# WebRTC WebRTC Information: - https://webrtc.org/ - https://webrtc.googlesource.com/src - https://webrtc.googlesource.com/src/+/refs/heads/master/docs/native-code/index.md - https://webrtc.googlesource.com/src/+/refs/heads/master/docs/native-code/development/prerequisite-sw/index.md - https://webrtc.googlesource.com/src/+/refs/heads/master/docs/native-code/development/index.md - https://www.chromium.org/developers/calendar - https://github.com/microsoft/winrtc - https://docs.microsoft.com/en-us/winrtc/getting-started - https://groups.google.com/g/discuss-webrtc \ See "PSA" posts for release information. - https://bugs.chromium.org/p/webrtc/issues/list - https://stackoverflow.com/questions/27809193/webrtc-not-building-for-windows - https://github.com/aisouard/libwebrtc/issues/57 ## Windows - M84 WebRTC's M84 release is currently used because it corresponded to Microsoft's latest WinRTC release at the time of development, and WinRTC is a source of potentially useful patches. The following notes document how the M84-based Windows VCPKG was created, using Visual Studio 2019. ### Set Up depot_tools Install Google's depot_tools. - Download depot_tools.zip. - Extract somewhere. - Add the extracted directory to the start of the system `PATH` environment variable. Configure depot_tools. - Set an environment variable `DEPOT_TOOLS_WIN_TOOLCHAIN=0` - Set an environment variable `GYP_MSVS_VERSION=2019` Initialize depot_tools. - VS2019 developer command prompt in the directory where the source tree will be created. - `gclient` ### Get the Code Fetch the code into a *\src* subdirectory. This may take some time! - `fetch --nohooks webrtc` Switch to the M84 branch. - `cd src` - `git checkout branch-heads/4147` Fetch all the subrepositories. - `gclient sync -D -r branch-heads/4147` ### Patch the Code #### Modify compiler switches - Edit *build\config\win\BUILD.gn*: - Change all `/MT` to `/MD`, and `/MTd` to `/MDd`. - Change all `cflags = [ "/MDd" ]` to `[ "/MDd", "-D_ITERATOR_DEBUG_LEVEL=2", "-D_HAS_ITERATOR_DEBUGGING=1" ]`. - Edit *build\config\compiler\BUILD.gn*:\ Change: ``` if (is_win) { if (is_clang) { cflags = [ "/Z7" ] # Debug information in the .obj files. } else { cflags = [ "/Zi" ] # Produce PDB file, no edit and continue. } ``` to: ``` if (is_win) { if (is_clang) { cflags = [ "/Z7", "/std:c++17", "/Zc:__cplusplus" ] # Debug information in the .obj files. } else { cflags = [ "/Zi", "/std:c++17", "/Zc:__cplusplus" ] # Produce PDB file, no edit and continue. } ``` #### H265 Codec Fixes https://bugs.webrtc.org/9213#c13 - Edit the following files: - *modules\video_coding\codecs\h264\h264_color_space.h* - *modules\video_coding\codecs\h264\h264_decoder_impl.h* - *modules\video_coding\codecs\h264\h264_encoder_impl.h* In each, comment out the following lines: ``` #if defined(WEBRTC_WIN) && !defined(__clang__) #error "See: bugs.webrtc.org/9213#c13." #endif ``` - Edit *third_party\ffmpeg\libavcodec\fft_template.c*:\ Comment out all of `ff_fft_init` except the fail clause at the end. - Edit *third_party\ffmpeg\libavcodec\pcm.c*:\ Comment out last line, containing `PCM Archimedes VIDC`. - Edit *third_party\ffmpeg\libavutil\x86\imgutils_init.c*:\ Add the following method to the end of the file: ``` void avpriv_emms_asm(void) {} // Fix missing symbol in FFMPEG. ``` #### Exclude BoringSSL A separate OpenSSL VCPKG is used for building Overte. The following patches are needed even though SSL is excluded in the `gn gen` build commands. - Rename *third_party\boringssl* to *third_party\boringssl-NO*. - Edit *third_party\libsrtp\BUILD.gn:\ Change: ``` public_deps = [ "//third_party/boringssl:boringssl", ] ``` To: ``` public_deps = [ # "//third_party/boringssl:boringssl", ] ``` - Edit *third_party\usrsctp\BUILD.gn*:\ Change: ``` deps = [ "//third_party/boringssl" ] ``` To: ``` deps = [ # "//third_party/boringssl" ] ``` - Edit *base\BUILD.gn*:\ In the code under: ``` # Use the base implementation of hash functions when building for # NaCl. Otherwise, use boringssl. ``` Change: ``` if (is_nacl) { ``` To: ``` # if (is_nacl) { if (true) { ``` - Edit *rtc_base\BUILD.gn*:\ Change: ``` if (rtc_build_ssl) { deps += [ "//third_party/boringssl" ] } else { ``` To: ``` if (rtc_build_ssl) { # deps += [ "//third_party/boringssl" ] } else { ``` ### Set Up OpenSSL Do one of the following to provide OpenSSL for building against: a. If you have built Overte, find the **HIFI_VCPKG_BASE** subdirectory used in your build and make note of the path to and including the *installed\x64-windows\include* directory (which includes an *openssl* directory). a. Follow https://github.com/overte-org/vcpkg to install *vcpkg* and then *openssl*. Make note of the path to and including the *packages\openssl-windows_x64-windows\include* directory (which includes an *openssl* directory). Copy the *\\openssl* directory to the following locations (i.e., add as *openssl* subdirectories): - *third_party\libsrtp\crypto\include* - *third_party\usrsctp\usrsctplib\usrsctplib* Also use the path in the `gn gen` commands, below, making sure to escape `\`s as `\\`s. ### Build and Package Use a VS2019 developer command prompt in the *src* directory. Create a release build of the WebRTC library: - `gn gen --ide=vs2019 out\Release --filters=//:webrtc "--args=is_debug=false is_clang=false use_custom_libcxx=false libcxx_is_shared=true symbol_level=2 use_lld=false rtc_include_tests=false rtc_build_tools=false rtc_build_examples=false proprietary_codecs=true rtc_use_h264=true enable_libaom=false rtc_enable_protobuf=false rtc_build_ssl=false rtc_ssl_root=\"\""` - `ninja -C out\Release` Create a debug build of the WebRTC library: - `gn gen --ide=vs2019 out\Debug --filters=//:webrtc "--args=is_debug=true is_clang=false use_custom_libcxx=false libcxx_is_shared=true enable_iterator_debugging=true use_lld=false rtc_include_tests=false rtc_build_tools=false rtc_build_examples=false proprietary_codecs=true rtc_use_h264=true enable_libaom=false rtc_enable_protobuf=false rtc_build_ssl=false rtc_ssl_root=\"\""` - `ninja -C out\Debug` Create VCPKG file: - Assemble files in VCPKG directory structure: Use the *copy-VCPKG-files-win.cmd* batch file per instructions in it. `cd ..`\ `copy-VCPKG-files-win` - Zip up the VCPKG *webrtc* directory created by the batch file. `cd vcpkg`\ `7z a -tzip webrtc-m84-yyyymmdd-windows.zip webrtc` - Calculate the SHA512 of the zip file. E.g., using a Windows PowerShell command window:\ `Get-FileHash -Algorithm SHA512 | Format-List` - Convert the SHA512 to lower case. E.g., using Microsoft Word, select the SHA512 text and use Shift-F3 to change the case. - Host the zip file on the Web. - Update *CONTROL* and *portfile.cmake* with version number (revision date), zip file Web URL, and SHA512. ### Tidying up Disable the depot_tools: - Rename the *depot_tools* directory so that these tools don't interfere with the rest of your development environment for other work. ## Linux - M81 The original, High Fidelity-provided WebRTC VCPKG library is used for AEC (audio echo cancellation) only. **TODO:** Update to M84 and include WebRTC components per Windows WebRTC. ## MacOS - M78 The original, High Fidelity-provided WebRTC VCPKG library is used for AEC (audio echo cancellation) only. **TODO:** Update to M84 and include WebRTC components per Windows WebRTC.