avfilter: Add some missing FF_API_AVFILTERBUFFER ifdefs

libavfilter/buffer.c

@@ -22,7 +22,9 @@
 
 #include "avfilter.h"
 #include "internal.h"
+#include "version.h"
 
+#if FF_API_AVFILTERBUFFER
 /* TODO: buffer pool.  see comment for avfilter_default_get_video_buffer() */
 void ff_avfilter_default_free_buffer(AVFilterBuffer *ptr)
 {
@@ -173,3 +175,4 @@ void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *s
     default: break;
     }
 }
+#endif /* FF_API_AVFILTERBUFFER */

libavfilter/internal.h

@@ -26,6 +26,7 @@
 
 #include "avfilter.h"
 #include "thread.h"
+#include "version.h"
 
 #if !FF_API_AVFILTERPAD_PUBLIC
 /**
@@ -129,8 +130,10 @@ struct AVFilterInternal {
                    int *ret, int nb_jobs);
 };
 
+#if FF_API_AVFILTERBUFFER
 /** default handler for freeing audio/video buffer when there are no references left */
 void ff_avfilter_default_free_buffer(AVFilterBuffer *buf);
+#endif
 
 /** Tell is a format is contained in the provided list terminated by -1. */
 int ff_fmt_is_in(int fmt, const int *fmts);