PulseDroid Rtp

Similar to PulseDroid, but using module-rtp-send instead of module-simple-protocol-tcp. It turns out that my WIFI network is lossy and UDP works better. The code references a lot from the official hello-oboe example.

The icon can be found here, "Headphones by Crystal Gordon from the Noun Project", licensed with Creative Commons. It looks good, and I am not using it as a trademark. If this causes you trouble, please contact me.

The following is the script I use to setup my desktop:

pactl unload-module module-null-sink
pactl unload-module module-rtp-send
pactl load-module module-null-sink sink_name=rtp format=s16be channels=2 rate=48000
pactl load-module module-rtp-send source=rtp.monitor destination=224.0.0.56 port=4010 mtu=320

If the app is granted permission to start on boot, and was playing music before last shutdown, it will continue playing music upon next boot.

The following could be used to start playing using adb:

# start activity
adb shell am start -n 'me.wenxinwang.pulsedroidrtp/.MainActivity'

# setup params
adb shell am startservice -n 'me.wenxinwang.pulsedroidrtp/.PulseRtpAudioService' -a 'android.intent.action.MEDIA_BUTTON' -d 'udp://224.0.0.56:4010/?latency=0\&mtu=320\&max_latency=300\&num_channel=2\&mask_channel=0'
# or use start-foreground-service instead of startservice if things don't work

# toggle playing
adb shell input keyevent 85

Here's something that still confuses me:

• If mtu is set to 1280, there is noticable delay between audio and video (audio lags behind lips movement); if it's set to 320, I cannot notice the delay. 1280B contains 320 samples, which should be less than 7ms long. I wonder why this makes the delay noticable.

<img src="https://fdroid.gitlab.io/artwork/badge/get-it-on.png" alt="Get it on F-Droid" height="80">