[FFmpeg-cvslog] lavf: fall back to a more meaningful log instance name

[Anton Khirnov]

ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Thu Mar 30 11:20:48 2023 +0200| [dffb058f3b1f9a9b681d7e923eee77c170c5bf54] | committer: Anton Khirnov

lavf: fall back to a more meaningful log instance name

An uninitialized AVFormatContext instance with neither iformat nor
oformat set will currently log as 'NULL', which is confusing and
unhelpful. Print 'AVFormatContext' instead, which provides more
information.

This happens e.g. if choosing an output format fails in
avformat_alloc_output_context2().

E.g. with the following commandline:
 ffmpeg -i <input> -f foobar -y /dev/null
before: [NULL @ 0x5580377834c0] Requested output format 'foobar' is not a suitable output format
after:  [AVFormatContext @ 0x55fa15bb34c0] Requested output format 'foobar' is not a suitable output format

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=dffb058f3b1f9a9b681d7e923eee77c170c5bf54
---

 libavformat/options.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/options.c b/libavformat/options.c
index 22ad523b2d..e4a3aceed0 100644
--- a/libavformat/options.c
+++ b/libavformat/options.c
@@ -44,7 +44,7 @@ static const char* format_to_name(void* ptr)
     AVFormatContext* fc = (AVFormatContext*) ptr;
     if(fc->iformat) return fc->iformat->name;
     else if(fc->oformat) return fc->oformat->name;
-    else return "NULL";
+    else return fc->av_class->class_name;
 }
 
 static void *format_child_next(void *obj, void *prev)