avfilter: add mergeplanes filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -44,6 +44,7 @@ version <next>
 - Enhanced Low Delay AAC (ER AAC ELD) decoding (no LD SBR support)
 - Linux framebuffer output device
 - HEVC decoder, raw HEVC demuxer, HEVC demuxing in TS, Matroska and MP4
+- mergeplanes filter
 
 
 version 2.0:

MAINTAINERS

@@ -334,6 +334,7 @@ Filters:
   vf_extractplanes.c                    Paul B Mahol
   vf_histogram.c                        Paul B Mahol
   vf_il.c                               Paul B Mahol
+  vf_mergeplanes.c                      Paul B Mahol
   vf_psnr.c                             Paul B Mahol
   vf_scale.c                            Michael Niedermayer
   vf_separatefields.c                   Paul B Mahol

doc/filters.texi

@@ -5260,6 +5260,65 @@ lutyuv=y='bitand(val, 128+64+32)'
 @end example
 @end itemize
 
+@section mergeplanes
+
+Merge color channel components from several video streams.
+
+The filter accepts up to 4 input streams, and merge selected input
+planes to the output video.
+
+This filter accepts the following options:
+@table @option
+@item mapping
+Set input to output plane mapping. Default is @code{0}.
+
+The mappings is specified as a bitmap. It should be specified as a
+hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. 'Aa' describes the
+mapping for the first plane of the output stream. 'A' sets the number of
+the input stream to use (from 0 to 3), and 'a' the plane number of the
+corresponding input to use (from 0 to 3). The rest of the mappings is
+similar, 'Bb' describes the mapping for the output stream second
+plane, 'Cc' describes the mapping for the output stream third plane and
+'Dd' describes the mapping for the output stream fourth plane.
+
+@item format
+Set output pixel format. Default is @code{yuva444p}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Merge three gray video streams of same width and height into single video stream:
+@example
+[a0][a1][a2]mergeplanes=0x001020:yuv444p
+@end example
+
+@item
+Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
+@example
+[a0][a1]mergeplanes=0x00010210:yuva444p
+@end example
+
+@item
+Swap Y and A plane in yuva444p stream:
+@example
+format=yuva444p,mergeplanes=0x03010200:yuva444p
+@end example
+
+@item
+Swap U and V plane in yuv420p stream:
+@example
+format=yuv420p,mergeplanes=0x000201:yuv420p
+@end example
+
+@item
+Cast a rgb24 clip to yuv444p:
+@example
+format=rgb24,mergeplanes=0x000102:yuv444p
+@end example
+@end itemize
+
 @section mcdeint
 
 Apply motion-compensation deinterlacing.

libavfilter/Makefile

@@ -158,6 +158,7 @@ OBJS-$(CONFIG_LUT_FILTER)                    += vf_lut.o
 OBJS-$(CONFIG_LUTRGB_FILTER)                 += vf_lut.o
 OBJS-$(CONFIG_LUTYUV_FILTER)                 += vf_lut.o
 OBJS-$(CONFIG_MCDEINT_FILTER)                += vf_mcdeint.o
+OBJS-$(CONFIG_MERGEPLANES_FILTER)            += vf_mergeplanes.o framesync.o
 OBJS-$(CONFIG_MP_FILTER)                     += vf_mp.o
 OBJS-$(CONFIG_MPDECIMATE_FILTER)             += vf_mpdecimate.o
 OBJS-$(CONFIG_NEGATE_FILTER)                 += vf_lut.o

libavfilter/allfilters.c

@@ -154,6 +154,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(LUTRGB,         lutrgb,         vf);
     REGISTER_FILTER(LUTYUV,         lutyuv,         vf);
     REGISTER_FILTER(MCDEINT,        mcdeint,        vf);
+    REGISTER_FILTER(MERGEPLANES,    mergeplanes,    vf);
     REGISTER_FILTER(MP,             mp,             vf);
     REGISTER_FILTER(MPDECIMATE,     mpdecimate,     vf);
     REGISTER_FILTER(NEGATE,         negate,         vf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  89
+#define LIBAVFILTER_VERSION_MINOR  90
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \