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 "asterisk/translate.h"
  37 #include "asterisk/module.h"
  38 #include "asterisk/utils.h"
  39
  40 #include "ilbc/iLBC_encode.h"
  41 #include "ilbc/iLBC_decode.h"
  42
  43 /* Sample frame data */
  44 #include "slin_ilbc_ex.h"
  45 #include "ilbc_slin_ex.h"
  46
  47 #define USE_ILBC_ENHANCER       0
  48 #define ILBC_MS                         30
  49 /* #define ILBC_MS                      20 */
  50
  51 #define ILBC_FRAME_LEN  50      /* apparently... */
  52 #define ILBC_SAMPLES    240     /* 30ms at 8000 hz */
  53 #define BUFFER_SAMPLES  8000
  54
  55 struct ilbc_coder_pvt {
  56         iLBC_Enc_Inst_t enc;
  57         iLBC_Dec_Inst_t dec;
  58         /* Enough to store a full second */
  59         int16_t buf[BUFFER_SAMPLES];
  60 };
  61
  62 static int lintoilbc_new(struct ast_trans_pvt *pvt)
  63 {
  64         struct ilbc_coder_pvt *tmp = pvt->pvt;
  65
  66         initEncode(&tmp->enc, ILBC_MS);
  67
  68         return 0;
  69 }
  70
  71 static int ilbctolin_new(struct ast_trans_pvt *pvt)
  72 {
  73         struct ilbc_coder_pvt *tmp = pvt->pvt;
  74
  75         initDecode(&tmp->dec, ILBC_MS, USE_ILBC_ENHANCER);
  76
  77         return 0;
  78 }
  79
  80 static struct ast_frame *lintoilbc_sample(void)
  81 {
  82         static struct ast_frame f;
  83         f.frametype = AST_FRAME_VOICE;
  84         f.subclass = AST_FORMAT_SLINEAR;
  85         f.datalen = sizeof(slin_ilbc_ex);
  86         f.samples = sizeof(slin_ilbc_ex)/2;
  87         f.mallocd = 0;
  88         f.offset = 0;
  89         f.src = __PRETTY_FUNCTION__;
  90         f.data = slin_ilbc_ex;
  91         return &f;
  92 }
  93
  94 static struct ast_frame *ilbctolin_sample(void)
  95 {
  96         static struct ast_frame f;
  97         f.frametype = AST_FRAME_VOICE;
  98         f.subclass = AST_FORMAT_ILBC;
  99         f.datalen = sizeof(ilbc_slin_ex);
 100         /* All frames are 30 ms long */
 101         f.samples = ILBC_SAMPLES;
 102         f.mallocd = 0;
 103         f.offset = 0;
 104         f.src = __PRETTY_FUNCTION__;
 105         f.data = ilbc_slin_ex;
 106         return &f;
 107 }
 108
 109 /*! \brief decode a frame and store in outbuf */
 110 static int ilbctolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
 111 {
 112         struct ilbc_coder_pvt *tmp = pvt->pvt;
 113         int plc_mode = 1; /* 1 = normal data, 0 = plc */
 114         /* Assuming there's space left, decode into the current buffer at
 115            the tail location.  Read in as many frames as there are */
 116         int x,i;
 117         int16_t *dst = (int16_t *)pvt->outbuf;
 118         float tmpf[ILBC_SAMPLES];
 119
 120         if (f->datalen == 0) { /* native PLC, set fake f->datalen and clear plc_mode */
 121                 f->datalen = ILBC_FRAME_LEN;
 122                 f->samples = ILBC_SAMPLES;
 123                 plc_mode = 0;   /* do native plc */
 124                 pvt->samples += ILBC_SAMPLES;
 125         }
 126
 127         if (f->datalen % ILBC_FRAME_LEN) {
 128                 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);
 129                 return -1;
 130         }
 131
 132         for (x=0; x < f->datalen ; x += ILBC_FRAME_LEN) {
 133                 if (pvt->samples + ILBC_SAMPLES > BUFFER_SAMPLES) {
 134                         ast_log(LOG_WARNING, "Out of buffer space\n");
 135                         return -1;
 136                 }
 137                 iLBC_decode(tmpf, plc_mode ? f->data + x : NULL, &tmp->dec, plc_mode);
 138                 for ( i=0; i < ILBC_SAMPLES; i++)
 139                         dst[pvt->samples + i] = tmpf[i];
 140                 pvt->samples += ILBC_SAMPLES;
 141                 pvt->datalen += 2*ILBC_SAMPLES;
 142         }
 143         return 0;
 144 }
 145
 146 /*! \brief store a frame into a temporary buffer, for later decoding */
 147 static int lintoilbc_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
 148 {
 149         struct ilbc_coder_pvt *tmp = pvt->pvt;
 150
 151         /* Just add the frames to our stream */
 152         /* XXX We should look at how old the rest of our stream is, and if it
 153            is too old, then we should overwrite it entirely, otherwise we can
 154            get artifacts of earlier talk that do not belong */
 155         memcpy(tmp->buf + pvt->samples, f->data, f->datalen);
 156         pvt->samples += f->samples;
 157         return 0;
 158 }
 159
 160 /*! \brief encode the temporary buffer and generate a frame */
 161 static struct ast_frame *lintoilbc_frameout(struct ast_trans_pvt *pvt)
 162 {
 163         struct ilbc_coder_pvt *tmp = pvt->pvt;
 164         int datalen = 0;
 165         int samples = 0;
 166
 167         /* We can't work on anything less than a frame in size */
 168         if (pvt->samples < ILBC_SAMPLES)
 169                 return NULL;
 170         while (pvt->samples >= ILBC_SAMPLES) {
 171                 float tmpf[ILBC_SAMPLES];
 172                 int i;
 173
 174                 /* Encode a frame of data */
 175                 for (i = 0 ; i < ILBC_SAMPLES ; i++)
 176                         tmpf[i] = tmp->buf[samples + i];
 177                 iLBC_encode((unsigned char *) pvt->outbuf + datalen, tmpf, &tmp->enc);
 178
 179                 datalen += ILBC_FRAME_LEN;
 180                 samples += ILBC_SAMPLES;
 181                 pvt->samples -= ILBC_SAMPLES;
 182         }
 183
 184         /* Move the data at the end of the buffer to the front */
 185         if (pvt->samples)
 186                 memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2);
 187
 188         return ast_trans_frameout(pvt, datalen, samples);
 189 }
 190
 191 static struct ast_translator ilbctolin = {
 192         .name = "ilbctolin",
 193         .srcfmt = AST_FORMAT_ILBC,
 194         .dstfmt = AST_FORMAT_SLINEAR,
 195         .newpvt = ilbctolin_new,
 196         .framein = ilbctolin_framein,
 197         .sample = ilbctolin_sample,
 198         .desc_size = sizeof(struct ilbc_coder_pvt),
 199         .buf_size = BUFFER_SAMPLES * 2,
 200         .native_plc = 1,
 201 };
 202
 203 static struct ast_translator lintoilbc = {
 204         .name = "lintoilbc",
 205         .srcfmt = AST_FORMAT_SLINEAR,
 206         .dstfmt = AST_FORMAT_ILBC,
 207         .newpvt = lintoilbc_new,
 208         .framein = lintoilbc_framein,
 209         .frameout = lintoilbc_frameout,
 210         .sample = lintoilbc_sample,
 211         .desc_size = sizeof(struct ilbc_coder_pvt),
 212         .buf_size = (BUFFER_SAMPLES * ILBC_FRAME_LEN + ILBC_SAMPLES - 1) / ILBC_SAMPLES,
 213 };
 214
 215 static int unload_module(void)
 216 {
 217         int res;
 218
 219         res = ast_unregister_translator(&lintoilbc);
 220         res |= ast_unregister_translator(&ilbctolin);
 221
 222         return res;
 223 }
 224
 225 static int load_module(void)
 226 {
 227         int res;
 228
 229         res = ast_register_translator(&ilbctolin);
 230         if (!res)
 231                 res=ast_register_translator(&lintoilbc);
 232         else
 233                 ast_unregister_translator(&ilbctolin);
 234         if (res)
 235                 return AST_MODULE_LOAD_FAILURE;
 236         return AST_MODULE_LOAD_SUCCESS;
 237 }
 238
 239 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "iLBC Coder/Decoder");