| /* |
| 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 |
| |
| Modified in Oct 2004 by Hannu Savolainen |
| hannu@opensound.com |
| */ |
| #include "SDL_config.h" |
| |
| /* Allow access to a raw mixing buffer */ |
| |
| #include <stdio.h> /* For perror() */ |
| #include <string.h> /* For strerror() */ |
| #include <errno.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <signal.h> |
| #include <sys/time.h> |
| #include <sys/ioctl.h> |
| #include <sys/stat.h> |
| |
| #if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H |
| /* This is installed on some systems */ |
| #include <soundcard.h> |
| #else |
| /* This is recommended by OSS */ |
| #include <sys/soundcard.h> |
| #endif |
| |
| #include "SDL_timer.h" |
| #include "SDL_audio.h" |
| #include "../SDL_audiomem.h" |
| #include "../SDL_audio_c.h" |
| #include "../SDL_audiodev_c.h" |
| #include "SDL_dspaudio.h" |
| |
| /* The tag name used by DSP audio */ |
| #define DSP_DRIVER_NAME "dsp" |
| |
| /* 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, 0); |
| if ( fd >= 0 ) { |
| available = 1; |
| close(fd); |
| } |
| return(available); |
| } |
| |
| static void Audio_DeleteDevice(SDL_AudioDevice *device) |
| { |
| SDL_free(device->hidden); |
| SDL_free(device); |
| } |
| |
| static SDL_AudioDevice *Audio_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)); |
| 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 DSP_bootstrap = { |
| DSP_DRIVER_NAME, "OSS /dev/dsp standard audio", |
| Audio_Available, Audio_CreateDevice |
| }; |
| |
| /* This function waits until it is possible to write a full sound buffer */ |
| static void DSP_WaitAudio(_THIS) |
| { |
| /* Not needed at all since OSS handles waiting automagically */ |
| } |
| |
| static void DSP_PlayAudio(_THIS) |
| { |
| if (write(audio_fd, mixbuf, mixlen)==-1) |
| { |
| perror("Audio write"); |
| this->enabled = 0; |
| } |
| |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Wrote %d bytes of audio data\n", mixlen); |
| #endif |
| } |
| |
| static Uint8 *DSP_GetAudioBuf(_THIS) |
| { |
| return(mixbuf); |
| } |
| |
| static void DSP_CloseAudio(_THIS) |
| { |
| if ( mixbuf != NULL ) { |
| SDL_FreeAudioMem(mixbuf); |
| mixbuf = NULL; |
| } |
| if ( audio_fd >= 0 ) { |
| close(audio_fd); |
| audio_fd = -1; |
| } |
| } |
| |
| static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec) |
| { |
| char audiodev[1024]; |
| int format; |
| int value; |
| int frag_spec; |
| Uint16 test_format; |
| |
| /* Make sure fragment size stays a power of 2, or OSS fails. */ |
| /* I don't know which of these are actually legal values, though... */ |
| if (spec->channels > 8) |
| spec->channels = 8; |
| else if (spec->channels > 4) |
| spec->channels = 4; |
| else if (spec->channels > 2) |
| spec->channels = 2; |
| |
| /* Open the audio device */ |
| audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0); |
| if ( audio_fd < 0 ) { |
| SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); |
| return(-1); |
| } |
| mixbuf = NULL; |
| |
| /* Make the file descriptor use blocking writes with fcntl() */ |
| { long flags; |
| flags = fcntl(audio_fd, F_GETFL); |
| flags &= ~O_NONBLOCK; |
| if ( fcntl(audio_fd, F_SETFL, flags) < 0 ) { |
| SDL_SetError("Couldn't set audio blocking mode"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| } |
| |
| /* Get a list of supported hardware formats */ |
| if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) { |
| perror("SNDCTL_DSP_GETFMTS"); |
| SDL_SetError("Couldn't get audio format list"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| |
| /* Try for a closest match on audio format */ |
| format = 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: |
| if ( value & AFMT_U8 ) { |
| format = AFMT_U8; |
| } |
| break; |
| case AUDIO_S16LSB: |
| if ( value & AFMT_S16_LE ) { |
| format = AFMT_S16_LE; |
| } |
| break; |
| case AUDIO_S16MSB: |
| if ( value & AFMT_S16_BE ) { |
| format = AFMT_S16_BE; |
| } |
| break; |
| #if 0 |
| /* |
| * These formats are not used by any real life systems so they are not |
| * needed here. |
| */ |
| case AUDIO_S8: |
| if ( value & AFMT_S8 ) { |
| format = AFMT_S8; |
| } |
| break; |
| case AUDIO_U16LSB: |
| if ( value & AFMT_U16_LE ) { |
| format = AFMT_U16_LE; |
| } |
| break; |
| case AUDIO_U16MSB: |
| if ( value & AFMT_U16_BE ) { |
| format = AFMT_U16_BE; |
| } |
| break; |
| #endif |
| default: |
| format = 0; |
| break; |
| } |
| if ( ! format ) { |
| test_format = SDL_NextAudioFormat(); |
| } |
| } |
| if ( format == 0 ) { |
| SDL_SetError("Couldn't find any hardware audio formats"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| spec->format = test_format; |
| |
| /* Set the audio format */ |
| value = format; |
| if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
| (value != format) ) { |
| perror("SNDCTL_DSP_SETFMT"); |
| SDL_SetError("Couldn't set audio format"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| |
| /* Set the number of channels of output */ |
| value = spec->channels; |
| if ( ioctl(audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0 ) { |
| perror("SNDCTL_DSP_CHANNELS"); |
| SDL_SetError("Cannot set the number of channels"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| spec->channels = value; |
| |
| /* Set the DSP frequency */ |
| value = spec->freq; |
| if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) { |
| perror("SNDCTL_DSP_SPEED"); |
| SDL_SetError("Couldn't set audio frequency"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| spec->freq = value; |
| |
| /* Calculate the final parameters for this audio specification */ |
| SDL_CalculateAudioSpec(spec); |
| |
| /* Determine the power of two of the fragment size */ |
| for ( frag_spec = 0; (0x01U<<frag_spec) < spec->size; ++frag_spec ); |
| if ( (0x01U<<frag_spec) != spec->size ) { |
| SDL_SetError("Fragment size must be a power of two"); |
| DSP_CloseAudio(this); |
| return(-1); |
| } |
| frag_spec |= 0x00020000; /* two fragments, for low latency */ |
| |
| /* Set the audio buffering parameters */ |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Requesting %d fragments of size %d\n", |
| (frag_spec >> 16), 1<<(frag_spec&0xFFFF)); |
| #endif |
| if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) { |
| perror("SNDCTL_DSP_SETFRAGMENT"); |
| } |
| #ifdef DEBUG_AUDIO |
| { audio_buf_info info; |
| ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info); |
| fprintf(stderr, "fragments = %d\n", info.fragments); |
| fprintf(stderr, "fragstotal = %d\n", info.fragstotal); |
| fprintf(stderr, "fragsize = %d\n", info.fragsize); |
| fprintf(stderr, "bytes = %d\n", info.bytes); |
| } |
| #endif |
| |
| /* Allocate mixing buffer */ |
| mixlen = spec->size; |
| mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); |
| if ( mixbuf == NULL ) { |
| DSP_CloseAudio(this); |
| 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); |
| } |