sampling rate detection with jack?

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sampling rate detection with jack?

Bearcat M. Şándor
Alright, i took a walk and realized that this is a ignorant question.
Jack has a fixed sampling rate so it would not be able to detect how
many channels, or at what bitrate or sampling rate a given stream was.

So, i guess i'll change the question to "is there a way to do this?"

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Re: sampling rate detection with jack?

Paul Davis
2010/9/23 Bearcat M. <[hidden email]>:
> Alright, i took a walk and realized that this is a ignorant question.
> Jack has a fixed sampling rate so it would not be able to detect how
> many channels, or at what bitrate or sampling rate a given stream was.
>
> So, i guess i'll change the question to "is there a way to do this?"

no. this is why every audio file format except "raw" has a header file
to describe precisely this information (and more).
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Re: sampling rate detection with jack?

Bearcat M. Şándor
On Thu, 2010-09-23 at 21:17 -0400, Paul Davis wrote:
> 2010/9/23 Bearcat M. <[hidden email]>:
> > Alright, i took a walk and realized that this is a ignorant question.
> > Jack has a fixed sampling rate so it would not be able to detect how
> > many channels, or at what bitrate or sampling rate a given stream was.
> >
> > So, i guess i'll change the question to "is there a way to do this?"
>
> no. this is why every audio file format except "raw" has a header file
> to describe precisely this information (and more).

I wish i had a header file. What i'm trying to do is capture the audio
from a dualdisc through jack, from a media player and record it into
adour (which i am just starting to play with). I can't play it through
mplayer (which would tell me) as it's only accessible through a dvd
menu. I'm using totem instead. I can't find any listing on-line or
off-line what the sample rate of the pcm data on the disc is. I'm
wondering what to set up the ardour session as to keep it the same as
what's on the disk.  I doubt that it's 192 kHz, but it could be 48, 96
or 88.2.

Thanks,
Bearcat

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Re: sampling rate detection with jack?

Fons Adriaensen-2
On Fri, Sep 24, 2010 at 12:58:50AM -0600, Bearcat M. Şandor wrote:

> I wish i had a header file. What i'm trying to do is capture the audio
> from a dualdisc through jack, from a media player and record it into
> adour (which i am just starting to play with). I can't play it through
> mplayer (which would tell me) as it's only accessible through a dvd
> menu. I'm using totem instead. I can't find any listing on-line or
> off-line what the sample rate of the pcm data on the disc is. I'm
> wondering what to set up the ardour session as to keep it the same as
> what's on the disk.  I doubt that it's 192 kHz, but it could be 48, 96
> or 88.2.

If this is a dvd you should be able to mount it and look at the files
directly. If it's PCM the files would be standard types you canc check
with sndfile-info, if they are perceptually coded there is little point
in preserving the original sample rates. Any names, extensions, .... ?

Anyway if you can listen to it you can record it as well, in the worst
case just connect a sound card to the same signals that are feeding your
amplifier, record at 48 kHz.

Ciao,

--
FA

There are three of them, and Alleline.

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Re: sampling rate detection with jack?

Jan Weil
In reply to this post by Bearcat M. Şándor
Zitat von "Bearcat M. ?andor" <[hidden email]>:

> On Thu, 2010-09-23 at 21:17 -0400, Paul Davis wrote:
>> 2010/9/23 Bearcat M. <[hidden email]>:
>> > Alright, i took a walk and realized that this is a ignorant question.
>> > Jack has a fixed sampling rate so it would not be able to detect how
>> > many channels, or at what bitrate or sampling rate a given stream was.
>> >
>> > So, i guess i'll change the question to "is there a way to do this?"
>>
>> no. this is why every audio file format except "raw" has a header file
>> to describe precisely this information (and more).
>
> I wish i had a header file. What i'm trying to do is capture the audio
> from a dualdisc through jack, from a media player and record it into
> adour (which i am just starting to play with). I can't play it through
> mplayer (which would tell me) as it's only accessible through a dvd
> menu. I'm using totem instead. I can't find any listing on-line or
> off-line what the sample rate of the pcm data on the disc is. I'm
> wondering what to set up the ardour session as to keep it the same as
> what's on the disk.  I doubt that it's 192 kHz, but it could be 48, 96
> or 88.2.

If I remember correctly Audacity features some intelligence to "guess"  
the sampling rate and bit depth of headerless pcm data.

Maybe that helps

Jan
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Re: sampling rate detection with jack?

Bearcat M. Şándor
In reply to this post by Fons Adriaensen-2
On Fri, 2010-09-24 at 09:59 +0200, [hidden email] wrote:

> On Fri, Sep 24, 2010 at 12:58:50AM -0600, Bearcat M. Şandor wrote:
>
> > I wish i had a header file. What i'm trying to do is capture the audio
> > from a dualdisc through jack, from a media player and record it into
> > adour (which i am just starting to play with). I can't play it through
> > mplayer (which would tell me) as it's only accessible through a dvd
> > menu. I'm using totem instead. I can't find any listing on-line or
> > off-line what the sample rate of the pcm data on the disc is. I'm
> > wondering what to set up the ardour session as to keep it the same as
> > what's on the disk.  I doubt that it's 192 kHz, but it could be 48, 96
> > or 88.2.
>
> If this is a dvd you should be able to mount it and look at the files
> directly. If it's PCM the files would be standard types you canc check
> with sndfile-info, if they are perceptually coded there is little point
> in preserving the original sample rates. Any names, extensions, .... ?
>
It's a mounted Dualdisc that contains files in VIDEO_TS and nothing in
AUTIO_TS.  The files in VIDEO_TS are the usual ones (VOB, IFO, BUP).
Playing each in mplayer yields me a window for most of them that quickly
dissapears.  Opening it up in totem (which can read DVD menus) allows me
to select "PCM Stereo" and play it with gst_jack. Then i can route it
into audor.  However, i don't know which file totem is playing when i
select that, because playing them all via mplayer does not result in the
same lyrics+PCM sound. When playing the PCM track i get lyrics on the
screen, so it's PCM embedded in video which is probably why mplayer
can't figure it out.

I'll play with sndfile-info and see what that yields.

> Anyway if you can listen to it you can record it as well, in the worst
> case just connect a sound card to the same signals that are feeding your
> amplifier, record at 48 kHz.
>
> Ciao,
>
If worst comes to worst i'll just guess 96k, but it would be nice to
know how many channels are there too (i currently have a stereo set up,
but would want to record as many channels as are there for future use.

Thanks,

Bearcat

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Re: sampling rate detection with jack? [solved]

Bearcat M. Şándor
On Sat, 2010-09-25 at 14:13 -0600, Bearcat M. Şandor wrote:

> On Fri, 2010-09-24 at 09:59 +0200, [hidden email] wrote:
> > On Fri, Sep 24, 2010 at 12:58:50AM -0600, Bearcat M. Şandor wrote:
> >
> > > I wish i had a header file. What i'm trying to do is capture the audio
> > > from a dualdisc through jack, from a media player and record it into
> > > adour (which i am just starting to play with). I can't play it through
> > > mplayer (which would tell me) as it's only accessible through a dvd
> > > menu. I'm using totem instead. I can't find any listing on-line or
> > > off-line what the sample rate of the pcm data on the disc is. I'm
> > > wondering what to set up the ardour session as to keep it the same as
> > > what's on the disk.  I doubt that it's 192 kHz, but it could be 48, 96
> > > or 88.2.
> >
> > If this is a dvd you should be able to mount it and look at the files
> > directly. If it's PCM the files would be standard types you canc check
> > with sndfile-info, if they are perceptually coded there is little point
> > in preserving the original sample rates. Any names, extensions, .... ?
> >
> It's a mounted Dualdisc that contains files in VIDEO_TS and nothing in
> AUTIO_TS.  The files in VIDEO_TS are the usual ones (VOB, IFO, BUP).
> Playing each in mplayer yields me a window for most of them that quickly
> dissapears.  Opening it up in totem (which can read DVD menus) allows me
> to select "PCM Stereo" and play it with gst_jack. Then i can route it
> into audor.  However, i don't know which file totem is playing when i
> select that, because playing them all via mplayer does not result in the
> same lyrics+PCM sound. When playing the PCM track i get lyrics on the
> screen, so it's PCM embedded in video which is probably why mplayer
> can't figure it out.
>
> I'll play with sndfile-info and see what that yields.
>
> > Anyway if you can listen to it you can record it as well, in the worst
> > case just connect a sound card to the same signals that are feeding your
> > amplifier, record at 48 kHz.
> >
> > Ciao,
> >
> If worst comes to worst i'll just guess 96k, but it would be nice to
> know how many channels are there too (i currently have a stereo set up,
> but would want to record as many channels as are there for future use.
>
> Thanks,
>
> Bearcat
>
> _______________________________________________
> Jack-Devel mailing list
> [hidden email]
> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org

i got it worked out. dvd::rip will give you a catalog of what exactly is
on the disc/iso at what bit rates. After that i installed jack-capture
and all went well.  Im proud to say that i made the start and cut off
points with enough precision that cddb read the tracks correctly as the
original disc.

Thanks for all the suggestions and pointers. They helped a lot.

Bearcat

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