codecs/codec_ilbc.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * The iLBC code is from The IETF code base and is copyright The Internet Society (2004)
   5  *
   6  * Copyright (C) 1999 - 2005, Digium, Inc.
   7  *
   8  * Mark Spencer <markster@digium.com>
   9  *
  10  * See http://www.asterisk.org for more information about
  11  * the Asterisk project. Please do not directly contact
  12  * any of the maintainers of this project for assistance;
  13  * the project provides a web site, mailing lists and IRC
  14  * channels for your use.
  15  *
  16  * This program is free software, distributed under the terms of
  17  * the GNU General Public License Version 2. See the LICENSE file
  18  * at the top of the source tree.
  19  */
  20
  21 /*! \file
  22  *
  23  * \brief Translate between signed linear and Internet Low Bitrate Codec
  24  *
  25  * \ingroup codecs
  26  */
  27
  28 /*** MODULEINFO
  29         <defaultenabled>no</defaultenabled>
  30  ***/
  31
  32 #include "asterisk.h"
  33
  34 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  35
  36 #include <fcntl.h>
  37 #include <stdlib.h>
  38 #include <unistd.h>
  39 #include <netinet/in.h>
  40 #include <string.h>
  41 #include <stdio.h>
  42
  43 #include "asterisk/lock.h"
  44 #include "asterisk/translate.h"
  45 #include "asterisk/module.h"
  46 #include "asterisk/logger.h"
  47 #include "asterisk/channel.h"
  48 #include "asterisk/utils.h"
  49
  50 #include "ilbc/iLBC_encode.h"
  51 #include "ilbc/iLBC_decode.h"
  52
  53 /* Sample frame data */
  54 #include "slin_ilbc_ex.h"
  55 #include "ilbc_slin_ex.h"
  56
  57 #define USE_ILBC_ENHANCER       0
  58 #define ILBC_MS                         30
  59 /* #define ILBC_MS                      20 */
  60
  61 #define ILBC_FRAME_LEN  50      /* apparently... */
  62 #define ILBC_SAMPLES    240     /* 30ms at 8000 hz */
  63 #define BUFFER_SAMPLES  8000
  64
  65 struct ilbc_coder_pvt {
  66         iLBC_Enc_Inst_t enc;
  67         iLBC_Dec_Inst_t dec;
  68         /* Enough to store a full second */
  69         int16_t buf[BUFFER_SAMPLES];
  70 };
  71
  72 static int lintoilbc_new(struct ast_trans_pvt *pvt)
  73 {
  74         struct ilbc_coder_pvt *tmp = pvt->pvt;
  75
  76         initEncode(&tmp->enc, ILBC_MS);
  77
  78         return 0;
  79 }
  80
  81 static int ilbctolin_new(struct ast_trans_pvt *pvt)
  82 {
  83         struct ilbc_coder_pvt *tmp = pvt->pvt;
  84
  85         initDecode(&tmp->dec, ILBC_MS, USE_ILBC_ENHANCER);
  86
  87         return 0;
  88 }
  89
  90 static struct ast_frame *lintoilbc_sample(void)
  91 {
  92         static struct ast_frame f;
  93         f.frametype = AST_FRAME_VOICE;
  94         f.subclass = AST_FORMAT_SLINEAR;
  95         f.datalen = sizeof(slin_ilbc_ex);
  96         f.samples = sizeof(slin_ilbc_ex)/2;
  97         f.mallocd = 0;
  98         f.offset = 0;
  99         f.src = __PRETTY_FUNCTION__;
 100         f.data = slin_ilbc_ex;
 101         return &f;
 102 }
 103
 104 static struct ast_frame *ilbctolin_sample(void)
 105 {
 106         static struct ast_frame f;
 107         f.frametype = AST_FRAME_VOICE;
 108         f.subclass = AST_FORMAT_ILBC;
 109         f.datalen = sizeof(ilbc_slin_ex);
 110         /* All frames are 30 ms long */
 111         f.samples = ILBC_SAMPLES;
 112         f.mallocd = 0;
 113         f.offset = 0;
 114         f.src = __PRETTY_FUNCTION__;
 115         f.data = ilbc_slin_ex;
 116         return &f;
 117 }
 118
 119 /*! \brief decode a frame and store in outbuf */
 120 static int ilbctolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
 121 {
 122         struct ilbc_coder_pvt *tmp = pvt->pvt;
 123         int plc_mode = 1; /* 1 = normal data, 0 = plc */
 124         /* Assuming there's space left, decode into the current buffer at
 125            the tail location.  Read in as many frames as there are */
 126         int x,i;
 127         int16_t *dst = (int16_t *)pvt->outbuf;
 128         float tmpf[ILBC_SAMPLES];
 129
 130         if (f->datalen == 0) { /* native PLC, set fake f->datalen and clear plc_mode */
 131                 f->datalen = ILBC_FRAME_LEN;
 132                 f->samples = ILBC_SAMPLES;
 133                 plc_mode = 0;   /* do native plc */
 134                 pvt->samples += ILBC_SAMPLES;
 135         }
 136
 137         if (f->datalen % ILBC_FRAME_LEN) {
 138                 ast_log(LOG_WARNING, "Huh?  An ilbc frame that isn't a multiple of 50 bytes long from %s (%d)?\n", f->src, f->datalen);
 139                 return -1;
 140         }
 141
 142         for (x=0; x < f->datalen ; x += ILBC_FRAME_LEN) {
 143                 if (pvt->samples + ILBC_SAMPLES > BUFFER_SAMPLES) {
 144                         ast_log(LOG_WARNING, "Out of buffer space\n");
 145                         return -1;
 146                 }
 147                 iLBC_decode(tmpf, plc_mode ? f->data + x : NULL, &tmp->dec, plc_mode);
 148                 for ( i=0; i < ILBC_SAMPLES; i++)
 149                         dst[pvt->samples + i] = tmpf[i];
 150                 pvt->samples += ILBC_SAMPLES;
 151                 pvt->datalen += 2*ILBC_SAMPLES;
 152         }
 153         return 0;
 154 }
 155
 156 /*! \brief store a frame into a temporary buffer, for later decoding */
 157 static int lintoilbc_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
 158 {
 159         struct ilbc_coder_pvt *tmp = pvt->pvt;
 160
 161         /* Just add the frames to our stream */
 162         /* XXX We should look at how old the rest of our stream is, and if it
 163            is too old, then we should overwrite it entirely, otherwise we can
 164            get artifacts of earlier talk that do not belong */
 165         memcpy(tmp->buf + pvt->samples, f->data, f->datalen);
 166         pvt->samples += f->samples;
 167         return 0;
 168 }
 169
 170 /*! \brief encode the temporary buffer and generate a frame */
 171 static struct ast_frame *lintoilbc_frameout(struct ast_trans_pvt *pvt)
 172 {
 173         struct ilbc_coder_pvt *tmp = pvt->pvt;
 174         int datalen = 0;
 175         int samples = 0;
 176
 177         /* We can't work on anything less than a frame in size */
 178         if (pvt->samples < ILBC_SAMPLES)
 179                 return NULL;
 180         while (pvt->samples >= ILBC_SAMPLES) {
 181                 float tmpf[ILBC_SAMPLES];
 182                 int i;
 183
 184                 /* Encode a frame of data */
 185                 for (i = 0 ; i < ILBC_SAMPLES ; i++)
 186                         tmpf[i] = tmp->buf[samples + i];
 187                 iLBC_encode((unsigned char *) pvt->outbuf + datalen, tmpf, &tmp->enc);
 188
 189                 datalen += ILBC_FRAME_LEN;
 190                 samples += ILBC_SAMPLES;
 191                 pvt->samples -= ILBC_SAMPLES;
 192         }
 193
 194         /* Move the data at the end of the buffer to the front */
 195         if (pvt->samples)
 196                 memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2);
 197
 198         return ast_trans_frameout(pvt, datalen, samples);
 199 }
 200
 201 static struct ast_translator ilbctolin = {
 202         .name = "ilbctolin",
 203         .srcfmt = AST_FORMAT_ILBC,
 204         .dstfmt = AST_FORMAT_SLINEAR,
 205         .newpvt = ilbctolin_new,
 206         .framein = ilbctolin_framein,
 207         .sample = ilbctolin_sample,
 208         .desc_size = sizeof(struct ilbc_coder_pvt),
 209         .buf_size = BUFFER_SAMPLES * 2,
 210         .native_plc = 1,
 211 };
 212
 213 static struct ast_translator lintoilbc = {
 214         .name = "lintoilbc",
 215         .srcfmt = AST_FORMAT_SLINEAR,
 216         .dstfmt = AST_FORMAT_ILBC,
 217         .newpvt = lintoilbc_new,
 218         .framein = lintoilbc_framein,
 219         .frameout = lintoilbc_frameout,
 220         .sample = lintoilbc_sample,
 221         .desc_size = sizeof(struct ilbc_coder_pvt),
 222         .buf_size = (BUFFER_SAMPLES * ILBC_FRAME_LEN + ILBC_SAMPLES - 1) / ILBC_SAMPLES,
 223 };
 224
 225 static int unload_module(void)
 226 {
 227         int res;
 228
 229         res = ast_unregister_translator(&lintoilbc);
 230         res |= ast_unregister_translator(&ilbctolin);
 231
 232         return res;
 233 }
 234
 235 static int load_module(void)
 236 {
 237         int res;
 238
 239         res = ast_register_translator(&ilbctolin);
 240         if (!res)
 241                 res=ast_register_translator(&lintoilbc);
 242         else
 243                 ast_unregister_translator(&ilbctolin);
 244
 245         return res;
 246 }
 247
 248 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "iLBC Coder/Decoder");