Merge branch 'master' into submit_replace_fopen

Changelog

@@ -13,9 +13,9 @@ version 5.1:
 - pixelize video filter
 - colormap video filter
 - colorchart video source filter
-- blurdetect filter
 - multiply video filter
 - PGS subtitle frame merge bitstream filter
+- blurdetect filter
 
 
 version 5.0:

doc/filters.texi

@@ -8131,6 +8131,35 @@ tblend=all_mode=grainextract
 @subsection Commands
 This filter supports same @ref{commands} as options.
 
+@anchor{blockdetect}
+@section blockdetect
+
+Determines blockiness of frames without altering the input frames.
+
+Based on Remco Muijs and Ihor Kirenko: "A no-reference blocking artifact measure for adaptive video processing." 2005 13th European signal processing conference.
+
+The filter accepts the following options:
+
+@table @option
+@item period_min
+@item period_max
+Set minimum and maximum values for determining pixel grids (periods).
+Default values are [3,24].
+
+@item planes
+Set planes to filter. Default is first only.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Determine blockiness for the first plane and search for periods within [8,32]:
+@example
+blockdetect=period_min=8:period_max=32:planes=1
+@end example
+@end itemize
+
 @anchor{blurdetect}
 @section blurdetect
 

ffbuild/common.mak

@@ -29,6 +29,9 @@ $(foreach VAR,$(SILENT),$(eval override $(VAR) = @$($(VAR))))
 $(eval INSTALL = @$(call ECHO,INSTALL,$$(^:$(SRC_DIR)/%=%)); $(INSTALL))
 endif
 
+# Prepend to a recursively expanded variable without making it simply expanded.
+PREPEND = $(eval $(1) = $(patsubst %,$$(%), $(2)) $(value $(1)))
+
 # NASM requires -I path terminated with /
 IFLAGS     := -I. -I$(SRC_LINK)/
 CPPFLAGS   := $(IFLAGS) $(CPPFLAGS)
@@ -37,7 +40,9 @@ CCFLAGS     = $(CPPFLAGS) $(CFLAGS)
 OBJCFLAGS  += $(EOBJCFLAGS)
 OBJCCFLAGS  = $(CPPFLAGS) $(CFLAGS) $(OBJCFLAGS)
 ASFLAGS    := $(CPPFLAGS) $(ASFLAGS)
-CXXFLAGS   := $(CPPFLAGS) $(CFLAGS) $(CXXFLAGS)
+# Use PREPEND here so that later (target-dependent) additions to CPPFLAGS
+# end up in CXXFLAGS.
+$(call PREPEND,CXXFLAGS, CPPFLAGS CFLAGS)
 X86ASMFLAGS += $(IFLAGS:%=%/) -I$(<D)/ -Pconfig.asm
 
 HOSTCCFLAGS = $(IFLAGS) $(HOSTCPPFLAGS) $(HOSTCFLAGS)