lavfi: always build vsrc_buffer.

It's a part of public API.

configure

@@ -1525,14 +1525,12 @@ postproc_deps="gpl"
 
 # programs
 avconv_deps="avcodec avformat swscale"
-avconv_select="buffer_filter"
 avplay_deps="avcodec avformat swscale sdl"
 avplay_select="rdft"
 avprobe_deps="avcodec avformat"
 avserver_deps="avformat ffm_muxer fork rtp_protocol rtsp_demuxer"
 avserver_extralibs='$ldl'
 ffmpeg_deps="avcodec avformat swscale"
-ffmpeg_select="buffer_filter"
 
 doc_deps="texi2html"
 

libavfilter/Makefile

@@ -12,6 +12,7 @@ OBJS = allfilters.o                                                     \
        drawutils.o                                                      \
        formats.o                                                        \
        graphparser.o                                                    \
+       vsrc_buffer.o
 
 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o
 
@@ -59,7 +60,6 @@ OBJS-$(CONFIG_UNSHARP_FILTER)                += vf_unsharp.o
 OBJS-$(CONFIG_VFLIP_FILTER)                  += vf_vflip.o
 OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o
 
-OBJS-$(CONFIG_BUFFER_FILTER)                 += vsrc_buffer.o
 OBJS-$(CONFIG_COLOR_FILTER)                  += vsrc_color.o
 OBJS-$(CONFIG_FREI0R_SRC_FILTER)             += vf_frei0r.o
 OBJS-$(CONFIG_MOVIE_FILTER)                  += vsrc_movie.o

libavfilter/allfilters.c

@@ -80,7 +80,6 @@ void avfilter_register_all(void)
     REGISTER_FILTER (VFLIP,       vflip,       vf);
     REGISTER_FILTER (YADIF,       yadif,       vf);
 
-    REGISTER_FILTER (BUFFER,      buffer,      vsrc);
     REGISTER_FILTER (COLOR,       color,       vsrc);
     REGISTER_FILTER (FREI0R,      frei0r_src,  vsrc);
     REGISTER_FILTER (MOVIE,       movie,       vsrc);
@@ -89,4 +88,10 @@ void avfilter_register_all(void)
     REGISTER_FILTER (TESTSRC,     testsrc,     vsrc);
 
     REGISTER_FILTER (NULLSINK,    nullsink,    vsink);
+
+    /* vsrc_buffer is a part of public API => registered unconditionally */
+    {
+        extern avfilter_vsrc_buffer;
+        avfilter_register(&avfilter_vsrc_buffer);
+    }
 }