Commit Graph

14 Commits

Author SHA1 Message Date
Harald Welte 5785a4a8fc codec: Add functions for AMR s->d bits and d->s bits
These functions implement re-ordering of bits as per TS 06.90 / 26.101
based on the already existing tables we've had in libosmocoding.

Change-Id: Ia4ac2aea2e96f9185f082a07ca64dfc5276efb46
2020-05-14 14:51:22 +02:00
Philipp Maier 3a5917bd50 gsm690: Fix amr speech bit length table
The table amr_len_by_ft represents the length of the raw AMR speech bits
in bytes. The table is based on the Table found in RFC 4867 §3.6, Table 1,
Column "Total speech bits". The number of bits is divided by 8 and then
rounded up to get the number of consumed octets.

An AMR SID frame (including STI and MI) takes up 39 bits, this will
result in 5 octets, not in 7. Lets correct this.

Related: OS#2978
Change-Id: Icf330450981b32be5d1cee5b10aa92bac4cb72f5
2020-03-13 10:52:22 +01:00
Philipp Maier ae140bc84a ecu_fr: increase test coverage for FR ECU implementation
The ECU implementation for FR is currently tested by calling the related
functions directly and by using the generic ECU abstraction layer. However,
the test "test_fr_concealment" only tests directly. Lets add a version
that uses the generic ECU abstraction layer as well.

The generic ECU abstraction layer obsolets the public API functions
osmo_ecu_fr_reset() and osmo_ecu_fr_conceal(), lets tag those functions
as dprecated.

Change-Id: Ib0c8a9b164f14ea4fa00688f760a76cdb4890af4
2019-09-20 11:21:46 +02:00
Harald Welte 750d8311f5 codec/ecu: Introduce new generic Error Concealment Unit abstraction
We don't want to expose the details of a given ECU implementation to
the user (e.g. osmo-bts), but have a generic abstraction layer where
an ECU implementation can simply register a few call-back functions
with the generic core.

As the developer and copyright holder of the related code, I hereby
state that any ECU implementation using 'struct osmo_ecu_ops' and
registering with the 'osmo_ecu_register()' function shall not be
considered as a derivative work under any applicable copyright law;
the copyleft terms of GPLv2 shall hence not apply to any such ECU
implementation.

The intent of the above exception is to allow anyone to combine
third party Error Concealment Unit implementations with libosmocore,
including but not limited to such published by ETSI.

Change-Id: I4d33c9c7c2d4c7462ff38a49c178b65accae1915
2019-09-02 09:13:50 +00:00
Pau Espin 421068e643 tests: codec: ecu_fr: Add buffer with unequal XMAXC values
This buffer verifies that all XMAXC fields must be zero before the
entire buffer is considered as silent by osmo_ecu_fr_conceal().

Change-Id: I14a192d001b5e167437cedbe76a1a3dd84dde35c
2018-07-21 07:40:20 +00:00
Pau Espin bbccca60d6 tests: codec: ecu_fr: Print XMAXC fields
This makes it easy to debug how XMAXC fields are decreased every
iteration in osmo_ecu_fr_conceal().

Change-Id: I678d4be5e0b15b05873b0d3bf5ea5bbee7bef839
2018-07-21 07:40:20 +00:00
Philipp Maier 40def49ac4 libosmocodec: implement ECU (Error Concealment Unit) for FR
When a bad GSM voice frame is received, it's being replaced
by a silence frame. This may cause unpleasant audio effects.

This change implements a functionality to craft a replacement
frame from the last known good frame. Currently, only FR is
supported, support for other codecs may be added latter.

Change-Id: I06a21f60db01bfe1c2b838f93866fad1d53fdcd1
2018-01-15 20:12:03 +00:00
Harald Welte e08da97570 Fix/Update copyright notices; Add SPDX annotation
Let's fix some erroneous/accidential references to wrong license,
update copyright information where applicable and introduce a
SPDX-License-Identifier to all files.

Change-Id: I39af26c6aaaf5c926966391f6565fc5936be21af
2017-11-13 01:35:12 +09:00
Jean-Francois Dionne 43058efa93 Fix wrongful GSM FR codec SID frame detection in DTX.
Based on ETSI TS 101 318 section 5.1.2 the 95 bits SID code word
is not detected correctly due to a wrongful offset in the bits
location indexes.

Change-Id: I45d98c6edf267f313883503a65385190ffbc65ca
2017-06-09 08:14:18 +00:00
Harald Welte 3851e8ea7a introduce proper test case for GSM FR detection
our code is actually wrong, so let's skip the test until the fix is
applied in a follow-up patch.

Change-Id: I710c7871f959671deb3d18ab9062588f3056fd7c
2017-06-09 08:10:03 +00:00
Jean-Francois Dionne d02c8af6cc DTX: fix AMR SID-FIRST detection
Max's note: adjusted test output.

Change-Id: I46477c631bf86345cb757f31d7f2e2935b12adcc
Related: OS#1801
2017-01-10 23:28:12 +00:00
Max e9e5f8e4e9 Add null-pointer check to osmo_amr_rtp_dec()
Check that RTP payload we're about to decode is not NULL and return
proper error code instead of segfaulting. Add corresponding test case.

Change-Id: Ib6cda9900a41ed16bbfbde9df3de9d38e0a7469b
2016-11-07 15:19:47 +01:00
Max ec8f192fec Add functions to detect HR/FR SID frames
Add functions which check if given FR or HR frame (packed in RTP)
contains SID (SIlence Descriptor) and corresponding tests.

Related: OS#22
Change-Id: I4051e3c0d4fb9ee93d7e9e0ef4abaf9f18e227ca
Reviewed-on: https://gerrit.osmocom.org/160
Tested-by: Jenkins Builder
Reviewed-by: Harald Welte <laforge@gnumonks.org>
2016-06-01 10:44:06 +00:00
Max 92db150488 Add helper functions for AMR codec
* add functions to encode/decode various codec paramters from RTP payload with
  AMR frame according to RFC 4867
* those functions are extended version based on code from osmo-bts'
  amr.c by Andreas Eversberg
* add corresponding enum types and strings for logging
* add regression tests

It's useful both to replace manual parsing in osmo-bts with fuctions
covered by test suite and as a debugging helpers for issues related to
AMR.

Change-Id: Ia217679a07d3fbc970f435e20f6eac33d34bd597
Related: OS#1562
Reviewed-on: https://gerrit.osmocom.org/118
Tested-by: Jenkins Builder
Reviewed-by: Holger Freyther <holger@freyther.de>
2016-05-31 10:11:51 +00:00