Allow building without MPEG2 transcoding, and so without FFmpeg.

5 files changed, 37 insertions, 9 deletions

diff --git a/cscript b/cscript
index 1d75abdf..e8b425af 100644
--- a/cscript
+++ b/cscript
@@ -34,6 +34,10 @@
 import os
 import shutil
 
+
+option_defaults = { "mpeg2": True }
+
+
 def build_with_cpp17(target):
     return (
         target.platform.startswith('osx') or
@@ -54,7 +58,8 @@ def dependencies(target, options, for_package):
 
     if target.platform != 'linux' or target.distro != 'arch' or not for_package:
         # Use distro-provided FFmpeg and openjpeg on Arch (except when packaging), otherwise our own
-        deps.append(('ffmpeg', '693b3a8274ce407d0741d320849dc9433c748262', ffmpeg_options))
+        if options['mpeg2']:
+            deps.append(('ffmpeg', '693b3a8274ce407d0741d320849dc9433c748262', ffmpeg_options))
         deps.append(('openjpeg', 'ad8edaacd54a862940d0a77c41ecda5858b54d6e'))
 
     return deps
@@ -68,6 +73,8 @@ def build(target, options, for_package, version):
         target.command('sudo pacman --noconfirm -U libdcp*.zst')
     else:
         cmd = './waf configure --disable-examples --disable-dumpimage --disable-benchmarks --prefix=%s' % target.directory
+        if not options['mpeg2']:
+            cmd += ' --disable-mpeg2-transcode'
         if target.platform == 'linux':
             cmd += ' --static'
             if target.distro != 'ubuntu' or not target.version in ('16.04', '22.04'):
diff --git a/src/mono_mpeg2_picture_asset.cc b/src/mono_mpeg2_picture_asset.cc
index 9a879f0b..277bed2c 100644
--- a/src/mono_mpeg2_picture_asset.cc
+++ b/src/mono_mpeg2_picture_asset.cc
@@ -36,7 +36,9 @@
 #include "mono_mpeg2_picture_asset.h"
 #include "mono_mpeg2_picture_asset_reader.h"
 #include "mono_mpeg2_picture_asset_writer.h"
+#ifdef LIBDCP_MPEG2_TRANSCODE
 #include "mpeg2_transcode.h"
+#endif
 #include <asdcp/AS_DCP.h>
 
 
@@ -90,6 +92,7 @@ MonoMPEG2PictureAsset::start_write(boost::filesystem::path file, Behaviour behav
 bool
 MonoMPEG2PictureAsset::can_be_read() const
 {
+#ifdef LIBDCP_MPEG2_TRANSCODE
 	if (!MXF::can_be_read()) {
 		return false;
 	}
@@ -106,5 +109,8 @@ MonoMPEG2PictureAsset::can_be_read() const
 	}
 
 	return true;
+#else
+	return false;
+#endif
 }
 
diff --git a/src/wscript b/src/wscript
index 9b59b602..4fb4c359 100644
--- a/src/wscript
+++ b/src/wscript
@@ -58,7 +58,6 @@ def build(bld):
              exceptions.cc
              file.cc
              filesystem.cc
-             ffmpeg_image.cc
              font_asset.cc
              fsk.cc
              gamma_transfer_function.cc
@@ -86,7 +85,6 @@ def build(bld):
              mono_mpeg2_picture_frame.cc
              mpeg2_picture_asset.cc
              mpeg2_picture_asset_writer.cc
-             mpeg2_transcode.cc
              mxf.cc
              name_format.cc
              object.cc
@@ -181,7 +179,6 @@ def build(bld):
               identity_transfer_function.h
               interop_load_font_node.h
               interop_text_asset.h
-              ffmpeg_image.h
               j2k_picture_asset.h
               j2k_picture_asset_writer.h
               j2k_transcode.h
@@ -204,7 +201,6 @@ def build(bld):
               mono_mpeg2_picture_asset_writer.h
               mono_mpeg2_picture_frame.h
               mpeg2_picture_asset.h
-              mpeg2_transcode.h
               mxf.h
               name_format.h
               object.h
@@ -264,6 +260,15 @@ def build(bld):
               warnings.h
               """
 
+    if not bld.env.DISABLE_MPEG2_TRANSCODE:
+        source += """
+                  ffmpeg_image.cc
+                  mpeg2_transcode.cc
+                  """
+        headers += """
+                   ffmpeg_image.h
+                   mpeg2_transcode.h
+                   """
  
     uselib = 'BOOST_FILESYSTEM BOOST_SIGNALS2 BOOST_DATETIME OPENSSL SIGC++ LIBXML++ OPENJPEG CXML XMLSEC1 ASDCPLIB_DCPOMATIC XERCES AVCODEC AVUTIL FMT FAST_FLOAT HARU'
 
diff --git a/test/wscript b/test/wscript
index 3eaef516..da0b6172 100644
--- a/test/wscript
+++ b/test/wscript
@@ -99,8 +99,6 @@ def build(bld):
                  make_digest_test.cc
                  markers_test.cc
                  mca_test.cc
-                 mono_mpeg2_picture_read_test.cc
-                 mono_mpeg2_picture_write_test.cc
                  kdm_test.cc
                  key_test.cc
                  language_tag_test.cc
@@ -130,6 +128,12 @@ def build(bld):
     obj.target = 'tests'
     obj.install_path = ''
 
+    if bld.env.LIBDCP_MPEG2_TRANSCODE:
+        obj.source += """
+                      mono_mpeg2_picture_read_test.cc
+                      mono_mpeg2_picture_write_test.cc
+                      """
+
     obj = bld(features='cxx cxxprogram')
     obj.name   = 'subs_in_out'
     obj.uselib = uselib
diff --git a/wscript b/wscript
index 5d7a5aa8..146ff1fe 100644
--- a/wscript
+++ b/wscript
@@ -69,6 +69,7 @@ def options(opt):
     opt.add_option('--enable-openmp', action='store_true', default=False, help='enable use of OpenMP')
     opt.add_option('--openmp', default='gomp', help='specify OpenMP Library to use: omp, gomp (default), iomp')
     opt.add_option('--c++17', action='store_true', default=False, help='build with C++17 and libxml++-4.0')
+    opt.add_option('--disable-mpeg2-transcode', action='store_true', default=False, help='build without support for MPEG2 transcoding (then ffmpeg is not required)')
 
 def configure(conf):
     conf.load('compiler_cxx')
@@ -98,6 +99,7 @@ def configure(conf):
     conf.env.DISABLE_BENCHMARKS = conf.options.disable_benchmarks
     conf.env.DISABLE_EXAMPLES = conf.options.disable_examples
     conf.env.DISABLE_DUMPIMAGE = conf.options.disable_dumpimage
+    conf.env.DISABLE_MPEG2_TRANSCODE = conf.options.disable_mpeg2_transcode
     conf.env.STATIC = conf.options.static
     conf.env.API_VERSION = API_VERSION
 
@@ -132,6 +134,9 @@ def configure(conf):
     if conf.env.TARGET_LINUX:
         conf.check(lib='dl', uselib_store='DL', msg='Checking for library dl')
 
+    if not conf.env.DISABLE_MPEG2_TRANSCODE:
+        conf.env.append_value('CXXFLAGS', '-DLIBDCP_MPEG2_TRANSCODE')
+
     conf.check_cfg(package='openssl', args='--cflags --libs', uselib_store='OPENSSL', mandatory=True)
     conf.check_cxx(fragment="""
                    #include <openssl/x509.h>
@@ -280,8 +285,9 @@ def configure(conf):
                    lib=boost_libs('date_time'),
                    uselib_store='BOOST_DATETIME')
 
-    conf.check_cfg(package='libavcodec', args='--cflags --libs', uselib_store='AVCODEC', mandatory=True)
-    conf.check_cfg(package='libavutil', args='--cflags --libs', uselib_store='AVUTIL', mandatory=True)
+    if not conf.options.disable_mpeg2_transcode:
+        conf.check_cfg(package='libavcodec', args='--cflags --libs', uselib_store='AVCODEC', mandatory=True)
+        conf.check_cfg(package='libavutil', args='--cflags --libs', uselib_store='AVUTIL', mandatory=True)
 
     conf.check_cfg(package='fmt', args='--cflags --libs', uselib_store='FMT', mandatory=True)
     conf.check_cxx(header_name="fast_float/fast_float.h", uselib_store='FAST_FLOAT', mandatory=True)