fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/27430 )

Change subject: osmo-bts-trx: rx_tchh_fn(): fix HR SID detection (wrong offset) ......................................................................

osmo-bts-trx: rx_tchh_fn(): fix HR SID detection (wrong offset)

For some reason, gsm0503_tch_hr_decode() outputs frames with length of 15 bytes (120 bits), while according to TS 101 318, section 5.2 the GSM half rate codec has frame length of 14 bytes (112 bits).

osmo_hr_check_sid() follows TS 101 318 and expects a buffer of 14 bytes (112 bits), so we should skip the first octet prepended by tch_hr_reassemble().

Change-Id: Ie5fa776dcb2b2203a97aed56ecbf2450af7d87c1 Related: SYS#5853 --- M src/osmo-bts-trx/sched_lchan_tchh.c 1 file changed, 2 insertions(+), 1 deletion(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/30/27430/1

diff --git a/src/osmo-bts-trx/sched_lchan_tchh.c b/src/osmo-bts-trx/sched_lchan_tchh.c index 6252afd..afe68c4 100644 --- a/src/osmo-bts-trx/sched_lchan_tchh.c +++ b/src/osmo-bts-trx/sched_lchan_tchh.c @@ -147,8 +147,9 @@ */ rc = gsm0503_tch_hr_decode(tch_data, *bursts_p, fn_is_odd, &n_errors, &n_bits_total); + /* gsm0503_tch_hr_decode() prepends an additional 0x00 octet, skip it */ if (rc == (GSM_HR_BYTES + 1)) /* DTXu */ - lchan_set_marker(osmo_hr_check_sid(tch_data, rc), lchan); + lchan_set_marker(osmo_hr_check_sid(&tch_data[1], rc - 1), lchan); break; case GSM48_CMODE_SPEECH_AMR: /* AMR */ /* the first FN 0,8,17 or 1,9,18 defines that CMI is included