lavf/options_table: mark use_wallclock_as_timestamps as boolean

It is only used in a boolean context. Also clarify its documentation.
Signed-off-by: Moritz Barsnick <barsnick@gmx.net>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/formats.texi

@@ -147,7 +147,7 @@ a packet for each stream, regardless of the maximum timestamp
 difference between the buffered packets.
 
 @item use_wallclock_as_timestamps @var{integer} (@emph{input})
-Use wallclock as timestamps.
+Use wallclock as timestamps if set to 1. Default is 0.
 
 @item avoid_negative_ts @var{integer} (@emph{output})
 

libavformat/options_table.h

@@ -78,7 +78,7 @@ static const AVOption avformat_options[] = {
 {"careful",    "consider things that violate the spec, are fast to check and have not been seen in the wild as errors", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_CAREFUL }, INT_MIN, INT_MAX, D, "err_detect"},
 {"compliant",  "consider all spec non compliancies as errors", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_COMPLIANT }, INT_MIN, INT_MAX, D, "err_detect"},
 {"aggressive", "consider things that a sane encoder shouldn't do as an error", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_AGGRESSIVE }, INT_MIN, INT_MAX, D, "err_detect"},
-{"use_wallclock_as_timestamps", "use wallclock as timestamps", OFFSET(use_wallclock_as_timestamps), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX-1, D},
+{"use_wallclock_as_timestamps", "use wallclock as timestamps", OFFSET(use_wallclock_as_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, D},
 {"skip_initial_bytes", "set number of bytes to skip before reading header and frames", OFFSET(skip_initial_bytes), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX-1, D},
 {"correct_ts_overflow", "correct single timestamp overflows", OFFSET(correct_ts_overflow), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, D},
 {"flush_packets", "enable flushing of the I/O context after each packet", OFFSET(flush_packets), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, E},