contribs: add libmad

contrib/src/mad/SHA512SUMS

+2cad30347fb310dc605c46bacd9da117f447a5cabedd8fefdb24ab5de641429e5ec5ce8af7aefa6a75a3f545d3adfa255e3fa0a2d50971f76bc0c4fc0400cc45  libmad-0.15.1b.tar.gz

contrib/src/mad/rules.mak

+# mad
+
+MAD_VERSION := 0.15.1b
+MAD_URL := $(CONTRIB_VIDEOLAN)/libmad-$(MAD_VERSION).tar.gz
+
+PKGS += mad
+
+$(TARBALLS)/libmad-$(MAD_VERSION).tar.gz:
+	$(call download,$(MAD_URL))
+
+.sum-mad: libmad-$(MAD_VERSION).tar.gz
+
+libmad: libmad-$(MAD_VERSION).tar.gz .sum-mad
+	$(UNPACK)
+ifdef HAVE_MACOSX
+	cd $@-$(MAD_VERSION) && sed \
+		-e 's%-march=i486%$(EXTRA_CFLAGS) $(EXTRA_LDFLAGS)%' \
+		-e 's%-dynamiclib%-dynamiclib -arch $(ARCH)%' \
+		-i.orig configure
+endif
+	mv $@-$(MAD_VERSION) $@
+	touch $@
+
+.mad: libmad
+	cd $< && $(HOSTVARS) CFLAGS="$(CFLAGS) -O3 $(NOTHUMB)" ./configure $(HOSTCONF)
+	cd $< && $(MAKE) install
+	touch $@