Update readme. (#687)

Author: jianjunz

README.md

@@ -5,9 +5,9 @@ The Open WebRTC Toolkit(OWT) client SDK for native Windows/Linux/Android/iOS app
 of real time communication applications on these platforms. It supports peer to peer communication, and conference mode communication working with
 Open WebRTC Toolkit conference server.
 
-- Supported Windows platform: Windows 8 and above.
+- Supported Windows platform: Windows 10 and above.
 - Supported Linux platform: Ubuntu 20.04 and above.
-- Supported iOS platform: iOS 9.0 and above.
+- Supported iOS platform: iOS 12.0 and above.
 
 ## Documentation
 To generate the API document, go to the `scripts` directory, and run `python build-win.py --docs` for Windows or `./gendoc.sh` in `talk/owt/docs/ios` for iOS.
@@ -18,12 +18,12 @@ You need [Doxygen](http://www.doxygen.nl/) in your path.
 
 ### Prepare the development environment
 Before you start, make sure you have the following prerequisites installed/configured:
-- [WebRTC stack build dependencies](https://webrtc.googlesource.com/src/+/refs/heads/master/docs/native-code/development/prerequisite-sw/index.md).
+- [WebRTC stack build dependencies](https://webrtc.googlesource.com/src/+/refs/heads/master/docs/native-code/development/prerequisite-sw/index.md), except the Visual Studio part.
 - [Proxy settings](https://github.com/open-webrtc-toolkit/owt-client-native/wiki/Proxy-config-for-building-native-SDK).
 
 The following dependencies are for Windows only:
-- [Visual Studio](https://chromium.googlesource.com/chromium/src/+/refs/heads/main/docs/windows_build_instructions.md#visual-studio).
-- [Intel Media SDK for Windows, version 2020 R1 or higher](https://software.intel.com/en-us/media-sdk/choose-download/client).
+- [Visual Studio](https://chromium.googlesource.com/chromium/src/+/refs/heads/main/docs/windows_build_instructions.md#visual-studio). Only Visual Studio 2022 version 17.4.4 is tested.
+- [Intel Media SDK for Windows, version 2021 R1 or higher](https://software.intel.com/en-us/media-sdk/choose-download/client).
 
 ### Get the code
 - Make sure you clone the source code to a directory named `src`.
@@ -51,7 +51,6 @@ target_os = []
 1. Go to the `src/scripts` directory, and run: `python build-win.py --gn_gen --sdk --tests --ssl_root /path/to/ssl --msdk_root /path/to/msdk --output_path /path/to/output`.
   - The optional `msdk_root` should be set to the directory of your Intel MediaSDK for Windows, version 2020 R1 or higher. This is typically
   `C:\Program Files (x86)\IntelSWTools\Intel(R) Media SDK 2020 R1\Software Development Kit`. If specified, will enable hardware accelerated video codecs for most of the video codecs.
-  - The optional `--sdk` is to inform the build script to use `lib.exe` that is part of Visual Studio toolchain for merging owt libraries with external openssl libraries.
 
 
 #### Linux
@@ -65,11 +64,10 @@ target_os = []
 Common build options shared by Windows and Linux:
   - By default `x86|Debug` library will be created. Specify `--arch x64` if you want to build x64 libraries; Specify `--scheme release` if release version of library is to be built.
   - The built binary will be under path specified by `--output_path`. If `--output_path` is not set, the built binary will be under `src/out` directory.
-  - The optional `--ssl_root` should be set to the root directory of lastest OpenSSL 3.0 series directory. If specified, build tool will search external OpenSSL headers in `ssl_root/include` and OpenSSL binaries in `ssl_root/bin`. But binaries are not included in OWT SDK, so applications still need to link libcrypto and libssl.
-  - Use `--gn_gen` to generate args.gn during the first build or when you change either `ssl_root`/`msdk_root`/`quic_root` options.
-  - The optional `--quic_root` should point to the directory containing WebTransport library pre-built from owt-sdk-quic repo. This will build the SDK with WebTransport enabled for 
-  conference mode. Refer to [README.webtransport](https://github.com/open-webrtc-toolkit/owt-client-native/blob/main/README.webtransport) for the version of webtransport library to be used.
+  - The optional `--ssl_root` should be set to the root directory of lastest OpenSSL 3.0 series directory. If specified, build tool will search external OpenSSL headers in `ssl_root/include` and OpenSSL binaries in `ssl_root/lib`. But binaries are not included in OWT SDK, so applications still need to link libcrypto and libssl.
+  - Use `--gn_gen` to generate args.gn during the first build or when you change either `ssl_root`/`msdk_root` options.
   - The optional `--tests` will trigger unit tests after build.
+  - Run `build*.py` with `--help` for argument description.
 
 #### iOS
 Update to latest macOS(Big Sur) and Xcode. iOS SDK can only be built on macOS.
@@ -78,16 +76,7 @@ Update to latest macOS(Big Sur) and Xcode. iOS SDK can only be built on macOS.
 1. Run `scripts\build.py`.
 
 #### Android
-1. Replace the last line of .gclient with target_os=["android"]
-1. Run gclient sync. It may take long time to download large amount of data.
-1. Build libwebrtc for OWT Android SDK with scripts/build_android.py.
-
-#### Linux
-- Run `gclient sync` in the directory that contains 'src'. It may take a long time to download a large amount of data.
-- Go to the `src/scripts` directory, and run: 
-`python build_linux.py --gn_gen --sdk --output_path /path/to/out --fake_audio`. The built binary will be under `output_path`, 
-- The document for sdk will also be copied to this directory if docs have been generated. 
-- If `output_path` is not set, the built binary will be under the `src/out` directory.
+This branch doesn't support Android build. owt-client-android depends on 5.0.x branch of this repository.
 
 
 ## How to contribute

scripts/build-win.py

@@ -166,7 +166,7 @@ def main():
                         help='VC runtime linkage. Currently not supported.')
     parser.add_argument('--ssl_root', help='Path for OpenSSL.')
     parser.add_argument('--msdk_root', help='Path for MSDK.')
-    parser.add_argument('--quic_root', help='Path to QUIC library')
+    parser.add_argument('--quic_root', help='Path to QUIC library. Not supported yet.')
     parser.add_argument('--scheme', default='debug', choices=('debug', 'release'),
                         help='Schemes for building. Supported value: debug, release')
     parser.add_argument('--gn_gen', default=False, action='store_true',

scripts/build.py

@@ -162,8 +162,8 @@ def runtest(ssl_root):
 def main():
   parser = argparse.ArgumentParser()
   parser.add_argument('--arch', default='arm64', dest='target_arch',
-      help='Target architectures. Could be multiple values seperated by comma.')
-  parser.add_argument('--ssl_root', help='Path for OpenSSL.')
+      help='Target architectures. Could be multiple values separated by comma.')
+  parser.add_argument('--ssl_root', help='Path for OpenSSL. Headers in include sub-folder, libcrypto.a and libssl.a in lib sub-folder.')
   parser.add_argument('--scheme', default='debug',
       help='Schemes for building. Supported value: debug, release')
   parser.add_argument('--skip_gn_gen', default=False, action='store_true',