This graph shows which files directly or indirectly include this file:
Go to the source code of this file.
Defines | |
#define | AST_LIN2MU(a) (__ast_lin2mu[((unsigned short)(a)) >> 2]) |
#define | AST_MULAW(a) (__ast_mulaw[(a)]) |
Functions | |
void | ast_ulaw_init (void) |
Set up mu-law conversion table. | |
Variables | |
unsigned char | __ast_lin2mu [16384] |
short | __ast_mulaw [256] |
Definition in file ulaw.h.
#define AST_LIN2MU | ( | a | ) | (__ast_lin2mu[((unsigned short)(a)) >> 2]) |
Definition at line 40 of file ulaw.h.
Referenced by fill_rxgain(), fill_txgain(), i4l_write(), lintoulaw_framein(), load_module(), and make_tone_burst().
#define AST_MULAW | ( | a | ) | (__ast_mulaw[(a)]) |
Definition at line 41 of file ulaw.h.
Referenced by ast_dsp_process(), fill_rxgain(), fill_txgain(), i4l_read(), load_module(), tdd_feed(), and ulawtolin_framein().
void ast_ulaw_init | ( | void | ) |
Set up mu-law conversion table.
To init the ulaw to slinear conversion stuff, this needs to be run.
Definition at line 84 of file ulaw.c.
References linear2ulaw().
Referenced by main().
00085 { 00086 int i; 00087 for(i = 0;i < 256;i++) { 00088 short mu,e,f,y; 00089 static short etab[]={0,132,396,924,1980,4092,8316,16764}; 00090 00091 mu = 255-i; 00092 e = (mu & 0x70)/16; 00093 f = mu & 0x0f; 00094 y = f * (1 << (e + 3)); 00095 y += etab[e]; 00096 if (mu & 0x80) y = -y; 00097 __ast_mulaw[i] = y; 00098 } 00099 /* set up the reverse (mu-law) conversion table */ 00100 for(i = -32768; i < 32768; i++) { 00101 __ast_lin2mu[((unsigned short)i) >> 2] = linear2ulaw(i); 00102 } 00103 00104 }
unsigned char __ast_lin2mu[16384] |
short __ast_mulaw[256] |