[FFmpeg-devel] [PATCH] avutil/opt: add AV_OPT_FLAG_FORCE_CONST

[Timo Rothenpieler]

---
 doc/APIchanges      |  3 +++
 libavutil/opt.c     | 14 ++++++++++++++
 libavutil/opt.h     |  5 +++++
 libavutil/version.h |  2 +-
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index 63e7a47126..da2c87909b 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2024-03-07
 
 API changes, most recent first:
 
+2024-04-xx - xxxxxxxxxx - lavu 59.15.101 - opt.h
+  Add AV_OPT_FLAG_FORCE_CONST.
+
 2024-04-11 - xxxxxxxxxx - lavc 61.5.102 - avcodec.h
   AVCodecContext.decoded_side_data may now be set by libavcodec after
   calling avcodec_open2().
diff --git a/libavutil/opt.c b/libavutil/opt.c
index d11e9d2ac5..9e51fa47f9 100644
--- a/libavutil/opt.c
+++ b/libavutil/opt.c
@@ -365,6 +365,20 @@ static int set_string_number(void *obj, void *target_obj, const AVOption *o, con
                 if (o_named->flags & AV_OPT_FLAG_DEPRECATED)
                     av_log(obj, AV_LOG_WARNING, "The \"%s\" option is deprecated: %s\n",
                            o_named->name, o_named->help);
+            } else if (o->flags & AV_OPT_FLAG_FORCE_CONST) {
+                av_log(obj, AV_LOG_ERROR, "The \"%s\" option only accepts one of its pre-defined constant values",
+                       o->name);
+                buf[0] = ':'; buf[1] = ' '; buf[2] = 0;
+                for (o_named = NULL; o_named = av_opt_next(target_obj, o_named); ) {
+                    if (o_named->type == AV_OPT_TYPE_CONST &&
+                        o_named->unit && o->unit &&
+                        !strcmp(o_named->unit, o->unit)) {
+                        av_log(obj, AV_LOG_ERROR, "%s%s", buf, o_named->name);
+                        buf[0] = ',';
+                    }
+                }
+                av_log(obj, AV_LOG_ERROR, "\n");
+                return AVERROR(EINVAL);
             } else {
                 if (o->unit) {
                     for (o_named = NULL; o_named = av_opt_next(target_obj, o_named); ) {
diff --git a/libavutil/opt.h b/libavutil/opt.h
index e6013662f6..67e2b687b2 100644
--- a/libavutil/opt.h
+++ b/libavutil/opt.h
@@ -305,6 +305,11 @@ enum AVOptionType{
  * Set if option constants can also reside in child objects.
  */
 #define AV_OPT_FLAG_CHILD_CONSTS    (1 << 18)
+/**
+ * The option will only accept AV_OPT_TYPE_CONST values.
+ * Any other user supplied values will be rejected.
+ */
+#define AV_OPT_FLAG_FORCE_CONST     (1 << 19)
 
 /**
  * May be set as default_val for AV_OPT_TYPE_FLAG_ARRAY options.
diff --git a/libavutil/version.h b/libavutil/version.h
index 1f2bddc022..5de2d92146 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -80,7 +80,7 @@
 
 #define LIBAVUTIL_VERSION_MAJOR  59
 #define LIBAVUTIL_VERSION_MINOR  15
-#define LIBAVUTIL_VERSION_MICRO 100
+#define LIBAVUTIL_VERSION_MICRO 101
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \
-- 
2.34.1