_get_typeof( write->in, VIPS_META_EXIF_NAME ) ) {
if( vips_image_get_blob( write->in, VIPS_META_EXIF_NAME,
(void *) &data, &data_length ) )
return( -1 );
if( !(ed = exif_data_new_from_data( data, data_length )) )
return( -1 );
}
else {
ed = exif_data_new();
exif_data_set_option( ed,
EXIF_DATA_OPTION_FOLLOW_SPECIFICATION );
exif_data_set_data_type( ed, EXIF_DATA_TYPE_COMPRESSED );
exif_data_set_byte_order( ed, EXIF_BYTE_ORDER_INTEL );
/* Create the mandatory EXIF fields with default data.
*/
exif_data_fix( ed );
}
/* Update EXIF tags from the image metadata.
*/
vips_exif_update( ed, write->in );
/* Update EXIF resolution from the vips image header.
*/
if( vips__set_exif_resolution( ed, write->in ) ) {
exif_data_free( ed );
return( -1 );
}
/* Update EXIF image dimensions from the vips image header.
*/
if( set_exif_dimensions( ed, write->in ) ) {
exif_data_free( ed );
return( -1 );
}
/* Update EXIF orientation from the vips image header.
*/
if( set_exif_orientation( ed, write->in ) ) {
exif_data_free( ed );
return( -1 );
}
/* Reserialise and write. exif_data_save_data() returns an int for some
* reason.
*/
exif_data_save_data( ed, &data, &idl );
if( !idl ) {
vips_error( "VipsJpeg", "%s", _( "error saving EXIF" ) );
exif_data_free( ed );
return( -1 );
}
data_length = idl;
#ifdef DEBUG
printf( "write_exif: attaching %zd bytes of EXIF\n", data_length );
#endif /*DEBUG*/
exif_data_free( ed );
jpeg_write_marker( &write->cinfo, JPEG_APP0 + 1, data, data_length );
free( data );
#else /*!HAVE_EXIF*/
/* No libexif ... just copy the embedded EXIF over.
*/
if( write_blob( write, VIPS_META_EXIF_NAME, JPEG_APP0 + 1 ) )
return( -1 );
#endif /*!HAVE_EXIF*/
return( 0 );
}
