multicast sound quality degrades over time

[aapgorilla]

Description of problem: When I start playing sound over RTP multicast everything is fine but sound quality degrades over a few minutes untill it just becomes a skipping sound. When I log out and back into the client desktop again the sound is okay again. Local audio is not affected and continues to play fine

This is the output from pulseaudio -vvv where the actual skipping starts:

D: module-rtp-recv.c: Updated sampling rate to 47506 Hz.                        
D: module-rtp-recv.c: Requesting rewind due to end of underrun                  
D: alsa-sink.c: Requested to rewind 52896 bytes.                                
D: alsa-sink.c: Limited to 52896 bytes.                                         
D: alsa-sink.c: before: 4408                                                    
D: alsa-sink.c: after: 3426                                                     
D: alsa-sink.c: Rewound 41112 bytes.                                            
D: sink.c: Processing rewind...                                                 
D: sink-input.c: Have to rewind 41112 bytes on render memblockq.                
D: source.c: Processing rewind...                                               
D: module-rtp-recv.c: Updating sample rate                                      
D: module-rtp-recv.c: wi=98342477 ri=97348545                                   
D: module-rtp-recv.c: Write index deviates by 1090,80 ms, expected 500,00 ms    
D: module-rtp-recv.c: Updated sampling rate to 52716 Hz.                        
D: module-rtp-recv.c: Requesting rewind due to end of underrun                  
D: alsa-sink.c: Requested to rewind 52896 bytes.                                
D: alsa-sink.c: Limited to 52896 bytes.                                         
D: alsa-sink.c: before: 4408                                                    
D: alsa-sink.c: after: 4148                                                     
D: alsa-sink.c: Rewound 49776 bytes.                                            
D: sink.c: Processing rewind...                                                 
D: sink-input.c: Have to rewind 49776 bytes on render memblockq.                
D: source.c: Processing rewind...                                               
D: module-rtp-recv.c: Requesting rewind due to end of underrun                  
D: alsa-sink.c: Requested to rewind 52896 bytes.                                
D: alsa-sink.c: Limited to 39672 bytes.                                         
D: alsa-sink.c: before: 3306                                                    
D: alsa-sink.c: after: 3291                                                     
D: alsa-sink.c: Rewound 39492 bytes.                                            
D: sink.c: Processing rewind...

[coling]

For reference this will be v0.9.19

[adlerweb]

Could be scheduler-related. I had a similar problem with RTP multicast: choppy sound and wrong sample rates. In my case switching from deadline to CFQ on the server solved most of these issues.

[jonaz]

I would like to point out that im having the exact same issue with pulseaudio 0.9.21-63-gd3efa-dirty (latest ubuntu).

Sound is okay for about 10-20 seconds then it just gets laggier and choppier until you can only hear static...

im using 2 computer with gigabit network so the bandwith is not an issue here.

[mkbosmans]

I'm seeing this to.

module-rtp-recv increases the sample rate to insanely high values pretty quickly

[mkbosmans]

Can you confirm that this patch solves the problem?

Obviously the patch is not suitable for inclusion in pulse as is, but it would be nice to have confirmation that the approach used is a right one.

[mkbosmans]

Should be solved by http://git.0pointer.de/?p=pulseaudio.git;a=commit;h=8534149fbe87c63a5af85f5610c0f62b45500d90 Feel free to reopen if the problem persists.