| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| #include "../../SDL_internal.h" |
| |
| #if SDL_AUDIO_DRIVER_ALSA |
| |
| /* Allow access to a raw mixing buffer */ |
| |
| #include <sys/types.h> |
| #include <signal.h> /* For kill() */ |
| #include <errno.h> |
| #include <string.h> |
| |
| #include "SDL_assert.h" |
| #include "SDL_timer.h" |
| #include "SDL_audio.h" |
| #include "../SDL_audio_c.h" |
| #include "SDL_alsa_audio.h" |
| |
| #ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC |
| #include "SDL_loadso.h" |
| #endif |
| |
| static int (*ALSA_snd_pcm_open) |
| (snd_pcm_t **, const char *, snd_pcm_stream_t, int); |
| static int (*ALSA_snd_pcm_close) (snd_pcm_t * pcm); |
| static snd_pcm_sframes_t (*ALSA_snd_pcm_writei) |
| (snd_pcm_t *, const void *, snd_pcm_uframes_t); |
| static snd_pcm_sframes_t (*ALSA_snd_pcm_readi) |
| (snd_pcm_t *, void *, snd_pcm_uframes_t); |
| static int (*ALSA_snd_pcm_recover) (snd_pcm_t *, int, int); |
| static int (*ALSA_snd_pcm_prepare) (snd_pcm_t *); |
| static int (*ALSA_snd_pcm_drain) (snd_pcm_t *); |
| static const char *(*ALSA_snd_strerror) (int); |
| static size_t(*ALSA_snd_pcm_hw_params_sizeof) (void); |
| static size_t(*ALSA_snd_pcm_sw_params_sizeof) (void); |
| static void (*ALSA_snd_pcm_hw_params_copy) |
| (snd_pcm_hw_params_t *, const snd_pcm_hw_params_t *); |
| static int (*ALSA_snd_pcm_hw_params_any) (snd_pcm_t *, snd_pcm_hw_params_t *); |
| static int (*ALSA_snd_pcm_hw_params_set_access) |
| (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_access_t); |
| static int (*ALSA_snd_pcm_hw_params_set_format) |
| (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_format_t); |
| static int (*ALSA_snd_pcm_hw_params_set_channels) |
| (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int); |
| static int (*ALSA_snd_pcm_hw_params_get_channels) |
| (const snd_pcm_hw_params_t *, unsigned int *); |
| static int (*ALSA_snd_pcm_hw_params_set_rate_near) |
| (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int *, int *); |
| static int (*ALSA_snd_pcm_hw_params_set_period_size_near) |
| (snd_pcm_t *, snd_pcm_hw_params_t *, snd_pcm_uframes_t *, int *); |
| static int (*ALSA_snd_pcm_hw_params_get_period_size) |
| (const snd_pcm_hw_params_t *, snd_pcm_uframes_t *, int *); |
| static int (*ALSA_snd_pcm_hw_params_set_periods_near) |
| (snd_pcm_t *, snd_pcm_hw_params_t *, unsigned int *, int *); |
| static int (*ALSA_snd_pcm_hw_params_get_periods) |
| (const snd_pcm_hw_params_t *, unsigned int *, int *); |
| static int (*ALSA_snd_pcm_hw_params_set_buffer_size_near) |
| (snd_pcm_t *pcm, snd_pcm_hw_params_t *, snd_pcm_uframes_t *); |
| static int (*ALSA_snd_pcm_hw_params_get_buffer_size) |
| (const snd_pcm_hw_params_t *, snd_pcm_uframes_t *); |
| static int (*ALSA_snd_pcm_hw_params) (snd_pcm_t *, snd_pcm_hw_params_t *); |
| static int (*ALSA_snd_pcm_sw_params_current) (snd_pcm_t *, |
| snd_pcm_sw_params_t *); |
| static int (*ALSA_snd_pcm_sw_params_set_start_threshold) |
| (snd_pcm_t *, snd_pcm_sw_params_t *, snd_pcm_uframes_t); |
| static int (*ALSA_snd_pcm_sw_params) (snd_pcm_t *, snd_pcm_sw_params_t *); |
| static int (*ALSA_snd_pcm_nonblock) (snd_pcm_t *, int); |
| static int (*ALSA_snd_pcm_wait)(snd_pcm_t *, int); |
| static int (*ALSA_snd_pcm_sw_params_set_avail_min) |
| (snd_pcm_t *, snd_pcm_sw_params_t *, snd_pcm_uframes_t); |
| static int (*ALSA_snd_pcm_reset)(snd_pcm_t *); |
| static int (*ALSA_snd_device_name_hint) (int, const char *, void ***); |
| static char* (*ALSA_snd_device_name_get_hint) (const void *, const char *); |
| static int (*ALSA_snd_device_name_free_hint) (void **); |
| |
| #ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC |
| #define snd_pcm_hw_params_sizeof ALSA_snd_pcm_hw_params_sizeof |
| #define snd_pcm_sw_params_sizeof ALSA_snd_pcm_sw_params_sizeof |
| |
| static const char *alsa_library = SDL_AUDIO_DRIVER_ALSA_DYNAMIC; |
| static void *alsa_handle = NULL; |
| |
| static int |
| load_alsa_sym(const char *fn, void **addr) |
| { |
| *addr = SDL_LoadFunction(alsa_handle, fn); |
| if (*addr == NULL) { |
| /* Don't call SDL_SetError(): SDL_LoadFunction already did. */ |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* cast funcs to char* first, to please GCC's strict aliasing rules. */ |
| #define SDL_ALSA_SYM(x) \ |
| if (!load_alsa_sym(#x, (void **) (char *) &ALSA_##x)) return -1 |
| #else |
| #define SDL_ALSA_SYM(x) ALSA_##x = x |
| #endif |
| |
| static int |
| load_alsa_syms(void) |
| { |
| SDL_ALSA_SYM(snd_pcm_open); |
| SDL_ALSA_SYM(snd_pcm_close); |
| SDL_ALSA_SYM(snd_pcm_writei); |
| SDL_ALSA_SYM(snd_pcm_readi); |
| SDL_ALSA_SYM(snd_pcm_recover); |
| SDL_ALSA_SYM(snd_pcm_prepare); |
| SDL_ALSA_SYM(snd_pcm_drain); |
| SDL_ALSA_SYM(snd_strerror); |
| SDL_ALSA_SYM(snd_pcm_hw_params_sizeof); |
| SDL_ALSA_SYM(snd_pcm_sw_params_sizeof); |
| SDL_ALSA_SYM(snd_pcm_hw_params_copy); |
| SDL_ALSA_SYM(snd_pcm_hw_params_any); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_access); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_format); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_channels); |
| SDL_ALSA_SYM(snd_pcm_hw_params_get_channels); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_rate_near); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_period_size_near); |
| SDL_ALSA_SYM(snd_pcm_hw_params_get_period_size); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_periods_near); |
| SDL_ALSA_SYM(snd_pcm_hw_params_get_periods); |
| SDL_ALSA_SYM(snd_pcm_hw_params_set_buffer_size_near); |
| SDL_ALSA_SYM(snd_pcm_hw_params_get_buffer_size); |
| SDL_ALSA_SYM(snd_pcm_hw_params); |
| SDL_ALSA_SYM(snd_pcm_sw_params_current); |
| SDL_ALSA_SYM(snd_pcm_sw_params_set_start_threshold); |
| SDL_ALSA_SYM(snd_pcm_sw_params); |
| SDL_ALSA_SYM(snd_pcm_nonblock); |
| SDL_ALSA_SYM(snd_pcm_wait); |
| SDL_ALSA_SYM(snd_pcm_sw_params_set_avail_min); |
| SDL_ALSA_SYM(snd_pcm_reset); |
| SDL_ALSA_SYM(snd_device_name_hint); |
| SDL_ALSA_SYM(snd_device_name_get_hint); |
| SDL_ALSA_SYM(snd_device_name_free_hint); |
| |
| return 0; |
| } |
| |
| #undef SDL_ALSA_SYM |
| |
| #ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC |
| |
| static void |
| UnloadALSALibrary(void) |
| { |
| if (alsa_handle != NULL) { |
| SDL_UnloadObject(alsa_handle); |
| alsa_handle = NULL; |
| } |
| } |
| |
| static int |
| LoadALSALibrary(void) |
| { |
| int retval = 0; |
| if (alsa_handle == NULL) { |
| alsa_handle = SDL_LoadObject(alsa_library); |
| if (alsa_handle == NULL) { |
| retval = -1; |
| /* Don't call SDL_SetError(): SDL_LoadObject already did. */ |
| } else { |
| retval = load_alsa_syms(); |
| if (retval < 0) { |
| UnloadALSALibrary(); |
| } |
| } |
| } |
| return retval; |
| } |
| |
| #else |
| |
| static void |
| UnloadALSALibrary(void) |
| { |
| } |
| |
| static int |
| LoadALSALibrary(void) |
| { |
| load_alsa_syms(); |
| return 0; |
| } |
| |
| #endif /* SDL_AUDIO_DRIVER_ALSA_DYNAMIC */ |
| |
| static const char * |
| get_audio_device(void *handle, const int channels) |
| { |
| const char *device; |
| |
| if (handle != NULL) { |
| return (const char *) handle; |
| } |
| |
| /* !!! FIXME: we also check "SDL_AUDIO_DEVICE_NAME" at the higher level. */ |
| device = SDL_getenv("AUDIODEV"); /* Is there a standard variable name? */ |
| if (device != NULL) { |
| return device; |
| } |
| |
| if (channels == 6) { |
| return "plug:surround51"; |
| } else if (channels == 4) { |
| return "plug:surround40"; |
| } |
| |
| return "default"; |
| } |
| |
| |
| /* This function waits until it is possible to write a full sound buffer */ |
| static void |
| ALSA_WaitDevice(_THIS) |
| { |
| /* We're in blocking mode, so there's nothing to do here */ |
| } |
| |
| |
| /* !!! FIXME: is there a channel swizzler in alsalib instead? */ |
| /* |
| * http://bugzilla.libsdl.org/show_bug.cgi?id=110 |
| * "For Linux ALSA, this is FL-FR-RL-RR-C-LFE |
| * and for Windows DirectX [and CoreAudio], this is FL-FR-C-LFE-RL-RR" |
| */ |
| #define SWIZ6(T, buf, numframes) \ |
| T *ptr = (T *) buf; \ |
| Uint32 i; \ |
| for (i = 0; i < numframes; i++, ptr += 6) { \ |
| T tmp; \ |
| tmp = ptr[2]; ptr[2] = ptr[4]; ptr[4] = tmp; \ |
| tmp = ptr[3]; ptr[3] = ptr[5]; ptr[5] = tmp; \ |
| } |
| |
| static SDL_INLINE void |
| swizzle_alsa_channels_6_64bit(void *buffer, Uint32 bufferlen) |
| { |
| SWIZ6(Uint64, buffer, bufferlen); |
| } |
| |
| static SDL_INLINE void |
| swizzle_alsa_channels_6_32bit(void *buffer, Uint32 bufferlen) |
| { |
| SWIZ6(Uint32, buffer, bufferlen); |
| } |
| |
| static SDL_INLINE void |
| swizzle_alsa_channels_6_16bit(void *buffer, Uint32 bufferlen) |
| { |
| SWIZ6(Uint16, buffer, bufferlen); |
| } |
| |
| static SDL_INLINE void |
| swizzle_alsa_channels_6_8bit(void *buffer, Uint32 bufferlen) |
| { |
| SWIZ6(Uint8, buffer, bufferlen); |
| } |
| |
| #undef SWIZ6 |
| |
| |
| /* |
| * Called right before feeding this->hidden->mixbuf to the hardware. Swizzle |
| * channels from Windows/Mac order to the format alsalib will want. |
| */ |
| static SDL_INLINE void |
| swizzle_alsa_channels(_THIS, void *buffer, Uint32 bufferlen) |
| { |
| if (this->spec.channels == 6) { |
| switch (SDL_AUDIO_BITSIZE(this->spec.format)) { |
| case 8: swizzle_alsa_channels_6_8bit(buffer, bufferlen); break; |
| case 16: swizzle_alsa_channels_6_16bit(buffer, bufferlen); break; |
| case 32: swizzle_alsa_channels_6_32bit(buffer, bufferlen); break; |
| case 64: swizzle_alsa_channels_6_64bit(buffer, bufferlen); break; |
| default: SDL_assert(!"unhandled bitsize"); break; |
| } |
| } |
| |
| /* !!! FIXME: update this for 7.1 if needed, later. */ |
| } |
| |
| |
| static void |
| ALSA_PlayDevice(_THIS) |
| { |
| const Uint8 *sample_buf = (const Uint8 *) this->hidden->mixbuf; |
| const int frame_size = (((int) SDL_AUDIO_BITSIZE(this->spec.format)) / 8) * |
| this->spec.channels; |
| snd_pcm_uframes_t frames_left = ((snd_pcm_uframes_t) this->spec.samples); |
| |
| swizzle_alsa_channels(this, this->hidden->mixbuf, frames_left); |
| |
| while ( frames_left > 0 && SDL_AtomicGet(&this->enabled) ) { |
| /* !!! FIXME: This works, but needs more testing before going live */ |
| /* ALSA_snd_pcm_wait(this->hidden->pcm_handle, -1); */ |
| int status = ALSA_snd_pcm_writei(this->hidden->pcm_handle, |
| sample_buf, frames_left); |
| |
| if (status < 0) { |
| if (status == -EAGAIN) { |
| /* Apparently snd_pcm_recover() doesn't handle this case - |
| does it assume snd_pcm_wait() above? */ |
| SDL_Delay(1); |
| continue; |
| } |
| status = ALSA_snd_pcm_recover(this->hidden->pcm_handle, status, 0); |
| if (status < 0) { |
| /* Hmm, not much we can do - abort */ |
| fprintf(stderr, "ALSA write failed (unrecoverable): %s\n", |
| ALSA_snd_strerror(status)); |
| SDL_OpenedAudioDeviceDisconnected(this); |
| return; |
| } |
| continue; |
| } |
| sample_buf += status * frame_size; |
| frames_left -= status; |
| } |
| } |
| |
| static Uint8 * |
| ALSA_GetDeviceBuf(_THIS) |
| { |
| return (this->hidden->mixbuf); |
| } |
| |
| static int |
| ALSA_CaptureFromDevice(_THIS, void *buffer, int buflen) |
| { |
| Uint8 *sample_buf = (Uint8 *) buffer; |
| const int frame_size = (((int) SDL_AUDIO_BITSIZE(this->spec.format)) / 8) * |
| this->spec.channels; |
| const int total_frames = buflen / frame_size; |
| snd_pcm_uframes_t frames_left = total_frames; |
| |
| SDL_assert((buflen % frame_size) == 0); |
| |
| while ( frames_left > 0 && SDL_AtomicGet(&this->enabled) ) { |
| /* !!! FIXME: This works, but needs more testing before going live */ |
| /* ALSA_snd_pcm_wait(this->hidden->pcm_handle, -1); */ |
| int status = ALSA_snd_pcm_readi(this->hidden->pcm_handle, |
| sample_buf, frames_left); |
| |
| if (status < 0) { |
| /*printf("ALSA: capture error %d\n", status);*/ |
| if (status == -EAGAIN) { |
| /* Apparently snd_pcm_recover() doesn't handle this case - |
| does it assume snd_pcm_wait() above? */ |
| SDL_Delay(1); |
| continue; |
| } |
| status = ALSA_snd_pcm_recover(this->hidden->pcm_handle, status, 0); |
| if (status < 0) { |
| /* Hmm, not much we can do - abort */ |
| fprintf(stderr, "ALSA read failed (unrecoverable): %s\n", |
| ALSA_snd_strerror(status)); |
| return -1; |
| } |
| continue; |
| } |
| |
| /*printf("ALSA: captured %d bytes\n", status * frame_size);*/ |
| sample_buf += status * frame_size; |
| frames_left -= status; |
| } |
| |
| swizzle_alsa_channels(this, buffer, total_frames - frames_left); |
| |
| return (total_frames - frames_left) * frame_size; |
| } |
| |
| static void |
| ALSA_FlushCapture(_THIS) |
| { |
| ALSA_snd_pcm_reset(this->hidden->pcm_handle); |
| } |
| |
| static void |
| ALSA_CloseDevice(_THIS) |
| { |
| if (this->hidden->pcm_handle) { |
| /* Wait for the submitted audio to drain |
| ALSA_snd_pcm_drop() can hang, so don't use that. |
| */ |
| Uint32 delay = ((this->spec.samples * 1000) / this->spec.freq) * 2; |
| SDL_Delay(delay); |
| |
| ALSA_snd_pcm_close(this->hidden->pcm_handle); |
| } |
| SDL_free(this->hidden->mixbuf); |
| SDL_free(this->hidden); |
| } |
| |
| static int |
| ALSA_finalize_hardware(_THIS, snd_pcm_hw_params_t *hwparams, int override) |
| { |
| int status; |
| snd_pcm_uframes_t bufsize; |
| |
| /* "set" the hardware with the desired parameters */ |
| status = ALSA_snd_pcm_hw_params(this->hidden->pcm_handle, hwparams); |
| if ( status < 0 ) { |
| return(-1); |
| } |
| |
| /* Get samples for the actual buffer size */ |
| status = ALSA_snd_pcm_hw_params_get_buffer_size(hwparams, &bufsize); |
| if ( status < 0 ) { |
| return(-1); |
| } |
| if ( !override && bufsize != this->spec.samples * 2 ) { |
| return(-1); |
| } |
| |
| /* !!! FIXME: Is this safe to do? */ |
| this->spec.samples = bufsize / 2; |
| |
| /* This is useful for debugging */ |
| if ( SDL_getenv("SDL_AUDIO_ALSA_DEBUG") ) { |
| snd_pcm_uframes_t persize = 0; |
| unsigned int periods = 0; |
| |
| ALSA_snd_pcm_hw_params_get_period_size(hwparams, &persize, NULL); |
| ALSA_snd_pcm_hw_params_get_periods(hwparams, &periods, NULL); |
| |
| fprintf(stderr, |
| "ALSA: period size = %ld, periods = %u, buffer size = %lu\n", |
| persize, periods, bufsize); |
| } |
| |
| return(0); |
| } |
| |
| static int |
| ALSA_set_period_size(_THIS, snd_pcm_hw_params_t *params, int override) |
| { |
| const char *env; |
| int status; |
| snd_pcm_hw_params_t *hwparams; |
| snd_pcm_uframes_t frames; |
| unsigned int periods; |
| |
| /* Copy the hardware parameters for this setup */ |
| snd_pcm_hw_params_alloca(&hwparams); |
| ALSA_snd_pcm_hw_params_copy(hwparams, params); |
| |
| if ( !override ) { |
| env = SDL_getenv("SDL_AUDIO_ALSA_SET_PERIOD_SIZE"); |
| if ( env ) { |
| override = SDL_atoi(env); |
| if ( override == 0 ) { |
| return(-1); |
| } |
| } |
| } |
| |
| frames = this->spec.samples; |
| status = ALSA_snd_pcm_hw_params_set_period_size_near( |
| this->hidden->pcm_handle, hwparams, &frames, NULL); |
| if ( status < 0 ) { |
| return(-1); |
| } |
| |
| periods = 2; |
| status = ALSA_snd_pcm_hw_params_set_periods_near( |
| this->hidden->pcm_handle, hwparams, &periods, NULL); |
| if ( status < 0 ) { |
| return(-1); |
| } |
| |
| return ALSA_finalize_hardware(this, hwparams, override); |
| } |
| |
| static int |
| ALSA_set_buffer_size(_THIS, snd_pcm_hw_params_t *params, int override) |
| { |
| const char *env; |
| int status; |
| snd_pcm_hw_params_t *hwparams; |
| snd_pcm_uframes_t frames; |
| |
| /* Copy the hardware parameters for this setup */ |
| snd_pcm_hw_params_alloca(&hwparams); |
| ALSA_snd_pcm_hw_params_copy(hwparams, params); |
| |
| if ( !override ) { |
| env = SDL_getenv("SDL_AUDIO_ALSA_SET_BUFFER_SIZE"); |
| if ( env ) { |
| override = SDL_atoi(env); |
| if ( override == 0 ) { |
| return(-1); |
| } |
| } |
| } |
| |
| frames = this->spec.samples * 2; |
| status = ALSA_snd_pcm_hw_params_set_buffer_size_near( |
| this->hidden->pcm_handle, hwparams, &frames); |
| if ( status < 0 ) { |
| return(-1); |
| } |
| |
| return ALSA_finalize_hardware(this, hwparams, override); |
| } |
| |
| static int |
| ALSA_OpenDevice(_THIS, void *handle, const char *devname, int iscapture) |
| { |
| int status = 0; |
| snd_pcm_t *pcm_handle = NULL; |
| snd_pcm_hw_params_t *hwparams = NULL; |
| snd_pcm_sw_params_t *swparams = NULL; |
| snd_pcm_format_t format = 0; |
| SDL_AudioFormat test_format = 0; |
| unsigned int rate = 0; |
| unsigned int channels = 0; |
| |
| /* Initialize all variables that we clean on shutdown */ |
| this->hidden = (struct SDL_PrivateAudioData *) |
| SDL_malloc((sizeof *this->hidden)); |
| if (this->hidden == NULL) { |
| return SDL_OutOfMemory(); |
| } |
| SDL_zerop(this->hidden); |
| |
| /* Open the audio device */ |
| /* Name of device should depend on # channels in spec */ |
| status = ALSA_snd_pcm_open(&pcm_handle, |
| get_audio_device(handle, this->spec.channels), |
| iscapture ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK, |
| SND_PCM_NONBLOCK); |
| |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't open audio device: %s", |
| ALSA_snd_strerror(status)); |
| } |
| |
| this->hidden->pcm_handle = pcm_handle; |
| |
| /* Figure out what the hardware is capable of */ |
| snd_pcm_hw_params_alloca(&hwparams); |
| status = ALSA_snd_pcm_hw_params_any(pcm_handle, hwparams); |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't get hardware config: %s", |
| ALSA_snd_strerror(status)); |
| } |
| |
| /* SDL only uses interleaved sample output */ |
| status = ALSA_snd_pcm_hw_params_set_access(pcm_handle, hwparams, |
| SND_PCM_ACCESS_RW_INTERLEAVED); |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't set interleaved access: %s", |
| ALSA_snd_strerror(status)); |
| } |
| |
| /* Try for a closest match on audio format */ |
| status = -1; |
| for (test_format = SDL_FirstAudioFormat(this->spec.format); |
| test_format && (status < 0);) { |
| status = 0; /* if we can't support a format, it'll become -1. */ |
| switch (test_format) { |
| case AUDIO_U8: |
| format = SND_PCM_FORMAT_U8; |
| break; |
| case AUDIO_S8: |
| format = SND_PCM_FORMAT_S8; |
| break; |
| case AUDIO_S16LSB: |
| format = SND_PCM_FORMAT_S16_LE; |
| break; |
| case AUDIO_S16MSB: |
| format = SND_PCM_FORMAT_S16_BE; |
| break; |
| case AUDIO_U16LSB: |
| format = SND_PCM_FORMAT_U16_LE; |
| break; |
| case AUDIO_U16MSB: |
| format = SND_PCM_FORMAT_U16_BE; |
| break; |
| case AUDIO_S32LSB: |
| format = SND_PCM_FORMAT_S32_LE; |
| break; |
| case AUDIO_S32MSB: |
| format = SND_PCM_FORMAT_S32_BE; |
| break; |
| case AUDIO_F32LSB: |
| format = SND_PCM_FORMAT_FLOAT_LE; |
| break; |
| case AUDIO_F32MSB: |
| format = SND_PCM_FORMAT_FLOAT_BE; |
| break; |
| default: |
| status = -1; |
| break; |
| } |
| if (status >= 0) { |
| status = ALSA_snd_pcm_hw_params_set_format(pcm_handle, |
| hwparams, format); |
| } |
| if (status < 0) { |
| test_format = SDL_NextAudioFormat(); |
| } |
| } |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't find any hardware audio formats"); |
| } |
| this->spec.format = test_format; |
| |
| /* Set the number of channels */ |
| status = ALSA_snd_pcm_hw_params_set_channels(pcm_handle, hwparams, |
| this->spec.channels); |
| channels = this->spec.channels; |
| if (status < 0) { |
| status = ALSA_snd_pcm_hw_params_get_channels(hwparams, &channels); |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't set audio channels"); |
| } |
| this->spec.channels = channels; |
| } |
| |
| /* Set the audio rate */ |
| rate = this->spec.freq; |
| status = ALSA_snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, |
| &rate, NULL); |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't set audio frequency: %s", |
| ALSA_snd_strerror(status)); |
| } |
| this->spec.freq = rate; |
| |
| /* Set the buffer size, in samples */ |
| if ( ALSA_set_period_size(this, hwparams, 0) < 0 && |
| ALSA_set_buffer_size(this, hwparams, 0) < 0 ) { |
| /* Failed to set desired buffer size, do the best you can... */ |
| status = ALSA_set_period_size(this, hwparams, 1); |
| if (status < 0) { |
| return SDL_SetError("Couldn't set hardware audio parameters: %s", ALSA_snd_strerror(status)); |
| } |
| } |
| /* Set the software parameters */ |
| snd_pcm_sw_params_alloca(&swparams); |
| status = ALSA_snd_pcm_sw_params_current(pcm_handle, swparams); |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't get software config: %s", |
| ALSA_snd_strerror(status)); |
| } |
| status = ALSA_snd_pcm_sw_params_set_avail_min(pcm_handle, swparams, this->spec.samples); |
| if (status < 0) { |
| return SDL_SetError("Couldn't set minimum available samples: %s", |
| ALSA_snd_strerror(status)); |
| } |
| status = |
| ALSA_snd_pcm_sw_params_set_start_threshold(pcm_handle, swparams, 1); |
| if (status < 0) { |
| return SDL_SetError("ALSA: Couldn't set start threshold: %s", |
| ALSA_snd_strerror(status)); |
| } |
| status = ALSA_snd_pcm_sw_params(pcm_handle, swparams); |
| if (status < 0) { |
| return SDL_SetError("Couldn't set software audio parameters: %s", |
| ALSA_snd_strerror(status)); |
| } |
| |
| /* Calculate the final parameters for this audio specification */ |
| SDL_CalculateAudioSpec(&this->spec); |
| |
| /* Allocate mixing buffer */ |
| if (!iscapture) { |
| this->hidden->mixlen = this->spec.size; |
| this->hidden->mixbuf = (Uint8 *) SDL_malloc(this->hidden->mixlen); |
| if (this->hidden->mixbuf == NULL) { |
| return SDL_OutOfMemory(); |
| } |
| SDL_memset(this->hidden->mixbuf, this->spec.silence, this->hidden->mixlen); |
| } |
| |
| /* Switch to blocking mode for playback */ |
| ALSA_snd_pcm_nonblock(pcm_handle, 0); |
| |
| /* We're ready to rock and roll. :-) */ |
| return 0; |
| } |
| |
| typedef struct ALSA_Device |
| { |
| char *name; |
| SDL_bool iscapture; |
| struct ALSA_Device *next; |
| } ALSA_Device; |
| |
| static void |
| add_device(const int iscapture, const char *name, void *hint, ALSA_Device **pSeen) |
| { |
| ALSA_Device *dev = SDL_malloc(sizeof (ALSA_Device)); |
| char *desc = ALSA_snd_device_name_get_hint(hint, "DESC"); |
| char *handle = NULL; |
| char *ptr; |
| |
| if (!desc) { |
| SDL_free(dev); |
| return; |
| } else if (!dev) { |
| free(desc); |
| return; |
| } |
| |
| SDL_assert(name != NULL); |
| |
| /* some strings have newlines, like "HDA NVidia, HDMI 0\nHDMI Audio Output". |
| just chop the extra lines off, this seems to get a reasonable device |
| name without extra details. */ |
| if ((ptr = strchr(desc, '\n')) != NULL) { |
| *ptr = '\0'; |
| } |
| |
| /*printf("ALSA: adding %s device '%s' (%s)\n", iscapture ? "capture" : "output", name, desc);*/ |
| |
| handle = SDL_strdup(name); |
| if (!handle) { |
| free(desc); |
| SDL_free(dev); |
| return; |
| } |
| |
| SDL_AddAudioDevice(iscapture, desc, handle); |
| free(desc); |
| |
| dev->name = handle; |
| dev->iscapture = iscapture; |
| dev->next = *pSeen; |
| *pSeen = dev; |
| } |
| |
| |
| static SDL_atomic_t ALSA_hotplug_shutdown; |
| static SDL_Thread *ALSA_hotplug_thread; |
| |
| static int SDLCALL |
| ALSA_HotplugThread(void *arg) |
| { |
| SDL_sem *first_run_semaphore = (SDL_sem *) arg; |
| ALSA_Device *devices = NULL; |
| ALSA_Device *next; |
| ALSA_Device *dev; |
| Uint32 ticks; |
| |
| while (!SDL_AtomicGet(&ALSA_hotplug_shutdown)) { |
| void **hints = NULL; |
| if (ALSA_snd_device_name_hint(-1, "pcm", &hints) != -1) { |
| ALSA_Device *unseen = devices; |
| ALSA_Device *seen = NULL; |
| ALSA_Device *prev; |
| int i; |
| const char *match = "default:"; |
| size_t match_len = strlen(match); |
| |
| /* determine what kind of name to match. Use "hw:" devices if they |
| exist, otherwise use "default:" */ |
| for (i = 0; hints[i]; i++) { |
| char *name = ALSA_snd_device_name_get_hint(hints[i], "NAME"); |
| if (!name) { |
| continue; |
| } |
| |
| if (SDL_strncmp(name, "hw:", 3) == 0) { |
| match = "hw:"; |
| match_len = strlen(match); |
| free(name); |
| break; |
| } |
| |
| free(name); |
| } |
| |
| /* look through the list of device names to find matches */ |
| for (i = 0; hints[i]; i++) { |
| char *name = ALSA_snd_device_name_get_hint(hints[i], "NAME"); |
| if (!name) { |
| continue; |
| } |
| |
| /* only want physical hardware interfaces */ |
| if (SDL_strncmp(name, match, match_len) == 0) { |
| char *ioid = ALSA_snd_device_name_get_hint(hints[i], "IOID"); |
| const SDL_bool isoutput = (ioid == NULL) || (SDL_strcmp(ioid, "Output") == 0); |
| const SDL_bool isinput = (ioid == NULL) || (SDL_strcmp(ioid, "Input") == 0); |
| SDL_bool have_output = SDL_FALSE; |
| SDL_bool have_input = SDL_FALSE; |
| |
| free(ioid); |
| |
| if (!isoutput && !isinput) { |
| free(name); |
| continue; |
| } |
| |
| prev = NULL; |
| for (dev = unseen; dev; dev = next) { |
| next = dev->next; |
| if ( (SDL_strcmp(dev->name, name) == 0) && (((isinput) && dev->iscapture) || ((isoutput) && !dev->iscapture)) ) { |
| if (prev) { |
| prev->next = next; |
| } else { |
| unseen = next; |
| } |
| dev->next = seen; |
| seen = dev; |
| if (isinput) have_input = SDL_TRUE; |
| if (isoutput) have_output = SDL_TRUE; |
| } else { |
| prev = dev; |
| } |
| } |
| |
| if (isinput && !have_input) { |
| add_device(SDL_TRUE, name, hints[i], &seen); |
| } |
| if (isoutput && !have_output) { |
| add_device(SDL_FALSE, name, hints[i], &seen); |
| } |
| } |
| |
| free(name); |
| } |
| |
| ALSA_snd_device_name_free_hint(hints); |
| |
| devices = seen; /* now we have a known-good list of attached devices. */ |
| |
| /* report anything still in unseen as removed. */ |
| for (dev = unseen; dev; dev = next) { |
| /*printf("ALSA: removing %s device '%s'\n", dev->iscapture ? "capture" : "output", dev->name);*/ |
| next = dev->next; |
| SDL_RemoveAudioDevice(dev->iscapture, dev->name); |
| SDL_free(dev->name); |
| SDL_free(dev); |
| } |
| } |
| |
| /* On first run, tell ALSA_DetectDevices() that we have a complete device list so it can return. */ |
| if (first_run_semaphore) { |
| SDL_SemPost(first_run_semaphore); |
| first_run_semaphore = NULL; /* let other thread clean it up. */ |
| } |
| |
| /* Block awhile before checking again, unless we're told to stop. */ |
| ticks = SDL_GetTicks() + 5000; |
| while (!SDL_AtomicGet(&ALSA_hotplug_shutdown) && !SDL_TICKS_PASSED(SDL_GetTicks(), ticks)) { |
| SDL_Delay(100); |
| } |
| } |
| |
| /* Shutting down! Clean up any data we've gathered. */ |
| for (dev = devices; dev; dev = next) { |
| /*printf("ALSA: at shutdown, removing %s device '%s'\n", dev->iscapture ? "capture" : "output", dev->name);*/ |
| next = dev->next; |
| SDL_free(dev->name); |
| SDL_free(dev); |
| } |
| |
| return 0; |
| } |
| |
| static void |
| ALSA_DetectDevices(void) |
| { |
| /* Start the device detection thread here, wait for an initial iteration to complete. */ |
| SDL_sem *semaphore = SDL_CreateSemaphore(0); |
| if (!semaphore) { |
| return; /* oh well. */ |
| } |
| |
| SDL_AtomicSet(&ALSA_hotplug_shutdown, 0); |
| |
| ALSA_hotplug_thread = SDL_CreateThread(ALSA_HotplugThread, "SDLHotplugALSA", semaphore); |
| if (ALSA_hotplug_thread) { |
| SDL_SemWait(semaphore); /* wait for the first iteration to finish. */ |
| } |
| |
| SDL_DestroySemaphore(semaphore); |
| } |
| |
| static void |
| ALSA_Deinitialize(void) |
| { |
| if (ALSA_hotplug_thread != NULL) { |
| SDL_AtomicSet(&ALSA_hotplug_shutdown, 1); |
| SDL_WaitThread(ALSA_hotplug_thread, NULL); |
| ALSA_hotplug_thread = NULL; |
| } |
| |
| UnloadALSALibrary(); |
| } |
| |
| static int |
| ALSA_Init(SDL_AudioDriverImpl * impl) |
| { |
| if (LoadALSALibrary() < 0) { |
| return 0; |
| } |
| |
| /* Set the function pointers */ |
| impl->DetectDevices = ALSA_DetectDevices; |
| impl->OpenDevice = ALSA_OpenDevice; |
| impl->WaitDevice = ALSA_WaitDevice; |
| impl->GetDeviceBuf = ALSA_GetDeviceBuf; |
| impl->PlayDevice = ALSA_PlayDevice; |
| impl->CloseDevice = ALSA_CloseDevice; |
| impl->Deinitialize = ALSA_Deinitialize; |
| impl->CaptureFromDevice = ALSA_CaptureFromDevice; |
| impl->FlushCapture = ALSA_FlushCapture; |
| |
| impl->HasCaptureSupport = SDL_TRUE; |
| |
| return 1; /* this audio target is available. */ |
| } |
| |
| |
| AudioBootStrap ALSA_bootstrap = { |
| "alsa", "ALSA PCM audio", ALSA_Init, 0 |
| }; |
| |
| #endif /* SDL_AUDIO_DRIVER_ALSA */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |
