Enable Proprietary Codecs

Supported Codecs in Prebuilt NW.js Binary

As NW.js is based on Chromium, the media components are essentially the same.

In the pre-built NW.js, following codecs are supported:


and following demuxers are supported:


Enable Proprietary Codecs in NW.js

License and Patent Fee

Using MP3 and H.264 codecs requires you to pay attention to the patent royalties and the license of the source code. Consult a lawyer if you do not understand the licensing constraints and using patented media formats in your application. For more information about the license of the source code, check here


If you do NOT have the license, using this tip below or moving to other solutions does NOT make you eligible to redistribute the codecs.

Get FFmpeg Binaries from the Community

In recent versions of the Chromium project, FFmpeg was changed to be built-in. So, you can’t get the FFmpeg DLL from the official Chrome distribution anymore. However, you can get precompiled binaries from the community. Another alternative would be to build FFmpeg yourself by following the instructions below.

Build FFmpeg DLL without Building NW.js

If you are using pre-built NW.js, you can just only rebuild FFmpeg DLL and replace the bundled DLL in pre-built binaries. This will save lots of time in download size (~1G) comparing to building entire NW.js (~20G).

Step 1. Download zip package of customized Chromium from GitHub. You can find the corresponding version in https://github.com/nwjs/chromium.src/tags. Extract the zip package into a local folder, such as ~/nw. The unzipped package will include a sub directory. So the source folder is in ~/nw/<sub-directory-name>.

Step 2. Fetch dependencies

Since you are not building entire NW.js, you have to fetch following dependencies manually.

  • build/linux/*-sysroot: This is Linux only. Use build/linux/sysroot_scripts/install-sysroot.py --running-as-hook to install the dependencies.
  • tools/gyp: See DEPS file in the source folder for the repo and commit for this folder.
  • third_party/yasm/sources/patched-yasm: See DEPS file in the source folder for the repo and commit for this folder.
  • third_party/ffmpeg: see DEPS for commit and repo
  • third_party/llvm-build: Mac and Linux only. Use tools/clang/scripts/update.py --if-needed to download.

Step 3. Generate build targets with GYP

For Linux Developers

Please run build/install-build-deps.sh for the first time building FFmpeg DLL or NW.js before proceeding to the instructions below. You only have to run it once. This script will install the build dependencies automatically for you.

For Windows Developers

Please include clang=0 in GYP_DEFINES below because Clang build is not enabled on Windows.

cd path/to/nw/source/folder
export GYP_GENERATORS=ninja
export GYP_DEFINES="branding=Chrome ffmpeg_component=shared_library"
export PYTHONPATH="$PWD/build"
./tools/gyp/gyp -I build/common.gypi --depth=. ./third_party/ffmpeg/ffmpeg.gyp

Step 4. Build ffmpeg DLL

ninja -C out/Release ffmpeg

You will find the DLL in out/Release folder. The path and file name varies between platforms:

  • Windows: ffmpeg.dll
  • Mac OS X: libffmpeg.dylib
  • Linux: lib/libffmpeg.so

Step 5. Replace the bundled DLL in prebuild NW.js with the one you just built. The path and file name varies between platforms:

  • Windows: ffmpeg.dll
  • Mac OS X: nwjs.app/Contents/Versions/<chromium-version>/nwjs Framework.framework/libffmpeg.dylib
  • Linux lib/libffmpeg.so

Build Entire NW.js with Proprietary Codecs

If you don’t use official pre-built NW.js, you can build entire NW.js with proprietary codecs enabled by following the instructions below.

Step 1. Install prerequists and fetch the source code of NW.js. See Prerequisits and Get the Code sections in Building NW.js.

Step 2. Apply following patch to third_party/ffmpeg/ffmpeg.gyp to make ffmpeg include the codecs:

diff --git a/ffmpeg.gyp b/ffmpeg.gyp                   
index 294dd2e..7dfcd3a 100755                          
--- a/ffmpeg.gyp
+++ b/ffmpeg.gyp
@@ -72,7 +72,7 @@ 
       ['chromeos == 1', {
         'ffmpeg_branding%': '<(branding)OS',
       }, {  # otherwise, assume Chrome/Chromium.
-        'ffmpeg_branding%': '<(branding)',
+        'ffmpeg_branding%': 'Chrome'

Step 3. Regenerate the gyp files again with gclient runhooks.

Step 4. Rebuild NW.js with ninja -C out/Release nwjs. Then you will get NW.js as well as FFmpeg DLL with proprietary codecs. If you just want to rebuild the DLL, running ninja -C out/Release ffmpeg will do. The generated binaries can be found in out/Release.