avformat/format: temporarily use old next api

Should fix https://ffmpeg.org/pipermail/ffmpeg-devel/2018-February/225066.html

Signed-off-by: Muhammad Faiz <mfcc64@gmail.com>

libavformat/format.c

@@ -52,7 +52,9 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
                                 const char *mime_type)
 {
     AVOutputFormat *fmt = NULL, *fmt_found;
+#if !FF_API_NEXT
     void *i = 0;
+#endif
     int score_max, score;
 
     /* specific test for image sequences */
@@ -66,7 +68,13 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
     /* Find the proper file type. */
     fmt_found = NULL;
     score_max = 0;
-    while ((fmt = av_muxer_iterate(&i))) {
+#if FF_API_NEXT
+FF_DISABLE_DEPRECATION_WARNINGS
+    while ((fmt = av_oformat_next(fmt)))
+#else
+    while ((fmt = av_muxer_iterate(&i)))
+#endif
+     {
         score = 0;
         if (fmt->name && short_name && av_match_name(short_name, fmt->name))
             score += 100;
@@ -81,6 +89,9 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
             fmt_found = fmt;
         }
     }
+#if FF_API_NEXT
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
     return fmt_found;
 }