subprojects: Add libyuv and built if -Dandroid=enabled

Android HAL adaptation layer may need image processing, for
example, scaling and format conversion. Libyuv is a general image
processing. This adds libyuv to subprojects, so that it is forked
locally and can be used with Android HAL implementation code.

Signed-off-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

README.rst

@@ -47,7 +47,7 @@ A C++ toolchain: [required]
 	Either {g++, clang}
 
 Meson Build system: [required]
-        meson (>= 0.51) ninja-build pkg-config
+        meson (>= 0.55) ninja-build pkg-config
 
         If your distribution doesn't provide a recent enough version of meson,
         you can install or upgrade it using pip3.

meson.build

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: CC0-1.0
 
 project('libcamera', 'c', 'cpp',
-    meson_version : '>= 0.53',
+    meson_version : '>= 0.55',
     version : '0.0.0',
     default_options : [
         'werror=true',

src/android/meson.build

@@ -14,6 +14,23 @@ foreach dep : android_deps
     endif
 endforeach
 
+if android_enabled
+    cmake = import('cmake')
+
+    libyuv_vars = cmake.subproject_options()
+    libyuv_vars.add_cmake_defines({'CMAKE_POSITION_INDEPENDENT_CODE': 'ON'})
+    libyuv_vars.set_override_option('cpp_std', 'c++17')
+    libyuv_vars.append_compile_args('cpp',
+         '-Wno-sign-compare',
+         '-Wno-unused-variable',
+         '-Wno-unused-parameter')
+    libyuv_vars.append_link_args('-ljpeg')
+    libyuv = cmake.subproject('libyuv', options : libyuv_vars)
+    libyuv_dep = libyuv.dependency('yuv')
+
+    android_deps += [ libyuv_dep, ]
+endif
+
 android_hal_sources = files([
     'camera3_hal.cpp',
     'camera_hal_manager.cpp',

subprojects/.gitignore

@@ -0,0 +1 @@
+/libyuv

subprojects/libyuv.wrap

@@ -0,0 +1,4 @@
+[wrap-git]
+directory = libyuv
+url = https://chromium.googlesource.com/libyuv/libyuv.git
+revision = 93b1b332cd60b56ab90aea14182755e379c28a80