@@ -8526,6 +8526,12 @@ Float representation of @code{value} from metadata key.

 @item VALUE2

 Float representation of @code{value} as supplied by user in @code{value} option.

 @end table

+

+@item file

+If specified in @code{print} mode, output is written to the named file. When

+filename equals "-" data is written to standard output.

+If @code{file} option is not set, output is written to the log with AV_LOG_INFO

+loglevel.

 @end table

 @subsection Examples

@@ -81,8 +81,12 @@ typedef struct MetadataContext {

     AVExpr *expr;

     double var_values[VAR_VARS_NB];

+    FILE *file;

+    char *file_str;

+

     int (*compare)(struct MetadataContext *s,

                    const char *value1, const char *value2, size_t length);

+    void (*print)(AVFilterContext *ctx, const char *msg, ...) av_printf_format(2, 3);

 } MetadataContext;

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

@@ -104,6 +108,7 @@ static const AVOption filt_name##_options[] = {                     \

     {   "expr",    NULL, 0, AV_OPT_TYPE_CONST, {.i64 = METADATAF_EXPR    }, 0, 3, FLAGS, "function" }, \

     { "expr", "set expression for expr function", OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, FLAGS }, \

     { "length", "compare up to N chars for string function", OFFSET(length), AV_OPT_TYPE_INT,    {.i64 = INT_MAX }, 1, INT_MAX, FLAGS }, \

+    { "file", "set file where to print metadata information", OFFSET(file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS }, \

     { NULL }                                                            \

 }

@@ -155,6 +160,27 @@ static int parse_expr(MetadataContext *s, const char *value1, const char *value2

     return av_expr_eval(s->expr, s->var_values, NULL);

 }

+static void print_log(AVFilterContext *ctx, const char *msg, ...)

+{

+    va_list argument_list;

+

+    va_start(argument_list, msg);

+    if (msg)

+        av_vlog(ctx, AV_LOG_INFO, msg, argument_list);

+    va_end(argument_list);

+}

+

+static void print_file(AVFilterContext *ctx, const char *msg, ...)

+{

+    MetadataContext *s = ctx->priv;

+    va_list argument_list;

+

+    va_start(argument_list, msg);

+    if (msg)

+        vfprintf(s->file, msg, argument_list);

+    va_end(argument_list);

+}

+

 static av_cold int init(AVFilterContext *ctx)

 {

     MetadataContext *s = ctx->priv;

@@ -203,9 +229,37 @@ static av_cold int init(AVFilterContext *ctx)

         }

     }

+    if (s->file_str) {

+        if (!strcmp(s->file_str, "-")) {

+            s->file = stdout;

+        } else {

+            s->file = fopen(s->file_str, "w");

+            if (!s->file) {

+                int err = AVERROR(errno);

+                char buf[128];

+                av_strerror(err, buf, sizeof(buf));

+                av_log(ctx, AV_LOG_ERROR, "Could not open file %s: %s\n",

+                       s->file_str, buf);

+                return err;

+            }

+        }

+        s->print = print_file;

+    } else {

+        s->print = print_log;

+    }

+

     return 0;

 }

+static av_cold void uninit(AVFilterContext *ctx)

+{

+    MetadataContext *s = ctx->priv;

+

+    if (s->file && s->file != stdout)

+        fclose(s->file);

+    s->file = NULL;

+}

+

 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)

 {

     AVFilterContext *ctx = inlink->dst;

@@ -245,14 +299,14 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)

         break;

     case METADATA_PRINT:

         if (!s->key && e) {

-            av_log(ctx, AV_LOG_INFO, "frame %"PRId64" pts %"PRId64"\n", inlink->frame_count, frame->pts);

-            av_log(ctx, AV_LOG_INFO, "%s=%s\n", e->key, e->value);

+            s->print(ctx, "frame %"PRId64" pts %"PRId64"\n", inlink->frame_count, frame->pts);

+            s->print(ctx, "%s=%s\n", e->key, e->value);

             while ((e = av_dict_get(metadata, "", e, AV_DICT_IGNORE_SUFFIX)) != NULL) {

-                av_log(ctx, AV_LOG_INFO, "%s=%s\n", e->key, e->value);

+                s->print(ctx, "%s=%s\n", e->key, e->value);

             }

         } else if (e && e->value && (!s->value || (e->value && s->compare(s, e->value, s->value, s->length)))) {

-            av_log(ctx, AV_LOG_INFO, "frame %"PRId64" pts %"PRId64"\n", inlink->frame_count, frame->pts);

-            av_log(ctx, AV_LOG_INFO, "%s=%s\n", s->key, e->value);

+            s->print(ctx, "frame %"PRId64" pts %"PRId64"\n", inlink->frame_count, frame->pts);

+            s->print(ctx, "%s=%s\n", s->key, e->value);

         }

         return ff_filter_frame(outlink, frame);

         break;

@@ -301,6 +355,7 @@ AVFilter ff_af_ametadata = {

     .priv_size     = sizeof(MetadataContext),

     .priv_class    = &ametadata_class,

     .init          = init,

+    .uninit        = uninit,

     .query_formats = ff_query_formats_all,

     .inputs        = ainputs,

     .outputs       = aoutputs,

@@ -336,6 +391,7 @@ AVFilter ff_vf_metadata = {

     .priv_size   = sizeof(MetadataContext),

     .priv_class  = &metadata_class,

     .init        = init,

+    .uninit      = uninit,

     .inputs      = inputs,

     .outputs     = outputs,

     .flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,