gsm0808: add function gsm0808_chan_type_to_speech_code()
The permitted speech field used in channel type element (struct
gsm0808_channel_type) uses a different representation as
the type field in the speech codec element (struct
gsm0808_speech_codec)
This patch adds a function to convert from permitted speech to
speech codec type.
Change-Id: Ib26a9c20864459b2baaa04f49b6e7902ba44b7cb
diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index c11bf8d..b510644 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -71,3 +71,5 @@
/* Decode Cell Identifier List element */
int gsm0808_dec_cell_id_list(struct gsm0808_cell_id_list *cil,
const uint8_t *elem, uint8_t len);
+
+int gsm0808_chan_type_to_speech_code(uint8_t perm_spch);
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index 60fb91c..64ffec4 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -645,4 +645,41 @@
return (int)(elem - old_elem);
}
+/*! \brief Convert the representation of the permitted speech codec identifier
+ * that is used in struct gsm0808_channel_type to the speech codec
+ * representation we use in struct gsm0808_speech_codec.
+ * \param[in] perm_spch to be converted (see also gsm0808_permitted_speech)
+ * \returns GSM speech codec type; negative on error */
+int gsm0808_chan_type_to_speech_codec(uint8_t perm_spch)
+{
+ /*! The speech codec type, which is used in the channel type field to
+ * signal the permitted speech versions (codecs) has a different
+ * encoding than the type field in the speech codec type element
+ * (See also 3GPP TS 48.008, 3.2.2.11 and 3.2.2.103) */
+
+ switch (perm_spch) {
+ case GSM0808_PERM_FR1:
+ return GSM0808_SCT_FR1;
+ case GSM0808_PERM_FR2:
+ return GSM0808_SCT_FR2;
+ case GSM0808_PERM_FR3:
+ return GSM0808_SCT_FR3;
+ case GSM0808_PERM_FR4:
+ return GSM0808_SCT_FR4;
+ case GSM0808_PERM_FR5:
+ return GSM0808_SCT_FR5;
+ case GSM0808_PERM_HR1:
+ return GSM0808_SCT_HR1;
+ case GSM0808_PERM_HR3:
+ return GSM0808_SCT_HR3;
+ case GSM0808_PERM_HR4:
+ return GSM0808_SCT_HR4;
+ case GSM0808_PERM_HR6:
+ return GSM0808_SCT_HR6;
+ }
+
+ /* Invalid input */
+ return -EINVAL;
+}
+
/*! @} */
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 9613c4e..ccc5b9a 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -162,6 +162,7 @@
gsm0808_dec_encrypt_info;
gsm0808_enc_cell_id_list;
gsm0808_dec_cell_id_list;
+gsm0808_convert_to_speech_codec_type;
gsm0858_rsl_ul_meas_enc;