fixeria has submitted this change. ( https://gerrit.osmocom.org/c/libosmocore/+/33911 )
Change subject: gsm_08_08: define GSM0808_SCT_EXT (separately) ......................................................................
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 --- M include/osmocom/gsm/protocol/gsm_08_08.h M src/gsm/gsm0808.c M src/gsm/gsm0808_utils.c 3 files changed, 41 insertions(+), 3 deletions(-)
Approvals: Jenkins Builder: Verified osmith: Looks good to me, but someone else must approve pespin: Looks good to me, approved
diff --git a/include/osmocom/gsm/protocol/gsm_08_08.h b/include/osmocom/gsm/protocol/gsm_08_08.h index 967e4fe..1e211dc 100644 --- a/include/osmocom/gsm/protocol/gsm_08_08.h +++ b/include/osmocom/gsm/protocol/gsm_08_08.h @@ -557,6 +557,12 @@ GSM0808_SCT_CSD = 0xfd, /*!< CSData (see also TS 26.103) */ };
+/* Codec Extension (the real Codec Type follows in the next octet). + * This value is intentionally not included in gsm0808_speech_codec_type, + * because {enc,dec}_speech_codec() functions take care of the extended + * encoding internally. It shall not be used in struct gsm0808_speech_codec. */ +#define GSM0808_SCT_EXT 0x0f + extern const struct value_string gsm0808_speech_codec_type_names[]; static inline const char *gsm0808_speech_codec_type_name(enum gsm0808_speech_codec_type val) { return get_value_string(gsm0808_speech_codec_type_names, val); } diff --git a/src/gsm/gsm0808.c b/src/gsm/gsm0808.c index d115888..6ba6ef2 100644 --- a/src/gsm/gsm0808.c +++ b/src/gsm/gsm0808.c @@ -2478,6 +2478,7 @@ { GSM0808_SCT_HR3, "HR3" }, { GSM0808_SCT_HR4, "HR4" }, { GSM0808_SCT_HR6, "HR6" }, + { GSM0808_SCT_EXT, "Codec Extension" }, { GSM0808_SCT_CSD, "CSD" }, { 0, NULL } }; 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;
-
fixeria