a-Law to Signed linear conversion
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a-Law to Signed linear conversion
- Author
- Mark Spencer marks.nosp@m.ter@.nosp@m.digiu.nosp@m.m.co.nosp@m.m
Definition in file alaw.c.
static short int alaw2linear |
( |
unsigned char |
alaw | ) |
|
|
inlinestatic |
Definition at line 114 of file alaw.c.
References AMI_MASK.
Referenced by ast_alaw_init().
120 i = ((alaw & 0x0F) << 4) + 8 ;
121 seg = (((int) alaw & 0x70) >> 4);
123 i = (i + 0x100) << (seg - 1);
125 return (
short int) ((alaw & 0x80) ? i : -i);
void ast_alaw_init |
( |
void |
| ) |
|
To init the alaw to slinear conversion stuff, this needs to be run.
Definition at line 154 of file alaw.c.
References alaw2linear(), AST_ALAW, AST_ALAW_STEP, AST_LIN2A, ast_log(), linear2alaw(), LOG_NOTICE, and LOG_WARNING.
Referenced by main().
160 #ifndef G711_NEW_ALGORITHM
161 for (i = 0; i < 256; i++) {
165 for (i = -32768; i < 32768; i++) {
169 for (i = 0; i < 256; i++) {
178 #ifdef TEST_CODING_TABLES
179 for (i = -32768; i < 32768; ++i) {
180 #ifndef G711_NEW_ALGORITHM
190 if (e1 != e2 || d1 != d3 || d2 != d3) {
191 ast_log(
LOG_WARNING,
"a-Law coding tables test failed on %d: e1=%u, e2=%u, d1=%d, d2=%d\n",
192 i, (
unsigned)e1, (
unsigned)e2, (
int)d1, (
int)d2);
198 #ifdef TEST_TANDEM_TRANSCODING
200 for (i = -32768; i < 32768; ++i) {
208 if (e1 != e2 || e2 != e3 || d1 != d2 || d2 != d3) {
209 ast_log(
LOG_WARNING,
"a-Law tandem transcoding test failed on %d: e1=%u, e2=%u, d1=%d, d2=%d, d3=%d\n",
210 i, (
unsigned)e1, (
unsigned)e2, (
int)d1, (
int)d2, (
int)d3);
unsigned char __ast_lin2a[8192]
converts signed linear to alaw
static short int alaw2linear(unsigned char alaw)
void ast_log(int level, const char *file, int line, const char *function, const char *fmt,...)
Used for sending a log message This is the standard logger function. Probably the only way you will i...
static unsigned char linear2alaw(short int linear)
static unsigned char linear2alaw |
( |
short int |
linear | ) |
|
|
inlinestatic |
Definition at line 40 of file alaw.c.
References AMI_MASK.
Referenced by ast_alaw_init().
45 static int seg_end[8] =
47 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF
61 for (seg = 0; seg < 8; seg++) {
62 if (pcm_val <= seg_end[seg]) {
67 return ((seg << 4) | ((pcm_val >> ((seg) ? (seg + 3) : 4)) & 0x0F)) ^ mask;
unsigned char __ast_lin2a[8192] |
converts signed linear to alaw
Definition at line 148 of file alaw.c.