Usage: FFmpeg + Janus

[winlinvip]

We referred to WISH, WHIP and Janus: Part II to make it possible to use FFmpeg for publishing a stream to Janus via WHIP. We have also created a demo docker image janus-docker for quick testing.

git clone https://github.com/winlinvip/janus-docker.git
cd janus-docker

Initially, run the demo Docker that includes Janus server using the following command:

cd ~/git/janus-docker

ip="192.168.3.85" && sed -i '' "s/nat_1_1_mapping.*/nat_1_1_mapping=\"$ip\"/g" janus.jcfg # macOS
ip="192.168.3.85" && sed -I "s|^ *nat_1_1_mapping *=.*|nat_1_1_mapping = \"$ip\"|g" janus.jcfg # Linux

docker run --rm -it -p 8081:8080 -p 8188:8188 -p 8443:8443 -p 20000-20010:20000-20010/udp \
    -v $(pwd)/janus.jcfg:/usr/local/etc/janus/janus.jcfg \
    -v $(pwd)/janus.plugin.videoroom.jcfg:/usr/local/etc/janus/janus.plugin.videoroom.jcfg \
    -v $(pwd)/janus.transport.http.jcfg:/usr/local/etc/janus/janus.transport.http.jcfg \
    -v $(pwd)/janus.transport.websockets.jcfg:/usr/local/etc/janus/janus.transport.websockets.jcfg \
    -v $(pwd)/videoroomtest.js:/usr/local/share/janus/demos/videoroomtest.js \
    ossrs/janus:v1.0.12

Note: Kindly modify the IP address to your own IP address. You can use ifconfig or ipconfig to determine it.

After that, access the URL http://localhost:8081/videoroomtest.html?room=2345 in your browser to join the Janus room.

Next, download and run the Simple WHIP Server for Janus using the following command:

git clone https://github.com/meetecho/simple-whip-server.git
cd simple-whip-server
git checkout bd2d98898b9842bfc329443b46bcc906aab857aa
npm install
npm run build
npm run start

Generate a WHIP handler using curl, which will enable ffmpeg to join the same Janus room through WHIP:

curl -H 'Content-Type: application/json' -d '{"id": "abc123", "room": 2345}' \
    http://localhost:7080/whip/create

To download the code and build FFmpeg, you can use the following command.

cd ~/git 
git clone -b master https://github.com/winlinvip/ffmpeg-webrtc.git
cd ffmpeg-webrtc
./configure --enable-muxer=whip --enable-openssl --enable-version3 \
    --enable-libx264 --enable-gpl --enable-libopus
make -j

Note: To enable DTLS handshake, OpenSSL is mandatory. Please install OpenSSL, for instance, brew install openssl, and then configure the environment by running export PKG_CONFIG_PATH="/usr/local/opt/openssl@3/lib/pkgconfig".

Note: For demonstration purposes, you can install libx264 by running brew install x264 and libopus by running brew install opus.

Remark: Please use OpenSSL 1.0.2 and newer, because Janus requires DTLS 1.2.

Although WebRTC has the capability to support x264 main and high profiles without B frames, it is advisable to use the baseline profile for better compatibility. If your stream doesn't have these codecs, you can transcode it using FFmpeg.

~/git/ffmpeg-webrtc/ffmpeg -re -f lavfi -i testsrc=size=1280x720 -f lavfi -i sine=frequency=440 -pix_fmt yuv420p \
    -vcodec libx264 -profile:v baseline -r 25 -g 50 -acodec libopus -ar 48000 -ac 2 \
    -f whip 'http://localhost:7080/whip/endpoint/abc123'

# Or you can also capture your screen, and measure the end-to-end latency.
~/git/ffmpeg-webrtc/ffmpeg -f avfoundation -framerate 25 -pixel_format yuyv422 -i "2:0" \
    -vcodec libx264 -pix_fmt yuv420p -profile:v baseline -preset:v ultrafast \
    -b:v 800k -s 1024x576 -r 25 -g 50 -tune zerolatency -threads 1 -bf 0 \
    -acodec libopus -ar 48000 -ac 2 \
    -f whip 'http://localhost:7080/whip/endpoint/abc123'

After publishing the stream to the Janus room, you will be able to view it on the previously opened webpage. The image below shows that the latency is around 120ms.

Note: Sometimes, the latency might exceed 120ms, which could be due to my environment. We have reported an issue at here.