Merge pull request #3633 from naushir/develop

camera sw: Update build instruction for the new meson options

documentation/asciidoc/computers/camera/rpicam_apps_building.adoc

@@ -143,22 +143,22 @@ For desktop-based operating systems like Raspberry Pi OS, configure the `rpicam-
 
 [source,console]
 ----
-$ meson setup build -Denable_libav=true -Denable_drm=true -Denable_egl=true -Denable_qt=true -Denable_opencv=false -Denable_tflite=false
+$ meson setup build -Denable_libav=enabled -Denable_drm=enabled -Denable_egl=enabled -Denable_qt=enabled -Denable_opencv=disabled -Denable_tflite=disabled
 ----
 
 For headless operating systems like Raspberry Pi OS Lite, configure the `rpicam-apps` build with the following `meson` command:
 
 [source,console]
 ----
-$ meson setup build -Denable_libav=false -Denable_drm=true -Denable_egl=false -Denable_qt=false -Denable_opencv=false -Denable_tflite=false
+$ meson setup build -Denable_libav=disabled -Denable_drm=enabled -Denable_egl=disabled -Denable_qt=disabled -Denable_opencv=disabled -Denable_tflite=disabled
 ----
 
 [TIP]
 ======
 
 * Use `-Dneon_flags=armv8-neon` to enable optimisations for 32-bit OSes on Raspberry Pi 3 or Raspberry Pi 4.
-* Use `-Denable_opencv=true` if you have installed OpenCV and wish to use OpenCV-based post-processing stages.
-* Use `-Denable_tflite=true` if you have installed TensorFlow Lite and wish to use it in post-processing stages.
+* Use `-Denable_opencv=enabled` if you have installed OpenCV and wish to use OpenCV-based post-processing stages.
+* Use `-Denable_tflite=enabled` if you have installed TensorFlow Lite and wish to use it in post-processing stages.
 
 ======
 
@@ -188,19 +188,24 @@ The `meson` build configuration for `rpicam-apps` supports the following flags:
 
 `-Dneon_flags=armv8-neon`:: Speeds up certain post-processing features on Raspberry Pi 3 or Raspberry Pi 4 devices running a 32-bit OS.
 
-`-Denable_libav=true`:: Enables or disables `libav` encoder integration.
+`-Denable_libav=enabled`:: Enables or disables `libav` encoder integration.
 
-`-Denable_drm=true`:: Enables or disables **DRM/KMS preview rendering**, a preview window used in the absence of a desktop environment.
+`-Denable_drm=enabled`:: Enables or disables **DRM/KMS preview rendering**, a preview window used in the absence of a desktop environment.
 
-`-Denable_egl=true`:: Enables or disables the non-Qt desktop environment-based preview. Disable if your system lacks a desktop environment.
+`-Denable_egl=enabled`:: Enables or disables the non-Qt desktop environment-based preview. Disable if your system lacks a desktop environment.
 
-`-Denable_qt=true`:: Enables or disables support for the Qt-based implementation of the preview window. Disable if you do not have a desktop environment installed or if you have no intention of using the Qt-based preview window. The Qt-based preview is normally not recommended because it is computationally very expensive, however it does work with X display forwarding.
+`-Denable_qt=enabled`:: Enables or disables support for the Qt-based implementation of the preview window. Disable if you do not have a desktop environment installed or if you have no intention of using the Qt-based preview window. The Qt-based preview is normally not recommended because it is computationally very expensive, however it does work with X display forwarding.
 
-`-Denable_opencv=true`:: Forces OpenCV-based post-processing stages to link or not link. Requires OpenCV to enable. Defaults to `true` when OpenCV is installed, `false` otherwise.
+`-Denable_opencv=enabled`:: Forces OpenCV-based post-processing stages to link or not link. Requires OpenCV to enable. Defaults to `disabled`.
 
-`-Denable_tflite=true`:: Enables or disables TensorFlow Lite post-processing stages. Disabled by default. Requires Tensorflow Lite to enable. Depending on how you have built and/or installed TFLite, you may need to tweak the `meson.build` file in the `post_processing_stages` directory.
+`-Denable_tflite=enabled`:: Enables or disables TensorFlow Lite post-processing stages. Disabled by default. Requires Tensorflow Lite to enable. Depending on how you have built and/or installed TFLite, you may need to tweak the `meson.build` file in the `post_processing_stages` directory.
+
+Each of the above options (except for `neon_flags`) supports the following values:
+
+* `enabled`: enables the option, fails the build if dependencies are not available
+* `disabled`: disables the option
+* `auto`: enables the option if dependencies are available
 
-NOTE: To disable any of the flags shown above with `true` as a value, replace `true` with `false`.
 
 
 ==== Building `libepoxy`