Update outdated GStreamer for Android instructions

GStreamer is now downloaded and set up for the build automatically as
part of the CMake configure step. A note has also been added to help
Windows users ensure that this works correctly.

src/VideoManager/VideoReceiver/GStreamer/README.md

@@ -16,36 +16,45 @@ For cases, when it is need to have more control over gstreamer logging than is a
 For the time being, the RTP UDP pipeline is somewhat hardcoded, using h.264 or h.265. It's best to use a camera capable of hardware encoding either h.264 (such as the Logitech C920) or h.265. On the sender end, for RTP (UDP Streaming) you would run something like this:
 
 h.264
+
 ```
 gst-launch-1.0 uvch264src initial-bitrate=1000000 average-bitrate=1000000 iframe-period=1000 device=/dev/video0 name=src auto-start=true src.vidsrc ! video/x-h264,width=1920,height=1080,framerate=24/1 ! h264parse ! rtph264pay ! udpsink host=xxx.xxx.xxx.xxx port=5600
 ```
 
 h.265
+
 ```
 ffmpeg -f v4l2 -i /dev/video1 -pix_fmt yuv420p -c:v libx265 -preset ultrafast -x265-params crf=23 -strict experimental -f rtp udp://xxx.xxx.xxx.xxx:5600
 ```
 
 Where xxx.xxx.xxx.xxx is the IP address where QGC is running.
 
-
 To test using a test source on localhost, you can run this command:
+
 ```
 gst-launch-1.0 videotestsrc pattern=ball ! video/x-raw,width=640,height=480 ! x264enc ! rtph264pay ! udpsink host=127.0.0.1 port=5600
 ```
+
 Or this one:
+
 ```
 gst-launch-1.0 videotestsrc ! video/x-raw,width=640,height=480 ! videoconvert ! x264enc ! rtph264pay ! udpsink host=127.0.0.1 port=5600
 ```
 
 On the receiving end, if you want to test it from the command line, you can use something like:
+
 ```
 gst-launch-1.0 udpsrc port=5600 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtpjitterbuffer ! rtph264depay ! h264parse ! avdec_h264 ! autovideosink fps-update-interval=1000 sync=false
 ```
+
 Or this one:
+
 ```
 gst-launch-1.0 udpsrc port=5600 ! application/x-rtp ! rtpjitterbuffer ! rtph264depay ! avdec_h264 ! videoconvert ! autovideosink
 ```
+
 Or this one, note that removing rtpjitterbuffer would reduce video latency as low latency mode is doing:
+
 ```
 gst-launch-1.0 udpsrc port=5600 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' ! rtpjitterbuffer ! parsebin ! decodebin ! autovideosink fps-update-interval=1000 sync=false
 ```
@@ -57,12 +66,15 @@ QGC also supports RTSP, TCP-MPEG2 and MPEG-TS (h.264) pipelines.
 ### Linux
 
 Use apt-get to install GStreamer 1.0
+
 ```
 list=$(apt-cache --names-only search ^gstreamer1.0-* | awk '{ print $1 }' | sed -e /-doc/d | grep -v gstreamer1.0-hybris)
 ```
+
 ```
 sudo apt-get install $list
 ```
+
 ```
 sudo apt-get install libgstreamer-plugins-base1.0-dev
 sudo apt-get install libgstreamer-plugins-bad1.0-dev 
@@ -75,12 +87,14 @@ The build system is setup to use pkgconfig and it will find the necessary header
 Download the gstreamer framework from here: http://gstreamer.freedesktop.org/data/pkg/osx. Supported version is 1.18.6. QGC may work with newer version, but it is untested.
 
 You need two packages:
+
 - [gstreamer-1.0-devel-1.18.6-x86_64.pkg](https://gstreamer.freedesktop.org/data/pkg/osx/1.18.6/gstreamer-1.0-devel-1.18.6-x86_64.pkg)
 - [gstreamer-1.0-1.18.6-x86_64.pkg](https://gstreamer.freedesktop.org/data/pkg/osx/1.18.6/gstreamer-1.0-1.18.6-x86_64.pkg)
 
 The installer places them under /Library/Frameworks/GStreamer.framework, which is where the QGC build system will look for it. That's all that is needed. When you build QGC and it finds the gstreamer framework, it automatically builds video streaming support.
 
 :point_right: To run gstreamer commands from the command line, you can add the path to find them (either in ~/.profile or ~/.bashrc):
+
 ```
 export PATH=$PATH:/Library/Frameworks/GStreamer.framework/Commands
 ```
@@ -93,32 +107,31 @@ The installer places them under ~/Library/Developer/GStreamer/iPhone.sdk/GStream
 
 ### Android
 
-Download the gstreamer from here: [gstreamer-1.0-android-universal-1.18.5.tar.xz](https://gstreamer.freedesktop.org/data/pkg/android/1.18.5/gstreamer-1.0-android-universal-1.18.5.tar.xz)
+An appropriate version of GStreamer will be automatically downloaded as part of the CMake configure step.
+
+#### Important Note for Windows Users
+
+During the build process for Android on Windows, to ensure support for UNIX-like symbolic links when not using elevated privileges, **Developer Mode** must be enabled. Without enabling Developer Mode, you may encounter linking issues with the automatically downloaded prebuilt version of GStreamer.
+
+To enable Developer Mode:
+
+1. Open the **Settings** app on Windows.
+2. Go to **System** > **For developers**.
+3. Enable **Developer Mode** by toggling the switch.
 
-Create a directory named "gstreamer-1.0-android-universal-1.18.5" under the root qgroundcontrol directory (the same directory qgroundcontrol.pro is located). Extract the downloaded archive under this directory. That's where the build system will look for it. Make sure your archive tool doesn't create any additional top level directories. The structure after extracting the archive should look like this:
-```
-qgroundcontrol
-├── gstreamer-1.0-android-universal-1.18.5
-│   │
-│   ├──armv7
-│   │   ├── bin
-│   │   ├── etc
-│   │   ├── include
-│   │   ├── lib
-│   │   └── share
-│   ├──x86
-```
 ### Windows
 
 Download the gstreamer framework from here: http://gstreamer.freedesktop.org/data/pkg/windows. Supported version is 1.18.1. QGC may work with newer version, but it is untested.
 
 You need two packages:
 
-#### 32-Bit: 
+#### 32-Bit:
+
 - [gstreamer-1.0-devel-msvc-x86-1.18.1.msi](https://gstreamer.freedesktop.org/data/pkg/windows/1.18.1/msvc/gstreamer-1.0-devel-msvc-x86-1.18.1.msi)
 - [gstreamer-1.0-msvc-x86-1.18.1.msi](https://gstreamer.freedesktop.org/data/pkg/windows/1.18.1/msvc/gstreamer-1.0-msvc-x86-1.18.1.msi)
 
-#### 64-Bit: 
+#### 64-Bit:
+
 - [gstreamer-1.0-devel-msvc-x86_64-1.18.1.msi](https://gstreamer.freedesktop.org/data/pkg/windows/1.18.1/msvc/gstreamer-1.0-devel-msvc-x86_64-1.18.1.msi)
 - [gstreamer-1.0-msvc-x86_64-1.18.1.msi](https://gstreamer.freedesktop.org/data/pkg/windows/1.18.1/msvc/gstreamer-1.0-msvc-x86_64-1.18.1.msi)