Mercurial > sdl-ios-xcode
view src/audio/dc/SDL_dcaudio.c @ 1668:4da1ee79c9af SDL-1.3
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author | Sam Lantinga <slouken@libsdl.org> |
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date | Mon, 29 May 2006 04:04:35 +0000 |
parents | 782fd950bd46 |
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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" /* Output dreamcast aica */ #include "SDL_timer.h" #include "SDL_audio.h" #include "../SDL_audiomem.h" #include "../SDL_audio_c.h" #include "../SDL_audiodev_c.h" #include "SDL_dcaudio.h" #include "aica.h" #include <dc/spu.h> /* Audio driver functions */ static int DCAUD_OpenAudio(_THIS, SDL_AudioSpec * spec); static void DCAUD_WaitAudio(_THIS); static void DCAUD_PlayAudio(_THIS); static Uint8 *DCAUD_GetAudioBuf(_THIS); static void DCAUD_CloseAudio(_THIS); /* Audio driver bootstrap functions */ static int DCAUD_Available(void) { return 1; } static void DCAUD_DeleteDevice(SDL_AudioDevice * device) { SDL_free(device->hidden); SDL_free(device); } static SDL_AudioDevice * DCAUD_CreateDevice(int devindex) { SDL_AudioDevice *this; /* Initialize all variables that we clean on shutdown */ this = (SDL_AudioDevice *) SDL_malloc(sizeof(SDL_AudioDevice)); if (this) { SDL_memset(this, 0, (sizeof *this)); this->hidden = (struct SDL_PrivateAudioData *) SDL_malloc((sizeof *this->hidden)); } if ((this == NULL) || (this->hidden == NULL)) { SDL_OutOfMemory(); if (this) { SDL_free(this); } return (0); } SDL_memset(this->hidden, 0, (sizeof *this->hidden)); /* Set the function pointers */ this->OpenAudio = DCAUD_OpenAudio; this->WaitAudio = DCAUD_WaitAudio; this->PlayAudio = DCAUD_PlayAudio; this->GetAudioBuf = DCAUD_GetAudioBuf; this->CloseAudio = DCAUD_CloseAudio; this->free = DCAUD_DeleteDevice; spu_init(); return this; } AudioBootStrap DCAUD_bootstrap = { "dcaudio", "Dreamcast AICA audio", DCAUD_Available, DCAUD_CreateDevice }; /* This function waits until it is possible to write a full sound buffer */ static void DCAUD_WaitAudio(_THIS) { if (this->hidden->playing) { /* wait */ while (aica_get_pos(0) / this->spec.samples == this->hidden->nextbuf) { thd_pass(); } } } #define SPU_RAM_BASE 0xa0800000 static void spu_memload_stereo8(int leftpos, int rightpos, void *src0, size_t size) { uint8 *src = src0; uint32 *left = (uint32 *) (leftpos + SPU_RAM_BASE); uint32 *right = (uint32 *) (rightpos + SPU_RAM_BASE); size = (size + 7) / 8; while (size--) { unsigned lval, rval; lval = *src++; rval = *src++; lval |= (*src++) << 8; rval |= (*src++) << 8; lval |= (*src++) << 16; rval |= (*src++) << 16; lval |= (*src++) << 24; rval |= (*src++) << 24; g2_write_32(left++, lval); g2_write_32(right++, rval); g2_fifo_wait(); } } static void spu_memload_stereo16(int leftpos, int rightpos, void *src0, size_t size) { uint16 *src = src0; uint32 *left = (uint32 *) (leftpos + SPU_RAM_BASE); uint32 *right = (uint32 *) (rightpos + SPU_RAM_BASE); size = (size + 7) / 8; while (size--) { unsigned lval, rval; lval = *src++; rval = *src++; lval |= (*src++) << 16; rval |= (*src++) << 16; g2_write_32(left++, lval); g2_write_32(right++, rval); g2_fifo_wait(); } } static void DCAUD_PlayAudio(_THIS) { SDL_AudioSpec *spec = &this->spec; unsigned int offset; if (this->hidden->playing) { /* wait */ while (aica_get_pos(0) / spec->samples == this->hidden->nextbuf) { thd_pass(); } } offset = this->hidden->nextbuf * spec->size; this->hidden->nextbuf ^= 1; /* Write the audio data, checking for EAGAIN on broken audio drivers */ if (spec->channels == 1) { spu_memload(this->hidden->leftpos + offset, this->hidden->mixbuf, this->hidden->mixlen); } else { offset /= 2; if ((this->spec.format & 255) == 8) { spu_memload_stereo8(this->hidden->leftpos + offset, this->hidden->rightpos + offset, this->hidden->mixbuf, this->hidden->mixlen); } else { spu_memload_stereo16(this->hidden->leftpos + offset, this->hidden->rightpos + offset, this->hidden->mixbuf, this->hidden->mixlen); } } if (!this->hidden->playing) { int mode; this->hidden->playing = 1; mode = (spec->format == AUDIO_S8) ? SM_8BIT : SM_16BIT; if (spec->channels == 1) { aica_play(0, mode, this->hidden->leftpos, 0, spec->samples * 2, spec->freq, 255, 128, 1); } else { aica_play(0, mode, this->hidden->leftpos, 0, spec->samples * 2, spec->freq, 255, 0, 1); aica_play(1, mode, this->hidden->rightpos, 0, spec->samples * 2, spec->freq, 255, 255, 1); } } } static Uint8 * DCAUD_GetAudioBuf(_THIS) { return (this->hidden->mixbuf); } static void DCAUD_CloseAudio(_THIS) { aica_stop(0); if (this->spec.channels == 2) aica_stop(1); if (this->hidden->mixbuf != NULL) { SDL_FreeAudioMem(this->hidden->mixbuf); this->hidden->mixbuf = NULL; } } static int DCAUD_OpenAudio(_THIS, SDL_AudioSpec * spec) { switch (spec->format & 0xff) { case 8: spec->format = AUDIO_S8; break; case 16: spec->format = AUDIO_S16LSB; break; default: SDL_SetError("Unsupported audio format"); return (-1); } /* Update the fragment size as size in bytes */ SDL_CalculateAudioSpec(spec); /* Allocate mixing buffer */ this->hidden->mixlen = spec->size; this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen); if (this->hidden->mixbuf == NULL) { return (-1); } SDL_memset(this->hidden->mixbuf, spec->silence, spec->size); this->hidden->leftpos = 0x11000; this->hidden->rightpos = 0x11000 + spec->size; this->hidden->playing = 0; this->hidden->nextbuf = 0; /* We're ready to rock and roll. :-) */ return (0); } /* vi: set ts=4 sw=4 expandtab: */