Dump chrome://webrtc-internals event log

Chrome 49 added a highly useful event log which, among other things, contains the RTP packet headers of any packets received or sent. See https://tokbox.com/blog/how-to-get-a-webrtc-diagnostic-recording-from-chrome-49/ for how to get it.

Usage

node dump event_log_file

To dump all incoming or outgoing RTP traffic into a PCAP:

node rtp.js event_log_file incoming | text2pcap -t "%T." -u 10000,20000 - some.pcap
node rtp.js event_log_file outgoing | text2pcap -t "%T." -u 10000,20000 - some.pcap

Generating the protobuf file

rtc_event_log.proto is generated from the description in the webrtc.org tree:

protoc-c webrtc/logging/rtc_event_log/rtc_event_log.proto -o rtc_event_log.proto