Add an unbundled ffmpeg.gyp file.

build/linux/unbundle/ffmpeg.gyp

Index: build/linux/unbundle/ffmpeg.gyp
diff --git a/build/linux/unbundle/sqlite.gyp b/build/linux/unbundle/ffmpeg.gyp
similarity index 55%
copy from build/linux/unbundle/sqlite.gyp
copy to build/linux/unbundle/ffmpeg.gyp
index 918da92801890c6fec27d2d3ea448335bb78db03..dfaaf0aee83668764b07c97846a035c933c4110d 100644
--- a/build/linux/unbundle/sqlite.gyp
+++ b/build/linux/unbundle/ffmpeg.gyp
@@ -5,22 +5,23 @@
 {
   'targets': [
     {
-      'target_name': 'sqlite',
+      'target_name': 'ffmpeg',
       'type': 'none',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags sqlite3)',
+          '<!@(pkg-config --cflags libavcodec libavformat libavutil)',
         ],
         'defines': [
-          'USE_SYSTEM_SQLITE',
+          '__STDC_CONSTANT_MACROS',
+          'USE_SYSTEM_FFMPEG',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other sqlite3)',
+          '<!@(pkg-config --libs-only-L --libs-only-other libavcodec libavformat libavutil)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l sqlite3)',
+          '<!@(pkg-config --libs-only-l libavcodec libavformat libavutil)',
         ],
       },
     },