avdevice/decklink: use boolean for list_devices option

For the document(indevs.texi and outdevs.texi) used it as boolean.

Reviewed-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>

libavdevice/decklink_dec_c.c

@@ -30,7 +30,7 @@
 #define DEC AV_OPT_FLAG_DECODING_PARAM
 
 static const AVOption options[] = {
-    { "list_devices", "list available devices"  , OFFSET(list_devices), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, DEC },
+    { "list_devices", "list available devices"  , OFFSET(list_devices), AV_OPT_TYPE_BOOL  , { .i64 = 0   }, 0, 1, DEC },
     { "list_formats", "list supported formats"  , OFFSET(list_formats), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, DEC },
     { "format_code",  "set format by fourcc"    , OFFSET(format_code),  AV_OPT_TYPE_STRING, { .str = NULL}, 0, 0, DEC },
     { "raw_format",   "pixel format to be returned by the card when capturing" , OFFSET(raw_format),  AV_OPT_TYPE_INT, { .i64 = 0}, 0, 5, DEC, "raw_format" },

libavdevice/decklink_enc_c.c

@@ -28,7 +28,7 @@
 #define OFFSET(x) offsetof(struct decklink_cctx, x)
 #define ENC AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
-    { "list_devices", "list available devices"  , OFFSET(list_devices), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, ENC },
+    { "list_devices", "list available devices"  , OFFSET(list_devices), AV_OPT_TYPE_BOOL  , { .i64 = 0   }, 0, 1, ENC },
     { "list_formats", "list supported formats"  , OFFSET(list_formats), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, ENC },
     { "preroll"     , "video preroll in seconds", OFFSET(preroll     ), AV_OPT_TYPE_DOUBLE, { .dbl = 0.5 }, 0, 5, ENC },
     { "duplex_mode" , "duplex mode"             , OFFSET(duplex_mode ), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 2, ENC, "duplex_mode"},