@@ -6,6 +6,7 @@ version <next>:

 - ported lenscorrection filter from frei0r filter

 - large optimizations in dctdnoiz to make it usable

 - request icecast metadata by default

+- support for using metadata in stream specifiers in fftools

 version 2.3:

@@ -821,6 +821,11 @@ To map all the streams except the second audio, use negative mappings

 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT

 @end example

+To pick the English audio stream:

+@example

+avconv -i INPUT -map 0:m:language:eng OUTPUT

+@end example

+

 Note that using this option disables the default mappings for this output file.

 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]

@@ -46,6 +46,13 @@ in the program with the id @var{program_id}. Otherwise, it matches all streams i

 program.

 @item #@var{stream_id} or i:@var{stream_id}

 Match the stream by stream id (e.g. PID in MPEG-TS container).

+@item m:@var{key}[:@var{value}]

+Matches streams with the metadata tag @var{key} having the specified value. If

+@var{value} is not given, matches streams that contain the given tag with any

+value.

+

+Note that in @command{avconv}, matching by metadata will only work properly for

+input files.

 @end table

 @section Generic options

@@ -4216,6 +4216,29 @@ int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,

         stream_id = strtol(spec, &endptr, 0);

         if (!*endptr)

             return stream_id == st->id;

+    } else if (*spec == 'm' && *(spec + 1) == ':') {

+        AVDictionaryEntry *tag;

+        char *key, *val;

+        int ret;

+

+        spec += 2;

+        val = strchr(spec, ':');

+

+        key = val ? av_strndup(spec, val - spec) : av_strdup(spec);

+        if (!key)

+            return AVERROR(ENOMEM);

+

+        tag = av_dict_get(st->metadata, key, NULL, 0);

+        if (tag) {

+            if (!val || !strcmp(tag->value, val + 1))

+                ret = 1;

+            else

+                ret = 0;

+        } else

+            ret = 0;

+

+        av_freep(&key);

+        return ret;

     } else if (!*spec) /* empty specifier, matches everything */

         return 1;