src/audio/paudio/SDL_paudio.c
author Sam Lantinga <slouken@libsdl.org>
Mon, 08 Dec 2008 00:25:42 +0000
branchSDL-1.2
changeset 4159 a1b03ba2fcd0
parent 1402 d910939febfa
child 6137 4720145f848b
permissions -rw-r--r--
Updated copyright date
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2009 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Carsten Griwodz
    20     griff@kom.tu-darmstadt.de
    21 
    22     based on linux/SDL_dspaudio.c by Sam Lantinga
    23 */
    24 #include "SDL_config.h"
    25 
    26 /* Allow access to a raw mixing buffer */
    27 
    28 #include <errno.h>
    29 #include <unistd.h>
    30 #include <fcntl.h>
    31 #include <sys/time.h>
    32 #include <sys/ioctl.h>
    33 #include <sys/stat.h>
    34 
    35 #include "SDL_timer.h"
    36 #include "SDL_audio.h"
    37 #include "../SDL_audiomem.h"
    38 #include "../SDL_audio_c.h"
    39 #include "../SDL_audiodev_c.h"
    40 #include "SDL_paudio.h"
    41 
    42 #define DEBUG_AUDIO 1
    43 
    44 /* A conflict within AIX 4.3.3 <sys/> headers and probably others as well.
    45  * I guess nobody ever uses audio... Shame over AIX header files.  */
    46 #include <sys/machine.h>
    47 #undef BIG_ENDIAN
    48 #include <sys/audio.h>
    49 
    50 /* The tag name used by paud audio */
    51 #define Paud_DRIVER_NAME         "paud"
    52 
    53 /* Open the audio device for playback, and don't block if busy */
    54 /* #define OPEN_FLAGS	(O_WRONLY|O_NONBLOCK) */
    55 #define OPEN_FLAGS	O_WRONLY
    56 
    57 /* Audio driver functions */
    58 static int Paud_OpenAudio(_THIS, SDL_AudioSpec *spec);
    59 static void Paud_WaitAudio(_THIS);
    60 static void Paud_PlayAudio(_THIS);
    61 static Uint8 *Paud_GetAudioBuf(_THIS);
    62 static void Paud_CloseAudio(_THIS);
    63 
    64 /* Audio driver bootstrap functions */
    65 
    66 static int Audio_Available(void)
    67 {
    68 	int fd;
    69 	int available;
    70 
    71 	available = 0;
    72 	fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0);
    73 	if ( fd >= 0 ) {
    74 		available = 1;
    75 		close(fd);
    76 	}
    77 	return(available);
    78 }
    79 
    80 static void Audio_DeleteDevice(SDL_AudioDevice *device)
    81 {
    82 	SDL_free(device->hidden);
    83 	SDL_free(device);
    84 }
    85 
    86 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
    87 {
    88 	SDL_AudioDevice *this;
    89 
    90 	/* Initialize all variables that we clean on shutdown */
    91 	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
    92 	if ( this ) {
    93 		SDL_memset(this, 0, (sizeof *this));
    94 		this->hidden = (struct SDL_PrivateAudioData *)
    95 				SDL_malloc((sizeof *this->hidden));
    96 	}
    97 	if ( (this == NULL) || (this->hidden == NULL) ) {
    98 		SDL_OutOfMemory();
    99 		if ( this ) {
   100 			SDL_free(this);
   101 		}
   102 		return(0);
   103 	}
   104 	SDL_memset(this->hidden, 0, (sizeof *this->hidden));
   105 	audio_fd = -1;
   106 
   107 	/* Set the function pointers */
   108 	this->OpenAudio = Paud_OpenAudio;
   109 	this->WaitAudio = Paud_WaitAudio;
   110 	this->PlayAudio = Paud_PlayAudio;
   111 	this->GetAudioBuf = Paud_GetAudioBuf;
   112 	this->CloseAudio = Paud_CloseAudio;
   113 
   114 	this->free = Audio_DeleteDevice;
   115 
   116 	return this;
   117 }
   118 
   119 AudioBootStrap Paud_bootstrap = {
   120 	Paud_DRIVER_NAME, "AIX Paudio",
   121 	Audio_Available, Audio_CreateDevice
   122 };
   123 
   124 /* This function waits until it is possible to write a full sound buffer */
   125 static void Paud_WaitAudio(_THIS)
   126 {
   127     fd_set fdset;
   128 
   129     /* See if we need to use timed audio synchronization */
   130     if ( frame_ticks ) {
   131         /* Use timer for general audio synchronization */
   132         Sint32 ticks;
   133 
   134         ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS;
   135         if ( ticks > 0 ) {
   136 	    SDL_Delay(ticks);
   137         }
   138     } else {
   139         audio_buffer  paud_bufinfo;
   140 
   141         /* Use select() for audio synchronization */
   142         struct timeval timeout;
   143         FD_ZERO(&fdset);
   144         FD_SET(audio_fd, &fdset);
   145 
   146         if ( ioctl(audio_fd, AUDIO_BUFFER, &paud_bufinfo) < 0 ) {
   147 #ifdef DEBUG_AUDIO
   148             fprintf(stderr, "Couldn't get audio buffer information\n");
   149 #endif
   150             timeout.tv_sec  = 10;
   151             timeout.tv_usec = 0;
   152         } else {
   153 	    long ms_in_buf = paud_bufinfo.write_buf_time;
   154             timeout.tv_sec  = ms_in_buf/1000;
   155 	    ms_in_buf       = ms_in_buf - timeout.tv_sec*1000;
   156             timeout.tv_usec = ms_in_buf*1000;
   157 #ifdef DEBUG_AUDIO
   158             fprintf( stderr,
   159 		     "Waiting for write_buf_time=%ld,%ld\n",
   160 		     timeout.tv_sec,
   161 		     timeout.tv_usec );
   162 #endif
   163 	}
   164 
   165 #ifdef DEBUG_AUDIO
   166         fprintf(stderr, "Waiting for audio to get ready\n");
   167 #endif
   168         if ( select(audio_fd+1, NULL, &fdset, NULL, &timeout) <= 0 ) {
   169             const char *message = "Audio timeout - buggy audio driver? (disabled)";
   170             /*
   171 	     * In general we should never print to the screen,
   172              * but in this case we have no other way of letting
   173              * the user know what happened.
   174              */
   175             fprintf(stderr, "SDL: %s - %s\n", strerror(errno), message);
   176             this->enabled = 0;
   177             /* Don't try to close - may hang */
   178             audio_fd = -1;
   179 #ifdef DEBUG_AUDIO
   180             fprintf(stderr, "Done disabling audio\n");
   181 #endif
   182         }
   183 #ifdef DEBUG_AUDIO
   184         fprintf(stderr, "Ready!\n");
   185 #endif
   186     }
   187 }
   188 
   189 static void Paud_PlayAudio(_THIS)
   190 {
   191 	int written;
   192 
   193 	/* Write the audio data, checking for EAGAIN on broken audio drivers */
   194 	do {
   195 		written = write(audio_fd, mixbuf, mixlen);
   196 		if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) {
   197 			SDL_Delay(1);	/* Let a little CPU time go by */
   198 		}
   199 	} while ( (written < 0) && 
   200 	          ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) );
   201 
   202 	/* If timer synchronization is enabled, set the next write frame */
   203 	if ( frame_ticks ) {
   204 		next_frame += frame_ticks;
   205 	}
   206 
   207 	/* If we couldn't write, assume fatal error for now */
   208 	if ( written < 0 ) {
   209 		this->enabled = 0;
   210 	}
   211 #ifdef DEBUG_AUDIO
   212 	fprintf(stderr, "Wrote %d bytes of audio data\n", written);
   213 #endif
   214 }
   215 
   216 static Uint8 *Paud_GetAudioBuf(_THIS)
   217 {
   218 	return mixbuf;
   219 }
   220 
   221 static void Paud_CloseAudio(_THIS)
   222 {
   223 	if ( mixbuf != NULL ) {
   224 		SDL_FreeAudioMem(mixbuf);
   225 		mixbuf = NULL;
   226 	}
   227 	if ( audio_fd >= 0 ) {
   228 		close(audio_fd);
   229 		audio_fd = -1;
   230 	}
   231 }
   232 
   233 static int Paud_OpenAudio(_THIS, SDL_AudioSpec *spec)
   234 {
   235 	char          audiodev[1024];
   236 	int           format;
   237 	int           bytes_per_sample;
   238 	Uint16        test_format;
   239 	audio_init    paud_init;
   240 	audio_buffer  paud_bufinfo;
   241 	audio_status  paud_status;
   242 	audio_control paud_control;
   243 	audio_change  paud_change;
   244 
   245 	/* Reset the timer synchronization flag */
   246 	frame_ticks = 0.0;
   247 
   248 	/* Open the audio device */
   249 	audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0);
   250 	if ( audio_fd < 0 ) {
   251 		SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));
   252 		return -1;
   253 	}
   254 
   255 	/*
   256 	 * We can't set the buffer size - just ask the device for the maximum
   257 	 * that we can have.
   258 	 */
   259 	if ( ioctl(audio_fd, AUDIO_BUFFER, &paud_bufinfo) < 0 ) {
   260 		SDL_SetError("Couldn't get audio buffer information");
   261 		return -1;
   262 	}
   263 
   264 	mixbuf = NULL;
   265 
   266 	if ( spec->channels > 1 )
   267 	    spec->channels = 2;
   268 	else
   269 	    spec->channels = 1;
   270 
   271 	/*
   272 	 * Fields in the audio_init structure:
   273 	 *
   274 	 * Ignored by us:
   275 	 *
   276 	 * paud.loadpath[LOAD_PATH]; * DSP code to load, MWave chip only?
   277 	 * paud.slot_number;         * slot number of the adapter
   278 	 * paud.device_id;           * adapter identification number
   279 	 *
   280 	 * Input:
   281 	 *
   282 	 * paud.srate;           * the sampling rate in Hz
   283 	 * paud.bits_per_sample; * 8, 16, 32, ...
   284 	 * paud.bsize;           * block size for this rate
   285 	 * paud.mode;            * ADPCM, PCM, MU_LAW, A_LAW, SOURCE_MIX
   286 	 * paud.channels;        * 1=mono, 2=stereo
   287 	 * paud.flags;           * FIXED - fixed length data
   288 	 *                       * LEFT_ALIGNED, RIGHT_ALIGNED (var len only)
   289 	 *                       * TWOS_COMPLEMENT - 2's complement data
   290 	 *                       * SIGNED - signed? comment seems wrong in sys/audio.h
   291 	 *                       * BIG_ENDIAN
   292 	 * paud.operation;       * PLAY, RECORD
   293 	 *
   294 	 * Output:
   295 	 *
   296 	 * paud.flags;           * PITCH            - pitch is supported
   297 	 *                       * INPUT            - input is supported
   298 	 *                       * OUTPUT           - output is supported
   299 	 *                       * MONITOR          - monitor is supported
   300 	 *                       * VOLUME           - volume is supported
   301 	 *                       * VOLUME_DELAY     - volume delay is supported
   302 	 *                       * BALANCE          - balance is supported
   303 	 *                       * BALANCE_DELAY    - balance delay is supported
   304 	 *                       * TREBLE           - treble control is supported
   305 	 *                       * BASS             - bass control is supported
   306 	 *                       * BESTFIT_PROVIDED - best fit returned
   307 	 *                       * LOAD_CODE        - DSP load needed
   308 	 * paud.rc;              * NO_PLAY         - DSP code can't do play requests
   309 	 *                       * NO_RECORD       - DSP code can't do record requests
   310 	 *                       * INVALID_REQUEST - request was invalid
   311 	 *                       * CONFLICT        - conflict with open's flags
   312 	 *                       * OVERLOADED      - out of DSP MIPS or memory
   313 	 * paud.position_resolution; * smallest increment for position
   314 	 */
   315 
   316         paud_init.srate = spec->freq;
   317 	paud_init.mode = PCM;
   318 	paud_init.operation = PLAY;
   319 	paud_init.channels = spec->channels;
   320 
   321 	/* Try for a closest match on audio format */
   322 	format = 0;
   323 	for ( test_format = SDL_FirstAudioFormat(spec->format);
   324 						! format && test_format; ) {
   325 #ifdef DEBUG_AUDIO
   326 		fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
   327 #endif
   328 		switch ( test_format ) {
   329 			case AUDIO_U8:
   330 			    bytes_per_sample = 1;
   331 			    paud_init.bits_per_sample = 8;
   332 			    paud_init.flags = TWOS_COMPLEMENT | FIXED;
   333 			    format = 1;
   334 			    break;
   335 			case AUDIO_S8:
   336 			    bytes_per_sample = 1;
   337 			    paud_init.bits_per_sample = 8;
   338 			    paud_init.flags = SIGNED |
   339 					      TWOS_COMPLEMENT | FIXED;
   340 			    format = 1;
   341 			    break;
   342 			case AUDIO_S16LSB:
   343 			    bytes_per_sample = 2;
   344 			    paud_init.bits_per_sample = 16;
   345 			    paud_init.flags = SIGNED |
   346 					      TWOS_COMPLEMENT | FIXED;
   347 			    format = 1;
   348 			    break;
   349 			case AUDIO_S16MSB:
   350 			    bytes_per_sample = 2;
   351 			    paud_init.bits_per_sample = 16;
   352 			    paud_init.flags = BIG_ENDIAN |
   353 					      SIGNED |
   354 					      TWOS_COMPLEMENT | FIXED;
   355 			    format = 1;
   356 			    break;
   357 			case AUDIO_U16LSB:
   358 			    bytes_per_sample = 2;
   359 			    paud_init.bits_per_sample = 16;
   360 			    paud_init.flags = TWOS_COMPLEMENT | FIXED;
   361 			    format = 1;
   362 			    break;
   363 			case AUDIO_U16MSB:
   364 			    bytes_per_sample = 2;
   365 			    paud_init.bits_per_sample = 16;
   366 			    paud_init.flags = BIG_ENDIAN |
   367 					      TWOS_COMPLEMENT | FIXED;
   368 			    format = 1;
   369 			    break;
   370 			default:
   371 				break;
   372 		}
   373 		if ( ! format ) {
   374 			test_format = SDL_NextAudioFormat();
   375 		}
   376 	}
   377 	if ( format == 0 ) {
   378 #ifdef DEBUG_AUDIO
   379             fprintf(stderr, "Couldn't find any hardware audio formats\n");
   380 #endif
   381 	    SDL_SetError("Couldn't find any hardware audio formats");
   382 	    return -1;
   383 	}
   384 	spec->format = test_format;
   385 
   386 	/*
   387 	 * We know the buffer size and the max number of subsequent writes
   388 	 * that can be pending. If more than one can pend, allow the application
   389 	 * to do something like double buffering between our write buffer and
   390 	 * the device's own buffer that we are filling with write() anyway.
   391 	 *
   392 	 * We calculate spec->samples like this because SDL_CalculateAudioSpec()
   393 	 * will give put paud_bufinfo.write_buf_cap (or paud_bufinfo.write_buf_cap/2)
   394 	 * into spec->size in return.
   395 	 */
   396 	if ( paud_bufinfo.request_buf_cap == 1 )
   397 	{
   398 	    spec->samples = paud_bufinfo.write_buf_cap
   399 			  / bytes_per_sample
   400 			  / spec->channels;
   401 	}
   402 	else
   403 	{
   404 	    spec->samples = paud_bufinfo.write_buf_cap
   405 			  / bytes_per_sample
   406 			  / spec->channels
   407 			  / 2;
   408 	}
   409         paud_init.bsize = bytes_per_sample * spec->channels;
   410 
   411 	SDL_CalculateAudioSpec(spec);
   412 
   413 	/*
   414 	 * The AIX paud device init can't modify the values of the audio_init
   415 	 * structure that we pass to it. So we don't need any recalculation
   416 	 * of this stuff and no reinit call as in linux dsp and dma code.
   417 	 *
   418 	 * /dev/paud supports all of the encoding formats, so we don't need
   419 	 * to do anything like reopening the device, either.
   420 	 */
   421 	if ( ioctl(audio_fd, AUDIO_INIT, &paud_init) < 0 ) {
   422 	    switch ( paud_init.rc )
   423 	    {
   424 	    case 1 :
   425 		SDL_SetError("Couldn't set audio format: DSP can't do play requests");
   426 		return -1;
   427 		break;
   428 	    case 2 :
   429 		SDL_SetError("Couldn't set audio format: DSP can't do record requests");
   430 		return -1;
   431 		break;
   432 	    case 4 :
   433 		SDL_SetError("Couldn't set audio format: request was invalid");
   434 		return -1;
   435 		break;
   436 	    case 5 :
   437 		SDL_SetError("Couldn't set audio format: conflict with open's flags");
   438 		return -1;
   439 		break;
   440 	    case 6 :
   441 		SDL_SetError("Couldn't set audio format: out of DSP MIPS or memory");
   442 		return -1;
   443 		break;
   444 	    default :
   445 		SDL_SetError("Couldn't set audio format: not documented in sys/audio.h");
   446 		return -1;
   447 		break;
   448 	    }
   449 	}
   450 
   451 	/* Allocate mixing buffer */
   452 	mixlen = spec->size;
   453 	mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
   454 	if ( mixbuf == NULL ) {
   455 		return -1;
   456 	}
   457 	SDL_memset(mixbuf, spec->silence, spec->size);
   458 
   459 	/*
   460 	 * Set some paramters: full volume, first speaker that we can find.
   461 	 * Ignore the other settings for now.
   462 	 */
   463 	paud_change.input = AUDIO_IGNORE;         /* the new input source */
   464         paud_change.output = OUTPUT_1;            /* EXTERNAL_SPEAKER,INTERNAL_SPEAKER,OUTPUT_1 */
   465         paud_change.monitor = AUDIO_IGNORE;       /* the new monitor state */
   466         paud_change.volume = 0x7fffffff;          /* volume level [0-0x7fffffff] */
   467         paud_change.volume_delay = AUDIO_IGNORE;  /* the new volume delay */
   468         paud_change.balance = 0x3fffffff;         /* the new balance */
   469         paud_change.balance_delay = AUDIO_IGNORE; /* the new balance delay */
   470         paud_change.treble = AUDIO_IGNORE;        /* the new treble state */
   471         paud_change.bass = AUDIO_IGNORE;          /* the new bass state */
   472         paud_change.pitch = AUDIO_IGNORE;         /* the new pitch state */
   473 
   474 	paud_control.ioctl_request = AUDIO_CHANGE;
   475 	paud_control.request_info = (char*)&paud_change;
   476 	if ( ioctl(audio_fd, AUDIO_CONTROL, &paud_control) < 0 ) {
   477 #ifdef DEBUG_AUDIO
   478             fprintf(stderr, "Can't change audio display settings\n" );
   479 #endif
   480 	}
   481 
   482 	/*
   483 	 * Tell the device to expect data. Actual start will wait for
   484 	 * the first write() call.
   485 	 */
   486 	paud_control.ioctl_request = AUDIO_START;
   487 	paud_control.position = 0;
   488 	if ( ioctl(audio_fd, AUDIO_CONTROL, &paud_control) < 0 ) {
   489 #ifdef DEBUG_AUDIO
   490             fprintf(stderr, "Can't start audio play\n" );
   491 #endif
   492 	    SDL_SetError("Can't start audio play");
   493 	    return -1;
   494 	}
   495 
   496         /* Check to see if we need to use select() workaround */
   497         { char *workaround;
   498                 workaround = SDL_getenv("SDL_DSP_NOSELECT");
   499                 if ( workaround ) {
   500                         frame_ticks = (float)(spec->samples*1000)/spec->freq;
   501                         next_frame = SDL_GetTicks()+frame_ticks;
   502                 }
   503         }
   504 
   505 	/* Get the parent process id (we're the parent of the audio thread) */
   506 	parent = getpid();
   507 
   508 	/* We're ready to rock and roll. :-) */
   509 	return 0;
   510 }
   511