tree f77820c3c5f8fb429b9c3db80317f1d37f1220fb
parent 547a65aae20f5e152084e7a05f9d2ec1c692ec1c
author Vadim Yanitskiy <vyanitskiy@sysmocom.de> 1690230188 +0700
committer Vadim Yanitskiy <vyanitskiy@sysmocom.de> 1690233792 +0700

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