avformat/mxfenc: allow user comments for opatom muxer

Reviewed-by: Tomas Härdin <tjoppen@acc.umu.se>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/muxers.texi

@@ -1629,7 +1629,7 @@ ffmpeg -i file.mpg -c copy \
      out.ts
 @end example
 
-@section mxf, mxf_d10
+@section mxf, mxf_d10, mxf_opatom
 
 MXF muxer.
 
@@ -1641,7 +1641,7 @@ The muxer options are:
 @item store_user_comments @var{bool}
 Set if user comments should be stored if available or never.
 IRT D-10 does not allow user comments. The default is thus to write them for
-mxf but not for mxf_d10
+mxf and mxf_opatom but not for mxf_d10
 @end table
 
 @section null

libavformat/mxfenc.c

@@ -3095,6 +3095,8 @@ static const AVOption opatom_options[] = {
     { "mxf_audio_edit_rate", "Audio edit rate for timecode",
         offsetof(MXFContext, audio_edit_rate), AV_OPT_TYPE_RATIONAL, {.dbl=25}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
     MXF_COMMON_OPTIONS
+    { "store_user_comments", "",
+      offsetof(MXFContext, store_user_comments), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
     { NULL },
 };