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			129 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			2.9 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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| 
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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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| 
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| #include "asterisk.h"
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| 
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| ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
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| 
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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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| 
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| #define BUFFER_SAMPLES   8000	/* size for the translation buffers */
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| 
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| static unsigned char mu2a[256];
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| static unsigned char a2mu[256];
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| 
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| /* Sample frame data */
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| #include "ex_ulaw.h"
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| #include "ex_alaw.h"
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| 
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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.ptr;
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| 	unsigned char *dst = pvt->outbuf.uc + pvt->samples;
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| 
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| 	pvt->samples += x;
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| 	pvt->datalen += x;
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| 
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| 	while (x--)
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| 		*dst++ = a2mu[*src++];
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| 
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| 	return 0;
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| }
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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.ptr;
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| 	unsigned char *dst = pvt->outbuf.uc + pvt->samples;
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| 
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| 	pvt->samples += x;
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| 	pvt->datalen += x;
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| 
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| 	while (x--)
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| 		*dst++ = mu2a[*src++];
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| 
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| 	return 0;
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| }
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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 = alaw_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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| 
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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 = ulaw_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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| 
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| /*! \brief standard module glue */
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| 
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| static int unload_module(void)
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| {
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| 	int res;
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| 
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| 	res = ast_unregister_translator(&ulawtoalaw);
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| 	res |= ast_unregister_translator(&alawtoulaw);
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| 
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| 	return res;
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| }
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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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| 
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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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| 
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| AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "A-law and Mulaw direct Coder/Decoder");
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