[pulseaudio-discuss] How to control latency with CLI?

[Steven Wawryk]

>>>       * Whenever this source-output calls this function (outputting
>>> "rsmplr=30, flags=0x4" in the while loop), there seems to always be
>>> another immediately following call (outputting "limit=2304000bytes (1)"
>>> at the start of the function) with the*large*  2304000bytes limit that
>>> never executes the following "if" and "while" statement bodies.  Hence
>>> it never calls o->push().
>> The limit is the source's max rewind amount, and I see a bug related to
>> that in module-remap-source (I wouldn't be surprised if it's in other
>> filter sources too). The remap source max rewind is supposed to mirror
>> the master source max rewind, but when the master source max rewind
>> changes, the remap source max rewind isn't updated. The remap source
>> should set the update_max_rewind source output callback, and use the
>> callback to update its own max rewind to match the master source.
>>
>> If the max rewind isn't updated, as is now the case, it will stay at
>> whatever value the master source had when the remap source got loaded.
>> At that time there are likely no streams that are forcing lower
>> latency, leading to a too high max rewind value when a low latency
>> stream appears.
>
> This seems to be confirmed by the fact that the only max_rewind 
> changes (other than after creation) happen in the module-rtp-send module.
>
> Given the platform configuration difficulties I have, can you think of 
> a CLI-based work-around for this?


Further confirmation: I removed the module-remap-source load from the 
CLI script, then loaded it manually *after* everything else had started 
up, and the latency has dropped from 4-5minutes to about 1second.  I 
guess this hints at a CLI work-around, but I still need to get the 
latency down if I can.

Thanks for the help Tanu.

Steve