cgifsave: Make loop counts more accurate (#2709)

TheEssem · web-flow · commit d4eb2e82d212 · 2022-03-10T12:30:57.000Z
* cgifsave: Added "noloop" option * cgifsave: Change loop count logic * make sure nsgifload returns the correct loop count * Revert "make sure nsgifload returns the correct loop count" This reverts commit 77550f0. * Add fallback
diff --git a/libvips/foreign/cgifsave.c b/libvips/foreign/cgifsave.c
@@ -310,11 +310,19 @@ vips_foreign_save_cgif_write_frame( VipsForeignSaveCgif *cgif )
 	 */
 	if( !cgif->cgif_context ) {
 		cgif->cgif_config.pGlobalPalette = cgif->palette_rgb;
+#ifdef HAVE_CGIF_ATTR_NO_LOOP
+		cgif->cgif_config.attrFlags = CGIF_ATTR_IS_ANIMATED | ( cgif->loop == 1 ? CGIF_ATTR_NO_LOOP : 0 );
+#else
 		cgif->cgif_config.attrFlags = CGIF_ATTR_IS_ANIMATED;
+#endif/*HAVE_CGIF_ATTR_NO_LOOP*/
 		cgif->cgif_config.width = frame_rect->width;
 		cgif->cgif_config.height = frame_rect->height;
 		cgif->cgif_config.numGlobalPaletteEntries = cgif->lp->count;
+#ifdef HAVE_CGIF_ATTR_NO_LOOP
+		cgif->cgif_config.numLoops = cgif->loop > 1 ? cgif->loop - 1 : cgif->loop;
+#else
 		cgif->cgif_config.numLoops = cgif->loop;
+#endif/*HAVE_CGIF_ATTR_NO_LOOP*/
 		cgif->cgif_config.pWriteFn = vips__cgif_write;
 		cgif->cgif_config.pContext = (void *) cgif->target;
 
diff --git a/meson.build b/meson.build
@@ -238,6 +238,9 @@ if quantisation_package.found()
     if cgif_dep.found()
         libvips_deps += cgif_dep
         cfg_var.set('HAVE_CGIF', '1')
+        if cc.compiles('#include <cgif.h>\nint i = CGIF_ATTR_NO_LOOP;', name: 'Has CGIF_ATTR_NO_LOOP', dependencies: cgif_dep)
+            cfg_var.set('HAVE_CGIF_ATTR_NO_LOOP', '1')
+        endif
     endif
 endif
 
