- the data in the read buffer, that was put there by the hardware,

  may not be the same sample size as what userland is to receive.
  account for the discrepency between the sample sizes when comparing
  how much to copy out with what userland expects.

- only copy out the part of the buffer that is in the format userland
  expects.

emu(4) can now record with all encodings it claims to be able to.
that is, dd if=/dev/audio of=foo does as audio(4) says (monaural
mu-law) and does it correctly.

AFAIKS, the only other driver that sets a read factor is uaudio(4),
and that depends on what the hardware supports.

tested on i386, amd64 and sgi with 3 different emu(4) cards

1 files changed, 5 insertions, 4 deletions

diff --git a/sys/dev/audio.c b/sys/dev/audio.c
index 64e28fa0137..40e4112abd7 100644
--- a/sys/dev/audio.c
+++ b/sys/dev/audio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: audio.c,v 1.64 2007/07/14 02:31:33 jakemsr Exp $	*/
+/*	$OpenBSD: audio.c,v 1.65 2007/07/17 10:35:10 jakemsr Exp $	*/
 /*	$NetBSD: audio.c,v 1.119 1999/11/09 16:50:47 augustss Exp $	*/
 
 /*
@@ -1237,13 +1237,14 @@ audio_read(dev_t dev, struct uio *uio, int ioflag)
 		if (n < cc)
 			cc = n;	/* don't read beyond end of buffer */
 
-		if (uio->uio_resid < cc)
-			cc = uio->uio_resid; /* and no more than we want */
+		 /* and no more than we want */
+		if (uio->uio_resid < cc / sc->sc_rparams.factor)
+			cc = uio->uio_resid * sc->sc_rparams.factor;
 
 		if (sc->sc_rparams.sw_code)
 			sc->sc_rparams.sw_code(sc->hw_hdl, outp, cc);
 		DPRINTFN(1,("audio_read: outp=%p, cc=%d\n", outp, cc));
-		error = uiomove(outp, cc, uio);
+		error = uiomove(outp, cc / sc->sc_rparams.factor, uio);
 		used -= cc;
 		outp += cc;
 		if (outp >= cb->end)