| /* |
| 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" |
| |
| /* Allow access to a raw mixing buffer */ |
| |
| #ifdef HAVE_SIGNAL_H |
| #include <signal.h> |
| #endif |
| #include <unistd.h> |
| |
| #include "SDL_timer.h" |
| #include "SDL_audio.h" |
| #include "../SDL_audiomem.h" |
| #include "../SDL_audio_c.h" |
| #include "../SDL_audiodev_c.h" |
| #include "SDL_artsaudio.h" |
| |
| #ifdef SDL_AUDIO_DRIVER_ARTS_DYNAMIC |
| #include "SDL_name.h" |
| #include "SDL_loadso.h" |
| #else |
| #define SDL_NAME(X) X |
| #endif |
| |
| /* The tag name used by artsc audio */ |
| #define ARTS_DRIVER_NAME "arts" |
| |
| /* Audio driver functions */ |
| static int ARTS_OpenAudio(_THIS, SDL_AudioSpec *spec); |
| static void ARTS_WaitAudio(_THIS); |
| static void ARTS_PlayAudio(_THIS); |
| static Uint8 *ARTS_GetAudioBuf(_THIS); |
| static void ARTS_CloseAudio(_THIS); |
| |
| #ifdef SDL_AUDIO_DRIVER_ARTS_DYNAMIC |
| |
| static const char *arts_library = SDL_AUDIO_DRIVER_ARTS_DYNAMIC; |
| static void *arts_handle = NULL; |
| static int arts_loaded = 0; |
| |
| static int (*SDL_NAME(arts_init))(void); |
| static void (*SDL_NAME(arts_free))(void); |
| static arts_stream_t (*SDL_NAME(arts_play_stream))(int rate, int bits, int channels, const char *name); |
| static int (*SDL_NAME(arts_stream_set))(arts_stream_t s, arts_parameter_t param, int value); |
| static int (*SDL_NAME(arts_stream_get))(arts_stream_t s, arts_parameter_t param); |
| static int (*SDL_NAME(arts_write))(arts_stream_t s, const void *buffer, int count); |
| static void (*SDL_NAME(arts_close_stream))(arts_stream_t s); |
| static int (*SDL_NAME(arts_suspended))(void); |
| static const char *(*SDL_NAME(arts_error_text))(int errorcode); |
| |
| static struct { |
| const char *name; |
| void **func; |
| } arts_functions[] = { |
| { "arts_init", (void **)&SDL_NAME(arts_init) }, |
| { "arts_free", (void **)&SDL_NAME(arts_free) }, |
| { "arts_play_stream", (void **)&SDL_NAME(arts_play_stream) }, |
| { "arts_stream_set", (void **)&SDL_NAME(arts_stream_set) }, |
| { "arts_stream_get", (void **)&SDL_NAME(arts_stream_get) }, |
| { "arts_write", (void **)&SDL_NAME(arts_write) }, |
| { "arts_close_stream", (void **)&SDL_NAME(arts_close_stream) }, |
| { "arts_suspended", (void **)&SDL_NAME(arts_suspended) }, |
| { "arts_error_text", (void **)&SDL_NAME(arts_error_text) }, |
| }; |
| |
| static void UnloadARTSLibrary() |
| { |
| if ( arts_loaded ) { |
| SDL_UnloadObject(arts_handle); |
| arts_handle = NULL; |
| arts_loaded = 0; |
| } |
| } |
| |
| static int LoadARTSLibrary(void) |
| { |
| int i, retval = -1; |
| |
| arts_handle = SDL_LoadObject(arts_library); |
| if ( arts_handle ) { |
| arts_loaded = 1; |
| retval = 0; |
| for ( i=0; i<SDL_arraysize(arts_functions); ++i ) { |
| *arts_functions[i].func = SDL_LoadFunction(arts_handle, arts_functions[i].name); |
| if ( !*arts_functions[i].func ) { |
| retval = -1; |
| UnloadARTSLibrary(); |
| break; |
| } |
| } |
| } |
| return retval; |
| } |
| |
| #else |
| |
| static void UnloadARTSLibrary() |
| { |
| return; |
| } |
| |
| static int LoadARTSLibrary(void) |
| { |
| return 0; |
| } |
| |
| #endif /* SDL_AUDIO_DRIVER_ARTS_DYNAMIC */ |
| |
| /* Audio driver bootstrap functions */ |
| |
| static int Audio_Available(void) |
| { |
| int available = 0; |
| |
| if ( LoadARTSLibrary() < 0 ) { |
| return available; |
| } |
| if ( SDL_NAME(arts_init)() == 0 ) { |
| if ( SDL_NAME(arts_suspended)() ) { |
| /* Play a stream so aRts doesn't crash */ |
| arts_stream_t stream2; |
| stream2=SDL_NAME(arts_play_stream)(44100, 16, 2, "SDL"); |
| SDL_NAME(arts_write)(stream2, "", 0); |
| SDL_NAME(arts_close_stream)(stream2); |
| available = 1; |
| } |
| SDL_NAME(arts_free)(); |
| } |
| UnloadARTSLibrary(); |
| |
| return available; |
| } |
| |
| static void Audio_DeleteDevice(SDL_AudioDevice *device) |
| { |
| SDL_free(device->hidden); |
| SDL_free(device); |
| UnloadARTSLibrary(); |
| } |
| |
| static SDL_AudioDevice *Audio_CreateDevice(int devindex) |
| { |
| SDL_AudioDevice *this; |
| |
| /* Initialize all variables that we clean on shutdown */ |
| LoadARTSLibrary(); |
| 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)); |
| stream = 0; |
| |
| /* Set the function pointers */ |
| this->OpenAudio = ARTS_OpenAudio; |
| this->WaitAudio = ARTS_WaitAudio; |
| this->PlayAudio = ARTS_PlayAudio; |
| this->GetAudioBuf = ARTS_GetAudioBuf; |
| this->CloseAudio = ARTS_CloseAudio; |
| |
| this->free = Audio_DeleteDevice; |
| |
| return this; |
| } |
| |
| AudioBootStrap ARTS_bootstrap = { |
| ARTS_DRIVER_NAME, "Analog Realtime Synthesizer", |
| Audio_Available, Audio_CreateDevice |
| }; |
| |
| /* This function waits until it is possible to write a full sound buffer */ |
| static void ARTS_WaitAudio(_THIS) |
| { |
| Sint32 ticks; |
| |
| /* Check to see if the thread-parent process is still alive */ |
| { static int cnt = 0; |
| /* Note that this only works with thread implementations |
| that use a different process id for each thread. |
| */ |
| if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ |
| if ( kill(parent, 0) < 0 ) { |
| this->enabled = 0; |
| } |
| } |
| } |
| |
| /* Use timer for general audio synchronization */ |
| ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; |
| if ( ticks > 0 ) { |
| SDL_Delay(ticks); |
| } |
| } |
| |
| static void ARTS_PlayAudio(_THIS) |
| { |
| int written; |
| |
| /* Write the audio data */ |
| written = SDL_NAME(arts_write)(stream, mixbuf, mixlen); |
| |
| /* If timer synchronization is enabled, set the next write frame */ |
| if ( frame_ticks ) { |
| next_frame += frame_ticks; |
| } |
| |
| /* If we couldn't write, assume fatal error for now */ |
| if ( written < 0 ) { |
| this->enabled = 0; |
| } |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Wrote %d bytes of audio data\n", written); |
| #endif |
| } |
| |
| static Uint8 *ARTS_GetAudioBuf(_THIS) |
| { |
| return(mixbuf); |
| } |
| |
| static void ARTS_CloseAudio(_THIS) |
| { |
| if ( mixbuf != NULL ) { |
| SDL_FreeAudioMem(mixbuf); |
| mixbuf = NULL; |
| } |
| if ( stream ) { |
| SDL_NAME(arts_close_stream)(stream); |
| stream = 0; |
| } |
| SDL_NAME(arts_free)(); |
| } |
| |
| static int ARTS_OpenAudio(_THIS, SDL_AudioSpec *spec) |
| { |
| int bits, frag_spec; |
| Uint16 test_format, format; |
| int error_code; |
| |
| /* Reset the timer synchronization flag */ |
| frame_ticks = 0.0; |
| |
| mixbuf = NULL; |
| |
| /* Try for a closest match on audio format */ |
| format = 0; |
| bits = 0; |
| for ( test_format = SDL_FirstAudioFormat(spec->format); |
| ! format && test_format; ) { |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Trying format 0x%4.4x\n", test_format); |
| #endif |
| switch ( test_format ) { |
| case AUDIO_U8: |
| bits = 8; |
| format = 1; |
| break; |
| case AUDIO_S16LSB: |
| bits = 16; |
| format = 1; |
| break; |
| default: |
| format = 0; |
| break; |
| } |
| if ( ! format ) { |
| test_format = SDL_NextAudioFormat(); |
| } |
| } |
| if ( format == 0 ) { |
| SDL_SetError("Couldn't find any hardware audio formats"); |
| return(-1); |
| } |
| spec->format = test_format; |
| |
| error_code = SDL_NAME(arts_init)(); |
| if ( error_code != 0 ) { |
| SDL_SetError("Unable to initialize ARTS: %s", SDL_NAME(arts_error_text)(error_code)); |
| return(-1); |
| } |
| if ( ! SDL_NAME(arts_suspended)() ) { |
| SDL_SetError("ARTS can not open audio device"); |
| return(-1); |
| } |
| stream = SDL_NAME(arts_play_stream)(spec->freq, bits, spec->channels, "SDL"); |
| |
| /* Calculate the final parameters for this audio specification */ |
| SDL_CalculateAudioSpec(spec); |
| |
| /* Determine the power of two of the fragment size */ |
| for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec ); |
| if ( (0x01<<frag_spec) != spec->size ) { |
| SDL_SetError("Fragment size must be a power of two"); |
| return(-1); |
| } |
| frag_spec |= 0x00020000; /* two fragments, for low latency */ |
| |
| #ifdef ARTS_P_PACKET_SETTINGS |
| SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_SETTINGS, frag_spec); |
| #else |
| SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_SIZE, frag_spec&0xffff); |
| SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_COUNT, frag_spec>>16); |
| #endif |
| spec->size = SDL_NAME(arts_stream_get)(stream, ARTS_P_PACKET_SIZE); |
| |
| /* Allocate mixing buffer */ |
| mixlen = spec->size; |
| mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); |
| if ( mixbuf == NULL ) { |
| return(-1); |
| } |
| SDL_memset(mixbuf, spec->silence, spec->size); |
| |
| /* Get the parent process id (we're the parent of the audio thread) */ |
| parent = getpid(); |
| |
| /* We're ready to rock and roll. :-) */ |
| return(0); |
| } |