res_format_attr_silk.c File Reference

SILK format attribute interface. More...

#include "asterisk.h"
#include <ctype.h>
#include "asterisk/module.h"
#include "asterisk/format.h"
#include "asterisk/logger.h"
#include "asterisk/strings.h"
#include "asterisk/utils.h"

Include dependency graph for res_format_attr_silk.c:

Go to the source code of this file.

Data Structures
struct	silk_attr
	SILK attribute structure. More...

Functions
static void	__reg_module (void)
static void	__unreg_module (void)
struct ast_module *	AST_MODULE_SELF_SYM (void)
static void	attr_init (struct silk_attr *attr)
static int	load_module (void)
static int	silk_clone (const struct ast_format *src, struct ast_format *dst)
static enum ast_format_cmp_res	silk_cmp (const struct ast_format *format1, const struct ast_format *format2)
static void	silk_destroy (struct ast_format *format)
static void	silk_generate_sdp_fmtp (const struct ast_format *format, unsigned int payload, struct ast_str **str)
static const void *	silk_get (const struct ast_format *format, const char *name)
static struct ast_format *	silk_getjoint (const struct ast_format *format1, const struct ast_format *format2)
static struct ast_format *	silk_parse_sdp_fmtp (const struct ast_format *format, const char *attributes)
static struct ast_format *	silk_set (const struct ast_format *format, const char *name, const char *value)
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 = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_CHANNEL_DEPEND, }
static const struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_format_interface	silk_interface

Detailed Description

SILK format attribute interface.

Author

David Vossel dvoss.nosp@m.el@d.nosp@m.igium.nosp@m..com

Definition in file res_format_attr_silk.c.

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 267 of file res_format_attr_silk.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 267 of file res_format_attr_silk.c.

AST_MODULE_SELF_SYM()

struct ast_module * AST_MODULE_SELF_SYM

(

void

)

Definition at line 267 of file res_format_attr_silk.c.

attr_init()

static void attr_init ( struct silk_attr *  attr )

static

Definition at line 59 of file res_format_attr_silk.c.

{
    memset(attr, 0, sizeof(*attr));
}

Referenced by silk_clone(), and silk_getjoint().

load_module()

static int load_module ( void  )

static

Definition at line 248 of file res_format_attr_silk.c.

{
    if (ast_format_interface_register("silk", &silk_interface)) {
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}

References ast_format_interface_register, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, and silk_interface.

silk_clone()

static int silk_clone ( const struct ast_format *  src, struct ast_format *  dst  )

static

Definition at line 64 of file res_format_attr_silk.c.

{
    struct silk_attr *original = ast_format_get_attribute_data(src);
    struct silk_attr *attr = ast_malloc(sizeof(*attr));
 
    if (!attr) {
        return -1;
    }
 
    if (original) {
        *attr = *original;
    } else {
        attr_init(attr);
    }
 
    ast_format_set_attribute_data(dst, attr);
 
    return 0;
}

References ast_format_get_attribute_data(), ast_format_set_attribute_data(), ast_malloc, and attr_init().

silk_cmp()

static enum ast_format_cmp_res silk_cmp ( const struct ast_format *  format1, const struct ast_format *  format2  )

static

Definition at line 135 of file res_format_attr_silk.c.

{
    if (ast_format_get_sample_rate(format1) == ast_format_get_sample_rate(format2)) {
        return AST_FORMAT_CMP_EQUAL;
    }
 
    return AST_FORMAT_CMP_NOT_EQUAL;
}

References AST_FORMAT_CMP_EQUAL, AST_FORMAT_CMP_NOT_EQUAL, and ast_format_get_sample_rate().

silk_destroy()

static void silk_destroy ( struct ast_format *  format )

static

Definition at line 52 of file res_format_attr_silk.c.

{
    struct silk_attr *attr = ast_format_get_attribute_data(format);
 
    ast_free(attr);
}

References ast_format_get_attribute_data(), and ast_free.

silk_generate_sdp_fmtp()

static void silk_generate_sdp_fmtp ( const struct ast_format *  format, unsigned int  payload, struct ast_str **  str  )

static

Definition at line 115 of file res_format_attr_silk.c.

{
    struct silk_attr *attr = ast_format_get_attribute_data(format);
 
    if (!attr) {
        return;
    }
 
    if ((attr->maxbitrate > 5000) && (attr->maxbitrate < 40000)) {
        ast_str_append(str, 0, "a=fmtp:%u maxaveragebitrate=%u\r\n", payload, attr->maxbitrate);
    }
 
    if (attr->dtx) {
        ast_str_append(str, 0, "a=fmtp:%u usedtx=%u\r\n", payload, attr->dtx);
    }
    if (attr->fec) {
        ast_str_append(str, 0, "a=fmtp:%u useinbandfec=%u\r\n", payload, attr->fec);
    }
}

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

silk_get()

static const void * silk_get ( const struct ast_format *  format, const char *  name  )

static

Definition at line 216 of file res_format_attr_silk.c.

{
    struct silk_attr *attr = ast_format_get_attribute_data(format);
    unsigned int *val;
 
    if (!strcasecmp(name, "max_bitrate")) {
        val = &attr->maxbitrate;
    } else if (!strcasecmp(name, "dtx")) {
        val = &attr->dtx;
    } else if (!strcasecmp(name, "fec")) {
        val = &attr->fec;
    } else if (!strcasecmp(name, "packetloss_percentage")) {
        val = &attr->packetloss_percentage;
    } else {
        ast_log(LOG_WARNING, "unknown attribute type %s\n", name);
        return NULL;
    }
 
    return val;
}

References ast_format_get_attribute_data(), ast_log, silk_attr::dtx, silk_attr::fec, LOG_WARNING, silk_attr::maxbitrate, name, NULL, and silk_attr::packetloss_percentage.

silk_getjoint()

static struct ast_format * silk_getjoint ( const struct ast_format *  format1, const struct ast_format *  format2  )

static

Definition at line 144 of file res_format_attr_silk.c.

{
    struct silk_attr *attr1 = ast_format_get_attribute_data(format1);
    struct silk_attr *attr2 = ast_format_get_attribute_data(format2);
    struct ast_format *jointformat;
    struct silk_attr *attr_res;
 
    if (ast_format_get_sample_rate(format1) != ast_format_get_sample_rate(format2)) {
        return NULL;
    }
 
    jointformat = ast_format_clone(format1);
    if (!jointformat) {
        return NULL;
    }
    attr_res = ast_format_get_attribute_data(jointformat);
 
    if (!attr1 || !attr2) {
        attr_init(attr_res);
    } else {
        /* 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 jointformat;
}

References ast_format_clone(), ast_format_get_attribute_data(), ast_format_get_sample_rate(), attr_init(), silk_attr::dtx, silk_attr::fec, MAX, silk_attr::maxbitrate, MIN, NULL, and silk_attr::packetloss_percentage.

silk_parse_sdp_fmtp()

static struct ast_format * silk_parse_sdp_fmtp ( const struct ast_format *  format, const char *  attributes  )

static

Definition at line 84 of file res_format_attr_silk.c.

{
    char *attribs = ast_strdupa(attributes), *attrib;
    struct ast_format *cloned;
    struct silk_attr *attr;
    unsigned int val;
 
    cloned = ast_format_clone(format);
    if (!cloned) {
        return NULL;
    }
    attr = ast_format_get_attribute_data(cloned);
 
    /* lower-case everything, so we are case-insensitive */
    for (attrib = attribs; *attrib; ++attrib) {
        *attrib = tolower(*attrib);
    } /* based on channels/chan_sip.c:process_a_sdp_image() */
 
    if (sscanf(attribs, "maxaveragebitrate=%30u", &val) == 1) {
        attr->maxbitrate = val;
    }
    if (sscanf(attribs, "usedtx=%30u", &val) == 1) {
        attr->dtx = val;
    }
    if (sscanf(attribs, "useinbandfec=%30u", &val) == 1) {
        attr->fec = val;
    }
 
    return cloned;
}

References ast_format_clone(), ast_format_get_attribute_data(), ast_strdupa, silk_attr::dtx, silk_attr::fec, silk_attr::maxbitrate, and NULL.

silk_set()

static struct ast_format * silk_set ( const struct ast_format *  format, const char *  name, const char *  value  )

static

Definition at line 183 of file res_format_attr_silk.c.

{
    struct ast_format *cloned;
    struct silk_attr *attr;
    unsigned int val;
 
    if (sscanf(value, "%30u", &val) != 1) {
        ast_log(LOG_WARNING, "Unknown value '%s' for attribute type '%s'\n",
            value, name);
        return NULL;
    }
 
    cloned = ast_format_clone(format);
    if (!cloned) {
        return NULL;
    }
    attr = ast_format_get_attribute_data(cloned);
 
    if (!strcasecmp(name, "max_bitrate")) {
        attr->maxbitrate = val;
    } else if (!strcasecmp(name, "dtx")) {
        attr->dtx = val;
    } else if (!strcasecmp(name, "fec")) {
        attr->fec = val;
    } else if (!strcasecmp(name, "packetloss_percentage")) {
        attr->packetloss_percentage = val;
    } else {
        ast_log(LOG_WARNING, "unknown attribute type %s\n", name);
    }
 
    return cloned;
}

References ast_format_clone(), ast_format_get_attribute_data(), ast_log, silk_attr::dtx, silk_attr::fec, LOG_WARNING, silk_attr::maxbitrate, name, NULL, silk_attr::packetloss_percentage, and value.

unload_module()

static int unload_module ( void  )

static

Definition at line 257 of file res_format_attr_silk.c.

{
    return 0;
}

Variable Documentation

__mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "SILK Format Attribute Module" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_CHANNEL_DEPEND, }

static

Definition at line 267 of file res_format_attr_silk.c.

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 267 of file res_format_attr_silk.c.

silk_interface

struct ast_format_interface silk_interface

static

Definition at line 237 of file res_format_attr_silk.c.

                                                    {
    .format_destroy = silk_destroy,
    .format_clone = silk_clone,
    .format_cmp = silk_cmp,
    .format_get_joint = silk_getjoint,
    .format_attribute_set = silk_set,
    .format_attribute_get = silk_get,
    .format_parse_sdp_fmtp = silk_parse_sdp_fmtp,
    .format_generate_sdp_fmtp = silk_generate_sdp_fmtp,
};

Referenced by load_module().