[Jack-Devel] jack_get_sample_rate

[Kjetil Matheussen]

(Added jack-devel mailing list again)

Yes, I would think that jack_get_sample_rate is the only way to know the
sample rate.

If qjackctl shows different information it must be a bug in qjackctl.
However, I noticed that your jack version is 7 years old. If qjackctl
displayed
the wrong information in 2009, it's probably been fixed now.


On Tue, Dec 13, 2016 at 11:00 AM, ROBERT WOLF <
robert.wolf at hercsmusicsystems.com.au> wrote:

> In this case I would understand as follows:
> 1. Starting JACK server with 22050 Hz sampling rate is more-or-less a
> recommendation only.
> 2. The way to know the sampling rate for sure is to call
> *jack_get_sample_rate*.
> 3. I can testify that the actual sampling rate is the same as reported by
> *jack_get_sampling_rate*, because if it was not then my program would
> sound differently.
>
> If my understanding is correct then I consider the case closed!
>
> Cheers,
>
> Robert
>
>
> On 13/12/16 20:13, Kjetil Matheussen wrote:
>
> (putting back jack-devel again)
>
> It just says that it configures for 22050Hz, it doesn't say whether it
> succeeded.
> So things seems to work as it should.
>
>
>
> On Tue, Dec 13, 2016 at 10:38 AM, ROBERT WOLF <robert.wolf@
> hercsmusicsystems.com.au> wrote:
>
>> Two programs show this information:
>>
>> 1. QJackCtl.
>> 2. When I run my own program *AND* jack server is not running, *THEN*
>> for some reason the jack server gets started (apparently using the command
>> stored in .jackdrc file) and I see the following printout:
>>
>> jackd 0.122.0
>> Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn
>> and others.
>> jackd comes with ABSOLUTELY NO WARRANTY
>> This is free software, and you are welcome to redistribute it
>> under certain conditions; see the file COPYING for details
>>
>> JACK compiled with System V SHM support.
>> loading driver ..
>> apparent rate = 22050
>> creating alsa driver ... hw:PCH,0|hw:PCH,0|1024|2|22050
>> |0|0|nomon|swmeter|-|32bit
>> ALSA lib conf.c:4578:(parse_args) Unknown parameter 1
>> ALSA lib conf.c:4711:(snd_config_expand) Parse arguments error: No such
>> file or directory
>> ALSA lib control.c:953:(snd_ctl_open_noupdate) Invalid CTL hw:PCH,0
>> control open "hw:PCH,0" (No such file or directory)
>> configuring for 22050Hz, period = 1024 frames (46.4 ms), buffer = 2
>> periods
>> ALSA: final selected sample format for capture: 32bit integer
>> little-endian
>> ALSA: use 2 periods for capture
>> ALSA: final selected sample format for playback: 32bit integer
>> little-endian
>> ALSA: use 2 periods for playback
>>
>>
>>
>> *HOWEVER!!!! **jack_get_sample_rate(...);* still reports *44100*.
>>
>> How intriguing?!
>>
>>
>>
>> On 13/12/16 19:53, Kjetil Matheussen wrote:
>>
>> Which program shows this window?
>>
>> (added jack-devel mailing list back to the conversation)
>>
>> On Tue, Dec 13, 2016 at 8:35 AM, ROBERT WOLF <
>> robert.wolf at hercsmusicsystems.com.au> wrote:
>>
>>> There is a window with messages and it says this:
>>>
>>> configuring for 22050Hz, period = 1024 frames (46.4 ms), buffer = 2
>>> periods
>>>
>>>
>>> On 13/12/16 11:09, Kjetil Matheussen wrote:
>>>
>>>
>>>
>>> On Mon, Dec 12, 2016 at 7:33 AM, ROBERT WOLF <
>>> robert.wolf at hercsmusicsystems.com.au> wrote:
>>>
>>>> Dear All,
>>>>
>>>> According to the documentation *jack_get_sample_rate* reports the
>>>> sample rate as was used by *jackd*.
>>>> This does not happen in my case.
>>>> I start *jackd* using different sampling rates (i.e. 22050, ect.).
>>>> JACK reports that it does indeed uses the selected sampling rate.
>>>>
>>>> But *jack_get_sample_rate* always returns 44100.
>>>>
>>>> Why?
>>>>
>>>>
>>> How did Jack report that it used the selected sampling rate?
>>> I.e. where did you read that?
>>>
>>>
>>>
>>>
>>
>>
>
>
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