lavfi: add xbr filter xBR

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Changelog

@@ -10,6 +10,7 @@ version <next>:
 - libutvideo YUV 4:2:2 10bit support
 - XCB-based screen-grabber
 - UDP-Lite support (RFC 3828)
+- xBR scaler
 
 version 2.4:
 - Icecast protocol

LICENSE.md

@@ -49,6 +49,7 @@ Specifically, the GPL parts of FFmpeg are:
     - vf_stereo3d.c
     - vf_super2xsai.c
     - vf_tinterlace.c
+    - vf_xbr.c
     - vsrc_mptestsrc.c
 
 Should you, for whatever reason, prefer to use version 3 of the (L)GPL, then

configure

@@ -2608,6 +2608,7 @@ vidstabtransform_filter_deps="libvidstab"
 pixfmts_super2xsai_test_deps="super2xsai_filter"
 tinterlace_merge_test_deps="tinterlace_filter"
 tinterlace_pad_test_deps="tinterlace_filter"
+xbr_filter_deps="gpl"
 zmq_filter_deps="libzmq"
 zoompan_filter_deps="swscale"
 

doc/filters.texi

@@ -9196,6 +9196,10 @@ Only deinterlace frames marked as interlaced.
 Default value is @samp{all}.
 @end table
 
+@section xbr
+Apply high-quality magnification filter which is designed for pixel art. It follows a set
+of edge-detection rules, see @url{http://www.libretro.com/forums/viewtopic.php?f=6&t=134}.
+
 @anchor{yadif}
 @section yadif
 

libavfilter/Makefile

@@ -198,6 +198,7 @@ OBJS-$(CONFIG_VIDSTABDETECT_FILTER)          += vidstabutils.o vf_vidstabdetect.
 OBJS-$(CONFIG_VIDSTABTRANSFORM_FILTER)       += vidstabutils.o vf_vidstabtransform.o
 OBJS-$(CONFIG_VIGNETTE_FILTER)               += vf_vignette.o
 OBJS-$(CONFIG_W3FDIF_FILTER)                 += vf_w3fdif.o
+OBJS-$(CONFIG_XBR_FILTER)                    += vf_xbr.o
 OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o
 OBJS-$(CONFIG_ZMQ_FILTER)                    += f_zmq.o
 OBJS-$(CONFIG_ZOOMPAN_FILTER)                += vf_zoompan.o

libavfilter/allfilters.c

@@ -213,6 +213,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(VIDSTABTRANSFORM, vidstabtransform, vf);
     REGISTER_FILTER(VIGNETTE,       vignette,       vf);
     REGISTER_FILTER(W3FDIF,         w3fdif,         vf);
+    REGISTER_FILTER(XBR,            xbr,            vf);
     REGISTER_FILTER(YADIF,          yadif,          vf);
     REGISTER_FILTER(ZMQ,            zmq,            vf);
     REGISTER_FILTER(ZOOMPAN,        zoompan,        vf);