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From: Clemens Ladisch <clemens@ladisch.de>
To: Sergej Sawazki <ce3a@gmx.de>, alsa-devel@alsa-project.org
Subject: Re: ASoC: How to declare volume TLV dB scale?
Date: Fri, 12 Jun 2015 18:28:54 +0200	[thread overview]
Message-ID: <557B08C6.7030300@ladisch.de> (raw)
In-Reply-To: <trinity-71513ec1-9daf-4f51-b0b3-8df7a0e9a7ec-1434110572856@3capp-gmx-bs58>

Sergej Sawazki wrote:
> could someone please help me to understand the mixer controls TLV scale?
> What would be the DECLARE_TLV_DB_SCALE values for the following example?
>
> reg. value:  0    ..  0x3ff
> phys. value: 0dB  .. -128dB
> volume:      100% ..  0%(mute)

0% volume would be -∞ dB.

And how are the register values mapped between the min/max values?
Does 0x200 correspond to -64 dB, or 50 % of the sample value, or
50 % of the volume?

> What does TLV actually stand for?

Type-length-value.  It's an implementation detail.


Regards,
Clemens
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  reply	other threads:[~2015-06-12 16:29 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-12 12:02 ASoC: How to declare volume TLV dB scale? Sergej Sawazki
2015-06-12 16:28 ` Clemens Ladisch [this message]
2015-06-12 19:26   ` Sergej Sawazki
2015-06-12 19:47     ` Clemens Ladisch
2015-06-13  7:15       ` Takashi Iwai
2015-06-13 10:10         ` Sergej Sawazki
2015-06-13 10:29           ` Clemens Ladisch
2015-06-13 10:45             ` Sergej Sawazki

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