From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Courtier-Dutton Subject: Re: Mixer volume dB settings. Date: Sun, 31 Jul 2005 16:07:22 +0100 Message-ID: <42ECE92A.6070609@superbug.demon.co.uk> References: <42ECC061.9070104@superbug.demon.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Jaroslav Kysela Cc: alsa-devel List-Id: alsa-devel@alsa-project.org Jaroslav Kysela wrote: > On Sun, 31 Jul 2005, James Courtier-Dutton wrote: > > >>Hi, >> >>I am thinking of a method to provide dB volume setting with alsamixer. >>My suggestion is to add another variable to the mixer control structure. >>This variable will be an integer identifying the conversion function. If >>set to 0, no conversion function has been defined. If set to 1 or above, >>use a lookup table in alsa-lib to select the conversion function. The >>user land api would then be: snd_mixer_convert_hardware_to_db( >>hardware_value, conversion_function, &db_value); >>snd_mixer_convert_db_to_hardware( db_value, conversion_function, >>hardware_value ) >> >>The reason for this, is that it seems to me that only the hardware >>driver will have full knowledge of what the conversion function should >>be, and setting a simple integer for conversion_function_type would seem >>the simplest solution. >> >>The global conversion functions could then be defined in an alsa-lib >>config file. >> >>This would also allow the application to increase/decrease the hardware >>value, but display to the user the dB value. >> >>Any comments? > > > I already defined the interface in alsa-lib/include/mixer.h. Look for dB > functions there. > > Also, the skeleton of the new mixer with abstraction layer is quite > finished. I need only implement a first real code for one driver as > example and we can start adding the abstraction code for all cards. > > Jaroslav > Shall we pick a card we both have. I have a intel8x0 motherboard, and most creative cards. Do you have either of those? ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click