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move file stuff into subclass, add rewind

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This commit is contained in:
John Cupitt 2019-02-10 05:26:07 +00:00
parent a454225ef7
commit 9fe013f72d
1 changed files with 126 additions and 76 deletions
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202
libvips/foreign/gifload.c
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@ -93,10 +93,29 @@
#define DISPOSE_PREVIOUS 3
#endif
/* TODO:
*
* - initial very quick scan to discover
* - number of pages in file
* - has_transparency;
* - has_colour;
* can we avoid decompression of every pixel?
*
* - once we know this, we can set the header of the output image
*
* - second slow scan driven by _generate to render pages as required, with a
* single page held as a memory image
*
* Try the fast scan idea first -- can we get everything we need quickly?
*
* Need vmethods for open/close/rewind in base class, implement in file and
* buffer.
*/
typedef struct _VipsForeignLoadGif {
VipsForeignLoad parent_object;
/* Load this page (frame number).
/* Load from this page (frame number).
*/
int page;
@ -150,13 +169,16 @@ typedef struct _VipsForeignLoadGif {
*/
int dispose;
/* The FILE* we read from.
*/
FILE *fp;
} VipsForeignLoadGif;
typedef VipsForeignLoadClass VipsForeignLoadGifClass;
typedef struct _VipsForeignLoadGifClass {
VipsForeignLoadClass parent_class;
/* Reset the read position. Subclasses must implement this. Close goes
* into _dispose, open is not virtual.
*/
int (*rewind)( VipsForeignLoadGif *gif );
} VipsForeignLoadGifClass;
G_DEFINE_ABSTRACT_TYPE( VipsForeignLoadGif, vips_foreign_load_gif,
VIPS_TYPE_FOREIGN_LOAD );
@ -268,74 +290,6 @@ vips_foreign_load_gif_close( VipsForeignLoadGif *gif )
gif->file = NULL;
}
#endif
VIPS_FREEF( fclose, gif->fp );
}
/* Our input function for file open. We can't use DGifOpenFileName(), since
* that just calls open() and won't work with unicode on win32. We can't use
* DGifOpenFileHandle() since that's an fd from open() and you can't pass those
* acoss DLL boundaries on Windows.
*/
static int
vips_giflib_file_read( GifFileType *file, GifByteType *buffer, int n )
{
FILE *fp = (FILE *) file->UserData;
return( (int) fread( (void *) buffer, 1, n, fp ) );
}
static int
vips_foreign_load_gif_open( VipsForeignLoadGif *gif, const char *filename )
{
g_assert( !gif->file );
g_assert( !gif->fp );
if( !(gif->fp = vips__file_open_read( filename, NULL, FALSE )) )
return( -1 );
#ifdef HAVE_GIFLIB_5
{
int error;
if( !(gif->file =
DGifOpen( gif->fp, vips_giflib_file_read, &error )) ) {
vips_foreign_load_gif_error_vips( gif, error );
return( -1 );
}
}
#else
if( !(gif->file = DGifOpen( gif->fp, vips_giflib_file_read )) ) {
vips_foreign_load_gif_error_vips( gif, GifLastError() );
return( -1 );
}
#endif
return( 0 );
}
static int
vips_foreign_load_gif_open_buffer( VipsForeignLoadGif *gif, InputFunc read_fn )
{
g_assert( !gif->file );
#ifdef HAVE_GIFLIB_5
{
int error;
if( !(gif->file = DGifOpen( gif, read_fn, &error )) ) {
vips_foreign_load_gif_error_vips( gif, error );
return( -1 );
}
}
#else
if( !(gif->file = DGifOpen( gif, read_fn )) ) {
vips_foreign_load_gif_error_vips( gif, GifLastError() );
return( -1 );
}
#endif
return( 0 );
}
static void
@ -946,6 +900,26 @@ vips_foreign_load_gif_pages( VipsForeignLoadGif *gif, VipsImage **out )
return( 0 );
}
/* Attempt to quickly scan a GIF and discover:
* - number of frames (pages)
* - mono or colour (check colourmap on each page)
* - has transparency (check bit in ext block on every page)
*/
static int
vips_foreign_load_gif_header( VipsForeignLoad *load )
{
VipsForeignLoadGifClass *class =
(VipsForeignLoadGifClass *) VIPS_OBJECT_GET_CLASS( load );
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
printf( "vips_foreign_load_gif_header:\n" );
if( class->rewind( gif ) )
return( -1 );
return( 0 );
}
static int
vips_foreign_load_gif_load( VipsForeignLoad *load )
{
@ -955,6 +929,9 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
VipsImage *im;
if( vips_foreign_load_gif_header( load ) )
return( -1 );
if( vips_foreign_load_gif_pages( gif, &t[0] ) )
return( -1 );
im = t[0];
@ -1052,6 +1029,10 @@ typedef struct _VipsForeignLoadGifFile {
*/
char *filename;
/* The FILE* we read from.
*/
FILE *fp;
} VipsForeignLoadGifFile;
typedef VipsForeignLoadGifClass VipsForeignLoadGifFileClass;
@ -1059,20 +1040,70 @@ typedef VipsForeignLoadGifClass VipsForeignLoadGifFileClass;
G_DEFINE_TYPE( VipsForeignLoadGifFile, vips_foreign_load_gif_file,
vips_foreign_load_gif_get_type() );
static void
vips_foreign_load_gif_file_dispose( GObject *gobject )
{
VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) gobject;
VIPS_FREEF( fclose, file->fp );
G_OBJECT_CLASS( vips_foreign_load_gif_file_parent_class )->
dispose( gobject );
}
/* Our input function for file open. We can't use DGifOpenFileName(), since
* that just calls open() and won't work with unicode on win32. We can't use
* DGifOpenFileHandle() since that's an fd from open() and you can't pass those
* across DLL boundaries on Windows.
*/
static int
vips_giflib_file_read( GifFileType *file, GifByteType *buffer, int n )
{
FILE *fp = (FILE *) file->UserData;
return( (int) fread( (void *) buffer, 1, n, fp ) );
}
static int
vips_foreign_load_gif_file_header( VipsForeignLoad *load )
{
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) load;
if( vips_foreign_load_gif_open( gif, file->filename ) )
g_assert( !gif->file );
g_assert( !file->fp );
if( !(file->fp = vips__file_open_read( file->filename, NULL, FALSE )) )
return( -1 );
#ifdef HAVE_GIFLIB_5
{
int error;
if( !(gif->file =
DGifOpen( file->fp, vips_giflib_file_read, &error )) ) {
vips_foreign_load_gif_error_vips( gif, error );
return( -1 );
}
}
#else
if( !(gif->file = DGifOpen( file->fp, vips_giflib_file_read )) ) {
vips_foreign_load_gif_error_vips( gif, GifLastError() );
return( -1 );
}
#endif
VIPS_SETSTR( load->out->filename, file->filename );
return( vips_foreign_load_gif_load( load ) );
}
static int
vips_foreign_load_gif_file_rewind( VipsForeignLoadGif *gif )
{
return( 0 );
}
static const char *vips_foreign_gif_suffs[] = {
".gif",
NULL
@ -1086,7 +1117,9 @@ vips_foreign_load_gif_file_class_init(
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsForeignClass *foreign_class = (VipsForeignClass *) class;
VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
VipsForeignLoadGifClass *gif_class = (VipsForeignLoadGifClass *) class;
gobject_class->dispose = vips_foreign_load_gif_file_dispose;
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
@ -1098,6 +1131,8 @@ vips_foreign_load_gif_file_class_init(
load_class->is_a = vips_foreign_load_gif_is_a;
load_class->header = vips_foreign_load_gif_file_header;
gif_class->rewind = vips_foreign_load_gif_file_rewind;
VIPS_ARG_STRING( class, "filename", 1,
_( "Filename" ),
_( "Filename to load from" ),
@ -1155,13 +1190,28 @@ vips_foreign_load_gif_buffer_header( VipsForeignLoad *load )
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
VipsForeignLoadGifBuffer *buffer = (VipsForeignLoadGifBuffer *) load;
g_assert( !gif->file );
/* Init the read point.
*/
buffer->p = buffer->buf->data;
buffer->bytes_to_go = buffer->buf->length;
if( vips_foreign_load_gif_open_buffer( gif, vips_giflib_buffer_read ) )
#ifdef HAVE_GIFLIB_5
{
int error;
if( !(gif->file = DGifOpen( gif, vips_giflib_buffer_read, &error )) ) {
vips_foreign_load_gif_error_vips( gif, error );
return( -1 );
}
}
#else
if( !(gif->file = DGifOpen( gif, vips_giflib_buffer_read )) ) {
vips_foreign_load_gif_error_vips( gif, GifLastError() );
return( -1 );
}
#endif
return( vips_foreign_load_gif_load( load ) );
}