Mercurial > sdl-ios-xcode
view src/audio/pulse/SDL_pulseaudio.c @ 4216:5b99971a27b4 SDL-1.2
Fixed bug #698
Hans de Goede 2009-02-13 01:10:52 PST
Since the new "glitch free" version of pulseaudio (used in Fedora 10 amongst
others), the sound of SDL using apps (like a simple playmus call) has been
crackling.
While looking in to fixing this I noticed that the current pulseaudio code in
SDL uses pa_simple. However pa_simple uses a thread to pump pulseaudio events
and ipc, given that SDL already has its own thread for audio handling this is
clearly suboptimal, leading to unnecessary context switching IPC, etc. Also
pa_simple does not allow one to implement the WaitAudio() callback for SDL
audiodrivers properly.
Given that my work is mostly a rewrite (although some original pieces remain)
I'm attaching the new .c and .h file, as that is easier to review then the huge
diff.
Let me know if you also want the diff.
This new version has the following features:
-no longer use an additional thread next to the SDL sound thread
-do not crackle with glitch free audio
-when used with a newer pulse, which does glitch free audio, the total latency
is
the same as with the alsa driver
-proper WaitAudio() implementation, saving another mixlen worth of latency
-adds a WaitDone() implementation
This patch has been written in consultancy with Lennart Poetering (the
pulseaudio author) and has been reviewed by him for correct use of the pa API.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 21 Sep 2009 09:27:08 +0000 |
parents | 3ce5bfddbaf6 |
children | 14f95e514408 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 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 Stéphan Kochen stephan@kochen.nl Based on parts of the ALSA and ESounD output drivers. */ #include "SDL_config.h" /* Allow access to an PulseAudio network stream mixing buffer */ #include <sys/types.h> #include <unistd.h> #include <signal.h> #include <errno.h> #include <pulse/pulseaudio.h> #include <pulse/simple.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_pulseaudio.h" #ifdef SDL_AUDIO_DRIVER_PULSE_DYNAMIC #include "SDL_name.h" #include "SDL_loadso.h" #else #define SDL_NAME(X) X #endif /* The tag name used by the driver */ #define PULSE_DRIVER_NAME "pulse" /* Audio driver functions */ static int PULSE_OpenAudio(_THIS, SDL_AudioSpec *spec); static void PULSE_WaitAudio(_THIS); static void PULSE_PlayAudio(_THIS); static Uint8 *PULSE_GetAudioBuf(_THIS); static void PULSE_CloseAudio(_THIS); static void PULSE_WaitDone(_THIS); #ifdef SDL_AUDIO_DRIVER_PULSE_DYNAMIC static const char *pulse_library = SDL_AUDIO_DRIVER_PULSE_DYNAMIC; static void *pulse_handle = NULL; static int pulse_loaded = 0; static pa_simple* (*SDL_NAME(pa_simple_new))( const char *server, const char *name, pa_stream_direction_t dir, const char *dev, const char *stream_name, const pa_sample_spec *ss, const pa_channel_map *map, const pa_buffer_attr *attr, int *error ); static void (*SDL_NAME(pa_simple_free))(pa_simple *s); static pa_channel_map* (*SDL_NAME(pa_channel_map_init_auto))( pa_channel_map *m, unsigned channels, pa_channel_map_def_t def ); pa_mainloop * (*SDL_NAME(pa_mainloop_new))(void); pa_mainloop_api * (*SDL_NAME(pa_mainloop_get_api))(pa_mainloop *m); int (*SDL_NAME(pa_mainloop_iterate))(pa_mainloop *m, int block, int *retval); void (*SDL_NAME(pa_mainloop_free))(pa_mainloop *m); pa_operation_state_t (*SDL_NAME(pa_operation_get_state))(pa_operation *o); void (*SDL_NAME(pa_operation_cancel))(pa_operation *o); void (*SDL_NAME(pa_operation_unref))(pa_operation *o); pa_context * (*SDL_NAME(pa_context_new))( pa_mainloop_api *m, const char *name); int (*SDL_NAME(pa_context_connect))( pa_context *c, const char *server, pa_context_flags_t flags, const pa_spawn_api *api); pa_context_state_t (*SDL_NAME(pa_context_get_state))(pa_context *c); void (*SDL_NAME(pa_context_disconnect))(pa_context *c); void (*SDL_NAME(pa_context_unref))(pa_context *c); pa_stream * (*SDL_NAME(pa_stream_new))(pa_context *c, const char *name, const pa_sample_spec *ss, const pa_channel_map *map); int (*SDL_NAME(pa_stream_connect_playback))(pa_stream *s, const char *dev, const pa_buffer_attr *attr, pa_stream_flags_t flags, pa_cvolume *volume, pa_stream *sync_stream); pa_stream_state_t (*SDL_NAME(pa_stream_get_state))(pa_stream *s); size_t (*SDL_NAME(pa_stream_writable_size))(pa_stream *s); int (*SDL_NAME(pa_stream_write))(pa_stream *s, const void *data, size_t nbytes, pa_free_cb_t free_cb, int64_t offset, pa_seek_mode_t seek); pa_operation * (*SDL_NAME(pa_stream_drain))(pa_stream *s, pa_stream_success_cb_t cb, void *userdata); int (*SDL_NAME(pa_stream_disconnect))(pa_stream *s); void (*SDL_NAME(pa_stream_unref))(pa_stream *s); static struct { const char *name; void **func; } pulse_functions[] = { { "pa_simple_new", (void **)&SDL_NAME(pa_simple_new) }, { "pa_simple_free", (void **)&SDL_NAME(pa_simple_free) }, { "pa_channel_map_init_auto", (void **)&SDL_NAME(pa_channel_map_init_auto) }, { "pa_mainloop_new", (void **)&SDL_NAME(pa_mainloop_new) }, { "pa_mainloop_get_api", (void **)&SDL_NAME(pa_mainloop_get_api) }, { "pa_mainloop_iterate", (void **)&SDL_NAME(pa_mainloop_iterate) }, { "pa_mainloop_free", (void **)&SDL_NAME(pa_mainloop_free) }, { "pa_operation_get_state", (void **)&SDL_NAME(pa_operation_get_state) }, { "pa_operation_cancel", (void **)&SDL_NAME(pa_operation_cancel) }, { "pa_operation_unref", (void **)&SDL_NAME(pa_operation_unref) }, { "pa_context_new", (void **)&SDL_NAME(pa_context_new) }, { "pa_context_connect", (void **)&SDL_NAME(pa_context_connect) }, { "pa_context_get_state", (void **)&SDL_NAME(pa_context_get_state) }, { "pa_context_disconnect", (void **)&SDL_NAME(pa_context_disconnect) }, { "pa_context_unref", (void **)&SDL_NAME(pa_context_unref) }, { "pa_stream_new", (void **)&SDL_NAME(pa_stream_new) }, { "pa_stream_connect_playback", (void **)&SDL_NAME(pa_stream_connect_playback) }, { "pa_stream_get_state", (void **)&SDL_NAME(pa_stream_get_state) }, { "pa_stream_writable_size", (void **)&SDL_NAME(pa_stream_writable_size) }, { "pa_stream_write", (void **)&SDL_NAME(pa_stream_write) }, { "pa_stream_drain", (void **)&SDL_NAME(pa_stream_drain) }, { "pa_stream_disconnect", (void **)&SDL_NAME(pa_stream_disconnect) }, { "pa_stream_unref", (void **)&SDL_NAME(pa_stream_unref) }, }; static void UnloadPulseLibrary() { if ( pulse_loaded ) { SDL_UnloadObject(pulse_handle); pulse_handle = NULL; pulse_loaded = 0; } } static int LoadPulseLibrary(void) { int i, retval = -1; pulse_handle = SDL_LoadObject(pulse_library); if ( pulse_handle ) { pulse_loaded = 1; retval = 0; for ( i=0; i<SDL_arraysize(pulse_functions); ++i ) { *pulse_functions[i].func = SDL_LoadFunction(pulse_handle, pulse_functions[i].name); if ( !*pulse_functions[i].func ) { retval = -1; UnloadPulseLibrary(); break; } } } return retval; } #else static void UnloadPulseLibrary() { return; } static int LoadPulseLibrary(void) { return 0; } #endif /* SDL_AUDIO_DRIVER_PULSE_DYNAMIC */ /* Audio driver bootstrap functions */ static int Audio_Available(void) { pa_sample_spec paspec; pa_simple *connection; int available; available = 0; if ( LoadPulseLibrary() < 0 ) { return available; } /* Connect with a dummy format. */ paspec.format = PA_SAMPLE_U8; paspec.rate = 11025; paspec.channels = 1; connection = SDL_NAME(pa_simple_new)( NULL, /* server */ "Test stream", /* application name */ PA_STREAM_PLAYBACK, /* playback mode */ NULL, /* device on the server */ "Simple DirectMedia Layer", /* stream description */ &paspec, /* sample format spec */ NULL, /* channel map */ NULL, /* buffering attributes */ NULL /* error code */ ); if ( connection != NULL ) { available = 1; SDL_NAME(pa_simple_free)(connection); } UnloadPulseLibrary(); return(available); } static void Audio_DeleteDevice(SDL_AudioDevice *device) { SDL_free(device->hidden); SDL_free(device); UnloadPulseLibrary(); } static SDL_AudioDevice *Audio_CreateDevice(int devindex) { SDL_AudioDevice *this; /* Initialize all variables that we clean on shutdown */ LoadPulseLibrary(); 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)); /* Set the function pointers */ this->OpenAudio = PULSE_OpenAudio; this->WaitAudio = PULSE_WaitAudio; this->PlayAudio = PULSE_PlayAudio; this->GetAudioBuf = PULSE_GetAudioBuf; this->CloseAudio = PULSE_CloseAudio; this->WaitDone = PULSE_WaitDone; this->free = Audio_DeleteDevice; return this; } AudioBootStrap PULSE_bootstrap = { PULSE_DRIVER_NAME, "PulseAudio", Audio_Available, Audio_CreateDevice }; /* This function waits until it is possible to write a full sound buffer */ static void PULSE_WaitAudio(_THIS) { int size; while(1) { if (SDL_NAME(pa_context_get_state)(context) != PA_CONTEXT_READY || SDL_NAME(pa_stream_get_state)(stream) != PA_STREAM_READY || SDL_NAME(pa_mainloop_iterate)(mainloop, 1, NULL) < 0) { this->enabled = 0; return; } size = SDL_NAME(pa_stream_writable_size)(stream); if (size >= mixlen) return; } } static void PULSE_PlayAudio(_THIS) { /* Write the audio data */ if (SDL_NAME(pa_stream_write)(stream, mixbuf, mixlen, NULL, 0LL, PA_SEEK_RELATIVE) < 0) this->enabled = 0; } static Uint8 *PULSE_GetAudioBuf(_THIS) { return(mixbuf); } static void PULSE_CloseAudio(_THIS) { if ( mixbuf != NULL ) { SDL_FreeAudioMem(mixbuf); mixbuf = NULL; } if ( stream != NULL ) { SDL_NAME(pa_stream_disconnect)(stream); SDL_NAME(pa_stream_unref)(stream); stream = NULL; } if (context != NULL) { SDL_NAME(pa_context_disconnect)(context); SDL_NAME(pa_context_unref)(context); context = NULL; } if (mainloop != NULL) { SDL_NAME(pa_mainloop_free)(mainloop); mainloop = NULL; } } /* Try to get the name of the program */ static char *get_progname(void) { char *progname = NULL; #ifdef __LINUX__ FILE *fp; static char temp[BUFSIZ]; SDL_snprintf(temp, SDL_arraysize(temp), "/proc/%d/cmdline", getpid()); fp = fopen(temp, "r"); if ( fp != NULL ) { if ( fgets(temp, sizeof(temp)-1, fp) ) { progname = SDL_strrchr(temp, '/'); if ( progname == NULL ) { progname = temp; } else { progname = progname+1; } } fclose(fp); } #endif return(progname); } static void stream_drain_complete(pa_stream *s, int success, void *userdata) { } static void PULSE_WaitDone(_THIS) { pa_operation *o; o = SDL_NAME(pa_stream_drain)(stream, stream_drain_complete, NULL); if (!o) return; while (SDL_NAME(pa_operation_get_state)(o) != PA_OPERATION_DONE) { if (SDL_NAME(pa_context_get_state)(context) != PA_CONTEXT_READY || SDL_NAME(pa_stream_get_state)(stream) != PA_STREAM_READY || SDL_NAME(pa_mainloop_iterate)(mainloop, 1, NULL) < 0) { SDL_NAME(pa_operation_cancel)(o); break; } } SDL_NAME(pa_operation_unref)(o); } static int PULSE_OpenAudio(_THIS, SDL_AudioSpec *spec) { int state; Uint16 test_format; pa_sample_spec paspec; pa_buffer_attr paattr; pa_channel_map pacmap; pa_stream_flags_t flags = 0; paspec.format = PA_SAMPLE_INVALID; for ( test_format = SDL_FirstAudioFormat(spec->format); test_format; ) { switch ( test_format ) { case AUDIO_U8: paspec.format = PA_SAMPLE_U8; break; case AUDIO_S16LSB: paspec.format = PA_SAMPLE_S16LE; break; case AUDIO_S16MSB: paspec.format = PA_SAMPLE_S16BE; break; } if ( paspec.format != PA_SAMPLE_INVALID ) break; } if (paspec.format == PA_SAMPLE_INVALID ) { SDL_SetError("Couldn't find any suitable audio formats"); return(-1); } spec->format = test_format; paspec.channels = spec->channels; paspec.rate = spec->freq; /* Calculate the final parameters for this audio specification */ #ifdef PA_STREAM_ADJUST_LATENCY spec->samples /= 2; /* Mix in smaller chunck to avoid underruns */ #endif SDL_CalculateAudioSpec(spec); /* Allocate mixing buffer */ mixlen = spec->size; mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); if ( mixbuf == NULL ) { return(-1); } SDL_memset(mixbuf, spec->silence, spec->size); /* Reduced prebuffering compared to the defaults. */ #ifdef PA_STREAM_ADJUST_LATENCY paattr.tlength = mixlen * 4; /* 2x original requested bufsize */ paattr.prebuf = -1; paattr.maxlength = -1; paattr.minreq = mixlen; /* -1 can lead to pa_stream_writable_size() >= mixlen never becoming true */ flags = PA_STREAM_ADJUST_LATENCY; #else paattr.tlength = mixlen*2; paattr.prebuf = mixlen*2; paattr.maxlength = mixlen*2; paattr.minreq = mixlen; #endif /* The SDL ALSA output hints us that we use Windows' channel mapping */ /* http://bugzilla.libsdl.org/show_bug.cgi?id=110 */ SDL_NAME(pa_channel_map_init_auto)( &pacmap, spec->channels, PA_CHANNEL_MAP_WAVEEX); /* Set up a new main loop */ if (!(mainloop = SDL_NAME(pa_mainloop_new)())) { PULSE_CloseAudio(this); SDL_SetError("pa_mainloop_new() failed"); return(-1); } mainloop_api = SDL_NAME(pa_mainloop_get_api)(mainloop); if (!(context = SDL_NAME(pa_context_new)(mainloop_api, get_progname()))) { PULSE_CloseAudio(this); SDL_SetError("pa_context_new() failed"); return(-1); } /* Connect to the PulseAudio server */ if (SDL_NAME(pa_context_connect)(context, NULL, 0, NULL) < 0) { PULSE_CloseAudio(this); SDL_SetError("Could not setup connection to PulseAudio"); return(-1); } do { if (SDL_NAME(pa_mainloop_iterate)(mainloop, 1, NULL) < 0) { PULSE_CloseAudio(this); SDL_SetError("pa_mainloop_iterate() failed"); return(-1); } state = SDL_NAME(pa_context_get_state)(context); if (!PA_CONTEXT_IS_GOOD(state)) { PULSE_CloseAudio(this); SDL_SetError("Could not connect to PulseAudio"); return(-1); } } while (state != PA_CONTEXT_READY); stream = SDL_NAME(pa_stream_new)( context, "Simple DirectMedia Layer", /* stream description */ &paspec, /* sample format spec */ &pacmap /* channel map */ ); if ( stream == NULL ) { PULSE_CloseAudio(this); SDL_SetError("Could not setup PulseAudio stream"); return(-1); } if (SDL_NAME(pa_stream_connect_playback)(stream, NULL, &paattr, flags, NULL, NULL) < 0) { PULSE_CloseAudio(this); SDL_SetError("Could not connect PulseAudio stream"); return(-1); } do { if (SDL_NAME(pa_mainloop_iterate)(mainloop, 1, NULL) < 0) { PULSE_CloseAudio(this); SDL_SetError("pa_mainloop_iterate() failed"); return(-1); } state = SDL_NAME(pa_stream_get_state)(stream); if (!PA_STREAM_IS_GOOD(state)) { PULSE_CloseAudio(this); SDL_SetError("Could not create to PulseAudio stream"); return(-1); } } while (state != PA_STREAM_READY); return(0); }