The command line tool neteq_rtpplay can be tested by running neteq_rtpplay_test.sh, which is not use on try bots, but it can be used before submitting any CLs that may break the behavior of the command line arguments of neteq_rtpplay.
Run neteq_rtpplay_test.sh as follows from the src/ folder:
src$ ./modules/audio_coding/neteq/tools/neteq_rtpplay_test.sh \ out/Default/neteq_rtpplay \ resources/audio_coding/neteq_opus.rtp \ resources/short_mixed_mono_48.pcm
You can replace the RTP and PCM files with any other compatible files. If you get an error using the files indicated above, try running gclient sync.
Requirements: awk and md5sum.