play-from-disk-fec

play-from-disk-fec

play-from-disk-fec demonstrates how to use forward error correction (FlexFEC-03) while sending video to your Chrome-based browser from files saved to disk. The example is designed to drop 40% of the media packets, but browser will recover them using the FEC packets and the delivered packets.

Instructions

Create IVF named output.ivf that contains a VP8/VP9/AV1 track

ffmpeg -i $INPUT_FILE -g 30 -b:v 2M output.ivf

Note: In the ffmpeg command which produces the .ivf file, the argument -b:v 2M specifies the video bitrate to be 2 megabits per second. We provide this default value to produce decent video quality, but if you experience problems with this configuration (such as dropped frames etc.), you can decrease this. See the ffmpeg documentation for more information on the format of the value.

Download play-from-disk-fec

go install github.com/pion/webrtc/v4/examples/play-from-disk-fec@latest

Open play-from-disk-fec example page

Open jsfiddle.net in your browser. You should see two text-areas and buttons for the offer-answer exchange.

Run play-from-disk-fec to generate an offer

The output.ivf you created should be in the same directory as play-from-disk-fec.

When you run play-from-disk-fec, it will generate an offer in base64 format and print it to stdout.

Input play-from-disk-fec's offer into your browser

Copy the base64 offer that play-from-disk-fec just emitted and paste it into the first text area in the jsfiddle (labeled "Remote Session Description")

Hit 'Start Session' in jsfiddle to generate an answer

Click the 'Start Session' button. This will process the offer and generate an answer, which will appear in the second text area.

Save the browser's answer to a file

Copy the base64-encoded answer from the second text area (labeled "Browser Session Description") and save it to a file named answer.txt in the same directory where you're running play-from-disk-fec.

Press Enter to continue

Once you've saved the answer to answer.txt, go back to the terminal where play-from-disk-fec is running and press Enter. The program will read the answer file and establish the connection.

Enjoy your video!

A video should start playing in your browser above the input boxes. play-from-disk-fec will exit when the file reaches the end

You can watch the stats about transmitted/dropped media & FEC packets in the stdout.

Congrats, you have used Pion WebRTC! Now start building something cool