coding: separate gsm0503_tch_a[fh]s_decode_inband()
These functions can be re-used for parsing in-band data from DTX
specific frames like SID_FIRST, SID_UPDATE, SID_ONSET, etc.
Change-Id: I0106de7a7f87517006e323299b2dc08457d1c6cf
Related: OS#5570
diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c
index 168e120..6f33b78 100644
--- a/src/coding/gsm0503_coding.c
+++ b/src/coding/gsm0503_coding.c
@@ -2115,6 +2115,26 @@
return 0;
}
+/* TCH/AFS: parse codec ID (CMI or CMC/CMR) from coded in-band data (16 bit) */
+static uint8_t gsm0503_tch_afs_decode_inband(const sbit_t *cB)
+{
+ unsigned int id = 0, best = 0;
+ unsigned int i, j, k;
+
+ for (i = 0; i < 4; i++) {
+ /* FIXME: why not using remaining (16 - 8) soft-bits here? */
+ for (j = 0, k = 0; j < 8; j++)
+ k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - ((int)cB[j]));
+
+ if (i == 0 || k < best) {
+ best = k;
+ id = i;
+ }
+ }
+
+ return id;
+}
+
/*! Perform channel decoding of a TCH/AFS channel according TS 05.03
* \param[out] tch_data Codec frame in RTP payload format
* \param[in] bursts buffer containing the symbols of 8 bursts
@@ -2157,7 +2177,7 @@
{
sbit_t iB[912], cB[456], h;
ubit_t d[244], p[6], conv[250];
- int i, j, k, best = 0, rv, len, steal = 0, id = -1;
+ int i, rv, len, steal = 0, id = -1;
*n_errors = 0; *n_bits_total = 0;
static ubit_t sid_first_dummy[64] = { 0 };
sbit_t sid_update_enc[256];
@@ -2236,18 +2256,8 @@
}
}
- for (i = 0; i < 4; i++) {
- for (j = 0, k = 0; j < 8; j++)
- k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - ((int)cB[j]));
-
- if (i == 0 || k < best) {
- best = k;
- id = i;
- }
- }
-
- /* Check if indicated codec fits into range of codecs */
- if (id >= codecs) {
+ /* Parse codec ID (CMI or CMC/CMR) and check if it fits into range of codecs */
+ if ((id = gsm0503_tch_afs_decode_inband(&cB[0])) >= codecs) {
/* Codec mode out of range, return id */
return id;
}
@@ -2578,6 +2588,26 @@
return -1;
}
+/* TCH/AHS: parse codec ID (CMI or CMC/CMR) from coded in-band data (16 bit) */
+static uint8_t gsm0503_tch_ahs_decode_inband(const sbit_t *cB)
+{
+ unsigned int id = 0, best = 0;
+ unsigned int i, j, k;
+
+ for (i = 0, k = 0; i < 4; i++) {
+ /* FIXME: why not using remaining (16 - 4) soft-bits here? */
+ for (j = 0, k = 0; j < 4; j++)
+ k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - ((int)cB[j]));
+
+ if (i == 0 || k < best) {
+ best = k;
+ id = i;
+ }
+ }
+
+ return id;
+}
+
/*! Perform channel decoding of a TCH/AFS channel according TS 05.03
* \param[out] tch_data Codec frame in RTP payload format
* \param[in] bursts buffer containing the symbols of 8 bursts
@@ -2622,7 +2652,7 @@
{
sbit_t iB[912], cB[456], h;
ubit_t d[244], p[6], conv[135];
- int i, j, k, best = 0, rv, len, steal = 0, id = -1;
+ int i, rv, len, steal = 0, id = -1;
static ubit_t sid_first_dummy[64] = { 0 };
/* only unmap the stealing bits */
@@ -2738,18 +2768,8 @@
}
}
- for (i = 0; i < 4; i++) {
- for (j = 0, k = 0; j < 4; j++)
- k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - ((int)cB[j]));
-
- if (i == 0 || k < best) {
- best = k;
- id = i;
- }
- }
-
- /* Check if indicated codec fits into range of codecs */
- if (id >= codecs) {
+ /* Parse codec ID (CMI or CMC/CMR) and check if it fits into range of codecs */
+ if ((id = gsm0503_tch_ahs_decode_inband(&cB[0])) >= codecs) {
/* Codec mode out of range, return id */
return id;
}