Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_MMX.c @ 4357:a10dac5858fe SDL-1.2
Recommendation from Lennart Poettering:
In ALSA_OpenAudio(): instead of setting period_size+n_periods OR
buffer_size I'd recommend copying the hwparams stuff before you do
this, then first try period_size+n_periods, and then apply it with
snd_pcm_hw_params() and check if that works. If it didn't you should
take the copy of hwparams and try setting buffer_size and apply that
via snd_pcm_hw_params() and check if that worked. And if that failed
too, then take the copy and don't apply neither period nor buffer
settings and see if that works.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 19 Oct 2009 02:23:21 +0000 |
| parents | a8e5b518e194 |
| children |
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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 Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr) This code is licensed under the LGPL (see COPYING for details) Assumes buffer size in bytes is a multiple of 16 Assumes SDL_MIX_MAXVOLUME = 128 */ /*********************************************** * Mixing for 16 bit signed buffers ***********************************************/ #if defined(SDL_BUGGY_MMX_MIXERS) /* buggy, so we're disabling them. --ryan. */ #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES) void SDL_MixAudio_MMX_S16(char* dst,char* src,unsigned int size,int volume) { __asm__ __volatile__ ( " movl %3,%%eax\n" /* eax = volume */ " movl %2,%%edx\n" /* edx = size */ " shrl $4,%%edx\n" /* process 16 bytes per iteration = 8 samples */ " jz .endS16\n" " pxor %%mm0,%%mm0\n" " movd %%eax,%%mm0\n" " movq %%mm0,%%mm1\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" /* mm0 = vol|vol|vol|vol */ ".align 8\n" " .mixloopS16:\n" " movq (%1),%%mm1\n" /* mm1 = a|b|c|d */ " movq %%mm1,%%mm2\n" /* mm2 = a|b|c|d */ " movq 8(%1),%%mm4\n" /* mm4 = e|f|g|h */ /* pré charger le buffer dst dans mm7 */ " movq (%0),%%mm7\n" /* mm7 = dst[0] */ /* multiplier par le volume */ " pmullw %%mm0,%%mm1\n" /* mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v) */ " pmulhw %%mm0,%%mm2\n" /* mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v) */ " movq %%mm4,%%mm5\n" /* mm5 = e|f|g|h */ " pmullw %%mm0,%%mm4\n" /* mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v) */ " pmulhw %%mm0,%%mm5\n" /* mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v) */ " movq %%mm1,%%mm3\n" /* mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v) */ " punpckhwd %%mm2,%%mm1\n" /* mm1 = a*v|b*v */ " movq %%mm4,%%mm6\n" /* mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v) */ " punpcklwd %%mm2,%%mm3\n" /* mm3 = c*v|d*v */ " punpckhwd %%mm5,%%mm4\n" /* mm4 = e*f|f*v */ " punpcklwd %%mm5,%%mm6\n" /* mm6 = g*v|h*v */ /* pré charger le buffer dst dans mm5 */ " movq 8(%0),%%mm5\n" /* mm5 = dst[1] */ /* diviser par 128 */ " psrad $7,%%mm1\n" /* mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME */ " add $16,%1\n" " psrad $7,%%mm3\n" /* mm3 = c*v/128|d*v/128 */ " psrad $7,%%mm4\n" /* mm4 = e*v/128|f*v/128 */ /* mm1 = le sample avec le volume modifié */ " packssdw %%mm1,%%mm3\n" /* mm3 = s(a*v|b*v|c*v|d*v) */ " psrad $7,%%mm6\n" /* mm6= g*v/128|h*v/128 */ " paddsw %%mm7,%%mm3\n" /* mm3 = adjust_volume(src)+dst */ /* mm4 = le sample avec le volume modifié */ " packssdw %%mm4,%%mm6\n" /* mm6 = s(e*v|f*v|g*v|h*v) */ " movq %%mm3,(%0)\n" " paddsw %%mm5,%%mm6\n" /* mm6 = adjust_volume(src)+dst */ " movq %%mm6,8(%0)\n" " add $16,%0\n" " dec %%edx\n" " jnz .mixloopS16\n" " emms\n" ".endS16:\n" : : "r" (dst), "r"(src),"m"(size), "m"(volume) : "eax","edx","memory" ); } /*////////////////////////////////////////////// */ /* Mixing for 8 bit signed buffers */ /*////////////////////////////////////////////// */ void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume) { __asm__ __volatile__ ( " movl %3,%%eax\n" /* eax = volume */ " movd %%eax,%%mm0\n" " movq %%mm0,%%mm1\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " psllq $16,%%mm0\n" " por %%mm1,%%mm0\n" " movl %2,%%edx\n" /* edx = size */ " shr $3,%%edx\n" /* process 8 bytes per iteration = 8 samples */ " cmp $0,%%edx\n" " je .endS8\n" ".align 8\n" " .mixloopS8:\n" " pxor %%mm2,%%mm2\n" /* mm2 = 0 */ " movq (%1),%%mm1\n" /* mm1 = a|b|c|d|e|f|g|h */ " movq %%mm1,%%mm3\n" /* mm3 = a|b|c|d|e|f|g|h */ /* on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0 */ " pcmpgtb %%mm1,%%mm2\n" /* mm2 = 11111111|00000000|00000000.... */ " punpckhbw %%mm2,%%mm1\n" /* mm1 = 0|a|0|b|0|c|0|d */ " punpcklbw %%mm2,%%mm3\n" /* mm3 = 0|e|0|f|0|g|0|h */ " movq (%0),%%mm2\n" /* mm2 = destination */ " pmullw %%mm0,%%mm1\n" /* mm1 = v*a|v*b|v*c|v*d */ " add $8,%1\n" " pmullw %%mm0,%%mm3\n" /* mm3 = v*e|v*f|v*g|v*h */ " psraw $7,%%mm1\n" /* mm1 = v*a/128|v*b/128|v*c/128|v*d/128 */ " psraw $7,%%mm3\n" /* mm3 = v*e/128|v*f/128|v*g/128|v*h/128 */ " packsswb %%mm1,%%mm3\n" /* mm1 = v*a/128|v*b/128|v*c/128|v*d/128|v*e/128|v*f/128|v*g/128|v*h/128 */ " paddsb %%mm2,%%mm3\n" /* add to destination buffer */ " movq %%mm3,(%0)\n" /* store back to ram */ " add $8,%0\n" " dec %%edx\n" " jnz .mixloopS8\n" ".endS8:\n" " emms\n" : : "r" (dst), "r"(src),"m"(size), "m"(volume) : "eax","edx","memory" ); } #endif #endif