doc: fate: Support building a plain text version

  Also create a plain text (.txt) file from fate.texi if the makeinfo
program is available.
Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

.gitignore

@@ -15,6 +15,7 @@ config.*
 doc/*.1
 doc/*.html
 doc/*.pod
+doc/fate.txt
 doxy
 ffmpeg
 ffplay

configure

@@ -1195,6 +1195,7 @@ HAVE_LIST="
     lzo1x_999_compress
     machine_ioctl_bt848_h
     machine_ioctl_meteor_h
+    makeinfo
     malloc_h
     MapViewOfFile
     memalign
@@ -3153,6 +3154,7 @@ fi
 enabled sdl && add_cflags $sdl_cflags && add_extralibs $sdl_libs
 
 texi2html -version > /dev/null 2>&1 && enable texi2html || disable texi2html
+makeinfo --version > /dev/null 2>&1 && enable makeinfo  || disable makeinfo
 
 check_header linux/fb.h
 check_header linux/videodev.h

doc/Makefile

@@ -9,7 +9,13 @@ HTMLPAGES   = $(PROGS-yes:%=doc/%.html)                                 \
               doc/libavfilter.html                                      \
               doc/platform.html                                         \
 
+TXTPAGES    = doc/fate.txt                                              \
+
+
 DOCS = $(HTMLPAGES) $(MANPAGES) $(PODPAGES)
+ifdef HAVE_MAKEINFO
+DOCS += $(TXTPAGES)
+endif
 
 all-$(CONFIG_DOC): documentation
 
@@ -17,6 +23,11 @@ documentation: $(DOCS)
 
 TEXIDEP = awk '/^@(verbatim)?include/ { printf "$@: $(@D)/%s\n", $$2 }' <$< >$(@:%=%.d)
 
+doc/%.txt: TAG = TXT
+doc/%.txt: doc/%.texi
+	$(Q)$(TEXIDEP)
+	$(M)makeinfo --force --no-headers -o $@ $< 2>/dev/null
+
 doc/%.html: TAG = HTML
 doc/%.html: doc/%.texi $(SRC_PATH)/doc/t2h.init
 	$(Q)$(TEXIDEP)
@@ -46,7 +57,7 @@ uninstall-man:
 	$(RM) $(addprefix "$(MANDIR)/man1/",$(ALLMANPAGES))
 
 clean::
-	$(RM) doc/*.html doc/*.pod doc/*.1 $(CLEANSUFFIXES:%=doc/%)
+	$(RM) $(TXTPAGES) doc/*.html doc/*.pod doc/*.1 $(CLEANSUFFIXES:%=doc/%)
 
 -include $(wildcard $(DOCS:%=%.d))