Save with 24 bits
I am searching for a way to save 24 bits values on an AIFF file i thought that keeping the 3 first bytes of an I32 should make it but it didn't work could anyone give me some clue ? thanks in advance -- Pascal Luquet Bien Entendu eMail : [EMAIL PROTECTED] www.BienEntendu.fr
Re: Save with 24 bits
Despite the name of your company, your question wasn't well understood. :) i should be specialized in intelligibility ... I have to apply my advices to myself :) But, are you sure you have the lowest 3 bytes? LV stores data in Hi/Low format for words and bytes in memory. You need the last 3 bytes. i don't think that keeping the lowest bytes would preserve the sign bit so i normalized my datas to a 32 bits value and keep the 3 highest bytes (i save on an AIFF file so don't have to swap bytes) just to be sure i tried to keep the lowest and had a similar result i think that my error comes from elsewhere so the diagram is : - wire my i32 array on a for loop - typecast each number to text - take the 3 first character - go outside the loop and write to file the array something should be wrong in it :(( -- Pascal Luquet Bien Entendu eMail : [EMAIL PROTECTED] www.BienEntendu.fr
Re: Save with 24 bits
thanks for the answers i tried to split the bytes with the split number function (and just taking the 3 first one) and it worked ! i don't know why i couldn't make it with concatenating bytes after a text conversion which should be equivalent ??? anyway it works ! -- Pascal Luquet Bien Entendu eMail : [EMAIL PROTECTED] www.BienEntendu.fr
Save with 24 bits
Pascal Despite the name of your company, your question wasn't well understood. :) But, are you sure you have the lowest 3 bytes? LV stores data in Hi/Low format for words and bytes in memory. You need the last 3 bytes. R. Glenn Givens P.Eng. Innovention Industries Inc. Burlington, ON, Canada www.innovin.com -- Subject: Save with 24 bits From: Infos - Bien Entendu [EMAIL PROTECTED] Date: Fri, 26 Mar 2004 00:06:37 +0100 I am searching for a way to save 24 bits values on an AIFF file i thought that keeping the 3 first bytes of an I32 should make it but it didn't work could anyone give me some clue ?
Re: Save with 24 bits
Infos - Bien Entendu [EMAIL PROTECTED] I am searching for a way to save 24 bits values on an AIFF file i thought that keeping the 3 first bytes of an I32 should make it but it didn't work could anyone give me some clue ? Since LabVIEW streams data always in big endian format (flatten to string, typecast or stream to disk) you will probably have to actually keep the last 3 bytes instead of the first 3. Rolf Kalbermatter CIT Engineering Nederland BVtel: +31 (070) 415 9190 Treubstraat 7H fax: +31 (070) 415 9191 2288 EG Rijswijkhttp://www.citengineering.com Netherlands mailto:[EMAIL PROTECTED]
Re: Save with 24 bits
Infos - Bien Entendu [EMAIL PROTECTED] wrote: i tried to split the bytes with the split number function (and just taking the 3 first one) and it worked ! i don't know why i couldn't make it with concatenating bytes after a text conversion which should be equivalent ??? No, it isn't! LabVIEWs flattened (typecast is also flattened) stream format is ALWAYS in big endian (aka most significant byte first). So just take the last three bytes instead of the first three of a four byte flattened I32 and make sure you append the bytes right. Just because Intel x86 uses little endian does not mean that is the right thing to do and LabVIEW as a multiplattform system had to standardize on something and they choose for the standard of almost all other CPUs including the one LabVIEW originated from and this is also the prefered network byte ordering for binary internet protocols. By the way I believe the Flatten Pixmap.vi, a subVI of Draw Unflattened Pixmap.vi in LabbVIEW 7 does more or less just what you need. Rolf Kalbermatter CIT Engineering Nederland BVtel: +31 (070) 415 9190 Treubstraat 7H fax: +31 (070) 415 9191 2288 EG Rijswijkhttp://www.citengineering.com Netherlands mailto:[EMAIL PROTECTED]
