avdevice/caca: Allow to list multiple dither option types at once

This can be achieved by using AV_OPT_TYPE_FLAGS instead of
AV_OPT_TYPE_STRING. It also avoids strcmp() when accessing
the option.

Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavdevice/caca.c

@@ -24,6 +24,13 @@
 #include "libavformat/mux.h"
 #include "avdevice.h"
 
+enum {
+    LIST_ALGORITHMS  = 1 << 0,
+    LIST_ANTIALIASES = 1 << 1,
+    LIST_CHARSETS    = 1 << 2,
+    LIST_COLORS      = 1 << 3,
+};
+
 typedef struct CACAContext {
     AVClass         *class;
     AVFormatContext *ctx;
@@ -38,7 +45,7 @@ typedef struct CACAContext {
     char            *charset, *color;
     char            *driver;
 
-    char            *list_dither;
+    int             list_dither;
     int             list_drivers;
 } CACAContext;
 
@@ -99,21 +106,14 @@ static int caca_write_header(AVFormatContext *s)
         return AVERROR_EXIT;
     }
     if (c->list_dither) {
-        if (!strcmp(c->list_dither, "colors")) {
+        if (c->list_dither & LIST_COLORS)
             list_dither_color(c);
-        } else if (!strcmp(c->list_dither, "charsets")) {
+        if (c->list_dither & LIST_CHARSETS)
             list_dither_charset(c);
-        } else if (!strcmp(c->list_dither, "algorithms")) {
+        if (c->list_dither & LIST_ALGORITHMS)
             list_dither_algorithm(c);
-        } else if (!strcmp(c->list_dither, "antialiases")) {
+        if (c->list_dither & LIST_ANTIALIASES)
             list_dither_antialias(c);
-        } else {
-            av_log(s, AV_LOG_ERROR,
-                   "Invalid argument '%s', for 'list_dither' option\n"
-                   "Argument must be one of 'algorithms, 'antialiases', 'charsets', 'colors'\n",
-                   c->list_dither);
-            return AVERROR(EINVAL);
-        }
         return AVERROR_EXIT;
     }
 
@@ -205,11 +205,11 @@ 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, {.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" },
-    { "colors",       NULL, 0, AV_OPT_TYPE_CONST, {.str = "colors"},     0, 0, ENC, "list_dither" },
+    { "list_dither", "list available dither options", OFFSET(list_dither), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, 0, INT_MAX, ENC, "list_dither" },
+    { "algorithms",   NULL, 0, AV_OPT_TYPE_CONST, {.i64 = LIST_ALGORITHMS },  0, 0, ENC, "list_dither" },
+    { "antialiases",  NULL, 0, AV_OPT_TYPE_CONST, {.i64 = LIST_ANTIALIASES }, 0, 0, ENC, "list_dither" },
+    { "charsets",     NULL, 0, AV_OPT_TYPE_CONST, {.i64 = LIST_CHARSETS },    0, 0, ENC, "list_dither" },
+    { "colors",       NULL, 0, AV_OPT_TYPE_CONST, {.i64 = LIST_COLORS },      0, 0, ENC, "list_dither" },
     { NULL },
 };