es1371.o sound module on a IBM405 gp walnut

2 messages, 2 authors, 2001-03-19 · open the first message on its own page

es1371.o sound module on a IBM405 gp walnut

From: Ralph Blach <hidden>
Date: 2001-03-18 16:32:32

I am trying to get an es1371. sound module working on an IBM405 walunt
developement kit.  8 bit sound works ok
but 16 bit sound sounds like noise.  Will this driver have to be made
Endian  aware?

Thanks in advance

--
Ralph "Chip" Blach
KF4WBK
Chapel Hill, North Carolina


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Re: es1371.o sound module on a IBM405 gp walnut

From: David Blythe <hidden>
Date: 2001-03-19 04:58:06

Ralph Blach wrote:
I am trying to get an es1371. sound module working on an IBM405 walunt
developement kit.  8 bit sound works ok
but 16 bit sound sounds like noise.  Will this driver have to be made
Endian  aware?
Yes and no.  A lot of the player programs are not very endian savy.
Typically what I have seen happen on bigendian ppc is that either the
player asks for AFMT_S16_LE  but really sends  AFMT_S16_BE samples and
you get noise (sox/play does this but I worked on a patch for this with
Chris Bagwell so hopefully it is available now) or it asks for
AFMT_S16_BE samples and the driver doesn't support this and the request
format ioctl defaults to AFMT_U8 instead and the player ends up sending
8 bit samples instead of 16, because it didn't also do a query for
AFMT_S16_LE.  An earlier version of madplay was doing this (I tooked the
easy way out and had our sound driver return AFMT_S16_LE as the default
format to get around this, but the query algorithm in madplay could be
made better).  It looks like the es1371 driver defaults to AFMT_U8.
	david

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