Mercurial > sdl-ios-xcode
diff src/audio/nas/SDL_nasaudio.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 | e8157fcb3114 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/audio/nas/SDL_nasaudio.c Thu Apr 26 16:45:43 2001 +0000 @@ -0,0 +1,308 @@ +/* + 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 + + This driver was written by: + Erik Inge Bolsų + knan@mo.himolde.no +*/ + +#ifdef SAVE_RCSID +static char rcsid = + "@(#) $Id$"; +#endif + +/* Allow access to a raw mixing buffer */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <signal.h> +#include <unistd.h> + +#include "SDL_audio.h" +#include "SDL_error.h" +#include "SDL_audiomem.h" +#include "SDL_audio_c.h" +#include "SDL_timer.h" +#include "SDL_audiodev_c.h" +#include "SDL_nasaudio.h" + +/* The tag name used by artsc audio */ +#define NAS_DRIVER_NAME "nas" + +static struct SDL_PrivateAudioData *this2 = NULL; + +/* Audio driver functions */ +static int NAS_OpenAudio(_THIS, SDL_AudioSpec *spec); +static void NAS_WaitAudio(_THIS); +static void NAS_PlayAudio(_THIS); +static Uint8 *NAS_GetAudioBuf(_THIS); +static void NAS_CloseAudio(_THIS); + +/* Audio driver bootstrap functions */ + +static int Audio_Available(void) +{ + AuServer *aud = AuOpenServer("", 0, NULL, 0, NULL, NULL); + if (!aud) return 0; + + AuCloseServer(aud); + return 1; +} + +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)); + + /* Set the function pointers */ + this->OpenAudio = NAS_OpenAudio; + this->WaitAudio = NAS_WaitAudio; + this->PlayAudio = NAS_PlayAudio; + this->GetAudioBuf = NAS_GetAudioBuf; + this->CloseAudio = NAS_CloseAudio; + + this->free = Audio_DeleteDevice; + + return this; +} + +AudioBootStrap NAS_bootstrap = { + NAS_DRIVER_NAME, "Network Audio System", + Audio_Available, Audio_CreateDevice +}; + +/* This function waits until it is possible to write a full sound buffer */ +static void NAS_WaitAudio(_THIS) +{ + while ( this->hidden->buf_free < this->hidden->mixlen ) { + AuEvent ev; + AuNextEvent(this->hidden->aud, AuTrue, &ev); + AuDispatchEvent(this->hidden->aud, &ev); + } +} + +static void NAS_PlayAudio(_THIS) +{ + while (this->hidden->mixlen > this->hidden->buf_free) { /* We think the buffer is full? Yikes! Ask the server for events, + in the hope that some of them is LowWater events telling us more + of the buffer is free now than what we think. */ + AuEvent ev; + AuNextEvent(this->hidden->aud, AuTrue, &ev); + AuDispatchEvent(this->hidden->aud, &ev); + } + this->hidden->buf_free -= this->hidden->mixlen; + + /* Write the audio data */ + AuWriteElement(this->hidden->aud, this->hidden->flow, 0, this->hidden->mixlen, this->hidden->mixbuf, AuFalse, NULL); + + this->hidden->written += this->hidden->mixlen; + +#ifdef DEBUG_AUDIO + fprintf(stderr, "Wrote %d bytes of audio data\n", this->hidden->mixlen); +#endif +} + +static Uint8 *NAS_GetAudioBuf(_THIS) +{ + return(this->hidden->mixbuf); +} + +static void NAS_CloseAudio(_THIS) +{ + if ( this->hidden->mixbuf != NULL ) { + SDL_FreeAudioMem(this->hidden->mixbuf); + this->hidden->mixbuf = NULL; + } + if ( this->hidden->aud ) { + AuCloseServer(this->hidden->aud); + this->hidden->aud = 0; + } +} + +static unsigned char sdlformat_to_auformat(unsigned int fmt) +{ + switch (fmt) + { + case AUDIO_U8: + return AuFormatLinearUnsigned8; + case AUDIO_S8: + return AuFormatLinearSigned8; + case AUDIO_U16LSB: + return AuFormatLinearUnsigned16LSB; + case AUDIO_U16MSB: + return AuFormatLinearUnsigned16MSB; + case AUDIO_S16LSB: + return AuFormatLinearSigned16LSB; + case AUDIO_S16MSB: + return AuFormatLinearSigned16MSB; + } + return AuNone; +} + +static AuBool +event_handler(AuServer* aud, AuEvent* ev, AuEventHandlerRec* hnd) +{ + switch (ev->type) { + case AuEventTypeElementNotify: { + AuElementNotifyEvent* event = (AuElementNotifyEvent *)ev; + + switch (event->kind) { + case AuElementNotifyKindLowWater: + if (this2->buf_free >= 0) { + this2->really += event->num_bytes; + gettimeofday(&this2->last_tv, 0); + this2->buf_free += event->num_bytes; + } else { + this2->buf_free = event->num_bytes; + } + break; + case AuElementNotifyKindState: + switch (event->cur_state) { + case AuStatePause: + if (event->reason != AuReasonUser) { + if (this2->buf_free >= 0) { + this2->really += event->num_bytes; + gettimeofday(&this2->last_tv, 0); + this2->buf_free += event->num_bytes; + } else { + this2->buf_free = event->num_bytes; + } + } + break; + } + } + } + } + return AuTrue; +} + +static AuDeviceID +find_device(_THIS, int nch) +{ + int i; + for (i = 0; i < AuServerNumDevices(this->hidden->aud); i++) { + if ((AuDeviceKind(AuServerDevice(this->hidden->aud, i)) == + AuComponentKindPhysicalOutput) && + AuDeviceNumTracks(AuServerDevice(this->hidden->aud, i)) == nch) { + return AuDeviceIdentifier(AuServerDevice(this->hidden->aud, i)); + } + } + return AuNone; +} + +static int NAS_OpenAudio(_THIS, SDL_AudioSpec *spec) +{ + AuElement elms[3]; + int buffer_size; + Uint16 test_format, format; + + this->hidden->mixbuf = NULL; + + /* Try for a closest match on audio format */ + format = 0; + for ( test_format = SDL_FirstAudioFormat(spec->format); + ! format && test_format; ) { + format = sdlformat_to_auformat(test_format); + + if (format == AuNone) { + test_format = SDL_NextAudioFormat(); + } + } + if ( format == 0 ) { + SDL_SetError("Couldn't find any hardware audio formats"); + return(-1); + } + spec->format = test_format; + + this->hidden->aud = AuOpenServer("", 0, NULL, 0, NULL, NULL); + if (this->hidden->aud == 0) + { + SDL_SetError("Couldn't open connection to NAS server"); + return (-1); + } + + this->hidden->dev = find_device(this, spec->channels); + if ((this->hidden->dev == AuNone) || (!(this->hidden->flow = AuCreateFlow(this->hidden->aud, NULL)))) { + AuCloseServer(this->hidden->aud); + this->hidden->aud = 0; + SDL_SetError("Couldn't find a fitting playback device on NAS server"); + return (-1); + } + + buffer_size = spec->freq; + if (buffer_size < 4096) + buffer_size = 4096; + + if (buffer_size > 32768) + buffer_size = 32768; /* So that the buffer won't get unmanageably big. */ + + /* Calculate the final parameters for this audio specification */ + SDL_CalculateAudioSpec(spec); + + this2 = this->hidden; + + AuMakeElementImportClient(elms, spec->freq, format, spec->channels, AuTrue, + buffer_size, buffer_size / 4, 0, NULL); + AuMakeElementExportDevice(elms+1, 0, this->hidden->dev, spec->freq, + AuUnlimitedSamples, 0, NULL); + AuSetElements(this->hidden->aud, this->hidden->flow, AuTrue, 2, elms, NULL); + AuRegisterEventHandler(this->hidden->aud, AuEventHandlerIDMask, 0, this->hidden->flow, + event_handler, (AuPointer) NULL); + + AuStartFlow(this->hidden->aud, this->hidden->flow, NULL); + + /* Allocate mixing buffer */ + this->hidden->mixlen = spec->size; + this->hidden->mixbuf = (Uint8 *)SDL_AllocAudioMem(this->hidden->mixlen); + if ( this->hidden->mixbuf == NULL ) { + return(-1); + } + memset(this->hidden->mixbuf, spec->silence, spec->size); + + /* Get the parent process id (we're the parent of the audio thread) */ + this->hidden->parent = getpid(); + + /* We're ready to rock and roll. :-) */ + return(0); +}