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Pierre Marc Dumuid | 1 Oct 2006 01:06
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Re: audio levels

20*log10(2^24) = 144.5 dB

though if you consider that 1 bit is taken up for the sign (i.e. + or - 
) then
20*log10(2^23) =  138.5 dB

( Note how 6 dB = 2x )

Pierre

Herman Robak wrote:
> On Sat, 30 Sep 2006 17:45:23 +0200, Pierre Marc Dumuid 
> <pierre.dumuid@...> wrote:
>
>> I discoved that this is for the meter only, and the minimum that 
>> cinelerra forces to -Inf dB is -40 dB!! See cinelerra/virtualanode.C 
>> which contains:
>> if(fade_value <= INFINITYGAIN) fade_value = 0;
>>
>> and INFINITYGAIN is defined in guicast/units.h as:
>> #define INFINITYGAIN -40
> ...
>> Prior to discussions with j6t on IRC, I had been considering setting 
>> the "INFINITYGAIN" as a property of the current project (thus 24 bit 
>> audio freaks could specify huge attenuations).
>
>  I would like to know, with reference to authoritative sources, what the
> canonical dynamic range for 24 bits sampling is.  Is it linear, like 
> 16bit?
>
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bugzilla | 1 Oct 2006 02:47
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[Bug 231] Interlacing mode unknown in batch rendering

http://bugs.cinelerra.org/show_bug.cgi?id=231

------- Additional Comments From e.conti@...  2006-10-01 02:47 -------
The bug is still there in the latest revision (r908)

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bugzilla | 1 Oct 2006 02:46
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[Bug 287] St9bad_alloc error

http://bugs.cinelerra.org/show_bug.cgi?id=287

------- Additional Comments From e.conti@...  2006-10-01 02:46 -------
Well, I don't think crashing is a normal behaviour for an application when
there's no more memory available on the system. Displaying an error message or
using swap would be better...

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Robert Persson | 1 Oct 2006 07:41
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Re: audio levels

On Sun, 2006-01-10 at 08:27 +0930, Pierre Marc Dumuid wrote:
> Current SVN should now be more workable (see thread as I actually 
> described the issue as being a fact of shared range), since automation 
> ranges are more sane.

I'm having trouble understanding some of the technical stuff here. Does
what you're saying mean that I should, with current SVN, actually be
able to fade smoothly to nothing (or at least to as close to nothing as
makes no difference)? Miha's workaround is probably as good as you can
get with the current cinelerra release, but it still sounds like there
would be an audible glitch between low volume and mute. Have I
misunderstood this? The fact is that I won't be able to make practical
use of cinelerra unless I have full control of the sound levels.

Appreciatively
Robert
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Gour | 1 Oct 2006 07:57

Re: The term "Insertion Point" is used throughout the manual..

On Sat, 2006-09-30 at 09:22 +0930, Pierre Marc Dumuid wrote:

> I propose replacing the occurence of "insertion point" throughout the 
> manual with "timeline cursor", or even just "cursor"

I agree. Having good documentation is as important as program's
features.

> I understand there are 3 manual locations, (HV's, SVN's, and wiki).  Do 
> other's agree with the change in terminology.

Is is possible that CV of Cinelerra ships with some complete manual -
(X)HTML or even PDF?

Wiki is nice tool for getting input from many users, but it would be,
imho, very nice to have program shipped with fine user's manual instead
of forcing users to look at different places which are (sometimes) not
in sync with the latest released version?

I do not know whether Twiki has such ability, but eg. when I was taking
look Drupal some months ago, I noticed ability to export content in
DocBook and then get (X)HTML and/or PDF.

Sincerely,
Gour
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Miha Kitič | 1 Oct 2006 09:10

Re: audio levels

Citing Pierre:

"At the moment if you drag to -40 dB you force to -Inf dB."

If that is true then you should have little trouble even without
using mute. (At least as far as I understand it).

There is however a discussion going on to place the lowest
level at -96dB in the future. This is logical, because most of us
use 16bit sound (same as CD player).

16bit -> 2^16 = 65536

Which means that there is exactly 65536 possible levels
that sound signal can occupy. But because 1 bit is used
for the sign (+ or -) we can actually only use one half,
32768 levels. 

To put it in simple words - to make the loudest noise
completely silent, you must divide it with more than 32768
in order to make it 0.

Now let us put it into decibels:

x[dB] = 20log y

if y = 32768 then

x[db] = 20log (32768) = 20 * 4,515 = 90,3
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Pierre Marc Dumuid | 1 Oct 2006 09:58
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Re: The term "Insertion Point" is used throughout the manual..

There is already docs distributed with the SVN sources (look in the doc 
directory).
Would be better if non-coder's could tackle the documentation area.

Pierre

Gour wrote:
> On Sat, 2006-09-30 at 09:22 +0930, Pierre Marc Dumuid wrote:
>
>
>   
>> I propose replacing the occurence of "insertion point" throughout the 
>> manual with "timeline cursor", or even just "cursor"
>>     
>
> I agree. Having good documentation is as important as program's
> features.
>
>
>   
>> I understand there are 3 manual locations, (HV's, SVN's, and wiki).  Do 
>> other's agree with the change in terminology.
>>     
>
> Is is possible that CV of Cinelerra ships with some complete manual -
> (X)HTML or even PDF?
>
>
> Wiki is nice tool for getting input from many users, but it would be,
> imho, very nice to have program shipped with fine user's manual instead
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Pierre Marc Dumuid | 1 Oct 2006 10:09
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Re: audio levels


> 16bit -> 2^16 = 65536
>
> Which means that there is exactly 65536 possible levels
> that sound signal can occupy. But because 1 bit is used
> for the sign (+ or -) we can actually only use one half,
> 32768 levels. 
>
> To put it in simple words - to make the loudest noise
> completely silent, you must divide it with more than 32768
> in order to make it 0.
>   
hmm, thinking about it now, you need to divide it by 96 dB to get [32768 
-32768] to go to [0.5 -0.5] which would round down to zero.  Dividing by 
90 dB would get to [1 -1].  Going with 96 dB is probably the go (and 
people recognise that number).
> But if this will be applied, your keyframes set to -40dB may be heard.
> (-40dB = 100  --->  32768 / 100 = 327,68)
> Of course things now work in such a way (according to Pierre), that any
> sound divided by 100 or more is automatically muted (how this is
> realized, I don't know).
>   
It is realize by lines:

        if(fade_value <= INFINITYGAIN)
            value = 0;
        else
            value = DB::fromdb(fade_value);

in cinelerra/virtualanode.C  where INFINITYGAIN is defined in units.h as
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Miha Kitič | 1 Oct 2006 11:12

Re: audio levels

So Robert, if my understanding of C is correct...

When you set volume to or bellow -40dB
then mute is forced automatically. And this my
possible cause glitch. If this is an issue for you then
you have one of the several alternatives:

1. Find a version of cinelerra that doesn't force mute

2. Find another Video editing application

3. Wait for -96dB to be implemented or

4. Invoke the power of OpenSource...
Which basicaly means to get Cinelerra's source and

1. either set INFINITYGAIN units.h as -96 or
2. Comment the folowing lines

#        if(fade_value <= INFINITYGAIN)
#            value = 0;
#        else
	      value = DB::fromdb(fade_value);

Then recompile Cinelerra.
Then you can set any value of fade and have
completely smooth transition down to 0 (in theory of course).

All the best!
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bugzilla | 1 Oct 2006 12:24
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[Bug 327] Fade level not correctly updated on the slider bar

http://bugs.cinelerra.org/show_bug.cgi?id=327

------- Additional Comments From e.conti@...  2006-10-01 12:24 -------
I meant "the slider (on the LEFT of each track)".

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Gmane