slinfactory.h File Reference

A machine to gather up arbitrary frames and convert them to raw slinear on demand. More...

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Data Structures
struct	ast_slinfactory
Defines
#define	AST_SLINFACTORY_MAX_HOLD   1280
Functions
unsigned int	ast_slinfactory_available (const struct ast_slinfactory *sf)
	Retrieve number of samples currently in a slinfactory.
void	ast_slinfactory_destroy (struct ast_slinfactory *sf)
	Destroy the contents of a slinfactory.
int	ast_slinfactory_feed (struct ast_slinfactory *sf, struct ast_frame *f)
	Feed audio into a slinfactory.
void	ast_slinfactory_flush (struct ast_slinfactory *sf)
	Flush the contents of a slinfactory.
void	ast_slinfactory_init (struct ast_slinfactory *sf)
	Initialize a slinfactory.
int	ast_slinfactory_init_rate (struct ast_slinfactory *sf, unsigned int sample_rate)
	Initialize a slinfactory.
int	ast_slinfactory_read (struct ast_slinfactory *sf, short *buf, size_t samples)
	Read samples from a slinfactory.

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Detailed Description

A machine to gather up arbitrary frames and convert them to raw slinear on demand.

Definition in file slinfactory.h.

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Define Documentation

#define AST_SLINFACTORY_MAX_HOLD   1280

Definition at line 31 of file slinfactory.h.

Referenced by ast_slinfactory_read().

---

Function Documentation

unsigned int ast_slinfactory_available

(

const struct ast_slinfactory *

sf

)

Retrieve number of samples currently in a slinfactory.

Parameters:

sf

The slinfactory to peek into

Returns:

Number of samples in slinfactory

Definition at line 192 of file slinfactory.c.

References ast_slinfactory::size.

Referenced by ast_audiohook_write_frame(), audio_audiohook_write_list(), audiohook_read_frame_both(), audiohook_read_frame_single(), and softmix_bridge_thread().

{
   return sf->size;
}

void ast_slinfactory_destroy

(

struct ast_slinfactory *

sf

)

Destroy the contents of a slinfactory.

Parameters:

sf

The slinfactory that is no longer needed

This function will free any memory allocated for the contents of the slinfactory. It does not free the slinfactory itself. If the sf is malloc'd, then it must be explicitly free'd after calling this function.

Returns:

Nothing

Definition at line 60 of file slinfactory.c.

References ast_frfree, AST_LIST_REMOVE_HEAD, ast_translator_free_path(), f, ast_frame::frame_list, ast_slinfactory::queue, and ast_slinfactory::trans.

Referenced by ast_audiohook_destroy(), and softmix_bridge_leave().

{
   struct ast_frame *f;

   if (sf->trans) {
      ast_translator_free_path(sf->trans);
      sf->trans = NULL;
   }

   while ((f = AST_LIST_REMOVE_HEAD(&sf->queue, frame_list)))
      ast_frfree(f);
}

int ast_slinfactory_feed	(	struct ast_slinfactory *	sf,
		struct ast_frame *	f
	)

Feed audio into a slinfactory.

Parameters:

	sf	The slinfactory to feed into
	f	Frame containing audio to feed in

Returns:

Number of frames currently in factory

Definition at line 73 of file slinfactory.c.

References ast_frdup(), ast_frfree, ast_frisolate(), ast_getformatname(), AST_LIST_INSERT_TAIL, AST_LIST_NEXT, AST_LIST_TRAVERSE, ast_log(), ast_translate(), ast_translator_build_path(), ast_translator_free_path(), ast_frame::data, ast_slinfactory::format, ast_frame::frame_list, LOG_WARNING, ast_slinfactory::output_format, ast_frame::ptr, ast_slinfactory::queue, ast_frame::samples, ast_slinfactory::size, ast_frame::subclass, and ast_slinfactory::trans.

Referenced by ast_audiohook_write_frame(), and softmix_bridge_write().

{
   struct ast_frame *begin_frame = f, *duped_frame = NULL, *frame_ptr;
   unsigned int x = 0;

   /* In some cases, we can be passed a frame which has no data in it, but
    * which has a positive number of samples defined. Once such situation is
    * when a jitter buffer is in use and the jitter buffer interpolates a frame.
    * The frame it produces has data set to NULL, datalen set to 0, and samples
    * set to either 160 or 240.
    */
   if (!f->data.ptr) {
      return 0;
   }

   if (f->subclass != sf->output_format) {
      if (sf->trans && f->subclass != sf->format) {
         ast_translator_free_path(sf->trans);
         sf->trans = NULL;
      }

      if (!sf->trans) {
         if (!(sf->trans = ast_translator_build_path(sf->output_format, f->subclass))) {
            ast_log(LOG_WARNING, "Cannot build a path from %s to %s\n", ast_getformatname(f->subclass),
               ast_getformatname(sf->output_format));
            return 0;
         }
         sf->format = f->subclass;
      }

      if (!(begin_frame = ast_translate(sf->trans, f, 0))) {
         return 0;
      }
      
      if (!(duped_frame = ast_frisolate(begin_frame))) {
         return 0;
      }

      if (duped_frame != begin_frame) {
         ast_frfree(begin_frame);
      }
   } else {
      if (sf->trans) {
         ast_translator_free_path(sf->trans);
         sf->trans = NULL;
      }
      if (!(duped_frame = ast_frdup(f)))
         return 0;
   }

   AST_LIST_TRAVERSE(&sf->queue, frame_ptr, frame_list) {
      x++;
   }

   /* if the frame was translated, the translator may have returned multiple
      frames, so process each of them
   */
   for (begin_frame = duped_frame; begin_frame; begin_frame = AST_LIST_NEXT(begin_frame, frame_list)) {
      AST_LIST_INSERT_TAIL(&sf->queue, begin_frame, frame_list);
      sf->size += begin_frame->samples;
   }

   return x;
}

void ast_slinfactory_flush

(

struct ast_slinfactory *

sf

)

Flush the contents of a slinfactory.

Parameters:

sf

The slinfactory to flush

Returns:

Nothing

Definition at line 197 of file slinfactory.c.

References ast_frfree, AST_LIST_REMOVE_HEAD, ast_translator_free_path(), ast_frame::frame_list, ast_slinfactory::hold, ast_slinfactory::holdlen, ast_slinfactory::offset, ast_slinfactory::queue, ast_slinfactory::size, and ast_slinfactory::trans.

Referenced by ast_audiohook_write_frame().

{
   struct ast_frame *fr = NULL;

   if (sf->trans) {
      ast_translator_free_path(sf->trans);
      sf->trans = NULL;
   }

   while ((fr = AST_LIST_REMOVE_HEAD(&sf->queue, frame_list)))
      ast_frfree(fr);

   sf->size = sf->holdlen = 0;
   sf->offset = sf->hold;

   return;
}

void ast_slinfactory_init

(

struct ast_slinfactory *

sf

)

Initialize a slinfactory.

Parameters:

sf

The slinfactory to initialize

Returns:

Nothing

Definition at line 35 of file slinfactory.c.

References AST_FORMAT_SLINEAR, ast_slinfactory::hold, ast_slinfactory::offset, and ast_slinfactory::output_format.

Referenced by ast_audiohook_init(), and softmix_bridge_join().

{
   memset(sf, 0, sizeof(*sf));
   sf->offset = sf->hold;
   sf->output_format = AST_FORMAT_SLINEAR;
}

int ast_slinfactory_init_rate	(	struct ast_slinfactory *	sf,
		unsigned int	sample_rate
	)

Initialize a slinfactory.

Parameters:

	sf	The slinfactory to initialize
	sample_rate	The output sample rate desired

Returns:

0 on success, non-zero on failure

Definition at line 42 of file slinfactory.c.

References AST_FORMAT_SLINEAR, AST_FORMAT_SLINEAR16, ast_slinfactory::hold, ast_slinfactory::offset, and ast_slinfactory::output_format.

{
   memset(sf, 0, sizeof(*sf));
   sf->offset = sf->hold;
   switch (sample_rate) {
   case 8000:
      sf->output_format = AST_FORMAT_SLINEAR;
      break;
   case 16000:
      sf->output_format = AST_FORMAT_SLINEAR16;
      break;
   default:
      return -1;
   }

   return 0;
}

int ast_slinfactory_read	(	struct ast_slinfactory *	sf,
		short *	buf,
		size_t	samples
	)

Read samples from a slinfactory.

Parameters:

	sf	The slinfactory to read from
	buf	Buffer to put samples into
	samples	Number of samples wanted

Returns:

Number of samples read

Definition at line 138 of file slinfactory.c.

References ast_frfree, AST_LIST_REMOVE_HEAD, AST_SLINFACTORY_MAX_HOLD, ast_frame::data, ast_frame::frame_list, ast_slinfactory::hold, ast_slinfactory::holdlen, ast_slinfactory::offset, ast_frame::offset, ast_frame::ptr, ast_slinfactory::queue, ast_frame::samples, and ast_slinfactory::size.

Referenced by audio_audiohook_write_list(), audiohook_read_frame_both(), audiohook_read_frame_single(), and softmix_bridge_thread().

{
   struct ast_frame *frame_ptr;
   unsigned int sofar = 0, ineed, remain;
   short *frame_data, *offset = buf;

   while (sofar < samples) {
      ineed = samples - sofar;

      if (sf->holdlen) {
         if (sf->holdlen <= ineed) {
            memcpy(offset, sf->hold, sf->holdlen * sizeof(*offset));
            sofar += sf->holdlen;
            offset += sf->holdlen;
            sf->holdlen = 0;
            sf->offset = sf->hold;
         } else {
            remain = sf->holdlen - ineed;
            memcpy(offset, sf->offset, ineed * sizeof(*offset));
            sofar += ineed;
            sf->offset += ineed;
            sf->holdlen = remain;
         }
         continue;
      }
      
      if ((frame_ptr = AST_LIST_REMOVE_HEAD(&sf->queue, frame_list))) {
         frame_data = frame_ptr->data.ptr;
         
         if (frame_ptr->samples <= ineed) {
            memcpy(offset, frame_data, frame_ptr->samples * sizeof(*offset));
            sofar += frame_ptr->samples;
            offset += frame_ptr->samples;
         } else {
            remain = frame_ptr->samples - ineed;
            memcpy(offset, frame_data, ineed * sizeof(*offset));
            sofar += ineed;
            frame_data += ineed;
            if (remain > (AST_SLINFACTORY_MAX_HOLD - sf->holdlen)) {
               remain = AST_SLINFACTORY_MAX_HOLD - sf->holdlen;
            }
            memcpy(sf->hold, frame_data, remain * sizeof(*offset));
            sf->holdlen = remain;
         }
         ast_frfree(frame_ptr);
      } else {
         break;
      }
   }

   sf->size -= sofar;
   return sofar;
}