@@ -241,8 +241,13 @@ ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg

 @end example

 @table @option

-@item -start_number @var{number}

-Start the sequence from @var{number}.

+@item start_number @var{number}

+Start the sequence from @var{number}. Default value is 1. Must be a

+positive number.

+

+@item updatefirst 1|0

+If set to 1, update the first written image file again and

+again. Default value is 0.

 @end table

 The image muxer supports the .Y.U.V image file format. This format is

@@ -128,8 +128,8 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)

 #define OFFSET(x) offsetof(VideoMuxData, x)

 #define ENC AV_OPT_FLAG_ENCODING_PARAM

 static const AVOption muxoptions[] = {

-    { "updatefirst",  "",                            OFFSET(updatefirst), AV_OPT_TYPE_INT, { .i64 = 0 }, 0,       1, ENC },

-    { "start_number", "first number in the sequence", OFFSET(img_number), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, INT_MAX, ENC },

+    { "updatefirst",  "update the first image file",      OFFSET(updatefirst), AV_OPT_TYPE_INT, { .i64 = 0 }, 0,       1, ENC },

+    { "start_number", "set first number in the sequence", OFFSET(img_number), AV_OPT_TYPE_INT,  { .i64 = 1 }, 1, INT_MAX, ENC },

     { NULL },

 };