@@ -30,6 +30,7 @@ version <next>:

 - drop avserver, it was unmaintained for years and largely broken

 - Icecast protocol

 - request icecast metadata by default

+- support for using metadata in stream specifiers in avtools

 version 10:

@@ -1536,6 +1536,29 @@ int check_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)

         spec += 2;

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

         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;

@@ -720,6 +720,11 @@ To map all the streams except the second audio, use negative mappings

 avconv -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_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})

@@ -44,6 +44,13 @@ If @var{stream_index} is given, then matches stream number @var{stream_index} in

 program with id @var{program_id}. Otherwise matches all streams in this program.

 @item 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