add _header scan of whole gif

This commit is contained in:
John Cupitt 2019-02-10 22:09:25 +00:00
parent 9fe013f72d
commit 7037377f15

View File

@ -94,12 +94,6 @@
#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
*
@ -112,6 +106,21 @@
* buffer.
*/
#define VIPS_TYPE_FOREIGN_LOAD_GIF (vips_foreign_load_gif_get_type())
#define VIPS_FOREIGN_LOAD_GIF( obj ) \
(G_TYPE_CHECK_INSTANCE_CAST( (obj), \
VIPS_TYPE_FOREIGN_LOAD_GIF, VipsForeignLoadGif ))
#define VIPS_FOREIGN_LOAD_GIF_CLASS( klass ) \
(G_TYPE_CHECK_CLASS_CAST( (klass), \
VIPS_TYPE_FOREIGN_LOAD_GIF, VipsForeignLoadGifClass))
#define VIPS_IS_FOREIGN_LOAD_GIF( obj ) \
(G_TYPE_CHECK_INSTANCE_TYPE( (obj), VIPS_TYPE_FOREIGN_LOAD_GIF ))
#define VIPS_IS_FOREIGN_LOAD_GIF_CLASS( klass ) \
(G_TYPE_CHECK_CLASS_TYPE( (klass), VIPS_TYPE_FOREIGN_LOAD_GIF ))
#define VIPS_FOREIGN_LOAD_GIF_GET_CLASS( obj ) \
(G_TYPE_INSTANCE_GET_CLASS( (obj), \
VIPS_TYPE_FOREIGN_LOAD_GIF, VipsForeignLoadGifClass ))
typedef struct _VipsForeignLoadGif {
VipsForeignLoad parent_object;
@ -130,6 +139,9 @@ typedef struct _VipsForeignLoadGif {
int current_page;
/* Set for EOF detected.
*
* FIXME ... do we need this?
*
*/
gboolean eof;
@ -169,15 +181,20 @@ typedef struct _VipsForeignLoadGif {
*/
int dispose;
/* Params for DGifOpen(). Set by subclasses, called by base class in
* _open().
*/
void *userPtr;
InputFunc read_func;
} VipsForeignLoadGif;
typedef struct _VipsForeignLoadGifClass {
VipsForeignLoadClass parent_class;
/* Reset the read position. Subclasses must implement this. Close goes
* into _dispose, open is not virtual.
/* Close and reopen gif->file.
*/
int (*rewind)( VipsForeignLoadGif *gif );
int (*open)( VipsForeignLoadGif *gif );
} VipsForeignLoadGifClass;
G_DEFINE_ABSTRACT_TYPE( VipsForeignLoadGif, vips_foreign_load_gif,
@ -430,13 +447,6 @@ vips_foreign_load_gif_render( VipsForeignLoadGif *gif,
}
}
/* We need a line buffer to decompress to.
*/
if( !gif->line )
if( !(gif->line = VIPS_ARRAY( gif,
gif->file->SWidth, GifPixelType )) )
return( -1 );
if( file->Image.Interlace ) {
int i;
@ -492,8 +502,7 @@ vips_foreign_load_gif_render( VipsForeignLoadGif *gif,
}
static int
vips_foreign_load_gif_extension_next( VipsForeignLoadGif *gif,
GifByteType **extension )
vips_foreign_load_gif_next( VipsForeignLoadGif *gif, GifByteType **extension )
{
if( DGifGetExtensionNext( gif->file, extension ) == GIF_ERROR ) {
vips_foreign_load_gif_error( gif );
@ -506,99 +515,6 @@ vips_foreign_load_gif_extension_next( VipsForeignLoadGif *gif,
return( 0 );
}
static int
vips_foreign_load_gif_graphics_ext( VipsForeignLoadGif *gif,
GifByteType *extension )
{
VIPS_DEBUG_MSG( "gifload: type: graphics\n" );
if( extension[0] == 4 ) {
/* Bytes are flags, delay low, delay high,
* transparency. Flag bit 1 means transparency
* is being set.
*/
gif->transparency = -1;
if( extension[1] & 0x1 ) {
gif->transparency = extension[4];
gif->has_transparency = TRUE;
VIPS_DEBUG_MSG( "gifload: transparency %d\n",
gif->transparency );
}
/* Set the current dispose mode. This is read during frame load
* to set the meaning of background and transparent pixels.
*/
gif->dispose = (extension[1] >> 2) & 0x7;
VIPS_DEBUG_MSG( "gifload: dispose %d\n", gif->dispose );
if( !gif->has_delay ) {
gif->has_delay = TRUE;
gif->delay = extension[2] | (extension[3] << 8);
}
}
while( extension != NULL )
if( vips_foreign_load_gif_extension_next( gif, &extension ) )
return( -1 );
return( 0 );
}
static int
vips_foreign_load_gif_application_ext( VipsForeignLoadGif *gif,
GifByteType *extension )
{
gboolean have_netscape;
VIPS_DEBUG_MSG( "gifload: type: application\n" );
/* The 11-byte NETSCAPE extension.
*/
have_netscape = FALSE;
if( extension[0] == 11 &&
vips_isprefix( "NETSCAPE2.0", (const char *) (extension + 1) ) )
have_netscape = TRUE;
while( extension != NULL ) {
if( vips_foreign_load_gif_extension_next( gif, &extension ) )
return( -1 );
if( have_netscape &&
extension &&
extension[0] == 3 &&
extension[1] == 1 ) {
gif->loop = extension[2] | (extension[3] << 8);
VIPS_DEBUG_MSG( "gifload: seen loop %d\n",
gif->loop );
}
}
return( 0 );
}
static int
vips_foreign_load_gif_comment_ext( VipsForeignLoadGif *gif,
GifByteType *extension )
{
VIPS_DEBUG_MSG( "gifload: type: comment\n" );
if( !gif->comment ) {
/* Up to 257 with a NULL terminator.
*/
char comment[257];
vips_strncpy( comment, (char *) (extension + 1), 256 );
comment[extension[0]] = '\0';
gif->comment = g_strdup( comment );
}
while( extension != NULL )
if( vips_foreign_load_gif_extension_next( gif, &extension ) )
return( -1 );
return( 0 );
}
static int
vips_foreign_load_gif_extension( VipsForeignLoadGif *gif )
{
@ -613,34 +529,26 @@ vips_foreign_load_gif_extension( VipsForeignLoadGif *gif )
return( -1 );
}
if( extension )
switch( ext_code ) {
case GRAPHICS_EXT_FUNC_CODE:
if( vips_foreign_load_gif_graphics_ext( gif,
extension ) )
return( -1 );
break;
if( extension &&
ext_code == GRAPHICS_EXT_FUNC_CODE &&
extension[0] == 4 ) {
/* Bytes are flags, delay low, delay high,
* transparency. Flag bit 1 means transparency
* is being set.
*/
gif->transparency = -1;
if( extension[1] & 0x1 )
gif->transparency = extension[4];
case APPLICATION_EXT_FUNC_CODE:
if( vips_foreign_load_gif_application_ext( gif,
extension ) )
return( -1 );
break;
/* Set the current dispose mode. This is read during frame load
* to set the meaning of background and transparent pixels.
*/
gif->dispose = (extension[1] >> 2) & 0x7;
}
case COMMENT_EXT_FUNC_CODE:
if( vips_foreign_load_gif_comment_ext( gif, extension ) )
return( -1 );
break;
default:
/* Step over any NEXT blocks for unknown extensions.
*/
while( extension != NULL )
if( vips_foreign_load_gif_extension_next( gif,
&extension ) )
return( -1 );
break;
}
while( extension != NULL )
if( vips_foreign_load_gif_next( gif, &extension ) )
return( -1 );
return( 0 );
}
@ -900,6 +808,157 @@ vips_foreign_load_gif_pages( VipsForeignLoadGif *gif, VipsImage **out )
return( 0 );
}
/* Quickly scan an image record.
*/
static int
vips_foreign_load_gif_scan_image_record( VipsForeignLoadGif *gif )
{
GifFileType *file = gif->file;
ColorMapObject *map = file->Image.ColorMap ?
file->Image.ColorMap : file->SColorMap;
GifByteType *dummy;
/* Test for a non-greyscale colourmap for this frame.
*/
if( !gif->has_colour &&
map ) {
int i;
for( i = 0; i < map->ColorCount; i++ )
if( map->Colors[i].Red != map->Colors[i].Green ||
map->Colors[i].Green != map->Colors[i].Blue ) {
printf( "gifload: not mono\n" );
gif->has_colour = TRUE;
break;
}
}
/* Step over compressed image data.
*/
do {
if( DGifGetCodeNext( gif->file, &dummy ) == GIF_ERROR ) {
vips_foreign_load_gif_error( gif );
return( -1 );
}
} while( dummy != NULL );
return( 0 );
}
static int
vips_foreign_load_gif_scan_application_ext( VipsForeignLoadGif *gif,
GifByteType *extension )
{
gboolean have_netscape;
printf( "gifload: type: application\n" );
/* The 11-byte NETSCAPE extension.
*/
have_netscape = FALSE;
if( extension[0] == 11 &&
vips_isprefix( "NETSCAPE2.0", (const char*) (extension + 1) ) )
have_netscape = TRUE;
while( extension != NULL ) {
if( vips_foreign_load_gif_next( gif, &extension ) )
return( -1 );
if( have_netscape &&
extension &&
extension[0] == 3 &&
extension[1] == 1 ) {
gif->loop = extension[2] | (extension[3] << 8);
printf( "gifload: seen loop %d\n",
gif->loop );
}
}
return( 0 );
}
static int
vips_foreign_load_gif_scan_comment_ext( VipsForeignLoadGif *gif,
GifByteType *extension )
{
VIPS_DEBUG_MSG( "gifload: type: comment\n" );
if( !gif->comment ) {
/* Up to 257 with a NULL terminator.
*/
char comment[257];
vips_strncpy( comment, (char *) (extension + 1), 256 );
comment[extension[0]] = '\0';
gif->comment = g_strdup( comment );
}
while( extension != NULL )
if( vips_foreign_load_gif_next( gif, &extension ) )
return( -1 );
return( 0 );
}
static int
vips_foreign_load_gif_scan_extension( VipsForeignLoadGif *gif )
{
GifByteType *extension;
int ext_code;
printf( "gifload: EXTENSION_RECORD_TYPE\n" );
if( DGifGetExtension( gif->file, &ext_code, &extension ) ==
GIF_ERROR ) {
vips_foreign_load_gif_error( gif );
return( -1 );
}
if( extension )
switch( ext_code ) {
case GRAPHICS_EXT_FUNC_CODE:
if( extension[0] == 4 &&
extension[1] & 0x1 )
gif->has_transparency = TRUE;
if( !gif->has_delay ) {
gif->has_delay = TRUE;
gif->delay = extension[2] | (extension[3] << 8);
}
while( extension != NULL )
if( vips_foreign_load_gif_next(
gif, &extension ) )
return( -1 );
break;
case APPLICATION_EXT_FUNC_CODE:
if( vips_foreign_load_gif_scan_application_ext( gif,
extension ) )
return( -1 );
break;
case COMMENT_EXT_FUNC_CODE:
if( vips_foreign_load_gif_scan_comment_ext( gif,
extension ) )
return( -1 );
break;
default:
/* Step over any NEXT blocks for unknown extensions.
*/
while( extension != NULL )
if( vips_foreign_load_gif_next( gif,
&extension ) )
return( -1 );
break;
}
return( 0 );
}
/* Attempt to quickly scan a GIF and discover:
* - number of frames (pages)
* - mono or colour (check colourmap on each page)
@ -912,17 +971,78 @@ vips_foreign_load_gif_header( VipsForeignLoad *load )
(VipsForeignLoadGifClass *) VIPS_OBJECT_GET_CLASS( load );
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
GifRecordType record;
int n_pages;
printf( "vips_foreign_load_gif_header:\n" );
if( class->rewind( gif ) )
if( class->open( gif ) )
return( -1 );
printf( "vips_foreign_load_gif_header: starting page scan\n" );
n_pages = 0;
do {
if( DGifGetRecordType( gif->file, &record ) == GIF_ERROR ) {
vips_foreign_load_gif_error( gif );
return( -1 );
}
switch( record ) {
case IMAGE_DESC_RECORD_TYPE:
printf( "gifload: IMAGE_DESC_RECORD_TYPE\n" );
if( DGifGetImageDesc( gif->file ) == GIF_ERROR ) {
vips_foreign_load_gif_error( gif );
return( -1 );
}
/* Read in the image record.
*/
if( vips_foreign_load_gif_scan_image_record( gif ) )
return( -1 );
n_pages += 1;
break;
case EXTENSION_RECORD_TYPE:
/* We will need to fetch the extensions to check for
* cmaps and transparency.
*/
if( vips_foreign_load_gif_scan_extension( gif ) )
return( -1 );
break;
case TERMINATE_RECORD_TYPE:
printf( "gifload: TERMINATE_RECORD_TYPE\n" );
gif->eof = TRUE;
break;
case SCREEN_DESC_RECORD_TYPE:
printf( "gifload: SCREEN_DESC_RECORD_TYPE\n" );
break;
case UNDEFINED_RECORD_TYPE:
printf( "gifload: UNDEFINED_RECORD_TYPE\n" );
break;
default:
break;
}
} while( !gif->eof );
printf( "vips_foreign_load_gif_header: found %d pages\n", n_pages );
return( 0 );
}
static int
vips_foreign_load_gif_load( VipsForeignLoad *load )
{
VipsForeignLoadGifClass *class =
(VipsForeignLoadGifClass *) VIPS_OBJECT_GET_CLASS( load );
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
VipsImage **t = (VipsImage **)
vips_object_local_array( VIPS_OBJECT( load ), 4 );
@ -932,6 +1052,11 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
if( vips_foreign_load_gif_header( load ) )
return( -1 );
if( class->open( gif ) )
return( -1 );
printf( "vips_foreign_load_gif_load:\n" );
if( vips_foreign_load_gif_pages( gif, &t[0] ) )
return( -1 );
im = t[0];
@ -977,17 +1102,55 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
return( 0 );
}
static int
vips_foreign_load_gif_open( VipsForeignLoadGif *gif )
{
printf( "vips_foreign_load_gif_open:\n" );
#ifdef HAVE_GIFLIB_5
{
int error;
if( !(gif->file = DGifOpen( gif->userPtr, gif->read_func, &error )) ) {
vips_foreign_load_gif_error_vips( gif, error );
return( -1 );
}
}
#else
if( !(gif->file = DGifOpen( gif->userPtr, gif->read_func )) ) {
vips_foreign_load_gif_error_vips( gif, GifLastError() );
return( -1 );
}
#endif
gif->eof = FALSE;
/* Allocate a line buffer now that we have the GIF width.
*/
if( !gif->line )
if( !(gif->line = VIPS_ARRAY( gif,
gif->file->SWidth, GifPixelType )) )
return( -1 );
return( 0 );
}
static void
vips_foreign_load_gif_class_init( VipsForeignLoadGifClass *class )
{
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
VipsForeignLoadGifClass *gif_class = (VipsForeignLoadGifClass *) class;
gobject_class->dispose = vips_foreign_load_gif_dispose;
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
gif_class->open = vips_foreign_load_gif_open;
load_class->header = vips_foreign_load_gif_header;
load_class->load = vips_foreign_load_gif_load;
object_class->nickname = "gifload_base";
object_class->description = _( "load GIF with giflib" );
@ -1065,43 +1228,29 @@ vips_giflib_file_read( GifFileType *file, GifByteType *buffer, int n )
}
static int
vips_foreign_load_gif_file_header( VipsForeignLoad *load )
vips_foreign_load_gif_file_open( VipsForeignLoadGif *gif )
{
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) load;
VipsForeignLoad *load = (VipsForeignLoad *) gif;
VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) gif;
g_assert( !gif->file );
g_assert( !file->fp );
printf( "vips_foreign_load_gif_file_open:\n" );
if( !(file->fp = vips__file_open_read( file->filename, NULL, FALSE )) )
return( -1 );
if( !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 );
VIPS_SETSTR( load->out->filename, file->filename );
}
}
#else
if( !(gif->file = DGifOpen( file->fp, vips_giflib_file_read )) ) {
vips_foreign_load_gif_error_vips( gif, GifLastError() );
return( -1 );
}
#endif
else
rewind( file->fp );
VIPS_SETSTR( load->out->filename, file->filename );
vips_foreign_load_gif_close( gif );
gif->userPtr = file->fp;
gif->read_func = vips_giflib_file_read;
return( vips_foreign_load_gif_load( load ) );
}
static int
vips_foreign_load_gif_file_rewind( VipsForeignLoadGif *gif )
{
return( 0 );
return( VIPS_FOREIGN_LOAD_GIF_CLASS(
vips_foreign_load_gif_file_parent_class )->open( gif ) );
}
static const char *vips_foreign_gif_suffs[] = {
@ -1129,9 +1278,8 @@ vips_foreign_load_gif_file_class_init(
foreign_class->suffs = vips_foreign_gif_suffs;
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;
gif_class->open = vips_foreign_load_gif_file_open;
VIPS_ARG_STRING( class, "filename", 1,
_( "Filename" ),
@ -1185,35 +1333,20 @@ vips_giflib_buffer_read( GifFileType *file, GifByteType *buf, int n )
}
static int
vips_foreign_load_gif_buffer_header( VipsForeignLoad *load )
vips_foreign_load_gif_buffer_open( VipsForeignLoadGif *gif )
{
VipsForeignLoadGif *gif = (VipsForeignLoadGif *) load;
VipsForeignLoadGifBuffer *buffer = (VipsForeignLoadGifBuffer *) load;
VipsForeignLoadGifBuffer *buffer = (VipsForeignLoadGifBuffer *) gif;
g_assert( !gif->file );
printf( "vips_foreign_load_gif_buffer_open:\n" );
/* Init the read point.
*/
vips_foreign_load_gif_close( gif );
buffer->p = buffer->buf->data;
buffer->bytes_to_go = buffer->buf->length;
gif->userPtr = gif;
gif->read_func = 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 ) );
return( VIPS_FOREIGN_LOAD_GIF_CLASS(
vips_foreign_load_gif_file_parent_class )->open( gif ) );
}
static void
@ -1223,6 +1356,7 @@ vips_foreign_load_gif_buffer_class_init(
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
VipsForeignLoadGifClass *gif_class = (VipsForeignLoadGifClass *) class;
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
@ -1231,7 +1365,8 @@ vips_foreign_load_gif_buffer_class_init(
object_class->description = _( "load GIF with giflib" );
load_class->is_a_buffer = vips_foreign_load_gif_is_a_buffer;
load_class->header = vips_foreign_load_gif_buffer_header;
gif_class->open = vips_foreign_load_gif_buffer_open;
VIPS_ARG_BOXED( class, "buffer", 1,
_( "Buffer" ),