falconia has uploaded this change for review. (
https://gerrit.osmocom.org/c/libosmocore/+/32767 )
Change subject: coding: fix decoding of EFR triplicated bits
......................................................................
coding: fix decoding of EFR triplicated bits
In GSM 05.03 channel coding for EFR, there are 4 bits out of the
244-bit EFR codec frame that are triplicated before FR-like encoding,
and the decoder needs to apply a 2-out-of-3 majority voting function
to each of these triplicated bits after the FR-like decoding step.
For one of those 4 bits, this majority voting function was wrong
in the decoder implemented in gsm0503_tch_fr_decode() - fix it.
Change-Id: I47def75cdb066ed6372df4567404cc828589ed53
---
M src/coding/gsm0503_coding.c
1 file changed, 17 insertions(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/67/32767/1
diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c
index 07c8c98..1ef6393 100644
--- a/src/coding/gsm0503_coding.c
+++ b/src/coding/gsm0503_coding.c
@@ -1804,7 +1804,7 @@
s[119] = (sum >= 2);
memcpy(s + 121, w + 125, 53);
sum = s[172] + w[178] + w[179];
- s[172] = (sum > 2);
+ s[172] = (sum >= 2);
memcpy(s + 174, w + 180, 50);
sum = s[222] + w[230] + w[231];
s[222] = (sum >= 2);
--
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Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Change-Id: I47def75cdb066ed6372df4567404cc828589ed53
Gerrit-Change-Number: 32767
Gerrit-PatchSet: 1
Gerrit-Owner: falconia <falcon(a)freecalypso.org>
Gerrit-MessageType: newchange