Meant of periods and frames

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Meant of periods and frames

zappa-3
Hi people,
i'm a new user of jack at all, i'm italian => i don't speak english...

the question:
I don't understand what is the FRAMES/PERIOD and the PERIODS/BUFFER,
the definition in the man page of jackd is confused for me.
If possible i would want a theorist definition of it.
Example:
the sample rate is the frequency of sampling, the amount of samples take from the input;

frames/period and periods/buffer what is practically?

Sorry for my english...I hope is understood my problem

ciao
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Re: Meant of periods and frames

Florian Paul Schmidt-2
On Wednesday 15 August 2007, zappa wrote:

> Hi people,
> i'm a new user of jack at all, i'm italian => i don't speak english...
>
> the question:
> I don't understand what is the FRAMES/PERIOD and the PERIODS/BUFFER,
> the definition in the man page of jackd is confused for me.
> If possible i would want a theorist definition of it.
> Example:
> the sample rate is the frequency of sampling, the amount of samples take
>
> >from the input;
>
> frames/period and periods/buffer what is practically?
>
> Sorry for my english...I hope is understood my problem
>
> ciao

A frame of audio means 1 sample per channel.. E.g. if you have a 6-channel
signal and you process one frame of it you have processed one sample per
channel, 6 samples in total..

frames/period means frames per processing cycle (e.g. if you have 64
frames/period, then the buffersize per channel is 64 samples)

periods/buffer means how many periods are there [on windows a period is more
often called a "buffer"]. But in a typical double buffer scheme you have e.g.
two buffers combined into a single chunk of memory.. And in alsa speak, this
combined buffer is the "buffer" and the individual chunks in the buffers are
called periods [kinda, the terminology is a little squishy] So one period is
the first half of the buffer and the other period is the second half of the
buffer..

Flo

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Re: Meant of periods and frames

zappa-3
Thank's at all people,
in particular to FONS and FLORIAN for the detailed answers...

an ultimate question:
the signal is, e.g. the audio from my guitar attached at the input of the sound card?


2007/8/15, Florian Schmidt <[hidden email]>:
On Wednesday 15 August 2007, zappa wrote:

> Hi people,
> i'm a new user of jack at all, i'm italian => i don't speak english...
>
> the question:
> I don't understand what is the FRAMES/PERIOD and the PERIODS/BUFFER,
> the definition in the man page of jackd is confused for me.
> If possible i would want a theorist definition of it.
> Example:
> the sample rate is the frequency of sampling, the amount of samples take
>
> >from the input;
>
> frames/period and periods/buffer what is practically?
>
> Sorry for my english...I hope is understood my problem
>
> ciao

A frame of audio means 1 sample per channel.. E.g. if you have a 6-channel
signal and you process one frame of it you have processed one sample per
channel, 6 samples in total..

frames/period means frames per processing cycle (e.g. if you have 64
frames/period, then the buffersize per channel is 64 samples)

periods/buffer means how many periods are there [on windows a period is more
often called a "buffer"]. But in a typical double buffer scheme you have e.g.
two buffers combined into a single chunk of memory.. And in alsa speak, this
combined buffer is the "buffer" and the individual chunks in the buffers are
called periods [kinda, the terminology is a little squishy] So one period is
the first half of the buffer and the other period is the second half of the
buffer..

Flo

--
Palimm Palimm!
http://tapas.affenbande.org



--
Avete mai visto questi siti:
                                    Un bellissimo libro
http://www.lulu.com/content/702213
                                    Grafica Web
http://www.gorbolinanimator.altervista.org/index.html
                                    Musica
http://www.n-euro.it/
http://www.nomoneybluesband.it
http://www.myspace.com/thedimverge
                                  Informatica
http://es-lab.sc.unica.it/
http://www.slacky.eu
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