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Date: Tue, 17 Feb 2009 14:00:25 +0100 From: Stefan Klug Subject: [SDL] Possible bug, paused audio playing garbage On my WinCE device a paused audio device plays random garbage. This might also be the issue in the thread "sound cracks with SDL_mixer and AUDIO_S16LSB" I don't have that much knowledge of the SDL audio part, but the attached patch fixes it for me, and collapses two redundant ifs. I'm not sure if this is the correct way to fix this. Shouldn't the complete stream conversion part of the RunAudio loop be dependent on the paused property of the device? (not only the call to (*fill)(udata, istream, istream_len). Anyways. Would be great if the patch or a fix could find its way to SVN ;-) Cheers Stefan
author Sam Lantinga <slouken@libsdl.org>
date Mon, 23 Mar 2009 05:21:40 +0000
parents 99210400e8b9
children efb79807afe1
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/*
	m68k assembly mix routines

	Patrice Mandin
*/

#if defined(__M68000__) && defined(__GNUC__)
void
SDL_MixAudio_m68k_U8(char *dst, char *src, long len, long volume, char *mix8)
{
    __asm__ __volatile__("tstl	%2\n" "	beqs	stoploop_u8\n" "mixloop_u8:\n"
                         /* Mix a sample */
                         "	moveq	#0,%%d0\n" "	moveq	#0,%%d1\n" "	moveb	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	sub	#128,%%d0\n"    /* d0 -= 128 */
                         "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	moveb	%0@,%%d1\n"     /* d1 = *dst */
                         "	asr	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	add	#128,%%d0\n"    /* d0 += 128 */
                         "	add	%%d1,%%d0\n"
                         "	moveb	%4@(%%d0:w),%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_u8\n" "stoploop_u8:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8):  /* clobbered registers */
                         "d0", "d1", "cc", "memory");
}

void
SDL_MixAudio_m68k_S8(char *dst, char *src, long len, long volume)
{
    __asm__ __volatile__("tstl	%2\n"
                         "	beqs	stoploop_s8\n"
                         "	moveq	#-128,%%d2\n"
                         "	moveq	#127,%%d3\n" "mixloop_s8:\n"
                         /* Mix a sample */
                         "	moveq	#0,%%d0\n" "	moveq	#0,%%d1\n" "	moveb	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	moveb	%0@,%%d1\n"     /* d1 = *dst */
                         "	asr	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	add	%%d1,%%d0\n"
                         "	cmp	%%d2,%%d0\n"
                         "	bges	lower_limit_s8\n"
                         "	move	%%d2,%%d0\n"
                         "lower_limit_s8:\n"
                         "	cmp	%%d3,%%d0\n"
                         "	bles	upper_limit_s8\n"
                         "	move	%%d3,%%d0\n"
                         "upper_limit_s8:\n" "	moveb	%%d0,%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_s8\n" "stoploop_s8:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
                         "d0", "d1", "d2", "d3", "cc", "memory");
}

void
SDL_MixAudio_m68k_S16MSB(short *dst, short *src, long len, long volume)
{
    __asm__ __volatile__("tstl	%2\n"
                         "	beqs	stoploop_s16msb\n"
                         "	movel	#-32768,%%d2\n"
                         "	movel	#32767,%%d3\n"
                         "	lsrl	#1,%2\n" "mixloop_s16msb:\n"
                         /* Mix a sample */
                         "	move	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	move	%0@,%%d1\n"     /* d1 = *dst */
                         "	extl	%%d1\n" /* extend d1 to 32 bits */
                         "	asrl	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	addl	%%d1,%%d0\n"
                         "	cmpl	%%d2,%%d0\n"
                         "	bges	lower_limit_s16msb\n"
                         "	move	%%d2,%%d0\n"
                         "lower_limit_s16msb:\n"
                         "	cmpl	%%d3,%%d0\n"
                         "	bles	upper_limit_s16msb\n"
                         "	move	%%d3,%%d0\n"
                         "upper_limit_s16msb:\n" "	move	%%d0,%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_s16msb\n" "stoploop_s16msb:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
                         "d0", "d1", "d2", "d3", "cc", "memory");
}

void
SDL_MixAudio_m68k_S16LSB(short *dst, short *src, long len, long volume)
{
    __asm__ __volatile__("tstl	%2\n"
                         "	beqs	stoploop_s16lsb\n"
                         "	movel	#-32768,%%d2\n"
                         "	movel	#32767,%%d3\n"
                         "	lsrl	#1,%2\n" "mixloop_s16lsb:\n"
                         /* Mix a sample */
                         "	move	%1@+,%%d0\n"    /* d0 = *src++ */
                         "	rorw	#8,%%d0\n" "	muls	%3,%%d0\n"      /* d0 *= volume (0<=volume<=128) */
                         "	move	%0@,%%d1\n"     /* d1 = *dst */
                         "	rorw	#8,%%d1\n" "	extl	%%d1\n" /* extend d1 to 32 bits */
                         "	asrl	#7,%%d0\n"      /* d0 /= 128 (SDL_MIX_MAXVOLUME) */
                         "	addl	%%d1,%%d0\n"
                         "	cmpl	%%d2,%%d0\n"
                         "	bges	lower_limit_s16lsb\n"
                         "	move	%%d2,%%d0\n"
                         "lower_limit_s16lsb:\n"
                         "	cmpl	%%d3,%%d0\n"
                         "	bles	upper_limit_s16lsb\n"
                         "	move	%%d3,%%d0\n"
                         "upper_limit_s16lsb:\n"
                         "	rorw	#8,%%d0\n" "	move	%%d0,%0@+\n"
                         /* Loop till done */
                         "	subql	#1,%2\n" "	bhis	mixloop_s16lsb\n" "stoploop_s16lsb:\n": /* no return value */
                         :      /* input */
                         "a"(dst), "a"(src), "d"(len), "d"(volume):     /* clobbered registers */
                         "d0", "d1", "d2", "d3", "cc", "memory");
}
#endif
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