[sac-dev] byte order and swapping]

[Brian Savage]

I do not see the inherent advantage to going to a single byte order over 
allowing the sac program to read two different byte orders seamlessly.
What does that gain us ?

I would agree that SAC would need better documentation about the file 
formats and how certain operations are done.
Arthur would you be willing the document the file formats ?

Brian

Brian Savage wrote:
> I forgot to post to the list, but instead sent just to George.
> This is George's response to me.
> 
> Hi Brian -
> 
> On Monday, November 21, 2005, at 06:22 PM, Brian Savage wrote:
> 
>> It sounds like whatever we decide, the file formats (SAC and SGF) need 
>> to be documented.
> 
> 
> Amen.  But where?  There really isn't any "formal" SAC documentation
> any more, just broken links hanging around on the web and outdated
> pieces of paper that I have from old SAC manuals.  It would be valuable
> to have that roff source code (or whatever word processor LLNL used)
> available somewhere to build modern documentation from.
> 
>>
>> Concerning SGF.  If it has always written the files in the same way, 
>> why change it, make it the standard and document it.
> 
> 
> I'm not sure whether SAC always wrote files that way, but for as long
> as I've worked on it it has.  Still, that may not be the way that
> others like Arthur have written SGF files!  You are implicitly
> abandoning that community (which is probably small).
> 
>>
>> Concerning SAC.  If we decide all SAC files should be in big endian 
>> format (or even little) I am certain there will be an outcry from the 
>> community who uses Sac for processing and as a data file format.
> 
> 
> I'm not as certain as you are about this.  MacSAC users haven't
> complained about initially having to use sactosac with whatever
> heritage their data is.
> 
>> If we specify an endianness, we are introducing more bugs on linux 
>> machines as they will not be able to read current sac files which are 
>> written in little endian.
> 
> 
> Previous comments apply.  It is simple to modify sactosac to always
> write big-endian or little-endian.  Besides, SAC isn't an archival
> format, but a processing format.  One doesn't need to change anything
> until it is used.
> 
>>
>> Brian
>>
> 
> PS if you meant to post your response to the list, only I got it.  You
> can post this and get both if you want.
> 
> 
>      George Helffrich
> 
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