x11vnc: more tweaks to -8to24 XGETIMAGE_8TO24

1 files changed, 13 insertions, 2 deletions

diff --git a/x11vnc/help.c b/x11vnc/help.c
index f68b92b..cbd8870 100644
--- a/x11vnc/help.c
+++ b/x11vnc/help.c
@@ -174,10 +174,21 @@ void print_help(int mode) {
 "                       to periodically refresh the screen (at the cost of\n"
 "                       bandwidth).\n"
 "\n"
+"                       Debugging for this mode can be enabled by setting the\n"
+"                       environment variable DEBUG_8TO24 to 1, 2, or 3.\n"
+"\n"
+"                       If there are problems, to enable an even more\n"
+"                       experimental mode, set the environment variable\n"
+"                       XGETIMAGE_8TO24=1 before starting x11vnc.  This enables\n"
+"                       a scheme were XGetImage() is used to retrieve the 8bpp\n"
+"                       data instead of assuming that data is in bits 25-32.\n"
+"                       This mode is significantly slower than the above mode.\n"
+"\n"
 "                       Note that -8to24 does not work on displays with 8bpp\n"
 "                       default visual with depth 24 applications.  The Xserver\n"
-"                       -cc option can be used to switch the default depth on\n"
-"                       multidepth setups.\n"
+"                       -cc option can be used to switch the default depth\n"
+"                       on multidepth setups.  It may be possible to handle\n"
+"                       this case.\n"
 "\n"
 "-scale fraction        Scale the framebuffer by factor \"fraction\".  Values\n"
 "                       less than 1 shrink the fb, larger ones expand it.  Note:\n"