According to the BAP spec, the level 3 of the BASE contains codec
configuration LTVs specific to each BIS, in addition to the
configuration provided at level 2 (subgroup level) (v1.0.1,
section 3.7.2.2 Basic Audio Announcements).
Currently, when a Broadcast Sink parses the BASE discovered from a
Broadcast Source, level 3 LTV types that are not also present at
level 2 are not included in the final BIS cofiguration, causing
incorrect stream handling. This updates the BASE parsing logic to
consider level 3 LTVs.
---
src/shared/bap.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/src/shared/bap.c b/src/shared/bap.c
index 167501282..6ffeefa41 100644
--- a/src/shared/bap.c
+++ b/src/shared/bap.c
@@ -4,7 +4,7 @@
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2022 Intel Corporation. All rights reserved.
- * Copyright 2023-2024 NXP
+ * Copyright 2023-2025 NXP
*
*/
@@ -6921,6 +6921,24 @@ static void bap_sink_check_level2_ltv(size_t i, uint8_t l, uint8_t t,
util_ltv_push(merge_data->result, l, t, v);
}
+static void bap_sink_append_level3_ltv(size_t i, uint8_t l, uint8_t t,
+ uint8_t *v, void *user_data)
+{
+ struct bt_ltv_extract *merge_data = user_data;
+
+ merge_data->value = NULL;
+ util_ltv_foreach(merge_data->result->iov_base,
+ merge_data->result->iov_len,
+ &t,
+ bap_sink_check_level3_ltv, merge_data);
+
+ /* If the LTV at level 3 was not found in merged configuration,
+ * append value
+ */
+ if (!merge_data->value)
+ util_ltv_push(merge_data->result, l, t, v);
+}
+
static void check_local_pac(void *data, void *user_data)
{
struct bt_ltv_match *compare_data = user_data;
@@ -7028,6 +7046,14 @@ struct iovec *bt_bap_merge_caps(struct iovec *l2_caps, struct iovec *l3_caps)
NULL,
bap_sink_check_level2_ltv, &merge_data);
+ /* Append LTVs at level 3 (BIS) that were not found at
+ * level 2 (subgroup)
+ */
+ util_ltv_foreach(l3_caps->iov_base,
+ l3_caps->iov_len,
+ NULL,
+ bap_sink_append_level3_ltv, &merge_data);
+
return merge_data.result;
}
--
2.43.0
