casting listening on wrong ip address?

[trapier]

Have regularly had the same issue noted elsewhere whereby casting makes the "start" sound on the designated speaker, but then the playback cursor loops over the same two seconds in Poweramp and no music comes out of the speaker.

My phone is rooted so I checked and noted when this is happening that Poweramp is listening on an interface which is not reachable from my home network:

 

# ss -tnlp | grep mpz
LISTEN      0      50      [::ffff:192.0.0.4]:18888                    *:*                   users:(("mpz.audioplayer",pid=7114,fd=211))
LISTEN      0      50      [::ffff:192.0.0.4]:18889                    *:*                   users:(("mpz.audioplayer",pid=7114,fd=196))
#

This 192.0.0.4 address is a /32 on the v4-rmnet_data1 interface, which seems to be associated with the mobile data network.  It's inaccessible from my home wifi network.

In those instances where casting does work I see that Poweramp is bound to the the address of the phone's wlan0 interface.  Haven't yet figured out reliable steps to make it fail vs work.  I've experimented with using iptables on the phone to nat from wlan0 to this 192.0.0.4 address, but that hasn't yet helped.

This is incomplete in terms of a bug report, but figured it worth raising in the event that it sheds light on a potential improvement to the algorithm Poweramp uses to select a listening address for casting.

Poweramp build number
build-976-bundle-play [976004-c2601e58] Full Version 64 bit
device model Pixel 4A 5G
Android version 13
stock ROM
steps to reproduce not yet established

[trapier]

Found a reliable work-around for the issue is to disable mobile data before starting casting.  Automated this with Llamalab's Automate.  https://llamalab.com/automate/community/flows/46799

[andrewilley]

@maxmp Might this report help diagnose the other occasions where people have reported this issue with Chromecasting? Presumably it's related to contacting the support server via the internet? 

Andre

[6b6561]

@andrewilley I don't think this is related to Chromecast not able to get the media receiver issue that you describe. (CC has to download a media receiver from Max server, this receiver is what receives the audio stream from the phone).

This is a topic that has popped up a couple of times, Chromecast starts the playback but nothing is heard and I would assume that the receiver is on the CC at this point.

What's good in this troubleshooting is that @trapier found out that the Poweramp process is binding to the wrong interface on the phone and the workaround is to turn off mobile data during. That's a good thing as that can help other users having CC issues and it also gives @maxmp something to work against.