speaker.c File Reference

API to access an audio speaker; provides access to hardware speakers. More...

#include "platform.h"
#include "gnunet_speaker_lib.h"
#include "conversation.h"

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Data Structures
struct	Speaker
	Internal data structures for the speaker. More...

Functions
static int	enable (void *cls)
	Function that enables a speaker. More...
static void	disable (void *cls)
	Function that disables a speaker. More...
static void	destroy (void *cls)
	Function to destroy a speaker. More...
static void	play (void *cls, size_t data_size, const void *data)
	Function to cause a speaker to play audio data. More...
struct GNUNET_SPEAKER_Handle *	GNUNET_SPEAKER_create_from_hardware (const struct GNUNET_CONFIGURATION_Handle *cfg)
	Create a speaker that corresponds to the speaker hardware of our system. More...
void	GNUNET_SPEAKER_destroy (struct GNUNET_SPEAKER_Handle *speaker)
	Destroy a speaker. More...

Detailed Description

API to access an audio speaker; provides access to hardware speakers.

Author

Simon Dieterle

Andreas Fuchs

Christian Grothoff

Definition in file speaker.c.

Function Documentation

enable()

static int enable ( void *  cls )

static

Function that enables a speaker.

Parameters

cls	closure with the struct Speaker

Returns

GNUNET_OK on success, GNUNET_SYSERR on error

Definition at line 57 of file speaker.c.

{
  struct Speaker *spe = cls;
  static char *playback_helper_argv[] = {
    "gnunet-helper-audio-playback",
    NULL
  };
 
  spe->playback_helper = GNUNET_HELPER_start (GNUNET_NO,
                                              "gnunet-helper-audio-playback",
                                              playback_helper_argv,
                                              NULL,
                                              NULL, spe);
  if (NULL == spe->playback_helper)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Could not start playback audio helper.\n"));
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}

References _, GNUNET_ERROR_TYPE_ERROR, GNUNET_HELPER_start(), GNUNET_log, GNUNET_NO, GNUNET_OK, GNUNET_SYSERR, and Speaker::playback_helper.

Referenced by GNUNET_SPEAKER_create_from_hardware().

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disable()

static void disable ( void *  cls )

static

Function that disables a speaker.

Parameters

cls	closure with the struct Speaker

Definition at line 86 of file speaker.c.

{
  struct Speaker *spe = cls;
 
  if (NULL == spe->playback_helper)
  {
    GNUNET_break (0);
    return;
  }
  GNUNET_break (GNUNET_OK ==
                GNUNET_HELPER_kill (spe->playback_helper, GNUNET_NO));
  GNUNET_HELPER_destroy (spe->playback_helper);
  spe->playback_helper = NULL;
}

References GNUNET_break, GNUNET_HELPER_destroy(), GNUNET_HELPER_kill(), GNUNET_NO, GNUNET_OK, and Speaker::playback_helper.

Referenced by destroy(), and GNUNET_SPEAKER_create_from_hardware().

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destroy()

static void destroy ( void *  cls )

static

Function to destroy a speaker.

Parameters

cls	closure with the struct Speaker

Definition at line 108 of file speaker.c.

{
  struct Speaker *spe = cls;
 
  if (NULL != spe->playback_helper)
    disable (spe);
}

References disable(), and Speaker::playback_helper.

Referenced by GNUNET_SPEAKER_create_from_hardware().

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play()

static void play ( void *  cls, size_t  data_size, const void *  data  )

static

Function to cause a speaker to play audio data.

Parameters

cls	clsoure with the struct Speaker
data_size	number of bytes in data
data	audio data to play, format is opaque to the API but should be OPUS.

Definition at line 126 of file speaker.c.

{
  struct Speaker *spe = cls;
  char buf[sizeof(struct AudioMessage) + data_size];
  struct AudioMessage *am;
 
  if (NULL == spe->playback_helper)
  {
    GNUNET_break (0);
    return;
  }
  am = (struct AudioMessage *) buf;
  am->header.size = htons (sizeof(struct AudioMessage) + data_size);
  am->header.type = htons (GNUNET_MESSAGE_TYPE_CONVERSATION_AUDIO);
  GNUNET_memcpy (&am[1], data, data_size);
  (void) GNUNET_HELPER_send (spe->playback_helper,
                             &am->header,
                             GNUNET_NO,
                             NULL, NULL);
}

References buf, data, data_size, GNUNET_break, GNUNET_HELPER_send(), GNUNET_memcpy, GNUNET_MESSAGE_TYPE_CONVERSATION_AUDIO, GNUNET_NO, AudioMessage::header, Speaker::playback_helper, GNUNET_MessageHeader::size, and GNUNET_MessageHeader::type.

Referenced by GNUNET_SPEAKER_create_from_hardware().

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