Updated README with usage instructions

README.md

@@ -1,6 +1,20 @@
 #FFmpeg prebuilt for NW.js
 
-FFMpeg prebuilt binaries with proprietary codecs and build instructions for window, linux and osx.  
+FFMpeg prebuilt binaries with proprietary codecs and build instructions for window, linux and osx.
+
+##### Usage:
+
+build_ffmpeg.py [-h] [-c] [-nw NW_VERSION] [-tp TARGET_PLATFORM]
+                       [-ta TARGET_ARCH] [-pc]
+###### Arguments explanied:
+-  *-h, --help* : Show the help message and exit
+-  *-c, --clean* : Clean the workspace, removes downloaded source code
+-  *-nw NW_VERSION, --nw_version NW_VERSION* : Build ffmpeg for the specified Nw.js version
+-  *-tp TARGET_PLATFORM, --target_platform TARGET_PLATFORM* : Target platform, win, linux, mac...
+-  *-ta TARGET_ARCH, --target_arch TARGET_ARCH* : Target architecture, ia32, x64, arm64, arm...
+-  *-pc, --proprietary_codecs* : Build ffmpeg with proprietary codecs applied from  [build_ffmpeg.py patch](https://github.com/vzamanillo/nwjs-ffmpeg-prebuilt/blob/master/patch/build_ffmpeg_proprietary_codecs.patch#L17)
+
+###### Specific guides:  
 
 - [Windows guide](guides/build_windows.md)
 - [Linux guide](guides/build_linux.md)

build_ffmpeg.py

@@ -277,7 +277,7 @@ if proprietary_codecs:
     if not os.path.isfile('build_ffmpeg_patched.ok'):
         print "Applying codecs patch with ac3..."
         shutil.copy('../../patch/build_ffmpeg_proprietary_codecs.patch', 'third_party/ffmpeg/')
-        #apply codecs path
+        #apply codecs patch
         os.system('git apply --ignore-space-change --ignore-whitespace build_ffmpeg_proprietary_codecs.patch')
         with io.FileIO("build_ffmpeg_patched.ok", "w") as file:
             file.write("src/third_party/ffmpeg/chromium/scripts/build_ffmpeg.py already patched with proprietary codecs")

patch/build_ffmpeg_proprietary_codecs.patch

@@ -7,14 +7,14 @@ index cfbe54e..7e10c22 100755
        '--enable-rdft',
        '--enable-static',
 +      '--enable-nonfree',
- 
+
        # Disable features.
        '--disable-bzlib',
 @@ -320,6 +321,15 @@ def main(argv):
        '--disable-vdpau',
        '--disable-videotoolbox',
- 
-+      # PopcornTime codec
+
++      # PopcornTime codecs
 +      '--enable-decoder=aac,h264,mp3,mpeg4,hevc,ac3,aac3,mpegvideo,msmpeg4v1,msmpeg4v2,msmpeg4v3,flv,dca',
 +      '--enable-demuxer=mp3,mov,avi,flv,mp4,mpegvideo,dts,dtshd,mpegts,ogg',
 +      '--enable-parser=aac,h264,h263,mpegaudio,mpeg4video,ac3,aac3,dca,hevc,mepgvideo',