00001 /* 00002 * Asterisk -- A telephony toolkit for Linux. 00003 * 00004 * u-Law to Signed linear conversion 00005 * 00006 * Copyright (C) 1999, Mark Spencer 00007 * 00008 * Mark Spencer <markster@linux-support.net> 00009 * 00010 * This program is free software, distributed under the terms of 00011 * the GNU General Public License 00012 */ 00013 00014 #ifndef _ASTERISK_ULAW_H 00015 #define _ASTERISK_ULAW_H 00016 00017 //! Init the ulaw conversion stuff 00018 /*! 00019 * To init the ulaw to slinear conversion stuff, this needs to be run. 00020 */ 00021 extern void ast_ulaw_init(void); 00022 00023 //! converts signed linear to mulaw 00024 /*! 00025 */ 00026 extern unsigned char __ast_lin2mu[16384]; 00027 00028 //! help 00029 extern short __ast_mulaw[256]; 00030 00031 #define AST_LIN2MU(a) (__ast_lin2mu[((unsigned short)(a)) >> 2]) 00032 #define AST_MULAW(a) (__ast_mulaw[(a)]) 00033 00034 #endif
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