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trying to set EXIF_TAG_USER_COMMENT but not working
This commit is contained in:
John Cupitt 2018-07-03 14:55:47 +01:00
parent 1cc7dd6af7
commit c12cd6d2cb
1 changed files with 125 additions and 69 deletions
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194
libvips/foreign/exif.c
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@ -706,6 +706,69 @@ vips_exif_set_double( ExifData *ed,
typedef void (*write_fn)( ExifData *ed,
ExifEntry *entry, unsigned long component, void *data );
/* special header required for EXIF_TAG_USER_COMMENT.
*/
#define ASCII_COMMENT "ASCII\0\0\0"
/* data is a null-terminated utf-8 string.
*/
static void
vips_exif_set_string( ExifData *ed,
ExifEntry *entry, unsigned long component, const char *data )
{
ExifMem *mem = exif_mem_new_default();
void *buf;
int len;
const char *p;
char *q;
/* A copy of data which we may have to free.
*/
q = NULL;
/* The final " (xx, ASCII, yy, zz)" part of the string (if present) was
* added by us in _to_s(), we must remove it before setting the string
* back again.
*
* It may not be there if the user has changed the string.
*
* Leave p pointing to the trimmed string.
*/
len = strlen( data );
if( len > 0 &&
data[len - 1] == ')' &&
(p = strrchr( data, '(' )) &&
p - data > 0 &&
p[-1] == ' ' ) {
q = g_strdup( data );
q[p - data - 1] = '\0';
p = q;
}
else
p = data;
len = strlen( p );
/* The string in the entry must be allocated with the same allocator
* that was used to allocate the entry itself. We assume the entry was
* created with the default one.
*
* We have to write the ASCII charset tag and not write a
* null-terminator.
*/
buf = exif_mem_alloc( mem, len + sizeof( ASCII_COMMENT ) - 1 );
entry->data = buf;
entry->size = len;
entry->components = len;
entry->format = EXIF_FORMAT_ASCII;
memcpy( entry->data, ASCII_COMMENT, sizeof( ASCII_COMMENT ) - 1 );
memcpy( entry->data + sizeof(ASCII_COMMENT) - 1, p, len - 1 );
VIPS_FREEF( g_free, q );
VIPS_FREEF( exif_mem_unref, mem );
}
/* Write a tag. Update what's there, or make a new one.
*/
static void
@ -722,12 +785,19 @@ vips_exif_set_tag( ExifData *ed, int ifd, ExifTag tag, write_fn fn, void *data )
/* tag must be set before calling exif_content_add_entry.
*/
entry->tag = tag;
exif_content_add_entry( ed->ifd[ifd], entry );
exif_entry_initialize( entry, tag );
exif_entry_unref( entry );
fn( ed, entry, 0, data );
/* libexif makes us have a special path for string-valued
* fields :(
*/
if( tag == EXIF_TAG_USER_COMMENT ) {
vips_exif_set_string( ed, entry, 0, data );
}
else {
exif_entry_initialize( entry, tag );
fn( ed, entry, 0, data );
}
}
}
@ -869,13 +939,38 @@ vips_exif_set_thumbnail( ExifData *ed, VipsImage *im )
return( 0 );
}
/* See also vips_exif_to_s() ... keep in sync.
/* Skip any spaces.
*/
static const char *
skip_space( const char *p )
{
while( p && *p == ' ' )
p += 1;
return( p );
}
/* Skip to the end of this non-space sequence.
*/
static const char *
skip_nonspace( const char *p )
{
while( p && *p && *p != ' ' )
p += 1;
return( p );
}
/* See also vips_exif_to_s() ... keep in sync. Only the numeric types are
* handled here, since they can be updated. For string types, we have to
* destroy and recreate, see above.
*/
static void
vips_exif_from_s( ExifData *ed, ExifEntry *entry, const char *value )
{
unsigned long i;
const char *p;
int v;
if( entry->format == EXIF_FORMAT_SHORT ||
entry->format == EXIF_FORMAT_SSHORT ||
@ -884,26 +979,15 @@ vips_exif_from_s( ExifData *ed, ExifEntry *entry, const char *value )
if( entry->components >= 10 )
return;
/* Skip any leading spaces.
*/
p = value;
while( *p == ' ' )
p += 1;
for( i = 0; i < entry->components; i++ ) {
int value = atof( p );
if( !(p = skip_space( p )) )
break;
vips_exif_set_int( ed, entry, i, &value );
v = atof( p );
vips_exif_set_int( ed, entry, i, &v );
/* Skip to the next set of spaces, then to the
* beginning of the next item.
*/
while( *p && *p != ' ' )
p += 1;
while( *p == ' ' )
p += 1;
if( !*p )
break;
p = skip_nonspace( p );
}
}
else if( entry->format == EXIF_FORMAT_RATIONAL ||
@ -911,57 +995,16 @@ vips_exif_from_s( ExifData *ed, ExifEntry *entry, const char *value )
if( entry->components >= 10 )
return;
/* Skip any leading spaces.
*/
p = value;
while( *p == ' ' )
p += 1;
for( i = 0; i < entry->components; i++ ) {
if( !(p = skip_space( p )) )
break;
vips_exif_set_rational( ed, entry, i, (void *) p );
/* Skip to the next set of spaces, then to the
* beginning of the next item.
*/
while( *p && *p != ' ' )
p += 1;
while( *p == ' ' )
p += 1;
if( !*p )
break;
p = skip_nonspace( p );
}
}
else if( entry->format == EXIF_FORMAT_ASCII ) {
int len;
char *q;
/* A copy of value which we may have to free.
*/
q = NULL;
/* The final " (xx, ASCII, yy, zz)" part of the string was
* added by us in _to_s(), we must remove it before setting
* the string back again.
*
* It may not be there if the user has changed the string.
*
* Leave p as poointing to the trimmed string.
*/
len = strlen( value );
if( len > 0 &&
value[len - 1] == ')' &&
(p = strrchr( value, '(' )) &&
p - value > 0 &&
p[-1] == ' ' ) {
q = g_strdup( value );
q[p - value - 1] = '\0';
p = q;
}
else
p = value;
for( p = value + strlen( value ) - 1; p >= value; p-- )
}
}
@ -1048,6 +1091,12 @@ vips_exif_exif_entry( ExifEntry *entry, VipsExifRemove *ve )
if( strcmp( tag_name, "Orientation" ) == 0 &&
vips_image_get_typeof( ve->image, VIPS_META_ORIENTATION ) )
ve->to_remove = g_slist_prepend( ve->to_remove, entry );
/* If this is a string tag, we must also remove it ready for
* recreation, see the comment below.
*/
if( entry->format == EXIF_FORMAT_ASCII )
ve->to_remove = g_slist_prepend( ve->to_remove, entry );
}
static void *
@ -1091,14 +1140,17 @@ vips_exif_update( ExifData *ed, VipsImage *image )
VIPS_DEBUG_MSG( "vips_exif_update: \n" );
/* Walk the image and add any exif- that's set in image metadata.
*/
vips_image_map( image, vips_exif_image_field, ed );
/* If this exif came from the image (rather than being an exif block we
* have made afresh), then any fields which are in the block but not on
* the image must have been deliberately removed. Remove them from the
* block as well.
*
* If there are any string-valued fields (eg. comment etc.) which
* exist as libvips metadata tags, we must also remove those from the
* exif block.
*
* libexif does not allow you to change string lengths, you must make
* new tags, so we have to remove ready to re-add.
*/
if( vips_image_get_typeof( image, VIPS_META_EXIF_NAME ) ) {
ve.image = image;
@ -1107,6 +1159,10 @@ vips_exif_update( ExifData *ed, VipsImage *image )
(ExifDataForeachContentFunc) vips_exif_exif_content,
&ve );
}
/* Walk the image and add any exif- that's set in image metadata.
*/
vips_image_map( image, vips_exif_image_field, ed );
}
/* Examine the metadata tags on the image and update the EXIF block.