| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997-2012 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 */ |
| |
| #include <stdio.h> |
| #include <string.h> /* For strerror() */ |
| #include <errno.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <signal.h> |
| #include <sys/types.h> |
| #include <sys/time.h> |
| #include <sys/ioctl.h> |
| #include <sys/stat.h> |
| #include <sys/mman.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 |
| |
| #ifndef MAP_FAILED |
| #define MAP_FAILED ((Uint8 *)-1) |
| #endif |
| |
| #include "SDL_timer.h" |
| #include "SDL_audio.h" |
| #include "../SDL_audio_c.h" |
| #include "../SDL_audiodev_c.h" |
| #include "SDL_dmaaudio.h" |
| |
| /* The tag name used by DMA audio */ |
| #define DMA_DRIVER_NAME "dma" |
| |
| /* Open the audio device for playback, and don't block if busy */ |
| #define OPEN_FLAGS (O_RDWR|O_NONBLOCK) |
| |
| /* Audio driver functions */ |
| static int DMA_OpenAudio(_THIS, SDL_AudioSpec *spec); |
| static void DMA_WaitAudio(_THIS); |
| static void DMA_PlayAudio(_THIS); |
| static Uint8 *DMA_GetAudioBuf(_THIS); |
| static void DMA_CloseAudio(_THIS); |
| |
| /* Audio driver bootstrap functions */ |
| |
| static int Audio_Available(void) |
| { |
| int available; |
| int fd; |
| |
| available = 0; |
| |
| fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0); |
| if ( fd >= 0 ) { |
| int caps; |
| struct audio_buf_info info; |
| |
| if ( (ioctl(fd, SNDCTL_DSP_GETCAPS, &caps) == 0) && |
| (caps & DSP_CAP_TRIGGER) && (caps & DSP_CAP_MMAP) && |
| (ioctl(fd, SNDCTL_DSP_GETOSPACE, &info) == 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 = DMA_OpenAudio; |
| this->WaitAudio = DMA_WaitAudio; |
| this->PlayAudio = DMA_PlayAudio; |
| this->GetAudioBuf = DMA_GetAudioBuf; |
| this->CloseAudio = DMA_CloseAudio; |
| |
| this->free = Audio_DeleteDevice; |
| |
| return this; |
| } |
| |
| AudioBootStrap DMA_bootstrap = { |
| DMA_DRIVER_NAME, "OSS /dev/dsp DMA audio", |
| Audio_Available, Audio_CreateDevice |
| }; |
| |
| /* This function waits until it is possible to write a full sound buffer */ |
| static void DMA_WaitAudio(_THIS) |
| { |
| fd_set fdset; |
| |
| /* 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; |
| } |
| } |
| } |
| |
| /* See if we need to use timed audio synchronization */ |
| if ( frame_ticks ) { |
| /* Use timer for general audio synchronization */ |
| Sint32 ticks; |
| |
| ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; |
| if ( ticks > 0 ) { |
| SDL_Delay(ticks); |
| } |
| } else { |
| /* Use select() for audio synchronization */ |
| struct timeval timeout; |
| FD_ZERO(&fdset); |
| FD_SET(audio_fd, &fdset); |
| timeout.tv_sec = 10; |
| timeout.tv_usec = 0; |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Waiting for audio to get ready\n"); |
| #endif |
| if ( select(audio_fd+1, NULL, &fdset, NULL, &timeout) <= 0 ) { |
| const char *message = |
| #ifdef AUDIO_OSPACE_HACK |
| "Audio timeout - buggy audio driver? (trying ospace)"; |
| #else |
| "Audio timeout - buggy audio driver? (disabled)"; |
| #endif |
| /* In general we should never print to the screen, |
| but in this case we have no other way of letting |
| the user know what happened. |
| */ |
| fprintf(stderr, "SDL: %s\n", message); |
| #ifdef AUDIO_OSPACE_HACK |
| /* We may be able to use GET_OSPACE trick */ |
| frame_ticks = (float)(this->spec->samples*1000) / |
| this->spec->freq; |
| next_frame = SDL_GetTicks()+frame_ticks; |
| #else |
| this->enabled = 0; |
| /* Don't try to close - may hang */ |
| audio_fd = -1; |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Done disabling audio\n"); |
| #endif |
| #endif /* AUDIO_OSPACE_HACK */ |
| } |
| #ifdef DEBUG_AUDIO |
| fprintf(stderr, "Ready!\n"); |
| #endif |
| } |
| } |
| |
| static void DMA_PlayAudio(_THIS) |
| { |
| /* If timer synchronization is enabled, set the next write frame */ |
| if ( frame_ticks ) { |
| next_frame += frame_ticks; |
| } |
| return; |
| } |
| |
| static Uint8 *DMA_GetAudioBuf(_THIS) |
| { |
| count_info info; |
| int playing; |
| int filling; |
| |
| /* Get number of blocks, looping if we're not using select() */ |
| do { |
| if ( ioctl(audio_fd, SNDCTL_DSP_GETOPTR, &info) < 0 ) { |
| /* Uh oh... */ |
| this->enabled = 0; |
| return(NULL); |
| } |
| } while ( frame_ticks && (info.blocks < 1) ); |
| #ifdef DEBUG_AUDIO |
| if ( info.blocks > 1 ) { |
| printf("Warning: audio underflow (%d frags)\n", info.blocks-1); |
| } |
| #endif |
| playing = info.ptr / this->spec.size; |
| filling = (playing + 1)%num_buffers; |
| return (dma_buf + (filling * this->spec.size)); |
| } |
| |
| static void DMA_CloseAudio(_THIS) |
| { |
| if ( dma_buf != NULL ) { |
| munmap(dma_buf, dma_len); |
| dma_buf = NULL; |
| } |
| if ( audio_fd >= 0 ) { |
| close(audio_fd); |
| audio_fd = -1; |
| } |
| } |
| |
| static int DMA_ReopenAudio(_THIS, const char *audiodev, int format, int stereo, |
| SDL_AudioSpec *spec) |
| { |
| int frag_spec; |
| int value; |
| |
| /* Close and then reopen the audio device */ |
| close(audio_fd); |
| audio_fd = open(audiodev, O_RDWR, 0); |
| if ( audio_fd < 0 ) { |
| SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); |
| return(-1); |
| } |
| |
| /* 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); |
| } |
| |
| /* Set the audio buffering parameters */ |
| if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) { |
| SDL_SetError("Couldn't set audio fragment spec"); |
| return(-1); |
| } |
| |
| /* Set the audio format */ |
| value = format; |
| if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
| (value != format) ) { |
| SDL_SetError("Couldn't set audio format"); |
| return(-1); |
| } |
| |
| /* Set mono or stereo audio */ |
| value = (spec->channels > 1); |
| if ( (ioctl(audio_fd, SNDCTL_DSP_STEREO, &stereo) < 0) || |
| (value != stereo) ) { |
| SDL_SetError("Couldn't set audio channels"); |
| return(-1); |
| } |
| |
| /* Set the DSP frequency */ |
| value = spec->freq; |
| if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) { |
| SDL_SetError("Couldn't set audio frequency"); |
| return(-1); |
| } |
| spec->freq = value; |
| |
| /* We successfully re-opened the audio */ |
| return(0); |
| } |
| |
| static int DMA_OpenAudio(_THIS, SDL_AudioSpec *spec) |
| { |
| char audiodev[1024]; |
| int format; |
| int stereo; |
| int value; |
| Uint16 test_format; |
| struct audio_buf_info info; |
| |
| /* Reset the timer synchronization flag */ |
| frame_ticks = 0.0; |
| |
| /* 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); |
| } |
| dma_buf = NULL; |
| ioctl(audio_fd, SNDCTL_DSP_RESET, 0); |
| |
| /* Get a list of supported hardware formats */ |
| if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) { |
| SDL_SetError("Couldn't get audio format list"); |
| 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_S8: |
| if ( value & AFMT_S8 ) { |
| format = AFMT_S8; |
| } |
| 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; |
| 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; |
| 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; |
| |
| /* Set the audio format */ |
| value = format; |
| if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
| (value != format) ) { |
| SDL_SetError("Couldn't set audio format"); |
| return(-1); |
| } |
| |
| /* Set mono or stereo audio (currently only two channels supported) */ |
| stereo = (spec->channels > 1); |
| ioctl(audio_fd, SNDCTL_DSP_STEREO, &stereo); |
| if ( stereo ) { |
| spec->channels = 2; |
| } else { |
| spec->channels = 1; |
| } |
| |
| /* Because some drivers don't allow setting the buffer size |
| after setting the format, we must re-open the audio device |
| once we know what format and channels are supported |
| */ |
| if ( DMA_ReopenAudio(this, audiodev, format, stereo, spec) < 0 ) { |
| /* Error is set by DMA_ReopenAudio() */ |
| return(-1); |
| } |
| |
| /* Memory map the audio buffer */ |
| if ( ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info) < 0 ) { |
| SDL_SetError("Couldn't get OSPACE parameters"); |
| return(-1); |
| } |
| spec->size = info.fragsize; |
| spec->samples = spec->size / ((spec->format & 0xFF) / 8); |
| spec->samples /= spec->channels; |
| num_buffers = info.fragstotal; |
| dma_len = num_buffers*spec->size; |
| dma_buf = (Uint8 *)mmap(NULL, dma_len, PROT_WRITE, MAP_SHARED, |
| audio_fd, 0); |
| if ( dma_buf == MAP_FAILED ) { |
| SDL_SetError("DMA memory map failed"); |
| dma_buf = NULL; |
| return(-1); |
| } |
| SDL_memset(dma_buf, spec->silence, dma_len); |
| |
| /* Check to see if we need to use select() workaround */ |
| { char *workaround; |
| workaround = SDL_getenv("SDL_DSP_NOSELECT"); |
| if ( workaround ) { |
| frame_ticks = (float)(spec->samples*1000)/spec->freq; |
| next_frame = SDL_GetTicks()+frame_ticks; |
| } |
| } |
| |
| /* Trigger audio playback */ |
| value = 0; |
| ioctl(audio_fd, SNDCTL_DSP_SETTRIGGER, &value); |
| value = PCM_ENABLE_OUTPUT; |
| if ( ioctl(audio_fd, SNDCTL_DSP_SETTRIGGER, &value) < 0 ) { |
| SDL_SetError("Couldn't trigger audio output"); |
| return(-1); |
| } |
| |
| /* Get the parent process id (we're the parent of the audio thread) */ |
| parent = getpid(); |
| |
| /* We're ready to rock and roll. :-) */ |
| return(0); |
| } |