[pulseaudio-discuss] Dropped xxx samples. This is most likely because downstream can't keep up and is consuming samples too slowly.

[Georg Chini]

On 13.02.22 17:09, corbeille wrote:
> Hey Georg,
>
> I have updated my to raspios since last time : Debian GNU/Linux 11
> (bullseye).
> It comes with :
> - pulseaudio 14.2
> - GStreamer 1.18.4
>
> Is it also too old ?
> I was hoping to avoid installing pulseaudio from source.
> If so, I will give it a try...
> ++
>
> Jack

Well, 14.2 is at least not completely out of date. Nevertheless I would try
current git. What I wonder about is that the problem only occurs with a
second null sink. Are you sure about that? The two null sinks should not
interact at all. Maybe with the second null sink the problem occurs only
later?

I can understand that there is an issue, because the system time and sound
card time are normally different. So if the source for example (from a 
system
time perspective) delivers samples at 48003 Hz while the samples are played
with 48000 Hz you will have three samples left per second which pile up
pretty fast. module-loopback has mechanisms to deal with the rate difference
between source and sink. Maybe you can try to use a loopback from the alsa
source to a null-sink and then use the monitor of that null sink in your 
first
gst-launch command instead of using the alsa source directly.

Do you see increasing latency before the sound gets choppy?

>
>
> Le dimanche 13 février 2022 à 17:05 +0100, Georg Chini a écrit :
>> On 13.02.22 16:57, corbeille wrote:
>>> Hello,
>>>
>>> I did some additional tests.
>>> And it seems the problem occurs when I have a second null sink.
>>> With
>>> only one null sink, I don't have any problem. Weird.
>>>
>>> So here is an example of the configuration that causes the problem
>>> :
>>>
>>> 1st shell:
>>> $ pacmd load-module module-null-sink sink_name=MySink
>>> $ pacmd load-module module-null-sink sink_name=MySink2
>>>
>>> 2nd shell:
>>> $ gst-launch-1.0 pulsesrc device="alsa_input.usb-0d8c_C-
>>> Media_USB_Headphone_Set-00.analog-mono" ! audioconvert !
>>> audioresample
>>> ! pulsesink device=MySink
>>>
>>> 3rd shell:
>>> $ gst-launch-1.0 pulsesrc device=MySink.monitor ! audio/x-
>>> raw,channels=2 ! audioconvert ! audioresample ! opusenc ! oggmux !
>>> shout2send ip=... port=... mount=... password=...
>>>
>>> After 20 minutes, the sound becomes choppy and stop 4/5 minutes
>>> after.
>>>
>>> You can notice that I don't use the second null sink.
>>>
>>> Is it a normal behavior ? If so, how can I do to achieve this
>>> configuration on my RPi (by using multi null sink) :
>>>
>>> gst_input1 => MySink => gst output1
>>> gst_input2 => MySink2 => gst output2
>>>
>>> without any trouble ?
>>> Thanks.
>>> ++
>>>
>>> Jack
>>>
>>>
>>>
>>> Le vendredi 11 février 2022 à 21:33 +0100, corbeille a écrit :
>>>> Hello,
>>>>
>>>> I am using pulseaudio (version 12.2) to "join" two audio streams
>>>> created
>>>> with gstreamer (1.14.4) on a raspberry pi (Raspbian GNU/Linux 10
>>>> (buster)).
>>>>
>>>> Here the real things :
>>>>
>>>> In a first shell, i start with :
>>>> $ pacmd load-module module-null-sink sink_name=MySink
>>>>
>>>> Then I use gstreamer to get the sound from my audio input (in an
>>>> other
>>>> shell) :
>>>> $ gst-launch-1.0 pulsesrc
>>>> device="alsa_input.usb-0d8c_C-Media_USB_Headphone_Set-00.analog-
>>>> mono"
>>>> !
>>>> audioconvert ! audioresample ! pulsesink device=MySink
>>>>
>>>> and I send this sound on an icecast server (in an other shell) :
>>>> $ gst-launch-1.0 pulsesrc device=MySink.monitor !
>>>> "audio/x-raw,channels=2" ! audioconvert ! audioresample ! opusenc
>>>> !
>>>> oggmux ! shout2send ip=... port=... mount=... password=...
>>>>
>>>> Everything is fine, but after 10 minutes, I get in the 3rd shell
>>>> ($
>>>> gst-launch-1.0 pulsesrc device=MySink.monitor ! ...) a sequence
>>>> of
>>>> messages like :
>>>>
>>>> WARNING: from element
>>>> /GstPipeline:pipeline0/GstPulseSrc:pulsesrc0:
>>>> Can't record audio fast enough
>>>> Additional debug info:
>>>> gstaudiobasesrc.c(849): gst_audio_base_src_create ():
>>>> /GstPipeline:pipeline0/GstPulseSrc:pulsesrc0:
>>>> Dropped 10080 samples. This is most likely because downstream
>>>> can't
>>>> keep
>>>> up and is consuming samples too slowly.
>>>> WARNING: from element
>>>> /GstPipeline:pipeline0/GstPulseSrc:pulsesrc0:
>>>> Can't record audio fast enough
>>>> Additional debug info:
>>>> gstaudiobasesrc.c(849): gst_audio_base_src_create ():
>>>> /GstPipeline:pipeline0/GstPulseSrc:pulsesrc0:
>>>> Dropped 34560 samples. This is most likely because downstream
>>>> can't
>>>> keep
>>>> up and is consuming samples too slowly.
>>>> WARNING: from element
>>>> /GstPipeline:pipeline0/GstPulseSrc:pulsesrc0:
>>>> Can't record audio fast enough
>>>> Additional debug info:
>>>> gstaudiobasesrc.c(849): gst_audio_base_src_create ():
>>>> /GstPipeline:pipeline0/GstPulseSrc:pulsesrc0:
>>>> Dropped 48000 samples. This is most likely because downstream
>>>> can't
>>>> keep
>>>> up and is consuming samples too slowly.
>>>> ...
>>>>
>>>> The sound become glitchy and stop after 2 or 3 minutes.
>>>>
>>>> According to the message, the stream after "pulsesrc
>>>> device=MySink.monitor" is too slow. But I don't understand why.
>>>>
>>>> Do you know where is the problem in this setup and how to solve
>>>> it ?
>>>> Thanks !
>>>> ++
>>>>
>>>> Jack
>>>>
>> Hello,
>>
>> have you tried with a more recent version of pulseaudio? 12.2 is
>> pretty
>> old. You should use 15.0 or current git.
>>
>> Regards
>>          Georg
>>