frame.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * 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 Frame and codec manipulation routines
 *
 * \author Mark Spencer <markster@digium.com> 
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 224935 $")

#include "asterisk/_private.h"
#include "asterisk/lock.h"
#include "asterisk/frame.h"
#include "asterisk/channel.h"
#include "asterisk/cli.h"
#include "asterisk/term.h"
#include "asterisk/utils.h"
#include "asterisk/threadstorage.h"
#include "asterisk/linkedlists.h"
#include "asterisk/translate.h"
#include "asterisk/dsp.h"
#include "asterisk/file.h"

#if !defined(LOW_MEMORY)
static void frame_cache_cleanup(void *data);

/*! \brief A per-thread cache of frame headers */
AST_THREADSTORAGE_CUSTOM(frame_cache, NULL, frame_cache_cleanup);

/*! 
 * \brief Maximum ast_frame cache size
 *
 * In most cases where the frame header cache will be useful, the size
 * of the cache will stay very small.  However, it is not always the case that
 * the same thread that allocates the frame will be the one freeing them, so
 * sometimes a thread will never have any frames in its cache, or the cache
 * will never be pulled from.  For the latter case, we limit the maximum size. 
 */ 
#define FRAME_CACHE_MAX_SIZE  10

/*! \brief This is just so ast_frames, a list head struct for holding a list of
 *  ast_frame structures, is defined. */
AST_LIST_HEAD_NOLOCK(ast_frames, ast_frame);

struct ast_frame_cache {
   struct ast_frames list;
   size_t size;
};
#endif

#define SMOOTHER_SIZE 8000

enum frame_type {
   TYPE_HIGH,     /* 0x0 */
   TYPE_LOW,      /* 0x1 */
   TYPE_SILENCE,  /* 0x2 */
   TYPE_DONTSEND  /* 0x3 */
};

#define TYPE_MASK 0x3

struct ast_smoother {
   int size;
   int format;
   int flags;
   float samplesperbyte;
   unsigned int opt_needs_swap:1;
   struct ast_frame f;
   struct timeval delivery;
   char data[SMOOTHER_SIZE];
   char framedata[SMOOTHER_SIZE + AST_FRIENDLY_OFFSET];
   struct ast_frame *opt;
   int len;
};

/*! \brief Definition of supported media formats (codecs) */
static struct ast_format_list AST_FORMAT_LIST[] = {
   { AST_FORMAT_G723_1 , "g723", 8000, "G.723.1", 20, 30, 300, 30, 30 },                                  /*!< G723.1 */
   { AST_FORMAT_GSM, "gsm", 8000, "GSM", 33, 20, 300, 20, 20 },                                           /*!< codec_gsm.c */
   { AST_FORMAT_ULAW, "ulaw", 8000, "G.711 u-law", 80, 10, 150, 10, 20 },                                 /*!< codec_ulaw.c */
   { AST_FORMAT_ALAW, "alaw", 8000, "G.711 A-law", 80, 10, 150, 10, 20 },                                 /*!< codec_alaw.c */
   { AST_FORMAT_G726, "g726", 8000, "G.726 RFC3551", 40, 10, 300, 10, 20 },                               /*!< codec_g726.c */
   { AST_FORMAT_ADPCM, "adpcm" , 8000, "ADPCM", 40, 10, 300, 10, 20 },                                    /*!< codec_adpcm.c */
   { AST_FORMAT_SLINEAR, "slin", 8000, "16 bit Signed Linear PCM", 160, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE }, /*!< Signed linear */
   { AST_FORMAT_LPC10, "lpc10", 8000, "LPC10", 7, 20, 20, 20, 20 },                                       /*!< codec_lpc10.c */ 
   { AST_FORMAT_G729A, "g729", 8000, "G.729A", 10, 10, 230, 10, 20, AST_SMOOTHER_FLAG_G729 },             /*!< Binary commercial distribution */
   { AST_FORMAT_SPEEX, "speex", 8000, "SpeeX", 10, 10, 60, 10, 20 },                                      /*!< codec_speex.c */
   { AST_FORMAT_ILBC, "ilbc", 8000, "iLBC", 50, 30, 30, 30, 30 },                                         /*!< codec_ilbc.c */ /* inc=30ms - workaround */
   { AST_FORMAT_G726_AAL2, "g726aal2", 8000, "G.726 AAL2", 40, 10, 300, 10, 20 },                         /*!< codec_g726.c */
   { AST_FORMAT_G722, "g722", 16000, "G722", 80, 10, 150, 10, 20 },                                       /*!< codec_g722.c */
   { AST_FORMAT_SLINEAR16, "slin16", 16000, "16 bit Signed Linear PCM (16kHz)", 320, 10, 70, 10, 20, AST_SMOOTHER_FLAG_BE },    /*!< Signed linear (16kHz) */
   { AST_FORMAT_JPEG, "jpeg", 0, "JPEG image"},                                                           /*!< See format_jpeg.c */
   { AST_FORMAT_PNG, "png", 0, "PNG image"},                                                              /*!< PNG Image format */
   { AST_FORMAT_H261, "h261", 0, "H.261 Video" },                                                         /*!< H.261 Video Passthrough */
   { AST_FORMAT_H263, "h263", 0, "H.263 Video" },                                                         /*!< H.263 Passthrough support, see format_h263.c */
   { AST_FORMAT_H263_PLUS, "h263p", 0, "H.263+ Video" },                                                  /*!< H.263plus passthrough support See format_h263.c */
   { AST_FORMAT_H264, "h264", 0, "H.264 Video" },                                                         /*!< Passthrough support, see format_h263.c */
   { AST_FORMAT_MP4_VIDEO, "mpeg4", 0, "MPEG4 Video" },                                                   /*!< Passthrough support for MPEG4 */
   { AST_FORMAT_T140RED, "red", 1, "T.140 Realtime Text with redundancy"},                                 /*!< Redundant T.140 Realtime Text */
   { AST_FORMAT_T140, "t140", 0, "Passthrough T.140 Realtime Text" },                                     /*!< Passthrough support for T.140 Realtime Text */
};

struct ast_frame ast_null_frame = { AST_FRAME_NULL, };

static int smoother_frame_feed(struct ast_smoother *s, struct ast_frame *f, int swap)
{
   if (s->flags & AST_SMOOTHER_FLAG_G729) {
      if (s->len % 10) {
         ast_log(LOG_NOTICE, "Dropping extra frame of G.729 since we already have a VAD frame at the end\n");
         return 0;
      }
   }
   if (swap) {
      ast_swapcopy_samples(s->data + s->len, f->data.ptr, f->samples);
   } else {
      memcpy(s->data + s->len, f->data.ptr, f->datalen);
   }
   /* If either side is empty, reset the delivery time */
   if (!s->len || ast_tvzero(f->delivery) || ast_tvzero(s->delivery)) { /* XXX really ? */
      s->delivery = f->delivery;
   }
   s->len += f->datalen;

   return 0;
}

void ast_smoother_reset(struct ast_smoother *s, int bytes)
{
   memset(s, 0, sizeof(*s));
   s->size = bytes;
}

void ast_smoother_reconfigure(struct ast_smoother *s, int bytes)
{
   /* if there is no change, then nothing to do */
   if (s->size == bytes) {
      return;
   }
   /* set the new desired output size */
   s->size = bytes;
   /* if there is no 'optimized' frame in the smoother,
    *   then there is nothing left to do
    */
   if (!s->opt) {
      return;
   }
   /* there is an 'optimized' frame here at the old size,
    * but it must now be put into the buffer so the data
    * can be extracted at the new size
    */
   smoother_frame_feed(s, s->opt, s->opt_needs_swap);
   s->opt = NULL;
}

struct ast_smoother *ast_smoother_new(int size)
{
   struct ast_smoother *s;
   if (size < 1)
      return NULL;
   if ((s = ast_malloc(sizeof(*s))))
      ast_smoother_reset(s, size);
   return s;
}

int ast_smoother_get_flags(struct ast_smoother *s)
{
   return s->flags;
}

void ast_smoother_set_flags(struct ast_smoother *s, int flags)
{
   s->flags = flags;
}

int ast_smoother_test_flag(struct ast_smoother *s, int flag)
{
   return (s->flags & flag);
}

int __ast_smoother_feed(struct ast_smoother *s, struct ast_frame *f, int swap)
{
   if (f->frametype != AST_FRAME_VOICE) {
      ast_log(LOG_WARNING, "Huh?  Can't smooth a non-voice frame!\n");
      return -1;
   }
   if (!s->format) {
      s->format = f->subclass;
      s->samplesperbyte = (float)f->samples / (float)f->datalen;
   } else if (s->format != f->subclass) {
      ast_log(LOG_WARNING, "Smoother was working on %d format frames, now trying to feed %d?\n", s->format, f->subclass);
      return -1;
   }
   if (s->len + f->datalen > SMOOTHER_SIZE) {
      ast_log(LOG_WARNING, "Out of smoother space\n");
      return -1;
   }
   if (((f->datalen == s->size) ||
        ((f->datalen < 10) && (s->flags & AST_SMOOTHER_FLAG_G729))) &&
       !s->opt &&
       !s->len &&
       (f->offset >= AST_MIN_OFFSET)) {
      /* Optimize by sending the frame we just got
         on the next read, thus eliminating the douple
         copy */
      if (swap)
         ast_swapcopy_samples(f->data.ptr, f->data.ptr, f->samples);
      s->opt = f;
      s->opt_needs_swap = swap ? 1 : 0;
      return 0;
   }

   return smoother_frame_feed(s, f, swap);
}

struct ast_frame *ast_smoother_read(struct ast_smoother *s)
{
   struct ast_frame *opt;
   int len;

   /* IF we have an optimization frame, send it */
   if (s->opt) {
      if (s->opt->offset < AST_FRIENDLY_OFFSET)
         ast_log(LOG_WARNING, "Returning a frame of inappropriate offset (%d).\n",
                     s->opt->offset);
      opt = s->opt;
      s->opt = NULL;
      return opt;
   }

   /* Make sure we have enough data */
   if (s->len < s->size) {
      /* Or, if this is a G.729 frame with VAD on it, send it immediately anyway */
      if (!((s->flags & AST_SMOOTHER_FLAG_G729) && (s->len % 10)))
         return NULL;
   }
   len = s->size;
   if (len > s->len)
      len = s->len;
   /* Make frame */
   s->f.frametype = AST_FRAME_VOICE;
   s->f.subclass = s->format;
   s->f.data.ptr = s->framedata + AST_FRIENDLY_OFFSET;
   s->f.offset = AST_FRIENDLY_OFFSET;
   s->f.datalen = len;
   /* Samples will be improper given VAD, but with VAD the concept really doesn't even exist */
   s->f.samples = len * s->samplesperbyte;   /* XXX rounding */
   s->f.delivery = s->delivery;
   /* Fill Data */
   memcpy(s->f.data.ptr, s->data, len);
   s->len -= len;
   /* Move remaining data to the front if applicable */
   if (s->len) {
      /* In principle this should all be fine because if we are sending
         G.729 VAD, the next timestamp will take over anyawy */
      memmove(s->data, s->data + len, s->len);
      if (!ast_tvzero(s->delivery)) {
         /* If we have delivery time, increment it, otherwise, leave it at 0 */
         s->delivery = ast_tvadd(s->delivery, ast_samp2tv(s->f.samples, ast_format_rate(s->format)));
      }
   }
   /* Return frame */
   return &s->f;
}

void ast_smoother_free(struct ast_smoother *s)
{
   ast_free(s);
}

static struct ast_frame *ast_frame_header_new(void)
{
   struct ast_frame *f;

#if !defined(LOW_MEMORY)
   struct ast_frame_cache *frames;

   if ((frames = ast_threadstorage_get(&frame_cache, sizeof(*frames)))) {
      if ((f = AST_LIST_REMOVE_HEAD(&frames->list, frame_list))) {
         size_t mallocd_len = f->mallocd_hdr_len;
         memset(f, 0, sizeof(*f));
         f->mallocd_hdr_len = mallocd_len;
         f->mallocd = AST_MALLOCD_HDR;
         frames->size--;
         return f;
      }
   }
   if (!(f = ast_calloc_cache(1, sizeof(*f))))
      return NULL;
#else
   if (!(f = ast_calloc(1, sizeof(*f))))
      return NULL;
#endif

   f->mallocd_hdr_len = sizeof(*f);
   
   return f;
}

#if !defined(LOW_MEMORY)
static void frame_cache_cleanup(void *data)
{
   struct ast_frame_cache *frames = data;
   struct ast_frame *f;

   while ((f = AST_LIST_REMOVE_HEAD(&frames->list, frame_list)))
      ast_free(f);
   
   ast_free(frames);
}
#endif

static void __frame_free(struct ast_frame *fr, int cache)
{
   if (!fr->mallocd)
      return;

#if !defined(LOW_MEMORY)
   if (cache && fr->mallocd == AST_MALLOCD_HDR) {
      /* Cool, only the header is malloc'd, let's just cache those for now 
       * to keep things simple... */
      struct ast_frame_cache *frames;

      if ((frames = ast_threadstorage_get(&frame_cache, sizeof(*frames))) &&
          (frames->size < FRAME_CACHE_MAX_SIZE)) {
         AST_LIST_INSERT_HEAD(&frames->list, fr, frame_list);
         frames->size++;
         return;
      }
   }
#endif
   
   if (fr->mallocd & AST_MALLOCD_DATA) {
      if (fr->data.ptr) 
         ast_free(fr->data.ptr - fr->offset);
   }
   if (fr->mallocd & AST_MALLOCD_SRC) {
      if (fr->src)
         ast_free((void *) fr->src);
   }
   if (fr->mallocd & AST_MALLOCD_HDR) {
      ast_free(fr);
   }
}


void ast_frame_free(struct ast_frame *frame, int cache)
{
   struct ast_frame *next;

   for (next = AST_LIST_NEXT(frame, frame_list);
        frame;
        frame = next, next = frame ? AST_LIST_NEXT(frame, frame_list) : NULL) {
      __frame_free(frame, cache);
   }
}

/*!
 * \brief 'isolates' a frame by duplicating non-malloc'ed components
 * (header, src, data).
 * On return all components are malloc'ed
 */
struct ast_frame *ast_frisolate(struct ast_frame *fr)
{
   struct ast_frame *out;
   void *newdata;

   /* if none of the existing frame is malloc'd, let ast_frdup() do it
      since it is more efficient
   */
   if (fr->mallocd == 0) {
      return ast_frdup(fr);
   }

   /* if everything is already malloc'd, we are done */
   if ((fr->mallocd & (AST_MALLOCD_HDR | AST_MALLOCD_SRC | AST_MALLOCD_DATA)) ==
       (AST_MALLOCD_HDR | AST_MALLOCD_SRC | AST_MALLOCD_DATA)) {
      return fr;
   }

   if (!(fr->mallocd & AST_MALLOCD_HDR)) {
      /* Allocate a new header if needed */
      if (!(out = ast_frame_header_new())) {
         return NULL;
      }
      out->frametype = fr->frametype;
      out->subclass = fr->subclass;
      out->datalen = fr->datalen;
      out->samples = fr->samples;
      out->offset = fr->offset;
      /* Copy the timing data */
      ast_copy_flags(out, fr, AST_FRFLAG_HAS_TIMING_INFO);
      if (ast_test_flag(fr, AST_FRFLAG_HAS_TIMING_INFO)) {
         out->ts = fr->ts;
         out->len = fr->len;
         out->seqno = fr->seqno;
      }
   } else {
      out = fr;
   }
   
   if (!(fr->mallocd & AST_MALLOCD_SRC) && fr->src) {
      if (!(out->src = ast_strdup(fr->src))) {
         if (out != fr) {
            ast_free(out);
         }
         return NULL;
      }
   } else {
      out->src = fr->src;
      fr->src = NULL;
      fr->mallocd &= ~AST_MALLOCD_SRC;
   }
   
   if (!(fr->mallocd & AST_MALLOCD_DATA))  {
      if (!(newdata = ast_malloc(fr->datalen + AST_FRIENDLY_OFFSET))) {
         if (out->src != fr->src) {
            ast_free((void *) out->src);
         }
         if (out != fr) {
            ast_free(out);
         }
         return NULL;
      }
      newdata += AST_FRIENDLY_OFFSET;
      out->offset = AST_FRIENDLY_OFFSET;
      out->datalen = fr->datalen;
      memcpy(newdata, fr->data.ptr, fr->datalen);
      out->data.ptr = newdata;
   } else {
      out->data = fr->data;
      memset(&fr->data, 0, sizeof(fr->data));
      fr->mallocd &= ~AST_MALLOCD_DATA;
   }

   out->mallocd = AST_MALLOCD_HDR | AST_MALLOCD_SRC | AST_MALLOCD_DATA;
   
   return out;
}

struct ast_frame *ast_frdup(const struct ast_frame *f)
{
   struct ast_frame *out = NULL;
   int len, srclen = 0;
   void *buf = NULL;

#if !defined(LOW_MEMORY)
   struct ast_frame_cache *frames;
#endif

   /* Start with standard stuff */
   len = sizeof(*out) + AST_FRIENDLY_OFFSET + f->datalen;
   /* If we have a source, add space for it */
   /*
    * XXX Watch out here - if we receive a src which is not terminated
    * properly, we can be easily attacked. Should limit the size we deal with.
    */
   if (f->src)
      srclen = strlen(f->src);
   if (srclen > 0)
      len += srclen + 1;
   
#if !defined(LOW_MEMORY)
   if ((frames = ast_threadstorage_get(&frame_cache, sizeof(*frames)))) {
      AST_LIST_TRAVERSE_SAFE_BEGIN(&frames->list, out, frame_list) {
         if (out->mallocd_hdr_len >= len) {
            size_t mallocd_len = out->mallocd_hdr_len;

            AST_LIST_REMOVE_CURRENT(frame_list);
            memset(out, 0, sizeof(*out));
            out->mallocd_hdr_len = mallocd_len;
            buf = out;
            frames->size--;
            break;
         }
      }
      AST_LIST_TRAVERSE_SAFE_END;
   }
#endif

   if (!buf) {
      if (!(buf = ast_calloc_cache(1, len)))
         return NULL;
      out = buf;
      out->mallocd_hdr_len = len;
   }

   out->frametype = f->frametype;
   out->subclass = f->subclass;
   out->datalen = f->datalen;
   out->samples = f->samples;
   out->delivery = f->delivery;
   /* Set us as having malloc'd header only, so it will eventually
      get freed. */
   out->mallocd = AST_MALLOCD_HDR;
   out->offset = AST_FRIENDLY_OFFSET;
   if (out->datalen) {
      out->data.ptr = buf + sizeof(*out) + AST_FRIENDLY_OFFSET;
      memcpy(out->data.ptr, f->data.ptr, out->datalen);  
   } else {
      out->data.uint32 = f->data.uint32;
   }
   if (srclen > 0) {
      /* This may seem a little strange, but it's to avoid a gcc (4.2.4) compiler warning */
      char *src;
      out->src = buf + sizeof(*out) + AST_FRIENDLY_OFFSET + f->datalen;
      src = (char *) out->src;
      /* Must have space since we allocated for it */
      strcpy(src, f->src);
   }
   ast_copy_flags(out, f, AST_FRFLAG_HAS_TIMING_INFO);
   out->ts = f->ts;
   out->len = f->len;
   out->seqno = f->seqno;
   return out;
}

void ast_swapcopy_samples(void *dst, const void *src, int samples)
{
   int i;
   unsigned short *dst_s = dst;
   const unsigned short *src_s = src;

   for (i = 0; i < samples; i++)
      dst_s[i] = (src_s[i]<<8) | (src_s[i]>>8);
}


struct ast_format_list *ast_get_format_list_index(int idx) 
{
   return &AST_FORMAT_LIST[idx];
}

struct ast_format_list *ast_get_format_list(size_t *size) 
{
   *size = ARRAY_LEN(AST_FORMAT_LIST);
   return AST_FORMAT_LIST;
}

char* ast_getformatname(int format)
{
   int x;
   char *ret = "unknown";
   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits == format) {
         ret = AST_FORMAT_LIST[x].name;
         break;
      }
   }
   return ret;
}

char *ast_getformatname_multiple(char *buf, size_t size, int format)
{
   int x;
   unsigned len;
   char *start, *end = buf;

   if (!size)
      return buf;
   snprintf(end, size, "0x%x (", format);
   len = strlen(end);
   end += len;
   size -= len;
   start = end;
   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits & format) {
         snprintf(end, size,"%s|",AST_FORMAT_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) = ')';
   return buf;
}

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

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;
}

int ast_getformatbyname(const char *name)
{
   int x, all, format = 0;

   all = strcasecmp(name, "all") ? 0 : 1;
   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (all || 
           !strcasecmp(AST_FORMAT_LIST[x].name,name) ||
           !strcasecmp(AST_FORMAT_LIST[x].name, ast_expand_codec_alias(name))) {
         format |= AST_FORMAT_LIST[x].bits;
         if (!all)
            break;
      }
   }

   return format;
}

char *ast_codec2str(int codec)
{
   int x;
   char *ret = "unknown";
   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits == codec) {
         ret = AST_FORMAT_LIST[x].desc;
         break;
      }
   }
   return ret;
}

static char *show_codecs(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int i, found=0;
   char hex[25];

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show codecs [audio|video|image]";
      e->usage = 
         "Usage: core show codecs [audio|video|image]\n"
         "       Displays codec mapping\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }
   
   if ((a->argc < 3) || (a->argc > 4))
      return CLI_SHOWUSAGE;

   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, "%11s %9s %10s   TYPE   %8s   %s\n","INT","BINARY","HEX","NAME","DESC");
   ast_cli(a->fd, "--------------------------------------------------------------------------------\n");
   if ((a->argc == 3) || (!strcasecmp(a->argv[3],"audio"))) {
      found = 1;
      for (i=0;i<13;i++) {
         snprintf(hex,25,"(0x%x)",1<<i);
         ast_cli(a->fd, "%11u (1 << %2d) %10s  audio   %8s   (%s)\n",1 << i,i,hex,ast_getformatname(1<<i),ast_codec2str(1<<i));
      }
   }

   if ((a->argc == 3) || (!strcasecmp(a->argv[3],"image"))) {
      found = 1;
      for (i=16;i<18;i++) {
         snprintf(hex,25,"(0x%x)",1<<i);
         ast_cli(a->fd, "%11u (1 << %2d) %10s  image   %8s   (%s)\n",1 << i,i,hex,ast_getformatname(1<<i),ast_codec2str(1<<i));
      }
   }

   if ((a->argc == 3) || (!strcasecmp(a->argv[3],"video"))) {
      found = 1;
      for (i=18;i<22;i++) {
         snprintf(hex,25,"(0x%x)",1<<i);
         ast_cli(a->fd, "%11u (1 << %2d) %10s  video   %8s   (%s)\n",1 << i,i,hex,ast_getformatname(1<<i),ast_codec2str(1<<i));
      }
   }

   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)
{
   int codec, i, found=0;

   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", &codec) != 1)
      return CLI_SHOWUSAGE;

   for (i = 0; i < 32; i++)
      if (codec & (1 << i)) {
         found = 1;
         ast_cli(a->fd, "%11u (1 << %2d)  %s\n",1 << i,i,ast_codec2str(1<<i));
      }

   if (!found)
      ast_cli(a->fd, "Codec %d not found\n", codec);

   return CLI_SUCCESS;
}

/*! Dump a frame for debugging purposes */
void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix)
{
   const char noname[] = "unknown";
   char ftype[40] = "Unknown Frametype";
   char cft[80];
   char subclass[40] = "Unknown Subclass";
   char csub[80];
   char moreinfo[40] = "";
   char cn[60];
   char cp[40];
   char cmn[40];
   const char *message = "Unknown";

   if (!name)
      name = noname;


   if (!f) {
      ast_verbose("%s [ %s (NULL) ] [%s]\n", 
         term_color(cp, prefix, COLOR_BRMAGENTA, COLOR_BLACK, sizeof(cp)),
         term_color(cft, "HANGUP", COLOR_BRRED, COLOR_BLACK, sizeof(cft)), 
         term_color(cn, name, COLOR_YELLOW, COLOR_BLACK, sizeof(cn)));
      return;
   }
   /* XXX We should probably print one each of voice and video when the format changes XXX */
   if (f->frametype == AST_FRAME_VOICE)
      return;
   if (f->frametype == AST_FRAME_VIDEO)
      return;
   switch(f->frametype) {
   case AST_FRAME_DTMF_BEGIN:
      strcpy(ftype, "DTMF Begin");
      subclass[0] = f->subclass;
      subclass[1] = '\0';
      break;
   case AST_FRAME_DTMF_END:
      strcpy(ftype, "DTMF End");
      subclass[0] = f->subclass;
      subclass[1] = '\0';
      break;
   case AST_FRAME_CONTROL:
      strcpy(ftype, "Control");
      switch(f->subclass) {
      case AST_CONTROL_HANGUP:
         strcpy(subclass, "Hangup");
         break;
      case AST_CONTROL_RING:
         strcpy(subclass, "Ring");
         break;
      case AST_CONTROL_RINGING:
         strcpy(subclass, "Ringing");
         break;
      case AST_CONTROL_ANSWER:
         strcpy(subclass, "Answer");
         break;
      case AST_CONTROL_BUSY:
         strcpy(subclass, "Busy");
         break;
      case AST_CONTROL_TAKEOFFHOOK:
         strcpy(subclass, "Take Off Hook");
         break;
      case AST_CONTROL_OFFHOOK:
         strcpy(subclass, "Line Off Hook");
         break;
      case AST_CONTROL_CONGESTION:
         strcpy(subclass, "Congestion");
         break;
      case AST_CONTROL_FLASH:
         strcpy(subclass, "Flash");
         break;
      case AST_CONTROL_WINK:
         strcpy(subclass, "Wink");
         break;
      case AST_CONTROL_OPTION:
         strcpy(subclass, "Option");
         break;
      case AST_CONTROL_RADIO_KEY:
         strcpy(subclass, "Key Radio");
         break;
      case AST_CONTROL_RADIO_UNKEY:
         strcpy(subclass, "Unkey Radio");
         break;
      case AST_CONTROL_HOLD:
         strcpy(subclass, "Hold");
         break;
      case AST_CONTROL_UNHOLD:
         strcpy(subclass, "Unhold");
         break;
      case AST_CONTROL_T38_PARAMETERS:
         if (f->datalen != sizeof(struct ast_control_t38_parameters)) {
            message = "Invalid";
         } else {
            struct ast_control_t38_parameters *parameters = f->data.ptr;
            enum ast_control_t38 state = parameters->request_response;
            if (state == AST_T38_REQUEST_NEGOTIATE)
               message = "Negotiation Requested";
            else if (state == AST_T38_REQUEST_TERMINATE)
               message = "Negotiation Request Terminated";
            else if (state == AST_T38_NEGOTIATED)
               message = "Negotiated";
            else if (state == AST_T38_TERMINATED)
               message = "Terminated";
            else if (state == AST_T38_REFUSED)
               message = "Refused";
         }
         snprintf(subclass, sizeof(subclass), "T38_Parameters/%s", message);
         break;
      case -1:
         strcpy(subclass, "Stop generators");
         break;
      default:
         snprintf(subclass, sizeof(subclass), "Unknown control '%d'", f->subclass);
      }
      break;
   case AST_FRAME_NULL:
      strcpy(ftype, "Null Frame");
      strcpy(subclass, "N/A");
      break;
   case AST_FRAME_IAX:
      /* Should never happen */
      strcpy(ftype, "IAX Specific");
      snprintf(subclass, sizeof(subclass), "IAX Frametype %d", f->subclass);
      break;
   case AST_FRAME_TEXT:
      strcpy(ftype, "Text");
      strcpy(subclass, "N/A");
      ast_copy_string(moreinfo, f->data.ptr, sizeof(moreinfo));
      break;
   case AST_FRAME_IMAGE:
      strcpy(ftype, "Image");
      snprintf(subclass, sizeof(subclass), "Image format %s\n", ast_getformatname(f->subclass));
      break;
   case AST_FRAME_HTML:
      strcpy(ftype, "HTML");
      switch(f->subclass) {
      case AST_HTML_URL:
         strcpy(subclass, "URL");
         ast_copy_string(moreinfo, f->data.ptr, sizeof(moreinfo));
         break;
      case AST_HTML_DATA:
         strcpy(subclass, "Data");
         break;
      case AST_HTML_BEGIN:
         strcpy(subclass, "Begin");
         break;
      case AST_HTML_END:
         strcpy(subclass, "End");
         break;
      case AST_HTML_LDCOMPLETE:
         strcpy(subclass, "Load Complete");
         break;
      case AST_HTML_NOSUPPORT:
         strcpy(subclass, "No Support");
         break;
      case AST_HTML_LINKURL:
         strcpy(subclass, "Link URL");
         ast_copy_string(moreinfo, f->data.ptr, sizeof(moreinfo));
         break;
      case AST_HTML_UNLINK:
         strcpy(subclass, "Unlink");
         break;
      case AST_HTML_LINKREJECT:
         strcpy(subclass, "Link Reject");
         break;
      default:
         snprintf(subclass, sizeof(subclass), "Unknown HTML frame '%d'\n", f->subclass);
         break;
      }
      break;
   case AST_FRAME_MODEM:
      strcpy(ftype, "Modem");
      switch (f->subclass) {
      case AST_MODEM_T38:
         strcpy(subclass, "T.38");
         break;
      case AST_MODEM_V150:
         strcpy(subclass, "V.150");
         break;
      default:
         snprintf(subclass, sizeof(subclass), "Unknown MODEM frame '%d'\n", f->subclass);
         break;
      }
      break;
   default:
      snprintf(ftype, sizeof(ftype), "Unknown Frametype '%d'", f->frametype);
   }
   if (!ast_strlen_zero(moreinfo))
      ast_verbose("%s [ TYPE: %s (%d) SUBCLASS: %s (%d) '%s' ] [%s]\n",  
             term_color(cp, prefix, COLOR_BRMAGENTA, COLOR_BLACK, sizeof(cp)),
             term_color(cft, ftype, COLOR_BRRED, COLOR_BLACK, sizeof(cft)),
             f->frametype, 
             term_color(csub, subclass, COLOR_BRCYAN, COLOR_BLACK, sizeof(csub)),
             f->subclass, 
             term_color(cmn, moreinfo, COLOR_BRGREEN, COLOR_BLACK, sizeof(cmn)),
             term_color(cn, name, COLOR_YELLOW, COLOR_BLACK, sizeof(cn)));
   else
      ast_verbose("%s [ TYPE: %s (%d) SUBCLASS: %s (%d) ] [%s]\n",  
             term_color(cp, prefix, COLOR_BRMAGENTA, COLOR_BLACK, sizeof(cp)),
             term_color(cft, ftype, COLOR_BRRED, COLOR_BLACK, sizeof(cft)),
             f->frametype, 
             term_color(csub, subclass, COLOR_BRCYAN, COLOR_BLACK, sizeof(csub)),
             f->subclass, 
             term_color(cn, name, COLOR_YELLOW, COLOR_BLACK, sizeof(cn)));
}


/* 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)
{
   ast_cli_register_multiple(my_clis, sizeof(my_clis) / sizeof(struct ast_cli_entry));
   return 0;   
}

void ast_codec_pref_convert(struct ast_codec_pref *pref, char *buf, size_t size, int right) 
{
   int x, differential = (int) 'A', mem;
   char *from, *to;

   if (right) {
      from = pref->order;
      to = buf;
      mem = size;
   } else {
      to = pref->order;
      from = buf;
      mem = 32;
   }

   memset(to, 0, mem);
   for (x = 0; x < 32 ; x++) {
      if (!from[x])
         break;
      to[x] = right ? (from[x] + differential) : (from[x] - differential);
   }
}

int ast_codec_pref_string(struct ast_codec_pref *pref, char *buf, size_t size) 
{
   int x, codec; 
   size_t total_len, slen;
   char *formatname;
   
   memset(buf,0,size);
   total_len = size;
   buf[0] = '(';
   total_len--;
   for(x = 0; x < 32 ; x++) {
      if (total_len <= 0)
         break;
      if (!(codec = ast_codec_pref_index(pref,x)))
         break;
      if ((formatname = ast_getformatname(codec))) {
         slen = strlen(formatname);
         if (slen > total_len)
            break;
         strncat(buf, formatname, total_len - 1); /* safe */
         total_len -= slen;
      }
      if (total_len && x < 31 && ast_codec_pref_index(pref , x + 1)) {
         strncat(buf, "|", total_len - 1); /* safe */
         total_len--;
      }
   }
   if (total_len) {
      strncat(buf, ")", total_len - 1); /* safe */
      total_len--;
   }

   return size - total_len;
}

int ast_codec_pref_index(struct ast_codec_pref *pref, int idx)
{
   int slot = 0;

   if ((idx >= 0) && (idx < sizeof(pref->order))) {
      slot = pref->order[idx];
   }

   return slot ? AST_FORMAT_LIST[slot - 1].bits : 0;
}

/*! \brief Remove codec from pref list */
void ast_codec_pref_remove(struct ast_codec_pref *pref, int format)
{
   struct ast_codec_pref oldorder;
   int x, y = 0;
   int slot;
   int size;

   if (!pref->order[0])
      return;

   memcpy(&oldorder, pref, sizeof(oldorder));
   memset(pref, 0, sizeof(*pref));

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      slot = oldorder.order[x];
      size = oldorder.framing[x];
      if (! slot)
         break;
      if (AST_FORMAT_LIST[slot-1].bits != format) {
         pref->order[y] = slot;
         pref->framing[y++] = size;
      }
   }
   
}

/*! \brief Append codec to list */
int ast_codec_pref_append(struct ast_codec_pref *pref, int format)
{
   int x, newindex = 0;

   ast_codec_pref_remove(pref, format);

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits == format) {
         newindex = x + 1;
         break;
      }
   }

   if (newindex) {
      for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
         if (!pref->order[x]) {
            pref->order[x] = newindex;
            break;
         }
      }
   }

   return x;
}

/*! \brief Prepend codec to list */
void ast_codec_pref_prepend(struct ast_codec_pref *pref, int format, int only_if_existing)
{
   int x, newindex = 0;

   /* First step is to get the codecs "index number" */
   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits == format) {
         newindex = x + 1;
         break;
      }
   }
   /* Done if its unknown */
   if (!newindex)
      return;

   /* Now find any existing occurrence, or the end */
   for (x = 0; x < 32; x++) {
      if (!pref->order[x] || pref->order[x] == newindex)
         break;
   }

   if (only_if_existing && !pref->order[x])
      return;

   /* Move down to make space to insert - either all the way to the end,
      or as far as the existing location (which will be overwritten) */
   for (; x > 0; x--) {
      pref->order[x] = pref->order[x - 1];
      pref->framing[x] = pref->framing[x - 1];
   }

   /* And insert the new entry */
   pref->order[0] = newindex;
   pref->framing[0] = 0; /* ? */
}

/*! \brief Set packet size for codec */
int ast_codec_pref_setsize(struct ast_codec_pref *pref, int format, int framems)
{
   int x, idx = -1;

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits == format) {
         idx = x;
         break;
      }
   }

   if (idx < 0)
      return -1;

   /* size validation */
   if (!framems)
      framems = AST_FORMAT_LIST[idx].def_ms;

   if (AST_FORMAT_LIST[idx].inc_ms && framems % AST_FORMAT_LIST[idx].inc_ms) /* avoid division by zero */
      framems -= framems % AST_FORMAT_LIST[idx].inc_ms;

   if (framems < AST_FORMAT_LIST[idx].min_ms)
      framems = AST_FORMAT_LIST[idx].min_ms;

   if (framems > AST_FORMAT_LIST[idx].max_ms)
      framems = AST_FORMAT_LIST[idx].max_ms;

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (pref->order[x] == (idx + 1)) {
         pref->framing[x] = framems;
         break;
      }
   }

   return x;
}

/*! \brief Get packet size for codec */
struct ast_format_list ast_codec_pref_getsize(struct ast_codec_pref *pref, int format)
{
   int x, idx = -1, framems = 0;
   struct ast_format_list fmt = { 0, };

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (AST_FORMAT_LIST[x].bits == format) {
         fmt = AST_FORMAT_LIST[x];
         idx = x;
         break;
      }
   }

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      if (pref->order[x] == (idx + 1)) {
         framems = pref->framing[x];
         break;
      }
   }

   /* size validation */
   if (!framems)
      framems = AST_FORMAT_LIST[idx].def_ms;

   if (AST_FORMAT_LIST[idx].inc_ms && framems % AST_FORMAT_LIST[idx].inc_ms) /* avoid division by zero */
      framems -= framems % AST_FORMAT_LIST[idx].inc_ms;

   if (framems < AST_FORMAT_LIST[idx].min_ms)
      framems = AST_FORMAT_LIST[idx].min_ms;

   if (framems > AST_FORMAT_LIST[idx].max_ms)
      framems = AST_FORMAT_LIST[idx].max_ms;

   fmt.cur_ms = framems;

   return fmt;
}

/*! \brief Pick a codec */
int ast_codec_choose(struct ast_codec_pref *pref, int formats, int find_best)
{
   int x, ret = 0, slot;

   for (x = 0; x < ARRAY_LEN(AST_FORMAT_LIST); x++) {
      slot = pref->order[x];

      if (!slot)
         break;
      if (formats & AST_FORMAT_LIST[slot-1].bits) {
         ret = AST_FORMAT_LIST[slot-1].bits;
         break;
      }
   }
   if (ret & AST_FORMAT_AUDIO_MASK)
      return ret;

   ast_debug(4, "Could not find preferred codec - %s\n", find_best ? "Going for the best codec" : "Returning zero codec");

      return find_best ? ast_best_codec(formats) : 0;
}

int ast_parse_allow_disallow(struct ast_codec_pref *pref, int *mask, const char *list, int allowing) 
{
   int errors = 0;
   char *parse = NULL, *this = NULL, *psize = NULL;
   int format = 0, framems = 0;

   parse = ast_strdupa(list);
   while ((this = strsep(&parse, ","))) {
      framems = 0;
      if ((psize = strrchr(this, ':'))) {
         *psize++ = '\0';
         ast_debug(1, "Packetization for codec: %s is %s\n", this, psize);
         framems = atoi(psize);
         if (framems < 0) {
            framems = 0;
            errors++;
            ast_log(LOG_WARNING, "Bad packetization value for codec %s\n", this);
         }
      }
      if (!(format = ast_getformatbyname(this))) {
         ast_log(LOG_WARNING, "Cannot %s unknown format '%s'\n", allowing ? "allow" : "disallow", this);
         errors++;
         continue;
      }

      if (mask) {
         if (allowing)
            *mask |= format;
         else
            *mask &= ~format;
      }

      /* Set up a preference list for audio. Do not include video in preferences 
         since we can not transcode video and have to use whatever is offered
       */
      if (pref && (format & AST_FORMAT_AUDIO_MASK)) {
         if (strcasecmp(this, "all")) {
            if (allowing) {
               ast_codec_pref_append(pref, format);
               ast_codec_pref_setsize(pref, format, framems);
            }
            else
               ast_codec_pref_remove(pref, format);
         } else if (!allowing) {
            memset(pref, 0, sizeof(*pref));
         }
      }
   }
   return errors;
}

static int g723_len(unsigned char buf)
{
   enum frame_type type = buf & TYPE_MASK;

   switch(type) {
   case TYPE_DONTSEND:
      return 0;
      break;
   case TYPE_SILENCE:
      return 4;
      break;
   case TYPE_HIGH:
      return 24;
      break;
   case TYPE_LOW:
      return 20;
      break;
   default:
      ast_log(LOG_WARNING, "Badly encoded frame (%d)\n", type);
   }
   return -1;
}

static int g723_samples(unsigned char *buf, int maxlen)
{
   int pos = 0;
   int samples = 0;
   int res;
   while(pos < maxlen) {
      res = g723_len(buf[pos]);
      if (res <= 0)
         break;
      samples += 240;
      pos += res;
   }
   return samples;
}

static unsigned char get_n_bits_at(unsigned char *data, int n, int bit)
{
   int byte = bit / 8;       /* byte containing first bit */
   int rem = 8 - (bit % 8);  /* remaining bits in first byte */
   unsigned char ret = 0;
   
   if (n <= 0 || n > 8)
      return 0;

   if (rem < n) {
      ret = (data[byte] << (n - rem));
      ret |= (data[byte + 1] >> (8 - n + rem));
   } else {
      ret = (data[byte] >> (rem - n));
   }

   return (ret & (0xff >> (8 - n)));
}

static int speex_get_wb_sz_at(unsigned char *data, int len, int bit)
{
   static int SpeexWBSubModeSz[] = {
      0, 36, 112, 192,
      352, 0, 0, 0 };
   int off = bit;
   unsigned char c;

   /* skip up to two wideband frames */
   if (((len * 8 - off) >= 5) && 
      get_n_bits_at(data, 1, off)) {
      c = get_n_bits_at(data, 3, off + 1);
      off += SpeexWBSubModeSz[c];

      if (((len * 8 - off) >= 5) && 
         get_n_bits_at(data, 1, off)) {
         c = get_n_bits_at(data, 3, off + 1);
         off += SpeexWBSubModeSz[c];

         if (((len * 8 - off) >= 5) && 
            get_n_bits_at(data, 1, off)) {
            ast_log(LOG_WARNING, "Encountered corrupt speex frame; too many wideband frames in a row.\n");
            return -1;
         }
      }

   }
   return off - bit;
}

static int speex_samples(unsigned char *data, int len)
{
   static int SpeexSubModeSz[] = {
      5, 43, 119, 160,
      220, 300, 364, 492, 
      79, 0, 0, 0,
      0, 0, 0, 0 };
   static int SpeexInBandSz[] = { 
      1, 1, 4, 4,
      4, 4, 4, 4,
      8, 8, 16, 16,
      32, 32, 64, 64 };
   int bit = 0;
   int cnt = 0;
   int off;
   unsigned char c;

   while ((len * 8 - bit) >= 5) {
      /* skip wideband frames */
      off = speex_get_wb_sz_at(data, len, bit);
      if (off < 0)  {
         ast_log(LOG_WARNING, "Had error while reading wideband frames for speex samples\n");
         break;
      }
      bit += off;

      if ((len * 8 - bit) < 5) {
         ast_log(LOG_WARNING, "Not enough bits remaining after wide band for speex samples.\n");
         break;
      }

      /* get control bits */
      c = get_n_bits_at(data, 5, bit);
      bit += 5;

      if (c == 15) { 
         /* terminator */
         break; 
      } else if (c == 14) {
         /* in-band signal; next 4 bits contain signal id */
         c = get_n_bits_at(data, 4, bit);
         bit += 4;
         bit += SpeexInBandSz[c];
      } else if (c == 13) {
         /* user in-band; next 5 bits contain msg len */
         c = get_n_bits_at(data, 5, bit);
         bit += 5;
         bit += c * 8;
      } else if (c > 8) {
         /* unknown */
         break;
      } else {
         /* skip number bits for submode (less the 5 control bits) */
         bit += SpeexSubModeSz[c] - 5;
         cnt += 160; /* new frame */
      }
   }
   return cnt;
}

int ast_codec_get_samples(struct ast_frame *f)
{
   int samples=0;
   switch(f->subclass) {
   case AST_FORMAT_SPEEX:
      samples = speex_samples(f->data.ptr, f->datalen);
      break;
   case AST_FORMAT_G723_1:
      samples = g723_samples(f->data.ptr, f->datalen);
      break;
   case AST_FORMAT_ILBC:
      samples = 240 * (f->datalen / 50);
      break;
   case AST_FORMAT_GSM:
      samples = 160 * (f->datalen / 33);
      break;
   case AST_FORMAT_G729A:
      samples = f->datalen * 8;
      break;
   case AST_FORMAT_SLINEAR:
   case AST_FORMAT_SLINEAR16:
      samples = f->datalen / 2;
      break;
   case AST_FORMAT_LPC10:
      /* assumes that the RTP packet contains one LPC10 frame */
      samples = 22 * 8;
      samples += (((char *)(f->data.ptr))[7] & 0x1) * 8;
      break;
   case AST_FORMAT_ULAW:
   case AST_FORMAT_ALAW:
      samples = f->datalen;
      break;
   case AST_FORMAT_G722:
   case AST_FORMAT_ADPCM:
   case AST_FORMAT_G726:
   case AST_FORMAT_G726_AAL2:
      samples = f->datalen * 2;
      break;
   default:
      ast_log(LOG_WARNING, "Unable to calculate samples for format %s\n", ast_getformatname(f->subclass));
   }
   return samples;
}

int ast_codec_get_len(int format, int samples)
{
   int len = 0;

   /* XXX Still need speex, g723, and lpc10 XXX */ 
   switch(format) {
   case AST_FORMAT_G723_1:
      len = (samples / 240) * 20;
      break;
   case AST_FORMAT_ILBC:
      len = (samples / 240) * 50;
      break;
   case AST_FORMAT_GSM:
      len = (samples / 160) * 33;
      break;
   case AST_FORMAT_G729A:
      len = samples / 8;
      break;
   case AST_FORMAT_SLINEAR:
   case AST_FORMAT_SLINEAR16:
      len = samples * 2;
      break;
   case AST_FORMAT_ULAW:
   case AST_FORMAT_ALAW:
      len = samples;
      break;
   case AST_FORMAT_G722:
   case AST_FORMAT_ADPCM:
   case AST_FORMAT_G726:
   case AST_FORMAT_G726_AAL2:
      len = samples / 2;
      break;
   default:
      ast_log(LOG_WARNING, "Unable to calculate sample length for format %s\n", ast_getformatname(format));
   }

   return len;
}

int ast_frame_adjust_volume(struct ast_frame *f, int adjustment)
{
   int count;
   short *fdata = f->data.ptr;
   short adjust_value = abs(adjustment);

   if ((f->frametype != AST_FRAME_VOICE) || (f->subclass != AST_FORMAT_SLINEAR))
      return -1;

   if (!adjustment)
      return 0;

   for (count = 0; count < f->samples; count++) {
      if (adjustment > 0) {
         ast_slinear_saturated_multiply(&fdata[count], &adjust_value);
      } else if (adjustment < 0) {
         ast_slinear_saturated_divide(&fdata[count], &adjust_value);
      }
   }

   return 0;
}

int ast_frame_slinear_sum(struct ast_frame *f1, struct ast_frame *f2)
{
   int count;
   short *data1, *data2;

   if ((f1->frametype != AST_FRAME_VOICE) || (f1->subclass != AST_FORMAT_SLINEAR))
      return -1;

   if ((f2->frametype != AST_FRAME_VOICE) || (f2->subclass != AST_FORMAT_SLINEAR))
      return -1;

   if (f1->samples != f2->samples)
      return -1;

   for (count = 0, data1 = f1->data.ptr, data2 = f2->data.ptr;
        count < f1->samples;
        count++, data1++, data2++)
      ast_slinear_saturated_add(data1, data2);

   return 0;
}