@@ -8500,6 +8500,10 @@ Can be one of following:

 Values are interpreted as strings, returns true if @code{value} is same as metadata value up

 to N chars as set in @code{length} option.

+@item starts_with

+Values are interpreted as strings, returns true if metadata value starts with

+the @code{value} option string.

+

 @item less

 Values are interpreted as floats, returns true if metadata value is less than @code{value}.

@@ -49,6 +49,7 @@ enum MetadataMode {

 enum MetadataFunction {

     METADATAF_STRING,

+    METADATAF_STARTS_WITH,

     METADATAF_LESS,

     METADATAF_EQUAL,

     METADATAF_GREATER,

@@ -102,6 +103,7 @@ static const AVOption filt_name##_options[] = {                     \

     { "value", "set metadata value",     OFFSET(value),  AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, FLAGS }, \

     { "function", "function for comparing values", OFFSET(function), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, METADATAF_NB-1, FLAGS, "function" }, \

     {   "string",  NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_STRING  }, 0, 3, FLAGS, "function" }, \

+    {   "starts_with", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_STARTS_WITH }, 0, 0, FLAGS, "function" }, \

     {   "less",    NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_LESS    }, 0, 3, FLAGS, "function" }, \

     {   "equal",   NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_EQUAL   }, 0, 3, FLAGS, "function" }, \

     {   "greater", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_GREATER }, 0, 3, FLAGS, "function" }, \

@@ -117,6 +119,11 @@ static int string(MetadataContext *s, const char *value1, const char *value2, si

     return !strncmp(value1, value2, length);

 }

+static int starts_with(MetadataContext *s, const char *value1, const char *value2, size_t length)

+{

+    return !strncmp(value1, value2, strlen(value2));

+}

+

 static int equal(MetadataContext *s, const char *value1, const char *value2, size_t length)

 {

     float f1, f2;

@@ -201,6 +208,9 @@ static av_cold int init(AVFilterContext *ctx)

     case METADATAF_STRING:

         s->compare = string;

         break;

+    case METADATAF_STARTS_WITH:

+        s->compare = starts_with;

+        break;

     case METADATAF_LESS:

         s->compare = less;

         break;