[xine-devel] snapshot code in xine-ui introduces dependency on new libpng

[Juergen K. <jk...@to...>]

The new snapshot code in xine-ui introduces a dependancy on a relatively new
libpng; 1.0.8 is OK, while 1.0.5 is not.

How should we handle that?

For now, I've updated the configure.in checks, so that the new stuff we
need from libpng is tested, before we attempt to compile it (and
possibly fail during the compilation, because the installed libpng is
too old).


So, configuration of xine-ui 0.9.2 may now fail with:

    *** libpng is needed (PNG library is too old) ***

when the installed libpng was OK for 0.9.1 and earlier.
Is that good enough?  Or should we handle the problem more gracefully?



I've no idea what version of libpng is included in various "current" linux
distributions.  [The Debian 2.2 on sourceforge's compilefarm has 1.0.5]


Another option could be to tolerate an old libpng, and remove the snapshot
code or replace it with an error message, something like:


vs server: Diffing .
Index: configure.in
===================================================================
RCS file: /cvsroot/xine/xine-ui/configure.in,v
retrieving revision 1.69
diff -u -r1.69 configure.in
--- configure.in        2001/10/14 18:39:13     1.69
+++ configure.in        2001/10/14 18:51:32
@@ -224,12 +224,9 @@
        png_structp pp; 
        png_infop info; 
        png_colorp cmap; 
-       int dummy = PNG_TRANSFORM_IDENTITY;
 
        png_create_read_struct; 
        png_set_IHDR;
-       png_set_rows;
-       png_write_png;
        ], png_ok=yes, png_ok=no)
 
     AC_MSG_RESULT($png_ok)
Index: src/xitk/snapshot.c
===================================================================
RCS file: /cvsroot/xine/xine-ui/src/xitk/snapshot.c,v
retrieving revision 1.2
diff -u -r1.2 snapshot.c
--- src/xitk/snapshot.c 2001/10/14 18:39:13     1.2
+++ src/xitk/snapshot.c 2001/10/14 18:51:32
@@ -731,6 +731,7 @@
 
 void create_snapshot ( gGui_t *gGui )
 {
+#ifdef PNG_INFO_IMAGE_SUPPORTED
   int err = 0;
 
 
@@ -932,4 +933,7 @@
   printf("  prvt_image_free\n" );
   prvt_image_free( &image );
   return;
+#else
+  fprintf(stderr, "Sorry, your libpng is too old, snapshot function 
disabled\n");
+#endif
 }