gsm_08_08: define GSM0808_SCT_EXT (separately)
As per 3GPP TS 48.008, section 3.2.2.103, the "Codec Type" field may
contain either a certain 3GPP Speech Codec Type directly (4 bit value),
or the so called "Codec Extension" = 0xFh, in which case the real Codec
Type follows in the next octet as "Extended Codec Type".
CSD is such an example, the encoding is defined as follows:
8 7 6 5 4 3 2 1
+----+----+----+----+-------------------+
| -- | PI | PT | -- | 0xFh |
+----+----+----+----+-------------------+
| Extended Codec Type (CSData) |
+----+----+-----------------------------+
| R2 | R3 | |
+----+----+-----------------------------+
CSData is coded with 0xFDh or '1111 1101' (0xfd).
Let's have the "Codec Extension" value clearly defined in the header
file, but intentionally separate from the other GSM0808_SCT_* values.
Change-Id: Iafaa25070684d2ba400c75fa33e803651a5ce857
Related: OS#6110, OS#4393, OS#4394
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index b8e1ff0..778630d 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -255,7 +255,7 @@
header |= (1 << 4);
if (type_extended) {
- header |= 0x0f;
+ header |= GSM0808_SCT_EXT;
msgb_put_u8(msg, header);
msgb_put_u8(msg, sc->type);
} else {
@@ -347,7 +347,7 @@
/* An extended codec type needs at least two fields,
* bail if the input data length is not sufficient. */
- if ((header & 0x0F) == 0x0F && len < 2)
+ if ((header & 0x0F) == GSM0808_SCT_EXT && len < 2)
return -EINVAL;
elem++;
@@ -362,7 +362,7 @@
if (header & (1 << 4))
sc->tf = true;
- if ((header & 0x0F) != 0x0F) {
+ if ((header & 0x0F) != GSM0808_SCT_EXT) {
sc->type = (header & 0x0F);
} else {
sc->type = *elem;