Mercurial > sdl-ios-xcode
view src/audio/dsp/SDL_dspaudio.c @ 2191:29e07f91bc1f
Rename LockAudio,UnlockAudio to LockDevice,UnlockDevice. Also some small fixes
author | Patrice Mandin <patmandin@gmail.com> |
---|---|
date | Fri, 13 Jul 2007 23:58:22 +0000 |
parents | 579abbb51f80 |
children | 99210400e8b9 |
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/* 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_OUTPUT (O_WRONLY|O_NONBLOCK) #define OPEN_FLAGS_INPUT (O_RDONLY|O_NONBLOCK) static char **outputDevices = NULL; static int outputDeviceCount = 0; static char **inputDevices = NULL; static int inputDeviceCount = 0; static inline void free_device_list(char ***devs, int *count) { SDL_FreeUnixAudioDevices(devs, count); } static inline void build_device_list(int iscapture, char ***devs, int *count) { const int flags = ((iscapture) ? OPEN_FLAGS_INPUT : OPEN_FLAGS_OUTPUT); free_device_list(devs, count); SDL_EnumUnixAudioDevices(flags, 0, NULL, devs, count); } static inline void build_device_lists(void) { build_device_list(0, &outputDevices, &outputDeviceCount); build_device_list(1, &inputDevices, &inputDeviceCount); } static inline void free_device_lists(void) { free_device_list(&outputDevices, &outputDeviceCount); free_device_list(&inputDevices, &inputDeviceCount); } static void DSP_Deinitialize(void) { free_device_lists(); } static int DSP_DetectDevices(int iscapture) { if (iscapture) { build_device_list(1, &inputDevices, &inputDeviceCount); return inputDeviceCount; } else { build_device_list(0, &outputDevices, &outputDeviceCount); return outputDeviceCount; } return 0; /* shouldn't ever hit this. */ } static const char * DSP_GetDeviceName(int index, int iscapture) { if ((iscapture) && (index < inputDeviceCount)) { return inputDevices[index]; } else if ((!iscapture) && (index < outputDeviceCount)) { return outputDevices[index]; } SDL_SetError("No such device"); return NULL; } static void DSP_CloseDevice(_THIS) { if (this->hidden != NULL) { if (this->hidden->mixbuf != NULL) { SDL_FreeAudioMem(this->hidden->mixbuf); this->hidden->mixbuf = NULL; } if (this->hidden->audio_fd >= 0) { close(this->hidden->audio_fd); this->hidden->audio_fd = -1; } SDL_free(this->hidden); this->hidden = NULL; } } static int DSP_OpenDevice(_THIS, const char *devname, int iscapture) { const int flags = ((iscapture) ? OPEN_FLAGS_INPUT : OPEN_FLAGS_OUTPUT); int format; int value; int frag_spec; SDL_AudioFormat test_format; /* We don't care what the devname is...we'll try to open anything. */ /* ...but default to first name in the list... */ if (devname == NULL) { if (((iscapture) && (inputDeviceCount == 0)) || ((!iscapture) && (outputDeviceCount == 0))) { SDL_SetError("No such audio device"); return 0; } devname = ((iscapture) ? inputDevices[0] : outputDevices[0]); } /* 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 (this->spec.channels > 8) this->spec.channels = 8; else if (this->spec.channels > 4) this->spec.channels = 4; else if (this->spec.channels > 2) this->spec.channels = 2; /* Initialize all variables that we clean on shutdown */ this->hidden = (struct SDL_PrivateAudioData *) SDL_malloc((sizeof *this->hidden)); if (this->hidden == NULL) { SDL_OutOfMemory(); return 0; } SDL_memset(this->hidden, 0, (sizeof *this->hidden)); /* Open the audio device */ this->hidden->audio_fd = open(devname, flags, 0); if (this->hidden->audio_fd < 0) { DSP_CloseDevice(this); SDL_SetError("Couldn't open %s: %s", devname, strerror(errno)); return 0; } this->hidden->mixbuf = NULL; /* Make the file descriptor use blocking writes with fcntl() */ { long ctlflags; ctlflags = fcntl(this->hidden->audio_fd, F_GETFL); ctlflags &= ~O_NONBLOCK; if (fcntl(this->hidden->audio_fd, F_SETFL, ctlflags) < 0) { DSP_CloseDevice(this); SDL_SetError("Couldn't set audio blocking mode"); return 0; } } /* Get a list of supported hardware formats */ if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0) { perror("SNDCTL_DSP_GETFMTS"); DSP_CloseDevice(this); SDL_SetError("Couldn't get audio format list"); return 0; } /* Try for a closest match on audio format */ format = 0; for (test_format = SDL_FirstAudioFormat(this->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) { DSP_CloseDevice(this); SDL_SetError("Couldn't find any hardware audio formats"); return 0; } this->spec.format = test_format; /* Set the audio format */ value = format; if ((ioctl(this->hidden->audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || (value != format)) { perror("SNDCTL_DSP_SETFMT"); DSP_CloseDevice(this); SDL_SetError("Couldn't set audio format"); return 0; } /* Set the number of channels of output */ value = this->spec.channels; if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0) { perror("SNDCTL_DSP_CHANNELS"); DSP_CloseDevice(this); SDL_SetError("Cannot set the number of channels"); return 0; } this->spec.channels = value; /* Set the DSP frequency */ value = this->spec.freq; if (ioctl(this->hidden->audio_fd, SNDCTL_DSP_SPEED, &value) < 0) { perror("SNDCTL_DSP_SPEED"); DSP_CloseDevice(this); SDL_SetError("Couldn't set audio frequency"); return 0; } this->spec.freq = value; /* Calculate the final parameters for this audio specification */ SDL_CalculateAudioSpec(&this->spec); /* Determine the power of two of the fragment size */ for (frag_spec = 0; (0x01U << frag_spec) < this->spec.size; ++frag_spec); if ((0x01U << frag_spec) != this->spec.size) { DSP_CloseDevice(this); SDL_SetError("Fragment size must be a power of two"); return 0; } 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(this->hidden->audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0) { perror("SNDCTL_DSP_SETFRAGMENT"); } #ifdef DEBUG_AUDIO { audio_buf_info info; ioctl(this->hidden->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 */ this->hidden->mixlen = this->spec.size; this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen); if (this->hidden->mixbuf == NULL) { DSP_CloseDevice(this); SDL_OutOfMemory(); return 0; } SDL_memset(this->hidden->mixbuf, this->spec.silence, this->spec.size); /* We're ready to rock and roll. :-) */ return 1; } static void DSP_PlayDevice(_THIS) { const Uint8 *mixbuf = this->hidden->mixbuf; const int mixlen = this->hidden->mixlen; if (write(this->hidden->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_GetDeviceBuf(_THIS) { return (this->hidden->mixbuf); } static int DSP_Init(SDL_AudioDriverImpl * impl) { /* Set the function pointers */ impl->DetectDevices = DSP_DetectDevices; impl->GetDeviceName = DSP_GetDeviceName; impl->OpenDevice = DSP_OpenDevice; impl->PlayDevice = DSP_PlayDevice; impl->GetDeviceBuf = DSP_GetDeviceBuf; impl->CloseDevice = DSP_CloseDevice; impl->Deinitialize = DSP_Deinitialize; build_device_lists(); return 1; } AudioBootStrap DSP_bootstrap = { DSP_DRIVER_NAME, "OSS /dev/dsp standard audio", DSP_Init, 0 }; /* vi: set ts=4 sw=4 expandtab: */