# Build Instructions

Shaka Packager supports building on Windows, Mac and Linux host systems.

## Linux build dependencies

Most development is done on Ubuntu (currently 14.04, Trusty Tahr). The
dependencies mentioned here are only for Ubuntu. There are some instructions
for [other distros below](#notes-for-other-linux-distros).

```shell
sudo apt-get update
sudo apt-get install build-essential curl git python
```

Note that `Git` must be v1.7.5 or above.

## Mac system requirements

*   [Xcode](https://developer.apple.com/xcode) 7.3+.
*   The OS X 10.10 SDK or later. Run

    ```shell
    $ ls `xcode-select -p`/Platforms/MacOSX.platform/Developer/SDKs
    ```

    to check whether you have it.

## Windows system requirements

* Visual Studio 2015 Update 3, see below (no other version is supported).
* Windows 7 or newer.

Install Visual Studio 2015 Update 3 or later - Community Edition should work if
its license is appropriate for you. Use the Custom Install option and select:

- Visual C++, which will select three sub-categories including MFC
- Universal Windows Apps Development Tools > Tools (1.4.1) and Windows 10 SDK
  (10.0.14393)

## Install `depot_tools`

### Linux and Mac

Clone the `depot_tools` repository from Chromium:

```shell
$ git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
```

Add `depot_tools` to the end of your PATH (you will probably want to put this
in your `~/.bashrc` or `~/.zshrc`). Assuming you cloned `depot_tools` to
`/path/to/depot_tools`:

```shell
$ export PATH="$PATH:/path/to/depot_tools"
```

### Windows

Download the
[depot_tools bundle](https://storage.googleapis.com/chrome-infra/depot_tools.zip)
and extract it somewhere.

*** note
**Warning:** **DO NOT** use drag-n-drop or copy-n-paste extract from Explorer,
this will not extract the hidden “.git” folder which is necessary for
depot_tools to autoupdate itself. You can use “Extract all…” from the context
menu though.
***

Add depot_tools to the start of your PATH (must be ahead of any installs of
Python). Assuming you unzipped the bundle to C:\src\depot_tools, open:

Control Panel → System and Security → System → Advanced system settings

If you have Administrator access, Modify the PATH system variable and
put `C:\src\depot_tools` at the front (or at least in front of any directory
that might already have a copy of Python or Git).

If you don't have Administrator access, you can add a user-level PATH
environment variable and put `C:\src\depot_tools` at the front, but
if your system PATH has a Python in it, you will be out of luck.

Also, add a DEPOT_TOOLS_WIN_TOOLCHAIN system variable in the same way, and set
it to 0. This tells depot_tools to use your locally installed version of Visual
Studio (by default, depot_tools will try to use a google-internal version).

From a cmd.exe shell, run the command gclient (without arguments). On first
run, gclient will install all the Windows-specific bits needed to work with
the code, including msysgit and python.

* If you run gclient from a non-cmd shell (e.g., cygwin, PowerShell),
  it may appear to run properly, but msysgit, python, and other tools
  may not get installed correctly.
* If you see strange errors with the file system on the first run of gclient,
  you may want to
  [disable Windows Indexing](http://tortoisesvn.tigris.org/faq.html#cantmove2).

## Get the code

Create a `shaka_packager` directory for the checkout and change to it (you can
call this whatever you like and put it wherever you like, as long as the full
path has no spaces):

```shell
$ mkdir shaka_packager && cd shaka_packager
```

Run the `gclient` tool from `depot_tools` to check out the code and its
dependencies.

```shell
$ gclient config https://www.github.com/google/shaka-packager.git --name=src --unmanaged
$ gclient sync
```

To sync to a particular commit or version, add the '-r \<revision\>' flag to
`gclient sync`, e.g.

```shell
$ gclient sync -r 4cb5326355e1559d60b46167740e04624d0d2f51
```

```shell
$ gclient sync -r v1.2.0
```

If you don't want the full repo history, you can save some time by adding the
`--no-history` flag to `gclient sync`.

When the above commands completes, it will have created a hidden `.gclient` file
and a directory called `src` in the working directory. The remaining
instructions assume you have switched to the `src` directory:

```shell
$ cd src
```

### Build Shaka Packager

#### Linux and Mac

Shaka Packager uses [Ninja](https://ninja-build.org) as its main build tool,
which is bundled in depot_tools.

To build the code, run `ninja` command:

```shell
$ ninja -C out/Release
```

If you want to build debug code, replace `Release` above with `Debug`.

We also provide a mechanism to change build settings, for example,
you can change build system to `make` by overriding `GYP_GENERATORS`:

```shell
$ GYP_GENERATORS='make' gclient runhooks
```

Another example, you can also disable clang by overriding `GYP_DEFINES`:

```shell
$ GYP_DEFINES='clang=0' gclient runhooks
```

#### Windows

The instructions are similar, except that Windows allows using either `/` or `\`
as path separator:

```shell
$ ninja -C out/Release
$ ninja -C out\Release
```

Also, unlike Linux / Mac, 32-bit is chosen by default even if the system is
64-bit. 64-bit has to be enabled explicitly and the output directory is
configured to `out/%CONFIGURATION%_x64`, i.e.:

```shell
$ GYP_DEFINES='target_arch=x64' gclient runhooks
$ ninja -C out/Release_x64
```

### Build artifacts

After a successful build, you can find build artifacts including the main
`packager` binary in build output directory (`out/Release` or `out/Release_x64`
for release build).

See [Shaka Packager Documentation](https://google.github.io/shaka-packager/)
on how to use `Shaka Packager`.

### Update your checkout

To update an existing checkout, you can run

```shell
$ git pull origin master --rebase
$ gclient sync
```

The first command updates the primary Packager source repository and rebases on
top of tip-of-tree (aka the Git branch `origin/master`). You can also use other
common Git commands to update the repo.

The second command syncs dependencies to the appropriate versions and re-runs
hooks as needed.

## Cross compiling for ARM on Ubuntu host

The install-build-deps script can be used to install all the compiler
and library dependencies directly from Ubuntu:

```shell
$ ./pacakger/build/install-build-deps.sh
```

Install sysroot image and others using `gclient`:

```shell
$ GYP_CROSSCOMPILE=1 GYP_DEFINES="target_arch=arm" gclient runhooks
```

The build command is the same as in Ubuntu:

```shell
$ ninja -C out/Release
```

## Notes for other linux distros

### Arch Linux

Instead of running `sudo apt-get install` to install build dependencies, run:

```shell
$ sudo pacman -S --needed python2 git curl gcc gcc-libs make
$ sudo ln -sf python2 /usr/bin/python
```

Clang requires libtinfo.so.5 which is not available by default on Arch Linux.
You can get libtinfo from ncurses5-compat-libs in AUR:

```shell
$ git clone https://aur.archlinux.org/ncurses5-compat-libs.git
$ cd ncurses5-compat-libs
$ gpg --keyserver pgp.mit.edu --recv-keys F7E48EDB
$ makepkg -si
```

### Debian

Same as Ubuntu.

### Fedora

Instead of running `sudo apt-get install` to install build dependencies, run:

```shell
$ su -c 'yum install -y git python git curl gcc-c++ findutils bzip2 \
         ncurses-compat-libs'
```

### OpenSUSE

Use `zypper` command to install dependencies:

```shell
sudo zypper in git python python-xml git curl gcc-c++ tar
```

## Tips, tricks, and troubleshooting

### Xcode license agreement

If you're getting the error

> Agreeing to the Xcode/iOS license requires admin privileges, please re-run as
> root via sudo.

the Xcode license hasn't been accepted yet which (contrary to the message) any
user can do by running:

```shell
$ xcodebuild -license
```

Only accepting for all users of the machine requires root:

```shell
$ sudo xcodebuild -license
```

## Contributing

If you have improvements or fixes, we would love to have your contributions.
See https://github.com/google/shaka-packager/blob/master/CONTRIBUTING.md for
details.

We have continue integration tests setup on pull requests. You can also verify
locally by running the tests manually.

If you know which tests are affected by your change, you can limit which tests
are run using the `--gtest_filter` arg, e.g.:

```shell
$ out/Debug/mp4_unittest --gtest_filter="MP4MediaParserTest.*"
```

You can find out more about GoogleTest at its
[GitHub page](https://github.com/google/googletest).