Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_MMX.c @ 2661:d38309be5178 gsoc2008_audio_resampling
The windowed sinc filter generation code seems to be working fine. The FIR filtering code is also now working reasonably well. Occasionally the FIR filter will pop, but setting the normalization factor lower seems to help this. I suspect the problem is in the fixed point multiply/add. I also have a hunch the zero stuffing/sample discarding code is not correct, and I'll look at that soon to get it sorted out.
| author | Aaron Wishnick <schnarf@gmail.com> |
|---|---|
| date | Wed, 02 Jul 2008 08:04:50 +0000 |
| parents | c121d94672cb |
| children | 99210400e8b9 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 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(__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 /* vi: set ts=4 sw=4 expandtab: */