add yasm for ffmpeg

packages/f/ffmpeg/xmake.lua

@@ -24,6 +24,10 @@ package("ffmpeg")
         add_frameworks("CoreFoundation", "Foundation", "CoreVideo", "CoreMedia", "AudioToolbox", "VideoToolbox", "Security")
     end
 
+    if is_plat("macosx", "linux") then
+        add_deps("yasm")
+    end
+
     on_load(function (package)
         local configdeps = {zlib    = "zlib",
                             bzlib   = "bzip2",

packages/y/yasm/xmake.lua

@@ -0,0 +1,21 @@
+package("yasm")
+
+    set_kind("binary")
+    set_homepage("https://yasm.tortall.net/")
+    set_description("Modular BSD reimplementation of NASM.")
+
+    add_urls("https://www.tortall.net/projects/yasm/releases/yasm-$(version).tar.gz",
+             "https://ftp.openbsd.org/pub/OpenBSD/distfiles/yasm-$(version).tar.gz")
+    add_versions("1.3.0", "3dce6601b495f5b3d45b59f7d2492a340ee7e84b5beca17e48f862502bd5603f")
+
+    on_install("linux", "macosx", function (package)
+        local configs = {"--disable-python"}
+        if package:debug() then
+            table.insert(configs, "--enable-debug")
+        end
+        import("package.tools.autoconf").install(package)
+    end)
+
+    on_test(function (package)
+        os.vrun("yasm --version")
+    end)