Mercurial > sdl-ios-xcode
diff src/audio/sun/SDL_sunaudio.c @ 0:74212992fb08
Initial revision
author | Sam Lantinga <slouken@lokigames.com> |
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date | Thu, 26 Apr 2001 16:45:43 +0000 |
parents | |
children | 8758b8d42cd9 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/audio/sun/SDL_sunaudio.c Thu Apr 26 16:45:43 2001 +0000 @@ -0,0 +1,439 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997, 1998, 1999, 2000, 2001 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@devolution.com +*/ + +#ifdef SAVE_RCSID +static char rcsid = + "@(#) $Id$"; +#endif + +/* Allow access to a raw mixing buffer */ + +#include <stdlib.h> +#include <stdio.h> +#include <fcntl.h> +#include <errno.h> +#include <string.h> +#ifdef __NetBSD__ +#include <sys/ioctl.h> +#include <sys/audioio.h> +#endif +#ifdef __SVR4 +#include <sys/audioio.h> +#else +#include <sys/time.h> +#include <sys/types.h> +#endif +#include <unistd.h> + +#include "SDL_endian.h" +#include "SDL_audio.h" +#include "SDL_audiomem.h" +#include "SDL_audiodev_c.h" +#include "SDL_sunaudio.h" +#include "SDL_audio_c.h" +#include "SDL_timer.h" + +/* Open the audio device for playback, and don't block if busy */ +#define OPEN_FLAGS (O_WRONLY|O_NONBLOCK) + +/* Audio driver functions */ +static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec); +static void DSP_WaitAudio(_THIS); +static void DSP_PlayAudio(_THIS); +static Uint8 *DSP_GetAudioBuf(_THIS); +static void DSP_CloseAudio(_THIS); + +/* Audio driver bootstrap functions */ + +static int Audio_Available(void) +{ + int fd; + int available; + + available = 0; + fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 1); + if ( fd >= 0 ) { + available = 1; + close(fd); + } + return(available); +} + +static void Audio_DeleteDevice(SDL_AudioDevice *device) +{ + free(device->hidden); + free(device); +} + +static SDL_AudioDevice *Audio_CreateDevice(int devindex) +{ + SDL_AudioDevice *this; + + /* Initialize all variables that we clean on shutdown */ + this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice)); + if ( this ) { + memset(this, 0, (sizeof *this)); + this->hidden = (struct SDL_PrivateAudioData *) + malloc((sizeof *this->hidden)); + } + if ( (this == NULL) || (this->hidden == NULL) ) { + SDL_OutOfMemory(); + if ( this ) { + free(this); + } + return(0); + } + memset(this->hidden, 0, (sizeof *this->hidden)); + audio_fd = -1; + + /* Set the function pointers */ + this->OpenAudio = DSP_OpenAudio; + this->WaitAudio = DSP_WaitAudio; + this->PlayAudio = DSP_PlayAudio; + this->GetAudioBuf = DSP_GetAudioBuf; + this->CloseAudio = DSP_CloseAudio; + + this->free = Audio_DeleteDevice; + + return this; +} + +AudioBootStrap AUDIO_bootstrap = { + "audio", "UNIX /dev/audio interface", + Audio_Available, Audio_CreateDevice +}; + +#ifdef DEBUG_AUDIO +void CheckUnderflow(_THIS) +{ +#ifdef AUDIO_GETINFO + audio_info_t info; + int left; + + ioctl(audio_fd, AUDIO_GETINFO, &info); + left = (written - info.play.samples); + if ( written && (left == 0) ) { + fprintf(stderr, "audio underflow!\n"); + } +#endif +} +#endif + +void DSP_WaitAudio(_THIS) +{ +#ifdef AUDIO_GETINFO +#define SLEEP_FUDGE 10 /* 10 ms scheduling fudge factor */ + audio_info_t info; + Sint32 left; + + ioctl(audio_fd, AUDIO_GETINFO, &info); + left = (written - info.play.samples); + if ( left > fragsize ) { + Sint32 sleepy; + + sleepy = ((left - fragsize)/frequency); + sleepy -= SLEEP_FUDGE; + if ( sleepy > 0 ) { + SDL_Delay(sleepy); + } + } +#else + fd_set fdset; + + FD_ZERO(&fdset); + FD_SET(audio_fd, &fdset); + select(audio_fd+1, NULL, &fdset, NULL, NULL); +#endif +} + +void DSP_PlayAudio(_THIS) +{ + static Uint8 snd2au(int sample); + /* Write the audio data */ + if ( ulaw_only ) { + /* Assuming that this->spec.freq >= 8000 Hz */ + int accum, incr, pos; + Uint8 *aubuf; + + accum = 0; + incr = this->spec.freq/8; + aubuf = ulaw_buf; + switch (audio_fmt & 0xFF) { + case 8: { + Uint8 *sndbuf; + + sndbuf = mixbuf; + for ( pos=0; pos < fragsize; ++pos ) { + *aubuf = snd2au((0x80-*sndbuf)*64); + accum += incr; + while ( accum > 0 ) { + accum -= 1000; + sndbuf += 1; + } + aubuf += 1; + } + } + break; + case 16: { + Sint16 *sndbuf; + + sndbuf = (Sint16 *)mixbuf; + for ( pos=0; pos < fragsize; ++pos ) { + *aubuf = snd2au(*sndbuf/4); + accum += incr; + while ( accum > 0 ) { + accum -= 1000; + sndbuf += 1; + } + aubuf += 1; + } + } + break; + } +#ifdef DEBUG_AUDIO + CheckUnderflow(this); +#endif + if ( write(audio_fd, ulaw_buf, fragsize) < 0 ) { + /* Assume fatal error, for now */ + this->enabled = 0; + } + written += fragsize; + } else { +#ifdef DEBUG_AUDIO + CheckUnderflow(this); +#endif + if ( write(audio_fd, mixbuf, this->spec.size) < 0 ) { + /* Assume fatal error, for now */ + this->enabled = 0; + } + written += fragsize; + } +} + +Uint8 *DSP_GetAudioBuf(_THIS) +{ + return(mixbuf); +} + +void DSP_CloseAudio(_THIS) +{ + if ( mixbuf != NULL ) { + SDL_FreeAudioMem(mixbuf); + mixbuf = NULL; + } + if ( ulaw_buf != NULL ) { + free(ulaw_buf); + ulaw_buf = NULL; + } + close(audio_fd); +} + +int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec) +{ + char audiodev[1024]; +#ifdef AUDIO_SETINFO + int enc; +#endif + int desired_freq = spec->freq; + + /* Initialize our freeable variables, in case we fail*/ + audio_fd = -1; + mixbuf = NULL; + ulaw_buf = NULL; + + /* Determine the audio parameters from the AudioSpec */ + switch ( spec->format & 0xFF ) { + + case 8: { /* Unsigned 8 bit audio data */ + spec->format = AUDIO_U8; +#ifdef AUDIO_SETINFO + enc = AUDIO_ENCODING_LINEAR8; +#endif + } + break; + + case 16: { /* Signed 16 bit audio data */ + spec->format = AUDIO_S16SYS; +#ifdef AUDIO_SETINFO + enc = AUDIO_ENCODING_LINEAR; +#endif + } + break; + + default: { + SDL_SetError("Unsupported audio format"); + return(-1); + } + } + audio_fmt = spec->format; + + /* Open the audio device */ + audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 1); + if ( audio_fd < 0 ) { + SDL_SetError("Couldn't open %s: %s", audiodev, + strerror(errno)); + return(-1); + } + + ulaw_only = 0; /* modern Suns do support linear audio */ +#ifdef AUDIO_SETINFO + for(;;) { + audio_info_t info; + AUDIO_INITINFO(&info); /* init all fields to "no change" */ + + /* Try to set the requested settings */ + info.play.sample_rate = spec->freq; + info.play.channels = spec->channels; + info.play.precision = (enc == AUDIO_ENCODING_ULAW) + ? 8 : spec->format & 0xff; + info.play.encoding = enc; + if( ioctl(audio_fd, AUDIO_SETINFO, &info) == 0 ) { + + /* Check to be sure we got what we wanted */ + if(ioctl(audio_fd, AUDIO_GETINFO, &info) < 0) { + SDL_SetError("Error getting audio parameters: %s", + strerror(errno)); + return -1; + } + if(info.play.encoding == enc + && info.play.precision == (spec->format & 0xff) + && info.play.channels == spec->channels) { + /* Yow! All seems to be well! */ + spec->freq = info.play.sample_rate; + break; + } + } + + switch(enc) { + case AUDIO_ENCODING_LINEAR8: + /* unsigned 8bit apparently not supported here */ + enc = AUDIO_ENCODING_LINEAR; + spec->format = AUDIO_S16SYS; + break; /* try again */ + + case AUDIO_ENCODING_LINEAR: + /* linear 16bit didn't work either, resort to µ-law */ + enc = AUDIO_ENCODING_ULAW; + spec->channels = 1; + spec->freq = 8000; + spec->format = AUDIO_U8; + ulaw_only = 1; + break; + + default: + /* oh well... */ + SDL_SetError("Error setting audio parameters: %s", + strerror(errno)); + return -1; + } + } +#endif /* AUDIO_SETINFO */ + written = 0; + + /* We can actually convert on-the-fly to U-Law */ + if ( ulaw_only ) { + spec->freq = desired_freq; + fragsize = (spec->samples*1000)/(spec->freq/8); + frequency = 8; + ulaw_buf = (Uint8 *)malloc(fragsize); + if ( ulaw_buf == NULL ) { + SDL_OutOfMemory(); + return(-1); + } + spec->channels = 1; + } else { + fragsize = spec->samples; + frequency = spec->freq/1000; + } +#ifdef DEBUG_AUDIO + fprintf(stderr, "Audio device %s U-Law only\n", + ulaw_only ? "is" : "is not"); + fprintf(stderr, "format=0x%x chan=%d freq=%d\n", + spec->format, spec->channels, spec->freq); +#endif + + /* Update the fragment size as size in bytes */ + SDL_CalculateAudioSpec(spec); + + /* Allocate mixing buffer */ + mixbuf = (Uint8 *)SDL_AllocAudioMem(spec->size); + if ( mixbuf == NULL ) { + SDL_OutOfMemory(); + return(-1); + } + memset(mixbuf, spec->silence, spec->size); + + /* We're ready to rock and roll. :-) */ + return(0); +} + +/************************************************************************/ +/* This function (snd2au()) copyrighted: */ +/************************************************************************/ +/* Copyright 1989 by Rich Gopstein and Harris Corporation */ +/* */ +/* Permission to use, copy, modify, and distribute this software */ +/* and its documentation for any purpose and without fee is */ +/* hereby granted, provided that the above copyright notice */ +/* appears in all copies and that both that copyright notice and */ +/* this permission notice appear in supporting documentation, and */ +/* that the name of Rich Gopstein and Harris Corporation not be */ +/* used in advertising or publicity pertaining to distribution */ +/* of the software without specific, written prior permission. */ +/* Rich Gopstein and Harris Corporation make no representations */ +/* about the suitability of this software for any purpose. It */ +/* provided "as is" without express or implied warranty. */ +/************************************************************************/ + +static Uint8 snd2au(int sample) +{ + + int mask; + + if (sample < 0) { + sample = -sample; + mask = 0x7f; + } else { + mask = 0xff; + } + + if (sample < 32) { + sample = 0xF0 | (15 - sample / 2); + } else if (sample < 96) { + sample = 0xE0 | (15 - (sample - 32) / 4); + } else if (sample < 224) { + sample = 0xD0 | (15 - (sample - 96) / 8); + } else if (sample < 480) { + sample = 0xC0 | (15 - (sample - 224) / 16); + } else if (sample < 992) { + sample = 0xB0 | (15 - (sample - 480) / 32); + } else if (sample < 2016) { + sample = 0xA0 | (15 - (sample - 992) / 64); + } else if (sample < 4064) { + sample = 0x90 | (15 - (sample - 2016) / 128); + } else if (sample < 8160) { + sample = 0x80 | (15 - (sample - 4064) / 256); + } else { + sample = 0x80; + } + return (mask & sample); +}