Merge pull request #1895 from carlfm01/windows-docs

Add Windows build doc

README.md

@@ -57,6 +57,7 @@ See the output of `deepspeech -h` for more information on the use of `deepspeech
 * [Python 3.6](https://www.python.org/)
 * [Git Large File Storage](https://git-lfs.github.com/)
 * Mac or Linux environment
+* Go to [build README](examples/net_framework/README.md) to start building DeepSpeech for Windows from source.
 
 ## Getting the code
 

examples/net_framework/README.md

@@ -0,0 +1,134 @@
+# Building DeepSpeech native client for Windows
+
+Now we can build the native client of DeepSpeech and run inference on Windows using the C# client, to do that we need to compile the `native_client`.
+
+**Table of Contents**
+
+- [Prerequisites](#prerequisites)
+- [Getting the code](#getting-the-code)
+- [Configuring the paths](#configuring-the-paths)
+- [Adding environment variables](#adding-environment-variables)
+    - [MSYS2 paths](#msys2-paths)
+    - [BAZEL path](#bazel-path)
+    - [Python path](#python-path)
+    - [CUDA paths](#cuda-paths)
+- [Building the native_client](#building-the-native_client)
+    - [Build for CPU](#cpu)
+    - [Build with CUDA support](#gpu-with-cuda)
+- [Using the generated library](#using-the-generated-library)
+## Prerequisites
+
+* [Python 3.6](https://www.python.org/)
+* [Git Large File Storage](https://git-lfs.github.com/)
+* [MSYS2(x86_64)](https://www.msys2.org/)
+* [Bazel v0.17.2](https://github.com/bazelbuild/bazel/releases)
+* [Windows 10 SDK](https://developer.microsoft.com/en-us/windows/downloads/windows-10-sdk)
+* Windows 10
+* [Visual Studio 2017 Community](https://visualstudio.microsoft.com/vs/community/) 
+
+Inside the Visual Studio Installer enable `MS Build Tools` and `VC++ 2015.3 v14.00 (v140) toolset for desktop`.
+
+If you want to enable CUDA support you need to install:
+
+* [CUDA 9.0 and cuDNN 7.3.1](https://developer.nvidia.com/cuda-90-download-archive) 
+
+It may compile with other versions, as we don't extensively test other versions, we highly recommend sticking to the recommended versions in order to avoid compilation errors caused by incompatible versions.
+
+## Getting the code
+
+We need to clone `mozilla/DeepSpeech` and `mozilla/tensorflow`.
+
+```bash
+git clone https://github.com/mozilla/DeepSpeech
+```
+
+```bash
+git clone https://github.com/mozilla/tensorflow
+```
+
+## Configuring the paths
+
+We need to create a symbolic link, for this example let's suppose that we cloned into `D:\cloned` and now the structure looks like:
+
+    .
+    ├── D:\
+    │   ├── cloned                 # Contains DeepSpeech and tensorflow side by side
+    │   │   ├── DeepSpeech         # Root of the cloned DeepSpeech
+    │   │   ├── tensorflow         # Root of the cloned Mozilla's tensorflow 
+    └── ...
+
+Change your path accordingly to your path structure, for the structure above we are going to use the following command:
+
+```bash
+mklink /d "D:\cloned\tensorflow\native_client" "D:\cloned\DeepSpeech\native_client"
+```
+
+## Adding environment variables
+
+After you have installed the requirements there are few environment variables that we need to add to our `PATH` variable of the system variables.
+
+#### MSYS2 paths
+
+For MSYS2 we need to add `bin` directory, if you installed in the default route the path that we need to add should looks like `C:\msys64\usr\bin`. Now we can run `pacman`:
+
+```bash
+pacman -Syu
+```
+
+```bash
+pacman -Su
+```
+
+```bash
+pacman -S patch unzip
+```
+
+#### BAZEL path
+
+For BAZEL we need to add the path to the executable, make sure you rename the executable to `bazel`.
+
+To check the version installed you can run:
+
+```bash
+bazel version
+```
+
+#### PYTHON path
+
+Add your `python.exe` path to the `PATH` variable.
+
+
+#### CUDA paths
+
+If you run CUDA enabled `native_client` we need to add the following to the `PATH` variable.
+
+```
+C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\bin
+```
+
+### Building the native_client
+
+There's one last command to run before building, you need to run the [configure.py](https://github.com/mozilla/tensorflow/blob/master/configure.py) inside `tensorflow` cloned directory.
+
+At this point we are ready to start building the `native_client`, go to `tensorflow` directory that you cloned, following our examples should be `D:\cloned\tensorflow`.  
+
+#### CPU
+We will add AVX/AVX2 support in the command, please make sure that your CPU supports these instructions before adding the flags, if not you can remove them.
+
+```bash
+bazel build -c opt --copt=/arch:AVX --copt=/arch:AVX2 //native_client:libdeepspeech.so
+```
+
+#### GPU with CUDA
+If you enabled CUDA in [configure.py](https://github.com/mozilla/tensorflow/blob/master/configure.py) configuration command now you can add `--config=cuda` to compile with CUDA support.
+
+```bash
+bazel build -c opt --config=cuda --copt=/arch:AVX --copt=/arch:AVX2 //native_client:libdeepspeech.so
+```
+
+Be patient, if you enabled AVX/AVX2 and CUDA it will take a long time. Finally you should see it stops and shows the path to the generated `libdeepspeech.so`.
+
+
+## Using the generated library
+
+As for now we can only use the generated `libdeepspeech.so` with the C# clients, go to [DeepSpeech/examples/net_framework/CSharpExamples/](https://github.com/mozilla/DeepSpeech/tree/master/examples/net_framework/CSharpExamples) in your DeepSpeech directory and open the Visual Studio solution, then we need to build in debug or release mode, finally we just need to copy `libdeepspeech.so` to the generated `x64/Debug` or `x64/Release` directory.