@@ -3068,6 +3068,10 @@ The x and y offsets for the text shadow position with respect to the

 position of the text. They can be either positive or negative

 values. Default value for both is "0".

+@item start_number

+The starting frame number for the n/frame_num variable. The default value

+is "0".

+

 @item tabsize

 The size in number of spaces to use for rendering the tab.

 Default value is 4.

@@ -164,6 +164,7 @@ typedef struct {

     AVTimecode  tc;                 ///< timecode context

     int tc24hmax;                   ///< 1 if timecode is wrapped to 24 hours, 0 otherwise

     int reload;                     ///< reload text file for each frame

+    int start_number;               ///< starting frame number for n/frame_num var

 } DrawTextContext;

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

@@ -198,6 +199,7 @@ static const AVOption drawtext_options[]= {

     {"rate",            "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},

     {"reload",     "reload text file for each frame",                       OFFSET(reload),     AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},

     {"fix_bounds", "if true, check and fix text coords to avoid clipping",  OFFSET(fix_bounds), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},

+    {"start_number", "start frame number for n/frame_num variable", OFFSET(start_number), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS},

     /* FT_LOAD_* flags */

     { "ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), AV_OPT_TYPE_FLAGS, { .i64 = FT_LOAD_DEFAULT | FT_LOAD_RENDER}, 0, INT_MAX, FLAGS, "ft_load_flags" },

@@ -614,7 +616,7 @@ static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp,

 {

     DrawTextContext *s = ctx->priv;

-    av_bprintf(bp, "%d", (int)s->var_values[VAR_N]);

+    av_bprintf(bp, "%d", (int)s->var_values[VAR_N]+s->start_number);

     return 0;

 }