ao_alsa.c

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/*
  ao_alsa9/1.x - ALSA-0.9.x-1.x output plugin for MPlayer

  (C) Alex Beregszaszi
  
  modified for real alsa-0.9.0-support by Zsolt Barat <[e-mail]>
  additional AC3 passthrough support by Andy Lo A Foe <[e-mail]>  
  08/22/2002 iec958-init rewritten and merged with common init, zsolt
  04/13/2004 merged with ao_alsa1.x, fixes provided by Jindrich Makovicka
  04/25/2004 printfs converted to mp_msg, Zsolt.
  
  Any bugreports regarding to this driver are welcome.
*/

#include <errno.h>
#include "mplayertm.h"
#include "mplaylib.h"
#include <stdarg.h>
#include <ctype.h>
#include <math.h>

#include "config.h"
#include "subopt-helper.h"
#include "mixer.h"
#include "mp_msg.h"
#include "help_mp.h"

#define ALSA_PCM_NEW_HW_PARAMS_API
#define ALSA_PCM_NEW_SW_PARAMS_API

#if HAVE_SYS_ASOUNDLIB_H
#include <sys/asoundlib.h>
#elif HAVE_ALSA_ASOUNDLIB_H
#include <alsa/asoundlib.h>
#else
#error "asoundlib.h is not in sys/ or alsa/ - please bugreport"
#endif


#include "audio_out.h"
#include "audio_out_internal.h"
#include "libaf/af_format.h"

static ao_info_t info = 
{
    "ALSA-0.9.x-1.x audio output",
    "alsa",
    "Alex Beregszaszi, Zsolt Barat <[e-mail]>",
    "under developement"
};

LIBAO_EXTERN(alsa)

static snd_pcm_t *alsa_handler;
static snd_pcm_format_t alsa_format;
static snd_pcm_hw_params_t *alsa_hwparams;
static snd_pcm_sw_params_t *alsa_swparams;

/* 16 sets buffersize to 16 * chunksize is as default 1024
 * which seems to be good avarge for most situations 
 * so buffersize is 16384 frames by default */
static int alsa_fragcount = 16;
static snd_pcm_uframes_t chunk_size = 1024;

static size_t bytes_per_sample;

static int ao_noblock = 0;

static int open_mode;
static int alsa_can_pause = 0;

#define ALSA_DEVICE_SIZE 256

#undef BUFFERTIME
#define SET_CHUNKSIZE

static void alsa_error_handler(const char *file, int line, const char *function,
			       int err, const char *format, ...)
{
  char tmp[0xc00];
  va_list va;

  va_start(va, format);
  vsnprintf(tmp, sizeof tmp, format, va);
  va_end(va);
  tmp[sizeof tmp - 1] = '\0';

  if (err)
    mp_msg(MSGT_AO, MSGL_ERR, "[AO_ALSA] alsa-lib: %s:%i:(%s) %s: %s\n",
	   file, line, function, tmp, snd_strerror(err));
  else
    mp_msg(MSGT_AO, MSGL_ERR, "[AO_ALSA] alsa-lib: %s:%i:(%s) %s\n",
	   file, line, function, tmp);
}

/* to set/get/query special features/parameters */
static int control(int cmd, void *arg)
{
  switch(cmd) {
  case AOCONTROL_QUERY_FORMAT:
    return CONTROL_TRUE;
  case AOCONTROL_GET_VOLUME:
  case AOCONTROL_SET_VOLUME:
    {
      ao_control_vol_t *vol = (ao_control_vol_t *)arg;

      int err;
      snd_mixer_t *handle;
      snd_mixer_elem_t *elem;
      snd_mixer_selem_id_t *sid;

      static char *mix_name = "PCM";
      static char *card = "default";
      static int mix_index = 0;

      long pmin, pmax;
      long get_vol, set_vol;
      float f_multi;

      if(mixer_channel) {
	 char *test_mix_index;

	 mix_name = strdup(mixer_channel);
	 if ((test_mix_index = strchr(mix_name, ','))){
		*test_mix_index = 0;
		test_mix_index++;
		mix_index = strtol(test_mix_index, &test_mix_index, 0);

		if (*test_mix_index){
		  mp_msg(MSGT_AO,MSGL_ERR,
		    MSGTR_AO_ALSA_InvalidMixerIndexDefaultingToZero);
		  mix_index = 0 ;
		}
	 }
      }
      if(mixer_device) card = mixer_device;

      if(ao_data.format == AF_FORMAT_AC3)
	return CONTROL_TRUE;

      //allocate simple id
      snd_mixer_selem_id_alloca(&sid);
	
      //sets simple-mixer index and name
      snd_mixer_selem_id_set_index(sid, mix_index);
      snd_mixer_selem_id_set_name(sid, mix_name);

      if (mixer_channel) {
	free(mix_name);
	mix_name = NULL;
      }

      if ((err = snd_mixer_open(&handle, 0)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_MixerOpenError, snd_strerror(err));
	return CONTROL_ERROR;
      }

      if ((err = snd_mixer_attach(handle, card)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_MixerAttachError, 
	       card, snd_strerror(err));
	snd_mixer_close(handle);
	return CONTROL_ERROR;
      }

      if ((err = snd_mixer_selem_register(handle, NULL, NULL)) < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_MixerRegisterError, snd_strerror(err));
	snd_mixer_close(handle);
	return CONTROL_ERROR;
      }
      err = snd_mixer_load(handle);
      if (err < 0) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_MixerLoadError, snd_strerror(err));
	snd_mixer_close(handle);
	return CONTROL_ERROR;
      }

      elem = snd_mixer_find_selem(handle, sid);
      if (!elem) {
	mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_UnableToFindSimpleControl,
	       snd_mixer_selem_id_get_name(sid), snd_mixer_selem_id_get_index(sid));
	snd_mixer_close(handle);
	return CONTROL_ERROR;
	}

      snd_mixer_selem_get_playback_volume_range(elem,&pmin,&pmax);
      f_multi = (100 / (float)(pmax - pmin));

      if (cmd == AOCONTROL_SET_VOLUME) {

	set_vol = vol->left / f_multi + pmin + 0.5;

	//setting channels
	if ((err = snd_mixer_selem_set_playback_volume(elem, 0, set_vol)) < 0) {
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_ErrorSettingLeftChannel, 
		 snd_strerror(err));
	  return CONTROL_ERROR;
	}
	mp_msg(MSGT_AO,MSGL_DBG2,"left=%li, ", set_vol);

	set_vol = vol->right / f_multi + pmin + 0.5;

	if ((err = snd_mixer_selem_set_playback_volume(elem, 1, set_vol)) < 0) {
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_ErrorSettingRightChannel, 
		 snd_strerror(err));
	  return CONTROL_ERROR;
	}
	mp_msg(MSGT_AO,MSGL_DBG2,"right=%li, pmin=%li, pmax=%li, mult=%f\n", 
	       set_vol, pmin, pmax, f_multi);

	if (snd_mixer_selem_has_playback_switch(elem)) {
	  int lmute = (vol->left == 0.0);
	  int rmute = (vol->right == 0.0);
	  if (snd_mixer_selem_has_playback_switch_joined(elem)) {
	    lmute = rmute = lmute && rmute;
	  } else {
	    snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_RIGHT, !rmute);
	  }
	  snd_mixer_selem_set_playback_switch(elem, SND_MIXER_SCHN_FRONT_LEFT, !lmute);
	}
      }
      else {
	snd_mixer_selem_get_playback_volume(elem, 0, &get_vol);
	vol->left = (get_vol - pmin) * f_multi;
	snd_mixer_selem_get_playback_volume(elem, 1, &get_vol);
	vol->right = (get_vol - pmin) * f_multi;

	mp_msg(MSGT_AO,MSGL_DBG2,"left=%f, right=%f\n",vol->left,vol->right);
      }
      snd_mixer_close(handle);
      return CONTROL_OK;
    }
    
  } //end switch
  return(CONTROL_UNKNOWN);
}

static void parse_device (char *dest, const char *src, int len)
{
  char *tmp;
  memmove(dest, src, len);
  dest[len] = 0;
  while ((tmp = strrchr(dest, '.')))
    tmp[0] = ',';
  while ((tmp = strrchr(dest, '=')))
    tmp[0] = ':';
}

static void print_help (void)
{
  mp_msg (MSGT_AO, MSGL_FATAL,
           MSGTR_AO_ALSA_CommandlineHelp);
}

static int str_maxlen(strarg_t *str) {
  if (str->len > ALSA_DEVICE_SIZE)
    return 0;
  return 1;
}

static int try_open_device(const char *device, int open_mode, int try_ac3)
{
  int err, len;
  char *ac3_device, *args;

  if (try_ac3) {
    /* to set the non-audio bit, use AES0=6 */
    len = strlen(device);
    ac3_device = malloc(len + 7 + 1);
    if (!ac3_device)
      return -ENOMEM;
    strcpy(ac3_device, device);
    args = strchr(ac3_device, ':');
    if (!args) {
      /* no existing parameters: add it behind device name */
      strcat(ac3_device, ":AES0=6");
    } else {
      do
	++args;
      while (isspace(*args));
      if (*args == '\0') {
	/* ":" but no parameters */
	strcat(ac3_device, "AES0=6");
      } else if (*args != '{') {
	/* a simple list of parameters: add it at the end of the list */
	strcat(ac3_device, ",AES0=6");
      } else {
	/* parameters in config syntax: add it inside the { } block */
	do
	  --len;
	while (len > 0 && isspace(ac3_device[len]));
	if (ac3_device[len] == '}')
	  strcpy(ac3_device + len, " AES0=6}");
      }
    }
    err = snd_pcm_open(&alsa_handler, ac3_device, SND_PCM_STREAM_PLAYBACK,
		       open_mode);
    free(ac3_device);
  }
  if (!try_ac3 || err < 0)
    err = snd_pcm_open(&alsa_handler, device, SND_PCM_STREAM_PLAYBACK,
		       open_mode);
  return err;
}

/*
    open & setup audio device
    return: 1=success 0=fail
*/
static int init(int rate_hz, int channels, int format, int flags)
{
    int err;
    int block;
    strarg_t device;
    snd_pcm_uframes_t bufsize;
    snd_pcm_uframes_t boundary;
    opt_t subopts[] = {
      {"block", OPT_ARG_BOOL, &block, NULL},
      {"device", OPT_ARG_STR, &device, (opt_test_f)str_maxlen},
      {NULL}
    };

    char alsa_device[ALSA_DEVICE_SIZE + 1];
    // make sure alsa_device is null-terminated even when using strncpy etc.
    memset(alsa_device, 0, ALSA_DEVICE_SIZE + 1);

    mp_msg(MSGT_AO,MSGL_V,"alsa-init: requested format: %d Hz, %d channels, %x\n", rate_hz,
	channels, format);
    alsa_handler = NULL;
#if SND_LIB_VERSION >= 0x010005
    mp_msg(MSGT_AO,MSGL_V,"alsa-init: using ALSA %s\n", snd_asoundlib_version());
#else
    mp_msg(MSGT_AO,MSGL_V,"alsa-init: compiled for ALSA-%s\n", SND_LIB_VERSION_STR);
#endif

    snd_lib_error_set_handler(alsa_error_handler);
    
    ao_data.samplerate = rate_hz;
    ao_data.format = format;
    ao_data.channels = channels;

    switch (format)
      {
      case AF_FORMAT_S8:
	alsa_format = SND_PCM_FORMAT_S8;
	break;
      case AF_FORMAT_U8:
	alsa_format = SND_PCM_FORMAT_U8;
	break;
      case AF_FORMAT_U16_LE:
	alsa_format = SND_PCM_FORMAT_U16_LE;
	break;
      case AF_FORMAT_U16_BE:
	alsa_format = SND_PCM_FORMAT_U16_BE;
	break;
#ifndef WORDS_BIGENDIAN
      case AF_FORMAT_AC3:
#endif
      case AF_FORMAT_S16_LE:
	alsa_format = SND_PCM_FORMAT_S16_LE;
	break;
#ifdef WORDS_BIGENDIAN
      case AF_FORMAT_AC3:
#endif
      case AF_FORMAT_S16_BE:
	alsa_format = SND_PCM_FORMAT_S16_BE;
	break;
      case AF_FORMAT_U32_LE:
	alsa_format = SND_PCM_FORMAT_U32_LE;
	break;
      case AF_FORMAT_U32_BE:
	alsa_format = SND_PCM_FORMAT_U32_BE;
	break;
      case AF_FORMAT_S32_LE:
	alsa_format = SND_PCM_FORMAT_S32_LE;
	break;
      case AF_FORMAT_S32_BE:
	alsa_format = SND_PCM_FORMAT_S32_BE;
	break;
      case AF_FORMAT_FLOAT_LE:
	alsa_format = SND_PCM_FORMAT_FLOAT_LE;
	break;
      case AF_FORMAT_FLOAT_BE:
	alsa_format = SND_PCM_FORMAT_FLOAT_BE;
	break;
      case AF_FORMAT_MU_LAW:
	alsa_format = SND_PCM_FORMAT_MU_LAW;
	break;
      case AF_FORMAT_A_LAW:
	alsa_format = SND_PCM_FORMAT_A_LAW;
	break;

      default:
	alsa_format = SND_PCM_FORMAT_MPEG; //? default should be -1
	break;
      }
    
    //subdevice parsing
    // set defaults
    block = 1;
    /* switch for spdif
     * sets opening sequence for SPDIF
     * sets also the playback and other switches 'on the fly'
     * while opening the abstract alias for the spdif subdevice
     * 'iec958'
     */
    if (format == AF_FORMAT_AC3) {
	device.str = "iec958";
	mp_msg(MSGT_AO,MSGL_V,"alsa-spdif-init: playing AC3, %i channels\n", channels);
    }
  else
        /* in any case for multichannel playback we should select
         * appropriate device
         */
        switch (channels) {
	case 1:
	case 2:
	  device.str = "default";
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: setup for 1/2 channel(s)\n");
	  break;
	case 4:
	  if (alsa_format == SND_PCM_FORMAT_FLOAT_LE)
	    // hack - use the converter plugin
	    device.str = "plug:surround40";
	  else
	    device.str = "surround40";
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround40\n");
	  break;
	case 6:
	  if (alsa_format == SND_PCM_FORMAT_FLOAT_LE)
	    device.str = "plug:surround51";
	  else
	    device.str = "surround51";
	  mp_msg(MSGT_AO,MSGL_V,"alsa-init: device set to surround51\n");
	  break;
	default:
	  device.str = "default";
	  mp_msg(MSGT_AO,MSGL_ERR,MSGTR_AO_ALSA_ChannelsNotSupported,channels);
        }
    device.len = strlen(device.str);
    if (subopt_parse(ao_subdevice, subopts) != 0) {
        print_help();
        return 0;
    }
    ao_noblock = !block;
    parse_device(alsa_device, device.str, device.len);