The various pieces of WebRTC do a lot of logging, and these logs can be very helpful to developers when trying to track down problems. This page provides instructions for turning these logging messages on so you can include them in bug reports, etc..
ICE/STUN/TURN
Set the following environment variables:
- R_LOG_DESTINATION=stderr
- R_LOG_LEVEL=3 (can be anything between 1 and 9) (See <https://dxr.mozilla.org/mozilla-central/source/media/mtransport/third_party/nrappkit/src/port/win32/include/csi_platform.h> for levels)
- R_LOG_VERBOSE=1 (if you want to include the module name generating the message)
Signaling (SDP offer/answer handling)
This uses the normal Mozilla NSPR logging infrastructure, which uses a comma-separated list of modules, each one with its indicated NSPR log level. For WebRTC, you'll be most interested in
- NSPR_LOG_MODULES=signaling:5,mtransport:5
- NSPR_LOG_FILE=/path/to/nspr.log (if you don't want the default stderr)
You can also add ",timestamp" to that list if you want each log message to include timestamps. Other options are available as well, and they are detailed under "Description" on the NSPR LOG MODULES MDN page.
getUserMedia
To log getUserMedia stuff, use NSPR_LOG_MODULES=mediamanager:5,getusermedia:5. For frame-by-frame logging, use mediamanager:6
Media (the GIPS stack: RTP/RTCP)
This also uses the Mozilla logging infrastructure, but it uses a bitmask to select which items are logged, instead of the default log levels. It also logs to a different destination by default.
- NSPR_LOG_MODULES=webrtc_trace:65535
- WEBRTC_TRACE_FILE=/path/to/WebRTC.log (the default is just "WebRTC.log")
- If WEBRTC_TRACE_FILE=nspr, the logs will be inserted into the NSPR logs. Note this may have a major performance impact.
The full list of logging options is found in the TraceLevel enum (see <http://mxr.mozilla.org/mozilla-central/source/media/webrtc/trunk/webrtc/common_types.h#83>).