Restore nasm support for ffmpeg building.

.travis.yml

@@ -32,6 +32,11 @@ matrix:
                         - libxrandr-dev
                         - libglew-dev
 
+        -
+            env: CXX_COMPILER=clang++-3.6 CC_COMPILER=clang-3.6 BUILD_TYPE=Release WITH_FFMPEG=ON
+            compiler: clang
+            addons: *clang36
+
         -
             env: CXX_COMPILER=g++-5 CC_COMPILER=gcc-5 BUILD_TYPE=Release WITH_FFMPEG=OFF
             compiler: gcc

CMake/Modules/Findnasm.cmake

@@ -0,0 +1,13 @@
+# Try to find the nasm assembly program.
+
+include(FindPackageHandleStandardArgs)
+
+find_program(NASM_EXECUTABLE nasm
+  HINTS $ENV{NASM_ROOT} ${NASM_ROOT}
+  PATH_SUFFIXES bin
+)
+
+find_package_handle_standard_args(nasm DEFAULT_MSG NASM_EXECUTABLE)
+
+mark_as_advanced(NASM_EXECUTABLE)
+

StepmaniaCore.cmake

@@ -212,6 +212,9 @@ if(WITH_OGG)
   endif()
 endif()
 
+find_package(nasm)
+find_package(yasm)
+
 if(WIN32)
   set(SYSTEM_PCRE_FOUND FALSE)
   find_package(DirectX REQUIRED)
@@ -367,9 +370,8 @@ elseif(LINUX)
     set(HAS_PTHREAD FALSE)
   endif()
 
-  find_package(yasm)
-  if (WITH_FFMPEG AND NOT YASM_FOUND)
-    message("YASM was not found. Please install if you wish for ffmpeg support.")
+  if (WITH_FFMPEG AND NOT YASM_FOUND AND NOT NASM_FOUND)
+    message("Neither NASM nor YASM were found. Please install at least one of them if you wish for ffmpeg support.")
     set(WITH_FFMPEG OFF)
   endif()