| /* |
| 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_dcaudio.h" |
| |
| #include "aica.h" |
| #include <dc/spu.h> |
| |
| #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_PlayDevice(_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_GetDeviceBuf(_THIS) |
| { |
| return (this->hidden->mixbuf); |
| } |
| |
| /* This function waits until it is possible to write a full sound buffer */ |
| static void |
| DCAUD_WaitDevice(_THIS) |
| { |
| if (this->hidden->playing) { |
| /* wait */ |
| while (aica_get_pos(0) / this->spec.samples == this->hidden->nextbuf) { |
| thd_pass(); |
| } |
| } |
| } |
| |
| static void |
| DCAUD_CloseDevice(_THIS) |
| { |
| if (this->hidden != NULL) { |
| 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; |
| } |
| SDL_free(this->hidden); |
| this->hidden = NULL; |
| |
| /* !!! FIXME: is there a reverse of spu_init()? */ |
| } |
| } |
| |
| static int |
| DCAUD_OpenDevice(_THIS, SDL_AudioSpec * spec) |
| { |
| SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format); |
| int valid_datatype = 0; |
| |
| /* Initialize all variables that we clean on shutdown */ |
| this->hidden = (struct SDL_PrivateAudioData *) |
| SDL_malloc((sizeof *this->hidden)); |
| if (this->hidden == NULL) { |
| SDL_OutOfMemory(); |
| return 0; |
| } |
| SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
| |
| spu_init(); |
| |
| while ((!valid_datatype) && (test_format)) { |
| spec->format = test_format; |
| switch (test_format) { |
| /* only formats Dreamcast accepts... */ |
| case AUDIO_S8: |
| case AUDIO_S16LSB: |
| valid_datatype = 1; |
| break; |
| |
| default: |
| test_format = SDL_NextAudioFormat(); |
| break; |
| } |
| } |
| |
| if (!valid_datatype) { /* shouldn't happen, but just in case... */ |
| DCAUD_CloseDevice(this); |
| SDL_SetError("Unsupported audio format"); |
| return 0; |
| } |
| |
| if (spec->channels > 2) |
| spec->channels = 2; /* no more than stereo on the Dreamcast. */ |
| |
| /* 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) { |
| DCAUD_CloseDevice(this); |
| SDL_OutOfMemory(); |
| return 0; |
| } |
| 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 1; |
| } |
| |
| static int |
| DCAUD_Init(SDL_AudioDriverImpl *impl) |
| { |
| /* Set the function pointers */ |
| impl->OpenDevice = DCAUD_OpenDevice; |
| impl->PlayDevice = DCAUD_PlayDevice; |
| impl->WaitDevice = DCAUD_WaitDevice; |
| impl->GetDeviceBuf = DCAUD_GetDeviceBuf; |
| impl->CloseDevice = DCAUD_CloseDevice; |
| impl->OnlyHasDefaultOutputDevice = 1; |
| |
| return 1; |
| } |
| |
| AudioBootStrap DCAUD_bootstrap = { |
| "dcaudio", "Dreamcast AICA audio", DCAUD_Init, 0 |
| }; |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |
