format.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2010, Digium, Inc.
 *
 * David Vossel <dvossel@digium.com>
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief Format API
 *
 * \author David Vossel <dvossel@digium.com>
 * \author Mark Spencer <markster@digium.com>
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 415728 $");

#include "asterisk/_private.h"
#include "asterisk/format.h"
#include "asterisk/astobj2.h"
#include "asterisk/lock.h"
#include "asterisk/frame.h"
#include "asterisk/utils.h"
#include "asterisk/cli.h"
#include "asterisk/rtp_engine.h"
#include "asterisk/config.h"

#define FORMAT_CONFIG "codecs.conf"

/*!
 * \brief Container for all the format attribute interfaces.
 * \note This container uses RWLOCKs instead of MUTEX locks.                                                             .
 * \note An ao2 container was chosen for fast lookup.
 */
static struct ao2_container *interfaces;

/*! a wrapper is used put interfaces into the ao2 container. */
struct interface_ao2_wrapper {
   enum ast_format_id id;
   const struct ast_format_attr_interface *interface;
};

/*! \brief Format List container, This container is never directly accessed outside
 * of this file, and It only exists for building the format_list_array. */
static struct ao2_container *format_list;
/*! \brief Format List array is a read only array protected by a read write lock.
 * This array may be used outside this file with the use of reference counting to
 * guarantee safety for access by multiple threads. */
static struct ast_format_list *format_list_array;
static size_t format_list_array_len = 0;
/*! \brief Locks the format list array so a reference can be taken safely. */
static ast_rwlock_t format_list_array_lock;

static int interface_cmp_cb(void *obj, void *arg, int flags)
{
   struct interface_ao2_wrapper *wrapper1 = obj;
   struct interface_ao2_wrapper *wrapper2 = arg;

   return (wrapper2->id == wrapper1->id) ? CMP_MATCH | CMP_STOP : 0;
}

static int interface_hash_cb(const void *obj, const int flags)
{
   const struct interface_ao2_wrapper *wrapper = obj;
   return wrapper->id;
}

void ast_format_copy(struct ast_format *dst, const struct ast_format *src)
{
   *dst = *src;
}

void ast_format_set_video_mark(struct ast_format *format)
{
   format->fattr.rtp_marker_bit = 1;
}

int ast_format_get_video_mark(const struct ast_format *format)
{
   return format->fattr.rtp_marker_bit;
}

static struct interface_ao2_wrapper *find_interface(const struct ast_format *format)
{
   struct interface_ao2_wrapper tmp_wrapper = {
      .id = format->id,
   };

   return ao2_find(interfaces, &tmp_wrapper, OBJ_POINTER);
}

static int has_interface(const struct ast_format *format)
{
   struct interface_ao2_wrapper *wrapper;

   wrapper = find_interface(format);
   if (!wrapper) {
      return 0;
   }
   ao2_ref(wrapper, -1);
   return 1;
}

int ast_format_sdp_parse(struct ast_format *format, const char *attributes)
{
   struct interface_ao2_wrapper *wrapper;
   int res;

   if (!(wrapper = find_interface(format))) {
      return 0;
   }

   ao2_rdlock(wrapper);
   if (!wrapper->interface || !wrapper->interface->format_attr_sdp_parse) {
      ao2_unlock(wrapper);
      ao2_ref(wrapper, -1);
      return 0;
   }

   res = wrapper->interface->format_attr_sdp_parse(&format->fattr, attributes);

   ao2_unlock(wrapper);
   ao2_ref(wrapper, -1);

   return res;
}

void ast_format_sdp_generate(const struct ast_format *format, unsigned int payload, struct ast_str **str)
{
   struct interface_ao2_wrapper *wrapper;

   if (!(wrapper = find_interface(format))) {
      return;
   }

   ao2_rdlock(wrapper);
   if (!wrapper->interface || !wrapper->interface->format_attr_sdp_generate) {
      ao2_unlock(wrapper);
      ao2_ref(wrapper, -1);
      return;
   }

   wrapper->interface->format_attr_sdp_generate(&format->fattr, payload, str);

   ao2_unlock(wrapper);
   ao2_ref(wrapper, -1);
}

/*! \internal
 * \brief set format attributes using an interface
 */
static int format_set_helper(struct ast_format *format, va_list ap)
{
   struct interface_ao2_wrapper *wrapper;

   if (!(wrapper = find_interface(format))) {
      ast_log(LOG_WARNING, "Could not find format interface to set.\n");
      return -1;
   }

   ao2_rdlock(wrapper);
   if (!wrapper->interface || !wrapper->interface->format_attr_set) {
      ao2_unlock(wrapper);
      ao2_ref(wrapper, -1);
      return -1;
   }

   wrapper->interface->format_attr_set(&format->fattr, ap);

   ao2_unlock(wrapper);
   ao2_ref(wrapper, -1);

   return 0;
}

struct ast_format *ast_format_append(struct ast_format *format, ... )
{
   va_list ap;
   va_start(ap, format);
   format_set_helper(format, ap);
   va_end(ap);

   return format;
}

struct ast_format *ast_format_set(struct ast_format *format, enum ast_format_id id, int set_attributes, ... )
{
   /* initialize the structure before setting it. */
   ast_format_clear(format);

   format->id = id;

   if (set_attributes) {
      va_list ap;
      va_start(ap, set_attributes);
      format_set_helper(format, ap);
      va_end(ap);
   }

   return format;
}

void ast_format_clear(struct ast_format *format)
{
   format->id = 0;
   memset(&format->fattr, 0, sizeof(format->fattr));
}

/*! \internal
 * \brief determine if a list of attribute key value pairs are set on a format
 */
static int format_isset_helper(const struct ast_format *format, va_list ap)
{
   int res;
   struct interface_ao2_wrapper *wrapper;
   struct ast_format tmp = {
      .id = format->id,
      .fattr = { { 0, }, },
   };

   if (!(wrapper = find_interface(format))) {
      return -1;
   }

   ao2_rdlock(wrapper);
   if (!wrapper->interface ||
      !wrapper->interface->format_attr_set ||
      !wrapper->interface->format_attr_cmp) {

      ao2_unlock(wrapper);
      ao2_ref(wrapper, -1);
      return -1;
   }

   /* if isset is present, use that function, else just build a new
    * format and use the cmp function */
   if (wrapper->interface->format_attr_isset) {
      res = wrapper->interface->format_attr_isset(&format->fattr, ap);
   } else {
      wrapper->interface->format_attr_set(&tmp.fattr, ap);
      /* use our tmp structure to tell if the attributes are set or not */
      res = wrapper->interface->format_attr_cmp(&tmp.fattr, &format->fattr);
      res = (res == AST_FORMAT_CMP_NOT_EQUAL) ? -1 : 0;
   }

   ao2_unlock(wrapper);
   ao2_ref(wrapper, -1);

   return res;
}

int ast_format_isset(const struct ast_format *format, ... )
{
   va_list ap;
   int res;

   va_start(ap, format);
   res = format_isset_helper(format, ap);
   va_end(ap);
   return res;
}

int ast_format_get_value(const struct ast_format *format, int key, void *value)
{
   int res = 0;
   struct interface_ao2_wrapper *wrapper;

   if (!(wrapper = find_interface(format))) {
      return -1;
   }
   ao2_rdlock(wrapper);
   if (!wrapper->interface ||
      !wrapper->interface->format_attr_get_val) {

      ao2_unlock(wrapper);
      ao2_ref(wrapper, -1);
      return -1;
   }

   res = wrapper->interface->format_attr_get_val(&format->fattr, key, value);

   ao2_unlock(wrapper);
   ao2_ref(wrapper, -1);

   return res;
}

/*! \internal
 * \brief cmp format attributes using an interface
 */
static enum ast_format_cmp_res format_cmp_helper(const struct ast_format *format1, const struct ast_format *format2)
{
   enum ast_format_cmp_res res = AST_FORMAT_CMP_EQUAL;
   struct interface_ao2_wrapper *wrapper;

   if (!(wrapper = find_interface(format1))) {
      return res;
   }

   ao2_rdlock(wrapper);
   if (!wrapper->interface || !wrapper->interface->format_attr_cmp) {
      ao2_unlock(wrapper);
      ao2_ref(wrapper, -1);
      return res;
   }

   res = wrapper->interface->format_attr_cmp(&format1->fattr, &format2->fattr);

   ao2_unlock(wrapper);
   ao2_ref(wrapper, -1);

   return res;
}

enum ast_format_cmp_res ast_format_cmp(const struct ast_format *format1, const struct ast_format *format2)
{
   if (format1->id != format2->id) {
      return AST_FORMAT_CMP_NOT_EQUAL;
   }

   return format_cmp_helper(format1, format2);
}

/*! \internal
 * \brief get joint format attributes using an interface
 */
static int format_joint_helper(const struct ast_format *format1, const struct ast_format *format2, struct ast_format *result)
{
   int res = 0;
   struct interface_ao2_wrapper *wrapper;

   if (!(wrapper = find_interface(format1))) {
      /* if no interface is present, we assume formats are joint by id alone */
      return res;
   }

   ao2_rdlock(wrapper);
   if (wrapper->interface && wrapper->interface->format_attr_get_joint) {
      res = wrapper->interface->format_attr_get_joint(&format1->fattr, &format2->fattr, &result->fattr);
   }
   ao2_unlock(wrapper);

   ao2_ref(wrapper, -1);

   return res;
}

int ast_format_joint(const struct ast_format *format1, const struct ast_format *format2, struct ast_format *result)
{
   if (format1->id != format2->id) {
      return -1;
   }
   result->id = format1->id;
   return format_joint_helper(format1, format2, result);
}


uint64_t ast_format_id_to_old_bitfield(enum ast_format_id id)
{
   switch (id) {
   /*! G.723.1 compression */
   case AST_FORMAT_G723_1:
      return (1ULL << 0);
   /*! GSM compression */
   case AST_FORMAT_GSM:
      return (1ULL << 1);
   /*! Raw mu-law data (G.711) */
   case AST_FORMAT_ULAW:
      return (1ULL << 2);
   /*! Raw A-law data (G.711) */
   case AST_FORMAT_ALAW:
      return (1ULL << 3);
   /*! ADPCM (G.726, 32kbps, AAL2 codeword packing) */
   case AST_FORMAT_G726_AAL2:
      return (1ULL << 4);
   /*! ADPCM (IMA) */
   case AST_FORMAT_ADPCM:
      return (1ULL << 5);
   /*! Raw 16-bit Signed Linear (8000 Hz) PCM */
   case AST_FORMAT_SLINEAR:
      return (1ULL << 6);
   /*! LPC10, 180 samples/frame */
   case AST_FORMAT_LPC10:
      return (1ULL << 7);
   /*! G.729A audio */
   case AST_FORMAT_G729A:
      return (1ULL << 8);
   /*! SpeeX Free Compression */
   case AST_FORMAT_SPEEX:
      return (1ULL << 9);
   /*! iLBC Free Compression */
   case AST_FORMAT_ILBC:
      return (1ULL << 10);
   /*! ADPCM (G.726, 32kbps, RFC3551 codeword packing) */
   case AST_FORMAT_G726:
      return (1ULL << 11);
   /*! G.722 */
   case AST_FORMAT_G722:
      return (1ULL << 12);
   /*! G.722.1 (also known as Siren7, 32kbps assumed) */
   case AST_FORMAT_SIREN7:
      return (1ULL << 13);
   /*! G.722.1 Annex C (also known as Siren14, 48kbps assumed) */
   case AST_FORMAT_SIREN14:
      return (1ULL << 14);
   /*! Raw 16-bit Signed Linear (16000 Hz) PCM */
   case AST_FORMAT_SLINEAR16:
      return (1ULL << 15);
   /*! G.719 (64 kbps assumed) */
   case AST_FORMAT_G719:
      return (1ULL << 32);
   /*! SpeeX Wideband (16kHz) Free Compression */
   case AST_FORMAT_SPEEX16:
      return (1ULL << 33);
   /*! Raw mu-law data (G.711) */
   case AST_FORMAT_TESTLAW:
      return (1ULL << 47);

   /*! H.261 Video */
   case AST_FORMAT_H261:
      return (1ULL << 18);
   /*! H.263 Video */
   case AST_FORMAT_H263:
      return (1ULL << 19);
   /*! H.263+ Video */
   case AST_FORMAT_H263_PLUS:
      return (1ULL << 20);
   /*! H.264 Video */
   case AST_FORMAT_H264:
      return (1ULL << 21);
   /*! MPEG4 Video */
   case AST_FORMAT_MP4_VIDEO:
      return (1ULL << 22);

   /*! JPEG Images */
   case AST_FORMAT_JPEG:
      return (1ULL << 16);
   /*! PNG Images */
   case AST_FORMAT_PNG:
      return (1ULL << 17);

   /*! T.140 RED Text format RFC 4103 */
   case AST_FORMAT_T140RED:
      return (1ULL << 26);
   /*! T.140 Text format - ITU T.140, RFC 4103 */
   case AST_FORMAT_T140:
      return (1ULL << 27);
   default:
      return 0; /* not supported by old bitfield. */
   }

   return 0;

}
uint64_t ast_format_to_old_bitfield(const struct ast_format *format)
{
   return ast_format_id_to_old_bitfield(format->id);
}

struct ast_format *ast_format_from_old_bitfield(struct ast_format *dst, uint64_t src)
{
   switch (src) {
   /*! G.723.1 compression */
   case (1ULL << 0):
      return ast_format_set(dst, AST_FORMAT_G723_1, 0);
   /*! GSM compression */
   case (1ULL << 1):
      return ast_format_set(dst, AST_FORMAT_GSM, 0);
   /*! Raw mu-law data (G.711) */
   case (1ULL << 2):
      return ast_format_set(dst, AST_FORMAT_ULAW, 0);
   /*! Raw A-law data (G.711) */
   case (1ULL << 3):
      return ast_format_set(dst, AST_FORMAT_ALAW, 0);
   /*! ADPCM (G.726, 32kbps, AAL2 codeword packing) */
   case (1ULL << 4):
      return ast_format_set(dst, AST_FORMAT_G726_AAL2, 0);
   /*! ADPCM (IMA) */
   case (1ULL << 5):
      return ast_format_set(dst, AST_FORMAT_ADPCM, 0);
   /*! Raw 16-bit Signed Linear (8000 Hz) PCM */
   case (1ULL << 6):
      return ast_format_set(dst, AST_FORMAT_SLINEAR, 0);
   /*! LPC10, 180 samples/frame */
   case (1ULL << 7):
      return ast_format_set(dst, AST_FORMAT_LPC10, 0);
   /*! G.729A audio */
   case (1ULL << 8):
      return ast_format_set(dst, AST_FORMAT_G729A, 0);
   /*! SpeeX Free Compression */
   case (1ULL << 9):
      return ast_format_set(dst, AST_FORMAT_SPEEX, 0);
   /*! iLBC Free Compression */
   case (1ULL << 10):
      return ast_format_set(dst, AST_FORMAT_ILBC, 0);
   /*! ADPCM (G.726, 32kbps, RFC3551 codeword packing) */
   case (1ULL << 11):
      return ast_format_set(dst, AST_FORMAT_G726, 0);
   /*! G.722 */
   case (1ULL << 12):
      return ast_format_set(dst, AST_FORMAT_G722, 0);
   /*! G.722.1 (also known as Siren7, 32kbps assumed) */
   case (1ULL << 13):
      return ast_format_set(dst, AST_FORMAT_SIREN7, 0);
   /*! G.722.1 Annex C (also known as Siren14, 48kbps assumed) */
   case (1ULL << 14):
      return ast_format_set(dst, AST_FORMAT_SIREN14, 0);
   /*! Raw 16-bit Signed Linear (16000 Hz) PCM */
   case (1ULL << 15):
      return ast_format_set(dst, AST_FORMAT_SLINEAR16, 0);
   /*! G.719 (64 kbps assumed) */
   case (1ULL << 32):
      return ast_format_set(dst, AST_FORMAT_G719, 0);
   /*! SpeeX Wideband (16kHz) Free Compression */
   case (1ULL << 33):
      return ast_format_set(dst, AST_FORMAT_SPEEX16, 0);
   /*! Raw mu-law data (G.711) */
   case (1ULL << 47):
      return ast_format_set(dst, AST_FORMAT_TESTLAW, 0);

   /*! H.261 Video */
   case (1ULL << 18):
      return ast_format_set(dst, AST_FORMAT_H261, 0);
   /*! H.263 Video */
   case (1ULL << 19):
      return ast_format_set(dst, AST_FORMAT_H263, 0);
   /*! H.263+ Video */
   case (1ULL << 20):
      return ast_format_set(dst, AST_FORMAT_H263_PLUS, 0);
   /*! H.264 Video */
   case (1ULL << 21):
      return ast_format_set(dst, AST_FORMAT_H264, 0);
   /*! MPEG4 Video */
   case (1ULL << 22):
      return ast_format_set(dst, AST_FORMAT_MP4_VIDEO, 0);

   /*! JPEG Images */
   case (1ULL << 16):
      return ast_format_set(dst, AST_FORMAT_JPEG, 0);
   /*! PNG Images */
   case (1ULL << 17):
      return ast_format_set(dst, AST_FORMAT_PNG, 0);

   /*! T.140 RED Text format RFC 4103 */
   case (1ULL << 26):
      return ast_format_set(dst, AST_FORMAT_T140RED, 0);
   /*! T.140 Text format - ITU T.140, RFC 4103 */
   case (1ULL << 27):
      return ast_format_set(dst, AST_FORMAT_T140, 0);
   }
   ast_format_clear(dst);
   return NULL;
}

enum ast_format_id ast_format_id_from_old_bitfield(uint64_t src)
{
   struct ast_format dst;
   if (ast_format_from_old_bitfield(&dst, src)) {
      return dst.id;
   }
   return 0;
}

int ast_format_is_slinear(const struct ast_format *format)
{
   if (format->id == AST_FORMAT_SLINEAR ||
      format->id == AST_FORMAT_SLINEAR12 ||
      format->id == AST_FORMAT_SLINEAR16 ||
      format->id == AST_FORMAT_SLINEAR24 ||
      format->id == AST_FORMAT_SLINEAR32 ||
      format->id == AST_FORMAT_SLINEAR44 ||
      format->id == AST_FORMAT_SLINEAR48 ||
      format->id == AST_FORMAT_SLINEAR96 ||
      format->id == AST_FORMAT_SLINEAR192) {
      return 1;
   }
   return 0;
}

enum ast_format_id ast_format_slin_by_rate(unsigned int rate)
{
   if (rate >= 192000) {
      return AST_FORMAT_SLINEAR192;
   } else if (rate >= 96000) {
      return AST_FORMAT_SLINEAR96;
   } else if (rate >= 48000) {
      return AST_FORMAT_SLINEAR48;
   } else if (rate >= 44100) {
      return AST_FORMAT_SLINEAR44;
   } else if (rate >= 32000) {
      return AST_FORMAT_SLINEAR32;
   } else if (rate >= 24000) {
      return AST_FORMAT_SLINEAR24;
   } else if (rate >= 16000) {
      return AST_FORMAT_SLINEAR16;
   } else if (rate >= 12000) {
      return AST_FORMAT_SLINEAR12;
   }
   return AST_FORMAT_SLINEAR;
}

const char* ast_getformatname(const struct ast_format *format)
{
   int x;
   const char *ret = "unknown";
   size_t f_len;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);
   for (x = 0; x < f_len; x++) {
      if (ast_format_cmp(&f_list[x].format, format) == AST_FORMAT_CMP_EQUAL) {
         ret = f_list[x].name;
         break;
      }
   }
   f_list = ast_format_list_destroy(f_list);
   return ret;
}


char *ast_getformatname_multiple_byid(char *buf, size_t size, enum ast_format_id id)
{
   int x;
   unsigned len;
   char *start, *end = buf;
   size_t f_len;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);

   if (!size) {
      f_list = ast_format_list_destroy(f_list);
      return buf;
   }
   snprintf(end, size, "(");
   len = strlen(end);
   end += len;
   size -= len;
   start = end;
   for (x = 0; x < f_len; x++) {
      if (f_list[x].format.id == id) {
         snprintf(end, size, "%s|", f_list[x].name);
         len = strlen(end);
         end += len;
         size -= len;
      }
   }
   if (start == end) {
      ast_copy_string(start, "nothing)", size);
   } else if (size > 1) {
      *(end - 1) = ')';
   }
   f_list = ast_format_list_destroy(f_list);
   return buf;
}

static struct ast_codec_alias_table {
   const char *alias;
   const char *realname;
} ast_codec_alias_table[] = {
   { "slinear", "slin"},
   { "slinear16", "slin16"},
   { "g723.1", "g723"},
   { "g722.1", "siren7"},
   { "g722.1c", "siren14"},
};

static const char *ast_expand_codec_alias(const char *in)
{
   int x;

   for (x = 0; x < ARRAY_LEN(ast_codec_alias_table); x++) {
      if (!strcmp(in,ast_codec_alias_table[x].alias))
         return ast_codec_alias_table[x].realname;
   }
   return in;
}

struct ast_format *ast_getformatbyname(const char *name, struct ast_format *result)
{
   int x;
   size_t f_len;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);

   for (x = 0; x < f_len; x++) {
      if (!strcasecmp(f_list[x].name, name) ||
          !strcasecmp(f_list[x].name, ast_expand_codec_alias(name))) {

         ast_format_copy(result, &f_list[x].format);
         f_list = ast_format_list_destroy(f_list);
         return result;
      }
   }
   f_list = ast_format_list_destroy(f_list);

   return NULL;
}

const char *ast_codec2str(struct ast_format *format)
{
   int x;
   const char *ret = "unknown";
   size_t f_len;
   const struct ast_format_list *f_list = ast_format_list_get(&f_len);

   for (x = 0; x < f_len; x++) {
      if (ast_format_cmp(&f_list[x].format, format) == AST_FORMAT_CMP_EQUAL) {
         ret = f_list[x].desc;
         break;
      }
   }
   f_list = ast_format_list_destroy(f_list);
   return ret;
}

int ast_format_rate(const struct ast_format *format)
{
   switch (format->id) {
   case AST_FORMAT_SLINEAR12:
      return 12000;
   case AST_FORMAT_SLINEAR24:
      return 24000;
   case AST_FORMAT_SLINEAR32:
      return 32000;
   case AST_FORMAT_SLINEAR44:
      return 44100;
   case AST_FORMAT_SLINEAR48:
      return 48000;
   case AST_FORMAT_SLINEAR96:
      return 96000;
   case AST_FORMAT_SLINEAR192:
      return 192000;
   case AST_FORMAT_G722:
   case AST_FORMAT_SLINEAR16:
   case AST_FORMAT_SIREN7:
   case AST_FORMAT_SPEEX16:
      return 16000;
   case AST_FORMAT_SIREN14:
   case AST_FORMAT_SPEEX32:
      return 32000;
   case AST_FORMAT_G719:
      return 48000;
   case AST_FORMAT_SILK:
      if (!(ast_format_isset(format,
         SILK_ATTR_KEY_SAMP_RATE,
         SILK_ATTR_VAL_SAMP_24KHZ,
         AST_FORMAT_ATTR_END))) {
         return 24000;
      } else if (!(ast_format_isset(format,
         SILK_ATTR_KEY_SAMP_RATE,
         SILK_ATTR_VAL_SAMP_16KHZ,
         AST_FORMAT_ATTR_END))) {
         return 16000;
      } else if (!(ast_format_isset(format,
         SILK_ATTR_KEY_SAMP_RATE,
         SILK_ATTR_VAL_SAMP_12KHZ,
         AST_FORMAT_ATTR_END))) {
         return 12000;
      } else {
         return 8000;
      }
   case AST_FORMAT_CELT:
   {
      int samplerate;
      if (!(ast_format_get_value(format,
         CELT_ATTR_KEY_SAMP_RATE,
         &samplerate))) {
         return samplerate;
      }
   }
   default:
      return 8000;
   }
}

static char *show_codecs(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int x, found=0;
   size_t f_len;
   const struct ast_format_list *f_list;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show codecs [audio|video|image|text]";
      e->usage =
         "Usage: core show codecs [audio|video|image|text]\n"
         "       Displays codec mapping\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if ((a->argc < 3) || (a->argc > 4)) {
      return CLI_SHOWUSAGE;
   }

   f_list = ast_format_list_get(&f_len);
   if (!ast_opt_dont_warn) {
      ast_cli(a->fd, "Disclaimer: this command is for informational purposes only.\n"
            "\tIt does not indicate anything about your configuration.\n");
   }

   ast_cli(a->fd, "%8s %5s %8s %s\n","ID","TYPE","NAME","DESCRIPTION");
   ast_cli(a->fd, "-----------------------------------------------------------------------------------\n");

   for (x = 0; x < f_len; x++) {
      if (a->argc == 4) {
         if (!strcasecmp(a->argv[3], "audio")) {
            if (AST_FORMAT_GET_TYPE(f_list[x].format.id) != AST_FORMAT_TYPE_AUDIO) {
               continue;
            }
         } else if (!strcasecmp(a->argv[3], "video")) {
            if (AST_FORMAT_GET_TYPE(f_list[x].format.id) != AST_FORMAT_TYPE_VIDEO) {
               continue;
            }
         } else if (!strcasecmp(a->argv[3], "image")) {
            if (AST_FORMAT_GET_TYPE(f_list[x].format.id) != AST_FORMAT_TYPE_IMAGE) {
               continue;
            }
         } else if (!strcasecmp(a->argv[3], "text")) {
            if (AST_FORMAT_GET_TYPE(f_list[x].format.id) != AST_FORMAT_TYPE_TEXT) {
               continue;
            }
         } else {
            continue;
         }
      }

      ast_cli(a->fd, "%8u %5s %8s (%s)\n",
         f_list[x].format.id,
         (AST_FORMAT_GET_TYPE(f_list[x].format.id) == AST_FORMAT_TYPE_AUDIO) ? "audio" :
         (AST_FORMAT_GET_TYPE(f_list[x].format.id)  == AST_FORMAT_TYPE_IMAGE)  ? "image" :
         (AST_FORMAT_GET_TYPE(f_list[x].format.id)  == AST_FORMAT_TYPE_VIDEO) ? "video" :
         (AST_FORMAT_GET_TYPE(f_list[x].format.id)  == AST_FORMAT_TYPE_TEXT)  ? "text"  :
         "(unk)",
         f_list[x].name,
         f_list[x].desc);
      found = 1;
   }

   f_list = ast_format_list_destroy(f_list);
   if (!found) {
      return CLI_SHOWUSAGE;
   } else {
      return CLI_SUCCESS;
   }
}

static char *show_codec_n(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   enum ast_format_id format_id;
   int x, found = 0;
   int type_punned_codec;
   size_t f_len;
   const struct ast_format_list *f_list;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show codec";
      e->usage =
         "Usage: core show codec <number>\n"
         "       Displays codec mapping\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 4) {
      return CLI_SHOWUSAGE;
   }

   if (sscanf(a->argv[3], "%30d", &type_punned_codec) != 1) {
      return CLI_SHOWUSAGE;
   }
   format_id = type_punned_codec;

   f_list = ast_format_list_get(&f_len);
   for (x = 0; x < f_len; x++) {
      if (f_list[x].format.id == format_id) {
         found = 1;
         ast_cli(a->fd, "%11u %s\n", (unsigned int) format_id, f_list[x].desc);
      }
   }

   if (!found) {
      ast_cli(a->fd, "Codec %u not found\n", format_id);
   }

   f_list = ast_format_list_destroy(f_list);
   return CLI_SUCCESS;
}

/* Builtin Asterisk CLI-commands for debugging */
static struct ast_cli_entry my_clis[] = {
   AST_CLI_DEFINE(show_codecs, "Displays a list of codecs"),
   AST_CLI_DEFINE(show_codec_n, "Shows a specific codec"),
};
int init_framer(void)
{
   return 0;
}

static int format_list_add_custom(struct ast_format_list *new)
{
   RAII_VAR(struct ast_format_list *, entry, NULL, ao2_cleanup);
   if (!(entry = ao2_alloc(sizeof(*entry), NULL))) {
      return -1;
   }
   memcpy(entry, new, sizeof(struct ast_format_list));
   entry->custom_entry = 1;
   ao2_link(format_list, entry);
   return 0;
}
static int format_list_add_static(
   const struct ast_format *format,
   const char *name,
   int samplespersecond,
   const char *description,
   int fr_len,
   int min_ms,
   int max_ms,
   int inc_ms,
   int def_ms,
   unsigned int flags,
   int cur_ms)
{
   struct ast_format_list *entry;
   if (!(entry = ao2_alloc(sizeof(*entry), NULL))) {
      return -1;
   }
   ast_format_copy(&entry->format, format);
   ast_copy_string(entry->name, name, sizeof(entry->name));
   ast_copy_string(entry->desc, description, sizeof(entry->desc));
   entry->samplespersecond = samplespersecond;
   entry->fr_len = fr_len;
   entry->min_ms = min_ms;
   entry->max_ms = max_ms;
   entry->inc_ms = inc_ms;
   entry->def_ms = def_ms;
   entry->flags = flags;
   entry->cur_ms = cur_ms;
   entry->custom_entry = 0;

   ao2_link(format_list, entry);
   ao2_ref(entry, -1);
   return 0;
}

static int list_all_custom(void *obj, void *arg, int flag)
{
   struct ast_format_list *entry = obj;
   return entry->custom_entry ? CMP_MATCH : 0;
}

static int list_cmp_cb(void *obj, void *arg, int flags)
{
   struct ast_format_list *entry1 = obj;
   struct ast_format_list *entry2 = arg;

   return (ast_format_cmp(&entry1->format, &entry2->format) == AST_FORMAT_CMP_EQUAL) ? CMP_MATCH | CMP_STOP : 0;
}

const struct ast_format_list *ast_format_list_get(size_t *size)
{
   struct ast_format_list *list;
   ast_rwlock_rdlock(&format_list_array_lock);
   ao2_ref(format_list_array, 1);
   list = format_list_array;
   *size = format_list_array_len;
   ast_rwlock_unlock(&format_list_array_lock);
   return list;
}
const struct ast_format_list *ast_format_list_destroy(const struct ast_format_list *list)
{
   ao2_ref((void *) list, -1);
   return NULL;
}

static int build_format_list_array(void)
{
   struct ast_format_list *tmp;
   size_t arraysize = sizeof(struct ast_format_list) * ao2_container_count(format_list);
   int i = 0;
   struct ao2_iterator it;

   ast_rwlock_wrlock(&format_list_array_lock);
   tmp = format_list_array;
   if (!(format_list_array = ao2_alloc(arraysize, NULL))) {
      format_list_array = tmp;
      ast_rwlock_unlock(&format_list_array_lock);
      return -1;
   }
   format_list_array_len = ao2_container_count(format_list);
   if (tmp) {
      ao2_ref(tmp, -1);
   }

   /* walk through the container adding elements to the static array */
   it = ao2_iterator_init(format_list, 0);
   while ((tmp = ao2_iterator_next(&it)) && (i < format_list_array_len)) {
      memcpy(&format_list_array[i], tmp, sizeof(struct ast_format_list));
      ao2_ref(tmp, -1);
      i++;
   }
   ao2_iterator_destroy(&it);

   ast_rwlock_unlock(&format_list_array_lock);
   return 0;
}

static int format_list_init(void)
{
   struct ast_format tmpfmt;
   if (!(format_list = ao2_container_alloc(1, NULL, list_cmp_cb))) {
      return -1;
   }
   /* initiate static entries XXX DO NOT CHANGE THIS ORDER! */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_G723_1, 0), "g723", 8000, "G.723.1", 20, 30, 300, 30, 30, 0, 0);       /*!< G723.1 */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_GSM, 0), "gsm",  8000, "GSM", 33, 20, 300, 20, 20, 0, 0);              /*!< codec_gsm.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_ULAW, 0), "ulaw", 8000, "G.711 u-law", 80, 10, 150, 10, 20, 0, 0);     /*!< codec_ulaw.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_ALAW, 0), "alaw", 8000, "G.711 A-law", 80, 10, 150, 10, 20, 0, 0);     /*!< codec_alaw.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_G726, 0), "g726", 8000, "G.726 RFC3551", 40, 10, 300, 10, 20, 0, 0);   /*!< codec_g726.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_ADPCM, 0), "adpcm" , 8000, "ADPCM", 40, 10, 300, 10, 20, 0, 0);        /*!< codec_adpcm.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR, 0), "slin", 8000, "16 bit Signed Linear PCM", 160, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0); /*!< Signed linear */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_LPC10, 0), "lpc10", 8000, "LPC10", 7, 20, 20, 20, 20, 0, 0);           /*!< codec_lpc10.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_G729A, 0), "g729", 8000, "G.729A", 10, 10, 230, 10, 20, AST_SMOOTHER_FLAG_G729, 0);   /*!< Binary commercial distribution */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SPEEX, 0), "speex", 8000, "SpeeX", 10, 10, 60, 10, 20, 0, 0);          /*!< codec_speex.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SPEEX16, 0), "speex16", 16000, "SpeeX 16khz", 10, 10, 60, 10, 20, 0, 0);   /*!< codec_speex.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_ILBC, 0), "ilbc", 8000, "iLBC", 50, 30, 30, 30, 30, 0, 0);                 /*!< codec_ilbc.c */ /* inc=30ms - workaround */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_G726_AAL2, 0), "g726aal2", 8000, "G.726 AAL2", 40, 10, 300, 10, 20, 0, 0); /*!< codec_g726.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_G722, 0), "g722", 16000, "G722", 80, 10, 150, 10, 20, 0, 0);               /*!< codec_g722.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR16, 0), "slin16", 16000, "16 bit Signed Linear PCM (16kHz)", 320, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (16kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_JPEG, 0), "jpeg", 0, "JPEG image", 0, 0, 0, 0 ,0 ,0 ,0);          /*!< See format_jpeg.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_PNG, 0), "png", 0, "PNG image", 0, 0, 0, 0 ,0 ,0 ,0);             /*!< PNG Image format */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_H261, 0), "h261", 0, "H.261 Video", 0, 0, 0, 0 ,0 ,0 ,0);         /*!< H.261 Video Passthrough */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_H263, 0), "h263", 0, "H.263 Video", 0, 0, 0, 0 ,0 ,0 ,0);         /*!< H.263 Passthrough support, see format_h263.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_H263_PLUS, 0), "h263p", 0, "H.263+ Video", 0, 0, 0,0 ,0 ,0, 0);  /*!< H.263plus passthrough support See format_h263.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_H264, 0), "h264", 0, "H.264 Video", 0, 0, 0, 0 ,0 ,0, 0);         /*!< Passthrough support, see format_h263.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_MP4_VIDEO, 0), "mpeg4", 0, "MPEG4 Video", 0, 0, 0, 0, 0 ,0, 0);   /*!< Passthrough support for MPEG4 */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_T140RED, 0), "red", 1, "T.140 Realtime Text with redundancy", 0, 0, 0,0 ,0 ,0, 0);     /*!< Redundant T.140 Realtime Text */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_T140, 0), "t140", 0, "Passthrough T.140 Realtime Text", 0, 0, 0, 0 ,0 ,0, 0);      /*!< Passthrough support for T.140 Realtime Text */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SIREN7, 0), "siren7", 16000, "ITU G.722.1 (Siren7, licensed from Polycom)", 80, 20, 80, 20, 20, 0, 0); /*!< Binary commercial distribution */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SIREN14, 0), "siren14", 32000, "ITU G.722.1 Annex C, (Siren14, licensed from Polycom)", 120, 20, 80, 20, 20, 0, 0); /*!< Binary commercial distribution */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_TESTLAW, 0), "testlaw", 8000, "G.711 test-law", 80, 10, 150, 10, 20, 0, 0);    /*!< codec_ulaw.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_G719, 0), "g719", 48000, "ITU G.719", 160, 20, 80, 20, 20, 0, 0);

   /* ORDER MAY CHANGE AFTER THIS POINT IN THE LIST */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SPEEX32, 0), "speex32", 32000, "SpeeX 32khz", 10, 10, 60, 10, 20, 0, 0);   /*!< codec_speex.c */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR12, 0), "slin12", 12000, "16 bit Signed Linear PCM (12kHz)", 240, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (12kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR24, 0), "slin24", 24000, "16 bit Signed Linear PCM (24kHz)", 480, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (24kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR32, 0), "slin32", 32000, "16 bit Signed Linear PCM (32kHz)", 640, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (32kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR44, 0), "slin44", 44100, "16 bit Signed Linear PCM (44kHz)", 882, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (44.1kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR48, 0), "slin48", 48000, "16 bit Signed Linear PCM (48kHz)", 960, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (48kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR96, 0), "slin96", 96000, "16 bit Signed Linear PCM (96kHz)", 1920, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (96kHz) */
   format_list_add_static(ast_format_set(&tmpfmt, AST_FORMAT_SLINEAR192, 0), "slin192", 192000, "16 bit Signed Linear PCM (192kHz)", 3840, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE, 0);/*!< Signed linear (192kHz) */

   return 0;
}

/*! \internal \brief Clean up resources on Asterisk shutdown */
static void format_list_shutdown(void)
{
   ast_rwlock_destroy(&format_list_array_lock);
   if (format_list) {
      ao2_t_ref(format_list, -1, "Unref format_list container in shutdown");
      format_list = NULL;
   }
   if (format_list_array) {
      ao2_t_ref(format_list_array, -1, "Unref format_list_array in shutdown");
      format_list_array = NULL;
   }
}

int ast_format_list_init(void)
{
   if (ast_rwlock_init(&format_list_array_lock)) {
      return -1;
   }
   if (format_list_init()) {
      goto init_list_cleanup;
   }
   if (build_format_list_array()) {
      goto init_list_cleanup;
   }

   ast_register_atexit(format_list_shutdown);
   return 0;
init_list_cleanup:

   format_list_shutdown();
   return -1;
}

/*! \internal \brief Clean up resources on Asterisk shutdown */
static void format_attr_shutdown(void)
{
   ast_cli_unregister_multiple(my_clis, ARRAY_LEN(my_clis));
   if (interfaces) {
      ao2_ref(interfaces, -1);
      interfaces = NULL;
   }
}

int ast_format_attr_init(void)
{
   interfaces = ao2_container_alloc_options(AO2_ALLOC_OPT_LOCK_RWLOCK,
      283, interface_hash_cb, interface_cmp_cb);
   if (!interfaces) {
      return -1;
   }

   ast_cli_register_multiple(my_clis, ARRAY_LEN(my_clis));
   ast_register_cleanup(format_attr_shutdown);
   return 0;
}

static int custom_celt_format(struct ast_format_list *entry, unsigned int maxbitrate, unsigned int framesize)
{
   if (!entry->samplespersecond) {
      ast_log(LOG_WARNING, "Custom CELT format definition '%s' requires sample rate to be defined.\n", entry->name);
   }
   ast_format_set(&entry->format, AST_FORMAT_CELT, 0);
   if (!has_interface(&entry->format)) {
      return -1;
   }

   snprintf(entry->desc, sizeof(entry->desc), "CELT Custom Format %ukhz", entry->samplespersecond/1000);

   ast_format_append(&entry->format,
      CELT_ATTR_KEY_SAMP_RATE, entry->samplespersecond,
      CELT_ATTR_KEY_MAX_BITRATE, maxbitrate,
      CELT_ATTR_KEY_FRAME_SIZE, framesize,
      AST_FORMAT_ATTR_END);

   entry->fr_len = 80;
   entry->min_ms = 20;
   entry->max_ms = 20;
   entry->inc_ms = 20;
   entry->def_ms = 20;
   return 0;
}

static int custom_silk_format(struct ast_format_list *entry, unsigned int maxbitrate, int usedtx, int usefec, int packetloss_percentage)
{
   if (!entry->samplespersecond) {
      ast_log(LOG_WARNING, "Custom SILK format definition '%s' requires sample rate to be defined.\n", entry->name);
   }
   ast_format_set(&entry->format, AST_FORMAT_SILK, 0);

   if (!has_interface(&entry->format)) {
      return -1;
   }

   switch (entry->samplespersecond) {
   case 8000:
      ast_copy_string(entry->desc, "SILK Custom Format 8khz", sizeof(entry->desc));
      ast_format_append(&entry->format,
         SILK_ATTR_KEY_SAMP_RATE, SILK_ATTR_VAL_SAMP_8KHZ,
         AST_FORMAT_ATTR_END);
      break;
   case 12000:
      ast_copy_string(entry->desc, "SILK Custom Format 12khz", sizeof(entry->desc));
      ast_format_append(&entry->format,
         SILK_ATTR_KEY_SAMP_RATE, SILK_ATTR_VAL_SAMP_12KHZ,
         AST_FORMAT_ATTR_END);
      break;
   case 16000:
      ast_copy_string(entry->desc, "SILK Custom Format 16khz", sizeof(entry->desc));
      ast_format_append(&entry->format,
         SILK_ATTR_KEY_SAMP_RATE, SILK_ATTR_VAL_SAMP_16KHZ,
         AST_FORMAT_ATTR_END);
      break;
   case 24000:
      ast_copy_string(entry->desc, "SILK Custom Format 24khz", sizeof(entry->desc));
      ast_format_append(&entry->format,
         SILK_ATTR_KEY_SAMP_RATE, SILK_ATTR_VAL_SAMP_24KHZ,
         AST_FORMAT_ATTR_END);
      break;
   default:
      ast_log(LOG_WARNING, "Custom SILK format definition '%s' can not support sample rate %u\n", entry->name, entry->samplespersecond);
      return -1;
   }
   ast_format_append(&entry->format,
         SILK_ATTR_KEY_MAX_BITRATE, maxbitrate,
         SILK_ATTR_KEY_DTX, usedtx ? 1 : 0,
         SILK_ATTR_KEY_FEC, usefec ? 1 : 0,
         SILK_ATTR_KEY_PACKETLOSS_PERCENTAGE, packetloss_percentage,
         AST_FORMAT_ATTR_END);

   entry->fr_len = 80;
   entry->min_ms = 20;
   entry->max_ms = 20;
   entry->inc_ms = 20;
   entry->def_ms = 20;
   return 0;
}

static int conf_process_format_name(const char *name, enum ast_format_id *id)
{
   if (!strcasecmp(name, "silk")) {
      *id = AST_FORMAT_SILK;
   } else if (!strcasecmp(name, "celt")) {
      *id = AST_FORMAT_CELT;
   } else {
      *id = 0;
      return -1;
   }
   return 0;
}

static int conf_process_sample_rate(const char *rate, unsigned int *result)
{
   if (!strcasecmp(rate, "8000")) {
      *result = 8000;
   } else if (!strcasecmp(rate, "12000")) {
      *result = 12000;
   } else if (!strcasecmp(rate, "16000")) {
      *result = 16000;
   } else if (!strcasecmp(rate, "24000")) {
      *result = 24000;
   } else if (!strcasecmp(rate, "32000")) {
      *result = 32000;
   } else if (!strcasecmp(rate, "44100")) {
      *result = 44100;
   } else if (!strcasecmp(rate, "48000")) {
      *result = 48000;
   } else if (!strcasecmp(rate, "96000")) {
      *result = 96000;
   } else if (!strcasecmp(rate, "192000")) {
      *result = 192000;
   } else {
      *result = 0;
      return -1;
   }

   return 0;
}
static int load_format_config(void)
{
   struct ast_flags config_flags = { 0, };
   struct ast_config *cfg = ast_config_load(FORMAT_CONFIG, config_flags);
   struct ast_format_list entry;
   struct ast_variable *var;
   char *cat = NULL;
   int add_it = 0;

   struct {
      enum ast_format_id id;
      unsigned int maxbitrate;
      unsigned int framesize;
      unsigned int packetloss_percentage;
      int usefec;
      int usedtx;
   } settings;

   if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEINVALID) {
      return 0;
   }

   /* remove all custom formats from the AO2 Container. Note, this has no affect on the
    * global format list until the list is rebuild.  That is why this is okay to do while
    * reloading the config. */
   ao2_callback(format_list, OBJ_NODATA | OBJ_UNLINK | OBJ_MULTIPLE, list_all_custom, NULL);

   while ((cat = ast_category_browse(cfg, cat))) {
      memset(&entry, 0, sizeof(entry));
      memset(&settings, 0, sizeof(settings));
      add_it = 0;

      if (!(ast_variable_retrieve(cfg, cat, "type"))) {
         continue;
      }
      ast_copy_string(entry.name, cat, sizeof(entry.name));
      var = ast_variable_browse(cfg, cat);
      for (var = ast_variable_browse(cfg, cat); var; var = var->next) {
         if (!strcasecmp(var->name, "type") && conf_process_format_name(var->value, &settings.id)) {
            ast_log(LOG_WARNING, "Can not make custom format type for '%s' at line %d of %s\n",
               var->value, var->lineno, FORMAT_CONFIG);
            continue;
         } else if (!strcasecmp(var->name, "samprate") && conf_process_sample_rate(var->value, &entry.samplespersecond)) {
            ast_log(LOG_WARNING, "Sample rate '%s' at line %d of %s is not supported.\n",
                  var->value, var->lineno, FORMAT_CONFIG);
         } else if (!strcasecmp(var->name, "maxbitrate")) {
            if (sscanf(var->value, "%30u", &settings.maxbitrate) != 1) {
               ast_log(LOG_WARNING, "maxbitrate '%s' at line %d of %s is not supported.\n",
                  var->value, var->lineno, FORMAT_CONFIG);
            }
         } else if (!strcasecmp(var->name, "framesize")) {
            if (sscanf(var->value, "%30u", &settings.framesize) != 1) {
               ast_log(LOG_WARNING, "framesize '%s' at line %d of %s is not supported.\n",
                  var->value, var->lineno, FORMAT_CONFIG);
            }
         } else if (!strcasecmp(var->name, "dtx")) {
            settings.usedtx = ast_true(var->value) ? 1 : 0;
         } else if (!strcasecmp(var->name, "fec")) {
            settings.usefec = ast_true(var->value) ? 1 : 0;
         } else if (!strcasecmp(var->name, "packetloss_percentage")) {
            if ((sscanf(var->value, "%30u", &settings.packetloss_percentage) != 1) || (settings.packetloss_percentage > 100)) {
               ast_log(LOG_WARNING, "packetloss_percentage '%s' at line %d of %s is not supported.\n",
                  var->value, var->lineno, FORMAT_CONFIG);
            }
         }
      }

      switch (settings.id) {
      case AST_FORMAT_SILK:
         if (!(custom_silk_format(&entry, settings.maxbitrate, settings.usedtx, settings.usefec, settings.packetloss_percentage))) {
            add_it = 1;
         }
         break;
      case AST_FORMAT_CELT:
         if (!(custom_celt_format(&entry, settings.maxbitrate, settings.framesize))) {
            add_it = 1;
         }
         break;
      default:
         ast_log(LOG_WARNING, "Can not create custom format %s\n", entry.name);
      }

      if (add_it) {
         format_list_add_custom(&entry);
      }
   }
   ast_config_destroy(cfg);
   build_format_list_array();
   return 0;
}

int ast_format_attr_reg_interface(const struct ast_format_attr_interface *interface)
{
   int x;
   size_t f_len;
   const struct ast_format_list *f_list;
   struct interface_ao2_wrapper *wrapper;
   struct interface_ao2_wrapper tmp_wrapper = {
      .id = interface->id,
   };

   /*
    * Grab the write lock before checking for duplicates in
    * anticipation of adding a new interface and to prevent a
    * duplicate from sneaking in between the check and add.
    */
   ao2_wrlock(interfaces);

   /* check for duplicates first*/
   if ((wrapper = ao2_find(interfaces, &tmp_wrapper, (OBJ_POINTER | OBJ_NOLOCK)))) {
      ao2_unlock(interfaces);
      ast_log(LOG_WARNING, "Can not register attribute interface for format id %u, interface already exists.\n", interface->id);
      ao2_ref(wrapper, -1);
      return -1;
   }

   wrapper = ao2_alloc_options(sizeof(*wrapper), NULL, AO2_ALLOC_OPT_LOCK_RWLOCK);
   if (!wrapper) {
      ao2_unlock(interfaces);
      return -1;
   }

   wrapper->interface = interface;
   wrapper->id = interface->id;

   /* The write lock is already held. */
   ao2_link_flags(interfaces, wrapper, OBJ_NOLOCK);
   ao2_unlock(interfaces);

   ao2_ref(wrapper, -1);

   /* This will find all custom formats in codecs.conf for this new registered interface */
   load_format_config();

   /* update the RTP engine to all custom formats created for this interface */
   f_list = ast_format_list_get(&f_len);
   for (x = 0; x < f_len; x++) {
      if (f_list[x].format.id == tmp_wrapper.id) {
         ast_rtp_engine_load_format(&f_list[x].format);
      }
   }
   f_list = ast_format_list_destroy(f_list);
   return 0;
}

int ast_format_attr_unreg_interface(const struct ast_format_attr_interface *interface)
{
   int x;
   size_t f_len;
   const struct ast_format_list *f_list;
   struct interface_ao2_wrapper *wrapper;
   struct interface_ao2_wrapper tmp_wrapper = {
      .id = interface->id,
   };

   if (!(wrapper = ao2_find(interfaces, &tmp_wrapper, (OBJ_POINTER | OBJ_UNLINK)))) {
      return -1;
   }

   ao2_wrlock(wrapper);
   wrapper->interface = NULL;
   ao2_unlock(wrapper);

   ao2_ref(wrapper, -1);

   /* update the RTP engine to remove all custom formats created for this interface */
   f_list = ast_format_list_get(&f_len);
   for (x = 0; x < f_len; x++) {
      if (f_list[x].format.id == tmp_wrapper.id) {
         ast_rtp_engine_unload_format(&f_list[x].format);
      }
   }

   /* This will remove all custom formats previously created for this interface */
   load_format_config();
   f_list = ast_format_list_destroy(f_list);
   return 0;
}