[pulseaudio-discuss] [PATCH 0/8] Rate update fixes

[David Henningsson]

On 08/12/2013 12:34 PM, Tanu Kaskinen wrote:
> On Mon, 2013-08-12 at 09:34 +0200, David Henningsson wrote:
>> On 08/09/2013 08:57 AM, Tanu Kaskinen wrote:
>>> While investigating a bug[1], I found several bugs in the rate update
>>> code related to monitor sources. This should make things work
>>> properly for non-passthrough streams. Things are probably still broken
>>> for passthrough streams, but that's a complex topic that I don't want
>>> to spend time on at the moment.
>>
>> And trying to understand the last patches, what is the scenario? You
>> start recording the monitor source at 48 kHz while the sink is silent,
>> and then sink starts playing back a 44.1 kHz stream. What happens?
> 
> The scenario for "source: Don't update the monitor source rate, if the
> sink is running" is that something is playing to the sink at 44.1 kHz,
> and then something connects to the monitor source at 48 kHz. What
> happens (without the patch) is that the monitor source rate changes, and
> the client thinks it's getting 48 kHz audio, while in reality the rate
> is 44.1 kHz.
> 
> The scenario for "source: When updating a monitor source's rate, update
> the sink rate too" is that nothing is playing and the device is
> configured to 44.1 kHz and then something connects to the monitor
> source. Again, without the patch, the monitor source changes rate to 48
> kHz, so that's what the client thinks it's getting. In reality, the sink
> runs at 44.1 kHz, so that's what's being fed to the monitor source too.
> At this point it's all silence, so it doesn't matter that much (the
> recorded audio length is just surprisingly short) but if something
> starts to play to the sink, that audio will be 44.1 kHz, while the
> client thinks it's 48 kHz.
> 
> I'll add something to the commit messages to make this clearer.
> 

So what happens instead in the scenarios above, *with* the patch? Is a
resampler automatically inserted on the source output?


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic