decoder/ffmpeg: query supported demuxers at runtime

NEWS

@@ -19,6 +19,7 @@ ver 0.24 (not yet released)
   - curl: fix busy loop after connection failed
 * decoder
   - ffmpeg: require FFmpeg 4.0 or later
+  - ffmpeg: query supported demuxers at runtime
   - gme: require GME 0.6 or later
   - hybrid_dsd: remove
   - opus: implement bitrate calculation

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -26,6 +26,7 @@
 #include "tag/MixRampParser.hxx"
 #include "input/InputStream.hxx"
 #include "pcm/CheckAudioFormat.hxx"
+#include "util/IterableSplitString.hxx"
 #include "util/ScopeExit.hxx"
 #include "util/StringAPI.hxx"
 #include "Log.hxx"
@@ -690,33 +691,22 @@ ffmpeg_protocols() noexcept
 	return protocols;
 }
 
-/**
+static std::set<std::string, std::less<>>
- * A list of extensions found for the formats supported by ffmpeg.
+ffmpeg_suffixes() noexcept
- * This list is current as of 02-23-09; To find out if there are more
+{
- * supported formats, check the ffmpeg changelog since this date for
+	std::set<std::string, std::less<>> suffixes;
- * more formats.
+
- */
+	void *demuxer_opaque = nullptr;
-static const char *const ffmpeg_suffixes[] = {
+	while (const auto input_format = av_demuxer_iterate(&demuxer_opaque)) {
-	"16sv", "3g2", "3gp", "4xm", "8svx",
+		if (input_format->extensions != nullptr) {
-	"aa3", "aac", "ac3", "adx", "afc", "aif",
+			for (const auto i : IterableSplitString(input_format->extensions, ','))
-	"aifc", "aiff", "al", "alaw", "amr", "anim", "apc", "ape", "asf",
+				suffixes.emplace(i);
-	"atrac", "au", "aud", "avi", "avm2", "avs", "bap", "bfi", "c93", "cak",
+		} else
-	"cin", "cmv", "cpk", "daud", "dct", "divx", "dts", "dv", "dvd", "dxa",
+			suffixes.emplace(input_format->name);
-	"eac3", "film", "flac", "flc", "fli", "fll", "flx", "flv", "g726",
+	}
-	"gsm", "gxf", "iss", "m1v", "m2v", "m2t", "m2ts",
+
-	"m4a", "m4b", "m4v",
+	return suffixes;
-	"mad",
+}
-	"mj2", "mjpeg", "mjpg", "mka", "mkv", "mlp", "mm", "mmf", "mov", "mp+",
-	"mp1", "mp2", "mp3", "mp4", "mpc", "mpeg", "mpg", "mpga", "mpp", "mpu",
-	"mve", "mvi", "mxf", "nc", "nsv", "nut", "nuv", "oga", "ogm", "ogv",
-	"ogx", "oma", "ogg", "omg", "opus", "psp", "pva", "qcp", "qt", "r3d", "ra",
-	"ram", "rl2", "rm", "rmvb", "roq", "rpl", "rvc", "shn", "smk", "snd",
-	"sol", "son", "spx", "str", "swf", "tak", "tgi", "tgq", "tgv", "thp", "ts",
-	"tsp", "tta", "xa", "xvid", "uv", "uv2", "vb", "vid", "vob", "voc",
-	"vp6", "vmd", "wav", "webm", "wma", "wmv", "wsaud", "wsvga", "wv",
-	"wve",
-	nullptr
-};
 
 static const char *const ffmpeg_mime_types[] = {
 	"application/flv",