decoder/ffmpeg: handle "*.opus" files

Yet another special case which is needed because Opus is a codec and
not a demuxer.

Author: MaxKellermann

NEWS

@@ -1,5 +1,6 @@
 ver 0.24.6 (not yet released)
 * decoder
+  - ffmpeg: handle "*.opus" files
   - mpg123: another workaround for libmpg123 ID3 corruption bug
   - opus: fix seeking in files with large OpusTags
 

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -726,6 +726,9 @@ ffmpeg_suffixes() noexcept
 			suffixes.emplace("dsf"sv);
 		} else if (StringIsEqual(codec->name, "dst")) {
 			suffixes.emplace("dst"sv);
+		} else if (StringIsEqual(codec->name, "opus") ||
+			   StringIsEqual(codec->name, "libopus")) {
+			suffixes.emplace("opus"sv);
 		} else if (StringStartsWith(codec->name, "wma"sv)) {
 			/* there are codecs "wmav1", "wmav2" etc. and
 			   they usually come in "*.wma" files */