160 lines
3.6 KiB
C
160 lines
3.6 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 1999 - 2005, Digium, Inc.
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*
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* Mark Spencer <markster@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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*
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* \brief codec_a_mu.c - translate between alaw and ulaw directly
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*
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* \ingroup codecs
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*/
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#include "asterisk.h"
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ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
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#include "asterisk/module.h"
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#include "asterisk/translate.h"
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#include "asterisk/alaw.h"
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#include "asterisk/ulaw.h"
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#include "asterisk/utils.h"
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#define BUFFER_SAMPLES 8000 /* size for the translation buffers */
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static unsigned char mu2a[256];
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static unsigned char a2mu[256];
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/* Sample frame data (Mu data is okay) */
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#include "ulaw_slin_ex.h"
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/*! \brief convert frame data and store into the buffer */
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static int alawtoulaw_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
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{
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int x = f->samples;
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unsigned char *src = f->data;
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unsigned char *dst = (unsigned char *)pvt->outbuf + pvt->samples;
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pvt->samples += x;
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pvt->datalen += x;
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while (x--)
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*dst++ = a2mu[*src++];
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return 0;
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}
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/*! \brief convert frame data and store into the buffer */
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static int ulawtoalaw_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
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{
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int x = f->samples;
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unsigned char *src = f->data;
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unsigned char *dst = (unsigned char *)pvt->outbuf + pvt->samples;
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pvt->samples += x;
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pvt->datalen += x;
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while (x--)
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*dst++ = mu2a[*src++];
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return 0;
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}
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/*
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* alawToLin_Sample. Just random data, somehow...
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*/
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static struct ast_frame *alawtoulaw_sample(void)
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{
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static struct ast_frame f;
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f.frametype = AST_FRAME_VOICE;
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f.subclass = AST_FORMAT_ALAW;
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f.datalen = sizeof(ulaw_slin_ex);
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f.samples = sizeof(ulaw_slin_ex);
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f.mallocd = 0;
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f.offset = 0;
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f.src = __PRETTY_FUNCTION__;
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f.data = ulaw_slin_ex; /* XXX what ? */
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return &f;
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}
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static struct ast_frame *ulawtoalaw_sample(void)
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{
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static struct ast_frame f;
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f.frametype = AST_FRAME_VOICE;
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f.subclass = AST_FORMAT_ULAW;
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f.datalen = sizeof(ulaw_slin_ex);
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f.samples = sizeof(ulaw_slin_ex);
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f.mallocd = 0;
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f.offset = 0;
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f.src = __PRETTY_FUNCTION__;
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f.data = ulaw_slin_ex;
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return &f;
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}
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static struct ast_translator alawtoulaw = {
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.name = "alawtoulaw",
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.srcfmt = AST_FORMAT_ALAW,
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.dstfmt = AST_FORMAT_ULAW,
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.framein = alawtoulaw_framein,
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.sample = alawtoulaw_sample,
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.buffer_samples = BUFFER_SAMPLES,
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.buf_size = BUFFER_SAMPLES,
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};
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static struct ast_translator ulawtoalaw = {
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.name = "ulawtoalaw",
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.srcfmt = AST_FORMAT_ULAW,
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.dstfmt = AST_FORMAT_ALAW,
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.framein = ulawtoalaw_framein,
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.sample = ulawtoalaw_sample,
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.buffer_samples = BUFFER_SAMPLES,
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.buf_size = BUFFER_SAMPLES,
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};
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/*! \brief standard module glue */
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static int unload_module(void)
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{
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int res;
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res = ast_unregister_translator(&ulawtoalaw);
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res |= ast_unregister_translator(&alawtoulaw);
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return res;
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}
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static int load_module(void)
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{
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int res;
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int x;
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for (x=0;x<256;x++) {
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mu2a[x] = AST_LIN2A(AST_MULAW(x));
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a2mu[x] = AST_LIN2MU(AST_ALAW(x));
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}
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res = ast_register_translator(&alawtoulaw);
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if (!res)
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res = ast_register_translator(&ulawtoalaw);
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else
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ast_unregister_translator(&alawtoulaw);
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if (res)
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return AST_MODULE_LOAD_FAILURE;
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return AST_MODULE_LOAD_SUCCESS;
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}
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AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "A-law and Mulaw direct Coder/Decoder");
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