avdevice/caca: change AV_OPT_TYPE_STRING to set .str default

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavdevice/caca.c

@@ -211,7 +211,7 @@ static const AVOption options[] = {
     { "charset",      "set charset used to render output", OFFSET(charset), AV_OPT_TYPE_STRING, {.str = "default" }, 0, 0, ENC },
     { "color",        "set color used to render output",   OFFSET(color),   AV_OPT_TYPE_STRING, {.str = "default" }, 0, 0, ENC },
     { "list_drivers", "list available drivers",  OFFSET(list_drivers), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, ENC },
-    { "list_dither", "list available dither options", OFFSET(list_dither), AV_OPT_TYPE_STRING, {.dbl=0}, 0, 1, ENC, "list_dither" },
+    { "list_dither", "list available dither options", OFFSET(list_dither), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 1, ENC, "list_dither" },
     { "algorithms",   NULL, 0, AV_OPT_TYPE_CONST, {.str = "algorithms"}, 0, 0, ENC, "list_dither" },
     { "antialiases",  NULL, 0, AV_OPT_TYPE_CONST, {.str = "antialiases"},0, 0, ENC, "list_dither" },
     { "charsets",     NULL, 0, AV_OPT_TYPE_CONST, {.str = "charsets"},   0, 0, ENC, "list_dither" },