lavf: add a flag for experimental (de)muxers

doc/APIchanges

@@ -14,6 +14,9 @@ libavutil:     2021-04-27
 
 API changes, most recent first:
 
+2022-01-xx - xxxxxxxxxx - lavf 59.13.100 - avformat.h
+  Add AVFMT_EXPERIMENTAL flag.
+
 2021-12-xx - xxxxxxxxxx - lavu 57.13.100 - hwcontext_videotoolbox.h
   Add av_vt_pixbuf_set_attachments
 

libavformat/avformat.h

@@ -463,6 +463,13 @@ typedef struct AVProbeData {
 /// Demuxer will use avio_open, no opened file should be provided by the caller.
 #define AVFMT_NOFILE        0x0001
 #define AVFMT_NEEDNUMBER    0x0002 /**< Needs '%d' in filename. */
+/**
+ * The muxer/demuxer is experimental and should be used with caution.
+ *
+ * - demuxers: will not be selected automatically by probing, must be specified
+ *             explicitly.
+ */
+#define AVFMT_EXPERIMENTAL  0x0004
 #define AVFMT_SHOW_IDS      0x0008 /**< Show format stream IDs numbers. */
 #define AVFMT_GLOBALHEADER  0x0040 /**< Format wants global header. */
 #define AVFMT_NOTIMESTAMPS  0x0080 /**< Format does not need / have any timestamps. */

libavformat/format.c

@@ -158,6 +158,8 @@ const AVInputFormat *av_probe_input_format3(const AVProbeData *pd,
     }
 
     while ((fmt1 = av_demuxer_iterate(&i))) {
+        if (fmt1->flags & AVFMT_EXPERIMENTAL)
+            continue;
         if (!is_opened == !(fmt1->flags & AVFMT_NOFILE) && strcmp(fmt1->name, "image2"))
             continue;
         score = 0;

libavformat/version.h

@@ -32,7 +32,7 @@
 // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
 // Also please add any ticket numbers that you believe might be affected here
 #define LIBAVFORMAT_VERSION_MAJOR  59
-#define LIBAVFORMAT_VERSION_MINOR  12
+#define LIBAVFORMAT_VERSION_MINOR  13
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \