[FFmpeg-devel] [PATCH v4 1/6] lavu/opt: Allow options to be arguments of other options

[Thilo Borgmann]

Adds AV_OPT_FLAG_ARGUMENT for options being used as arguments for other options.
Adds av_arg_show() to allow printing of such arguments in help output.
---
 doc/APIchanges      |  4 ++++
 libavutil/opt.c     | 14 +++++++++++++-
 libavutil/opt.h     |  8 ++++++++
 libavutil/version.h |  4 ++--
 4 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/doc/APIchanges b/doc/APIchanges
index 729f56be7b..e4b2fc8799 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -14,6 +14,10 @@ libavutil:     2021-04-27
 
 API changes, most recent first:
 
+2022-09-19 - xxxxxxxxxx - lavu 57.37.100 - opt.h
+  Add AV_OPT_FLAG_ARGUMENT.
+  Add av_arg_show() to print arguments to options.
+
 2022-09-03 - xxxxxxxxxx - lavu 57.36.100 - pixfmt.h
   Add AV_PIX_FMT_P012, AV_PIX_FMT_Y212, AV_PIX_FMT_XV30, AV_PIX_FMT_XV36
 
diff --git a/libavutil/opt.c b/libavutil/opt.c
index a3940f47fb..89ef111690 100644
--- a/libavutil/opt.c
+++ b/libavutil/opt.c
@@ -1256,7 +1256,7 @@ static void opt_list(void *obj, void *av_log_obj, const char *unit,
             av_log(av_log_obj, AV_LOG_INFO, "     %-15s ", opt->name);
         else
             av_log(av_log_obj, AV_LOG_INFO, "  %s%-17s ",
-                   (opt->flags & AV_OPT_FLAG_FILTERING_PARAM) ? " " : "-",
+                   (opt->flags & (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_ARGUMENT)) ? " " : "-",
                    opt->name);
 
         switch (opt->type) {
@@ -1329,6 +1329,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 av_log(av_log_obj, AV_LOG_INFO, "%-12s ", "");
                 break;
         }
+        if (!(opt->flags & AV_OPT_FLAG_ARGUMENT)) {
         av_log(av_log_obj, AV_LOG_INFO, "%c%c%c%c%c%c%c%c%c%c%c",
                (opt->flags & AV_OPT_FLAG_ENCODING_PARAM)  ? 'E' : '.',
                (opt->flags & AV_OPT_FLAG_DECODING_PARAM)  ? 'D' : '.',
@@ -1341,6 +1342,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
                (opt->flags & AV_OPT_FLAG_BSF_PARAM)       ? 'B' : '.',
                (opt->flags & AV_OPT_FLAG_RUNTIME_PARAM)   ? 'T' : '.',
                (opt->flags & AV_OPT_FLAG_DEPRECATED)      ? 'P' : '.');
+        }
 
         if (opt->help)
             av_log(av_log_obj, AV_LOG_INFO, " %s", opt->help);
@@ -1456,6 +1458,16 @@ int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags)
     return 0;
 }
 
+int av_arg_show(void *obj, void *av_log_obj)
+{
+    if (!obj)
+        return -1;
+
+    opt_list(obj, av_log_obj, NULL, AV_OPT_FLAG_ARGUMENT, 0, -1);
+
+    return 0;
+}
+
 void av_opt_set_defaults(void *s)
 {
     av_opt_set_defaults2(s, 0, 0);
diff --git a/libavutil/opt.h b/libavutil/opt.h
index 461b5d3b6b..dce3483237 100644
--- a/libavutil/opt.h
+++ b/libavutil/opt.h
@@ -297,6 +297,7 @@ typedef struct AVOption {
 #define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering
 #define AV_OPT_FLAG_DEPRECATED      (1<<17) ///< set if option is deprecated, users should refer to AVOption.help text for more information
 #define AV_OPT_FLAG_CHILD_CONSTS    (1<<18) ///< set if option constants can also reside in child objects
+#define AV_OPT_FLAG_ARGUMENT        (1<<19) ///< set if option is an argument to another option
 //FIXME think about enc-audio, ... style flags
 
     /**
@@ -386,6 +387,13 @@ typedef struct AVOptionRanges {
  */
 int av_opt_show2(void *obj, void *av_log_obj, int req_flags, int rej_flags);
 
+/**
+ * Show the obj arguments.
+ *
+ * @param av_log_obj log context to use for showing the options
+ */
+int av_arg_show(void *obj, void *av_log_obj);
+
 /**
  * Set the values of all AVOption fields to their default values.
  *
diff --git a/libavutil/version.h b/libavutil/version.h
index 0585fa7b80..9c44cef6aa 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -79,8 +79,8 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  57
-#define LIBAVUTIL_VERSION_MINOR  36
-#define LIBAVUTIL_VERSION_MICRO 102
+#define LIBAVUTIL_VERSION_MINOR  37
+#define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \
-- 
2.20.1 (Apple Git-117)