rtp: Add handling of BFI (Bad Frame Indicatior) of received TRAU frames
If a bad TRAU frame is received, it is forwarded to MNCC application
as GSM_BAD_FRAME. The application can now handle the GAP of missing
audio. (e.g. by extrapolation)
If TRAU frames are forwarded via RTP, bad frames are dropped, but frame
counter and timestamp of RTP sender state is incremented.
Conflicts:
openbsc/src/libtrau/rtp_proxy.c
[hfreyther: Merge without testcase, fix typo]
diff --git a/openbsc/src/libtrau/rtp_proxy.c b/openbsc/src/libtrau/rtp_proxy.c
index 52616a0..82f4063 100644
--- a/openbsc/src/libtrau/rtp_proxy.c
+++ b/openbsc/src/libtrau/rtp_proxy.c
@@ -206,6 +206,7 @@
int payload_type;
int payload_len;
int duration; /* in samples */
+ int is_bfi = 0;
if (rs->tx_action != RTP_SEND_DOWNSTREAM) {
/* initialize sequences */
@@ -236,6 +237,12 @@
payload_len = frame->data[0];
duration = RTP_GSM_DURATION;
break;
+ case GSM_BAD_FRAME:
+ payload_type = 0;
+ payload_len = 0;
+ duration = RTP_GSM_DURATION;
+ is_bfi = 1;
+ break;
default:
DEBUGPC(DLMUX, "unsupported message type %d\n",
frame->msg_type);
@@ -248,6 +255,13 @@
return -EINVAL;
}
+ if (is_bfi) {
+ /* In case of a bad frame, just count and drop packet. */
+ rs->transmit.timestamp += duration;
+ rs->transmit.sequence++;
+ return 0;
+ }
+
msg = msgb_alloc(sizeof(struct rtp_hdr) + payload_len, "RTP-GSM");
if (!msg)
return -ENOMEM;
diff --git a/openbsc/src/libtrau/trau_mux.c b/openbsc/src/libtrau/trau_mux.c
index 3831a80..b37c765 100644
--- a/openbsc/src/libtrau/trau_mux.c
+++ b/openbsc/src/libtrau/trau_mux.c
@@ -245,7 +245,10 @@
i++;
j++;
}
- frame->msg_type = GSM_TCHF_FRAME;
+ if (tf->c_bits[11]) /* BFI */
+ frame->msg_type = GSM_BAD_FRAME;
+ else
+ frame->msg_type = GSM_TCHF_FRAME;
frame->callref = callref;
msgb_put(msg, sizeof(struct gsm_data_frame) + 33);