codec_g722.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2008, Digium, Inc.
 *
 * Matthew Fredrickson <creslin@digium.com>
 * Russell Bryant <russell@digium.com>
 *
 * Special thanks to Steve Underwood for the implementation
 * and for doing the 8khz<->g.722 direct translation code.
 *
 * 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 codec_g722.c - translate between signed linear and ITU G.722-64kbps
 *
 * \author Matthew Fredrickson <creslin@digium.com>
 * \author Russell Bryant <russell@digium.com>
 *
 * \arg http://soft-switch.org/downloads/non-gpl-bits.tgz
 * \arg http://lists.digium.com/pipermail/asterisk-dev/2006-September/022866.html
 *
 * \ingroup codecs
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 150729 $")

#include "asterisk/linkedlists.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/translate.h"
#include "asterisk/utils.h"

#define BUFFER_SAMPLES   8096 /* size for the translation buffers */
#define BUF_SHIFT 5

#include "g722/g722.h"

/* Sample frame data */
#include "asterisk/slin.h"
#include "ex_g722.h"

struct g722_encoder_pvt {
   g722_encode_state_t g722;
};

struct g722_decoder_pvt {
   g722_decode_state_t g722;
};

/*! \brief init a new instance of g722_encoder_pvt. */
static int lintog722_new(struct ast_trans_pvt *pvt)
{
   struct g722_encoder_pvt *tmp = pvt->pvt;

   g722_encode_init(&tmp->g722, 64000, G722_SAMPLE_RATE_8000);

   return 0;
}

static int lin16tog722_new(struct ast_trans_pvt *pvt)
{
   struct g722_encoder_pvt *tmp = pvt->pvt;

   g722_encode_init(&tmp->g722, 64000, 0);

   return 0;
}

/*! \brief init a new instance of g722_encoder_pvt. */
static int g722tolin_new(struct ast_trans_pvt *pvt)
{
   struct g722_decoder_pvt *tmp = pvt->pvt;

   g722_decode_init(&tmp->g722, 64000, G722_SAMPLE_RATE_8000);

   return 0;
}

static int g722tolin16_new(struct ast_trans_pvt *pvt)
{
   struct g722_decoder_pvt *tmp = pvt->pvt;

   g722_decode_init(&tmp->g722, 64000, 0);

   return 0;
}

static int g722tolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
   struct g722_decoder_pvt *tmp = pvt->pvt;
   int out_samples;
   int in_samples;

   /* g722_decode expects the samples to be in the invalid samples / 2 format */
   in_samples = f->samples / 2;

   out_samples = g722_decode(&tmp->g722, &pvt->outbuf.i16[pvt->samples * sizeof(int16_t)], 
      (uint8_t *) f->data.ptr, in_samples);

   pvt->samples += out_samples;

   pvt->datalen += (out_samples * sizeof(int16_t));

   return 0;
}

static int lintog722_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
   struct g722_encoder_pvt *tmp = pvt->pvt;
   int outlen;

   outlen = g722_encode(&tmp->g722, (&pvt->outbuf.ui8[pvt->datalen]), 
      (int16_t *) f->data.ptr, f->samples);

   pvt->samples += outlen * 2;

   pvt->datalen += outlen;

   return 0;
}

static struct ast_translator g722tolin = {
   .name = "g722tolin",
   .srcfmt = AST_FORMAT_G722,
   .dstfmt = AST_FORMAT_SLINEAR,
   .newpvt = g722tolin_new,   /* same for both directions */
   .framein = g722tolin_framein,
   .sample = g722_sample,
   .desc_size = sizeof(struct g722_decoder_pvt),
   .buffer_samples = BUFFER_SAMPLES / sizeof(int16_t),
   .buf_size = BUFFER_SAMPLES,
   .plc_samples = 160,
};

static struct ast_translator lintog722 = {
   .name = "lintog722",
   .srcfmt = AST_FORMAT_SLINEAR,
   .dstfmt = AST_FORMAT_G722,
   .newpvt = lintog722_new,   /* same for both directions */
   .framein = lintog722_framein,
   .sample = slin8_sample,
   .desc_size = sizeof(struct g722_encoder_pvt),
   .buffer_samples = BUFFER_SAMPLES * 2,
   .buf_size = BUFFER_SAMPLES,
};

static struct ast_translator g722tolin16 = {
   .name = "g722tolin16",
   .srcfmt = AST_FORMAT_G722,
   .dstfmt = AST_FORMAT_SLINEAR16,
   .newpvt = g722tolin16_new, /* same for both directions */
   .framein = g722tolin_framein,
   .sample = g722_sample,
   .desc_size = sizeof(struct g722_decoder_pvt),
   .buffer_samples = BUFFER_SAMPLES / sizeof(int16_t),
   .buf_size = BUFFER_SAMPLES,
   .plc_samples = 160,
};

static struct ast_translator lin16tog722 = {
   .name = "lin16tog722",
   .srcfmt = AST_FORMAT_SLINEAR16,
   .dstfmt = AST_FORMAT_G722,
   .newpvt = lin16tog722_new, /* same for both directions */
   .framein = lintog722_framein,
   .sample = slin16_sample,
   .desc_size = sizeof(struct g722_encoder_pvt),
   .buffer_samples = BUFFER_SAMPLES * 2,
   .buf_size = BUFFER_SAMPLES,
};

static int parse_config(int reload)
{
   struct ast_variable *var;
   struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
   struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);

   if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEUNCHANGED || cfg == CONFIG_STATUS_FILEINVALID)
      return 0;
   for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
      if (!strcasecmp(var->name, "genericplc")) {
         g722tolin.useplc = ast_true(var->value) ? 1 : 0;
         ast_verb(3, "codec_g722: %susing generic PLC\n",
               g722tolin.useplc ? "" : "not ");
      }
   }
   ast_config_destroy(cfg);
   return 0;
}

static int reload(void)
{
   if (parse_config(1))
      return AST_MODULE_LOAD_DECLINE;
   return AST_MODULE_LOAD_SUCCESS;
}

static int unload_module(void)
{
   int res = 0;

   res |= ast_unregister_translator(&g722tolin);
   res |= ast_unregister_translator(&lintog722);
   res |= ast_unregister_translator(&g722tolin16);
   res |= ast_unregister_translator(&lin16tog722);

   return res;
}

static int load_module(void)
{
   int res = 0;

   if (parse_config(0))
      return AST_MODULE_LOAD_DECLINE;

   res |= ast_register_translator(&g722tolin);
   res |= ast_register_translator(&lintog722);
   res |= ast_register_translator(&g722tolin16);
   res |= ast_register_translator(&lin16tog722);

   if (res) {
      unload_module();
      return AST_MODULE_LOAD_FAILURE;
   }  

   return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "ITU G.722-64kbps G722 Transcoder",
      .load = load_module,
      .unload = unload_module,
      .reload = reload,
          );