From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martijn Sipkema" Subject: Re: more sample formats? too little place left. Date: Mon, 3 Jun 2002 16:00:25 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <002201c20b0f$6b7e75e0$0400a8c0@martijn> References: <007e01c208d2$31938120$0400a8c0@martijn> Reply-To: "Martijn Sipkema" Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Takashi Iwai Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org > > > it seems that USB audio supports 24 bit sample in 3 bytes format. > > > and additionally i've found there are 20bit and 18bit sample formats. > > > the world is large... > > > > > > an arising problem is that the number of formats is limited to 32. > > > already 26 format types are used. the rest are only 6, and not enough > > > if we put BE/LE and signed/unsigned for new formats, too. > > > > > > how can we solve this? extend to 64bit? no, it has too overhead. > > > add a new field for special formats? > > > > > > perhaps we don't need all of them for such special formats. > > > there are no unsigned types for such formats. > > > but anyway the left resource is too small. > > > > are formats currently a bit in a 'supported formats' flag? > > yes. > > the problem is that the bitmask is defined as unsigned int, und > limitied to 31 bits. > > if it's only in alsa driver, then it wouldn't be serious. > but apparently alsa-lib defines also mask as an integer. > theoretically, redefining this type won't cause any compatibility > problems, though, as long as you link alsa-lib dynamically. > (it's an obvious advantage of "complicated" alsa api :) perhaps not using a bitmask, but having two ioctls, one giving the number of supported formats, the other returning the format description taking an index argument, not unlike the EASI interface , might be better. --martijn _______________________________________________________________ Don't miss the 2002 Sprint PCS Application Developer's Conference August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm