[pulseaudio-discuss] A2DP - Bluetooth source to alsa sink audio routing

[Cristina Cristea]

Thanks Maarten, that really makes the sample rate adjustment to not be 
noticed by the listener.
Unfortunately, I still get the underrun issues. Here is a log snippet:

D: module-loopback.c: Loopback overall latency is 46.98 ms + 150.19 ms + 
135.29 ms = 332.46 ms
D: module-loopback.c: Should buffer 23600 bytes, buffered at minimum 0 bytes
I: module-loopback.c: New rate of 43510 Hz not within 2‰ of 44264 Hz, 
forcing smaller adjustment
D: module-loopback.c: [alsa_output.pci-0000_00_1b.0.analog-stereo] 
Updated sampling rate to 44175 Hz.
D: module-loopback.c: Loopback overall latency is 45.68 ms + 115.25 ms + 
137.67 ms = 298.60 ms
D: module-loopback.c: Should buffer 23552 bytes, buffered at minimum 0 bytes
I: module-loopback.c: New rate of 43512 Hz not within 2‰ of 44175 Hz, 
forcing smaller adjustment
D: module-loopback.c: [alsa_output.pci-0000_00_1b.0.analog-stereo] 
Updated sampling rate to 44086 Hz.
D: alsa-sink.c: Wakeup from ALSA!
I: module-loopback.c: Coud not peek into queue
I: module-loopback.c: Coud not peek into queue
I: module-loopback.c: Coud not peek into queue
I: module-loopback.c: Coud not peek into queue
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Requesting rewind due to end of underrun.
D: module-loopback.c: Loopback overall latency is 52.43 ms + 268.86 ms + 
135.29 ms = 456.58 ms
D: module-loopback.c: Should buffer 23512 bytes, buffered at minimum 0 bytes
I: module-loopback.c: New rate of 43513 Hz not within 2‰ of 44086 Hz, 
forcing smaller adjustment
D: module-loopback.c: [alsa_output.pci-0000_00_1b.0.analog-stereo] 
Updated sampling rate to 43997 Hz.
D: alsa-sink.c: Wakeup from ALSA!

Thanks,
Cristina

On 02/22/2011 04:23 PM, Maarten Bosmans wrote:
> 2011/2/22 Cristina Cristea<doina.cristina at gmail.com>:
>    
>> Hi guys,
>>
>> First of all, sorry if this problem has been discussed before. I'm new on
>> this list and haven't seen it on the archives.
>>
>> Shortly, I'm experiencing small underruns when playing music from the phone
>> to my computer through bluetooth. At about every 5-6 minutes, the music
>> stops  for 1-2 sec. and these messages are showed by pulseaudio:
>>
>> D: protocol-native.c: Underrun on 'lt-pacat', 0 bytes in queue.
>> D: protocol-native.c: Requesting rewind due to end of underrun.
>> D: alsa-sink.c: Requested to rewind 65536 bytes.
>> D: alsa-sink.c: Limited to 44400 bytes.
>> D: alsa-sink.c: before: 11100
>> D: alsa-sink.c: after: 11100
>> D: alsa-sink.c: Rewound 44400 bytes.src-sinc-best-quality
>> D: sink.c: Processing rewind...
>> D: sink-input.c: Have to rewind 44400 bytes on render memblockq.
>> D: source.c: Processing rewind...
>>
>> I am using pacat and paplay apps as follows: parec -r --format s16le
>> --channels 2 --rate 44100 | paplay -p
>>
>> I also tried to redirect audio with module-loopback module: load-module
>> module-loopback source=bluez_source.00_23_76_E3_F3_C5
>> sink=alsa_output.0.analog-stereo
>> The results are still dissatisfactory:
>> -the CPU load is about 60%
>>
>> -every 10 seconds, module-loopback is changing the sample rate which is not
>> so pleasant for the listener:
>> I: module-loopback.c: Loopback overall latency is 56.37 ms + 493.72 ms +
>> 135.29 ms = 685.38 ms
>> I: module-loopback.c: Should buffer 23552 bytes, buffered at minimum 24288
>> bytes
>> I: module-loopback.c: Old rate 44167 Hz, new rate 44118 Hz
>>      
> You can pass adjust_time=0 to module-loopback. This way the adjustment
> is never made and if the source and sink have the same rates, no
> resampling is necessary. The rate change from the log snippet above is
> inaudible, so should not be unpleasant for the listener.
>
> Without adjusting the rate, you will probably get the underruns every
> 5-6 minutes, just as in the pacat case. Can you try git master? At
> least this commit
> http://git.0pointer.de/?p=pulseaudio.git;a=commit;h=8b4cb54595baeeb1d9b7d11a842ef7946e43a55a
> should make the experience with module-loopback a bit better. (without
> adjust_time=0)
>
>    
>> -underruns are still showing and pulseaudio displays:
>> I: module-loopback.c: Coud not peek into queue
>>
>> I'm running a meego and have this sound card:
>> 0 [MID            ]: HDA-Intel - HDA Intel MID
>>                       HDA Intel MID at 0xd2c00000 irq 16
>>
>> I'm not sure if this is a bluez or pulseaudio issue. I have tried my
>> bluetooth and a bluetooth dongle and there is no difference.
>>
>> My question is: is there a better way to route audio in this case? One that
>> could synchronize better the bluetooth and the sound card?
>>
>> Thanks,
>> Cristina
>>      
> Maarten
>