SILK format attribute interface. More...

#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/format.h"

Include dependency graph for res_format_attr_silk.c:

Data Structures
struct	silk_attr
	SILK attribute structure. More...
Functions
static void	__reg_module (void)
static void	__unreg_module (void)
static int	load_module (void)
static enum ast_format_cmp_res	silk_cmp (const struct ast_format_attr fattr1, const struct ast_format_attr fattr2)
static int	silk_get_val (const struct ast_format_attr fattr, int key, void result)
static int	silk_getjoint (const struct ast_format_attr fattr1, const struct ast_format_attr fattr2, struct ast_format_attr *result)
static int	silk_isset (const struct ast_format_attr *fattr, va_list ap)
static void	silk_sdp_generate (const struct ast_format_attr format_attr, unsigned int payload, struct ast_str *str)
static int	silk_sdp_parse (struct ast_format_attr format_attr, const char attributes)
static void	silk_set (struct ast_format_attr *fattr, va_list ap)
static int	unload_module (void)
Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "SILK Format Attribute Module" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_CHANNEL_DEPEND, }
static struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_format_attr_interface	silk_interface

Detailed Description

SILK format attribute interface.

Author:: David Vossel <dvossel@digium.com>

Definition in file res_format_attr_silk.c.

Function Documentation

static void __reg_module ( void ) [static]

Definition at line 251 of file res_format_attr_silk.c.

static void __unreg_module ( void ) [static]

Definition at line 251 of file res_format_attr_silk.c.

static int load_module ( void ) [static]

Definition at line 232 of file res_format_attr_silk.c.

References ast_format_attr_reg_interface(), AST_MODULE_LOAD_DECLINE, and AST_MODULE_LOAD_SUCCESS.

{
   if (ast_format_attr_reg_interface(&silk_interface)) {
      return AST_MODULE_LOAD_DECLINE;
   }

   return AST_MODULE_LOAD_SUCCESS;
}

static enum ast_format_cmp_res silk_cmp	(	const struct ast_format_attr *	fattr1,
		const struct ast_format_attr *	fattr2
	)		`[static]`

Definition at line 80 of file res_format_attr_silk.c.

References AST_FORMAT_CMP_EQUAL, AST_FORMAT_CMP_NOT_EQUAL, and silk_attr::samplerate.

{
   struct silk_attr *attr1 = (struct silk_attr *) fattr1;
   struct silk_attr *attr2 = (struct silk_attr *) fattr2;

   if (attr1->samplerate == attr2->samplerate) {
      return AST_FORMAT_CMP_EQUAL;
   }
   return AST_FORMAT_CMP_NOT_EQUAL;
}

static int silk_get_val	(	const struct ast_format_attr *	fattr,
		int	key,
		void *	result
	)		`[static]`

Definition at line 91 of file res_format_attr_silk.c.

References ast_log(), silk_attr::dtx, silk_attr::fec, LOG_WARNING, silk_attr::maxbitrate, silk_attr::packetloss_percentage, silk_attr::samplerate, SILK_ATTR_KEY_DTX, SILK_ATTR_KEY_FEC, SILK_ATTR_KEY_MAX_BITRATE, SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE, and SILK_ATTR_KEY_SAMP_RATE.

{
   const struct silk_attr *attr = (struct silk_attr *) fattr;
   int *val = result;

   switch (key) {
   case SILK_ATTR_KEY_SAMP_RATE:
      *val = attr->samplerate;
      break;
   case SILK_ATTR_KEY_MAX_BITRATE:
      *val = attr->maxbitrate;
      break;
   case SILK_ATTR_KEY_DTX:
      *val = attr->dtx;
      break;
   case SILK_ATTR_KEY_FEC:
      *val = attr->fec;
      break;
   case SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE:
      *val = attr->packetloss_percentage;
      break;
   default:
      ast_log(LOG_WARNING, "unknown attribute type %d\n", key);
      return -1;
   }
   return 0;
}

static int silk_getjoint	(	const struct ast_format_attr *	fattr1,
		const struct ast_format_attr *	fattr2,
		struct ast_format_attr *	result
	)		`[static]`

Definition at line 161 of file res_format_attr_silk.c.

References silk_attr::dtx, silk_attr::fec, MAX, silk_attr::maxbitrate, MIN, silk_attr::packetloss_percentage, and silk_attr::samplerate.

{
   struct silk_attr *attr1 = (struct silk_attr *) fattr1;
   struct silk_attr *attr2 = (struct silk_attr *) fattr2;
   struct silk_attr *attr_res = (struct silk_attr *) result;
   int joint = -1;

   attr_res->samplerate = attr1->samplerate & attr2->samplerate;
   /* sample rate is the only attribute that has any bearing on if joint capabilities exist or not */
   if (attr_res->samplerate) {
      joint = 0;
   }
   /* Take the lowest max bitrate */
   attr_res->maxbitrate = MIN(attr1->maxbitrate, attr2->maxbitrate);

   /* Only do dtx if both sides want it. DTX is a trade off between
    * computational complexity and bandwidth. */
   attr_res->dtx = attr1->dtx && attr2->dtx ? 1 : 0;

   /* Only do FEC if both sides want it.  If a peer specifically requests not
    * to receive with FEC, it may be a waste of bandwidth. */
   attr_res->fec = attr1->fec && attr2->fec ? 1 : 0;

   /* Use the maximum packetloss percentage between the two attributes. This affects how
    * much redundancy is used in the FEC. */
   attr_res->packetloss_percentage = MAX(attr1->packetloss_percentage, attr2->packetloss_percentage);
   return joint;
}

static int silk_isset	(	const struct ast_format_attr *	fattr,
		va_list	ap
	)		`[static]`

Definition at line 119 of file res_format_attr_silk.c.

References AST_FORMAT_ATTR_END, ast_log(), silk_attr::dtx, silk_attr::fec, LOG_WARNING, silk_attr::maxbitrate, silk_attr::packetloss_percentage, silk_attr::samplerate, SILK_ATTR_KEY_DTX, SILK_ATTR_KEY_FEC, SILK_ATTR_KEY_MAX_BITRATE, SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE, and SILK_ATTR_KEY_SAMP_RATE.

{
   enum silk_attr_keys key;
   const struct silk_attr *attr = (struct silk_attr *) fattr;

   for (key = va_arg(ap, int);
      key != AST_FORMAT_ATTR_END;
      key = va_arg(ap, int))
   {
      switch (key) {
      case SILK_ATTR_KEY_SAMP_RATE:
         if (attr->samplerate != (va_arg(ap, int))) {
            return -1;
         }
         break;
      case SILK_ATTR_KEY_MAX_BITRATE:
         if (attr->maxbitrate != (va_arg(ap, int))) {
            return -1;
         }
         break;
      case SILK_ATTR_KEY_DTX:
         if (attr->dtx != (va_arg(ap, int))) {
            return -1;
         }
         break;
      case SILK_ATTR_KEY_FEC:
         if (attr->fec != (va_arg(ap, int))) {
            return -1;
         }
         break;
      case SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE:
         if (attr->packetloss_percentage != (va_arg(ap, int))) {
            return -1;
         }
         break;
      default:
         ast_log(LOG_WARNING, "unknown attribute type %d\n", key);
         return -1;
      }
   }
   return 0;
}

static void silk_sdp_generate	(	const struct ast_format_attr *	format_attr,
		unsigned int	payload,
		struct ast_str **	str
	)		`[static]`

Definition at line 68 of file res_format_attr_silk.c.

References ast_str_append(), silk_attr::dtx, silk_attr::fec, and silk_attr::maxbitrate.

{
   struct silk_attr *attr = (struct silk_attr *) format_attr;

   if ((attr->maxbitrate > 5000) && (attr->maxbitrate < 40000)) { 
      ast_str_append(str, 0, "a=fmtp:%d maxaveragebitrate=%d\r\n", payload, attr->maxbitrate);
   }

   ast_str_append(str, 0, "a=fmtp:%d usedtx=%d\r\n", payload, attr->dtx);
   ast_str_append(str, 0, "a=fmtp:%d useinbandfec=%d\r\n", payload, attr->fec);
}

static int silk_sdp_parse	(	struct ast_format_attr *	format_attr,
		const char *	attributes
	)		`[static]`

Definition at line 50 of file res_format_attr_silk.c.

References silk_attr::dtx, silk_attr::fec, and silk_attr::maxbitrate.

{
   struct silk_attr *attr = (struct silk_attr *) format_attr;
   unsigned int val;

   if (sscanf(attributes, "maxaveragebitrate=%30u", &val) == 1) {
      attr->maxbitrate = val;
   }
   if (sscanf(attributes, "usedtx=%30u", &val) == 1) {
      attr->dtx = val;
   }
   if (sscanf(attributes, "useinbandfec=%30u", &val) == 1) {
      attr->fec = val;
   }

   return 0;
}

static void silk_set	(	struct ast_format_attr *	fattr,
		va_list	ap
	)		`[static]`

Definition at line 190 of file res_format_attr_silk.c.

References AST_FORMAT_ATTR_END, ast_log(), silk_attr::dtx, silk_attr::fec, LOG_WARNING, silk_attr::maxbitrate, silk_attr::packetloss_percentage, silk_attr::samplerate, SILK_ATTR_KEY_DTX, SILK_ATTR_KEY_FEC, SILK_ATTR_KEY_MAX_BITRATE, SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE, and SILK_ATTR_KEY_SAMP_RATE.

{
   enum silk_attr_keys key;
   struct silk_attr *attr = (struct silk_attr *) fattr;

   for (key = va_arg(ap, int);
      key != AST_FORMAT_ATTR_END;
      key = va_arg(ap, int))
   {
      switch (key) {
      case SILK_ATTR_KEY_SAMP_RATE:
         attr->samplerate = (va_arg(ap, int));
         break;
      case SILK_ATTR_KEY_MAX_BITRATE:
         attr->maxbitrate = (va_arg(ap, int));
         break;
      case SILK_ATTR_KEY_DTX:
         attr->dtx = (va_arg(ap, int));
         break;
      case SILK_ATTR_KEY_FEC:
         attr->fec = (va_arg(ap, int));
         break;
      case SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE:
         attr->packetloss_percentage = (va_arg(ap, int));
         break;
      default:
         ast_log(LOG_WARNING, "unknown attribute type %d\n", key);
      }
   }
}

static int unload_module ( void ) [static]

Definition at line 241 of file res_format_attr_silk.c.

References ast_format_attr_unreg_interface().

{
   ast_format_attr_unreg_interface(&silk_interface);
   return 0;
}

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "SILK Format Attribute Module" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = AST_BUILDOPT_SUM, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_CHANNEL_DEPEND, } [static]

Definition at line 251 of file res_format_attr_silk.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 251 of file res_format_attr_silk.c.

struct ast_format_attr_interface silk_interface [static]

Definition at line 221 of file res_format_attr_silk.c.

Asterisk developer's documentation

Data Structures

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation