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, the following codecs are supported:

- theora
- vorbis
- vp8 & vp9
- pcm_u8, pcm_s16le, pcm_s24le, pcm_f32le, pcm_s16be & pcm_s24be
- mp3 (v0.22.1+)

… as well as these demuxers:

- ogg
- matroska
- wav

Enable Proprietary Codecs in NW.js

License and Patent Fee

Using the H.264 codec 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.

  • Git clone following folders with corresponding commits as in DEPS file:
    • buildtools
    • tools/gyp
    • third_party/yasm/sources/patched-yasm
    • third_party/ffmpeg
  • Download gn tools in buildtools/<os> by
    download_from_google_storage --no_resume \
                                 --platform=<platform> \
                                 --no_auth \
                                 --bucket chromium-gn \
                                 -s buildtools/<os>/<gn-exe>.sha1
    • <platform>: win32 for Windows; darwin for Mac; linux* for Linux
    • <os>: win for Windows; mac for Mac; linux64 for Linux
    • <gn-exe>: gn.exe for Windows; gn for Mac and Linux
  • [Mac and Linux] Download clang tools in third_party/llvm-build by
    python tools/clang/scripts/update.py --if-needed
  • [Linux] Download libraries in build/linux/*-sysroot by
    python build/linux/sysroot_scripts/install-sysroot.py --running-as-hook
  • [Mac] Download libc++-static library in third_party/libc++-static by
    download_from_google_storage --no_resume \
                                 --platform=darwin \
                                 --no_auth \
                                 --bucket chromium-libcpp \
                                 -s third_party/libc++-static/libc++.a.sha1

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.

Step 3. Replace BUILD.gn

Replace BUILD.gn in the root of the source code with following:

action("dummy") {
  deps = [
  script = "dummy"
  outputs = ["$target_gen_dir/dummy.txt"]

Step 4. Generate Ninja Files with GN Tools

cd path/to/nw/source/folder
gn gen //out/nw \
 --args='is_debug=false is_component_ffmpeg=true target_cpu="<target_cpu>" is_official_build=true ffmpeg_branding="Chrome"'

NOTE: <target_cpu> should be set to x86 or x64 for 32-bit or 64-bit build.

Step 4. Build ffmpeg DLL

ninja -C out/nw ffmpeg

You will find the DLL in out/nw 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. See Building NW.js for details of each steps.

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. Set ffmpeg_branding to Chrome when you configure GN.

Step 3. Regenerate the ninja files again.

Step 4. Rebuild NW.js.