[S] Change in gapk[master]: fmt_rtp_amr,fmt_rtp_efr: replace damaged packets with silence

[Matan Perelman]

Matan Perelman has uploaded this change for review. ( 
https://gerrit.osmocom.org/c/gapk/+/32094 )


Change subject: fmt_rtp_amr,fmt_rtp_efr: replace damaged packets with silence
......................................................................

fmt_rtp_amr,fmt_rtp_efr: replace damaged packets with silence

Change-Id: I7245aa0bc0955cc8b94d5401a15e694f50498093
---
M src/fmt_rtp_amr.c
M src/fmt_rtp_efr.c
2 files changed, 30 insertions(+), 0 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/gapk refs/changes/94/32094/1

diff --git a/src/fmt_rtp_amr.c b/src/fmt_rtp_amr.c
index a6a3c9f..02d74ca 100644
--- a/src/fmt_rtp_amr.c
+++ b/src/fmt_rtp_amr.c
@@ -27,6 +27,8 @@
 #include <osmocom/gapk/formats.h>
 #include <osmocom/gapk/utils.h>

+static const uint8_t SILENCE[] = {0x80, 0x44, 0x00, 0x00, 0x00, 0x00, 0x00};
+
 /* conversion function: RTP payload -> canonical format */
 static int
 rtp_amr_from_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len)
@@ -42,6 +44,12 @@
 static int
 rtp_amr_to_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len)
 {
+       /* Detect severely damaged frames according to RFC4867 4.3.2 */
+       if ((src[1] & 0x04) == 0) {
+               src = SILENCE;
+               src_len = sizeof(SILENCE);
+       }
+
        /* skip Payload Header according to RFC4867 4.4.1 */
        memcpy(dst, src+1, src_len-1);

diff --git a/src/fmt_rtp_efr.c b/src/fmt_rtp_efr.c
index 7afb1a3..34b8823 100644
--- a/src/fmt_rtp_efr.c
+++ b/src/fmt_rtp_efr.c
@@ -30,6 +30,15 @@
 #define EFR_LEN          31
 #define EFR_MAGIC 0xc

+static const uint8_t DAMAGED_PACKET[EFR_LEN] = {
+       0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
0x00, 0x00, 0x00,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
0x00, 0x00, 0x00, 0x00
+};
+static const uint8_t SILENCE[EFR_LEN] = {
+       0xcf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 
0xe0, 0x00, 0x00,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
0x00, 0x00, 0x00, 0x00
+};
+
 /* conversion function: RTP payload -> canonical format */
 static int
 rtp_efr_from_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len)
@@ -58,6 +67,10 @@
                return EFR_CANON_LEN;
        }

+       if (!memcmp(DAMAGED_PACKET, src, EFR_LEN)) {
+               src = SILENCE;
+       }
+
        for (i=0; i<(EFR_LEN-1); i++)
                dst[i] = (src[i] << 4) | (src[i+1] >> 4);
        dst[EFR_LEN-1] = src[EFR_LEN-1] << 4;

--
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Gerrit-Project: gapk
Gerrit-Branch: master
Gerrit-Change-Id: I7245aa0bc0955cc8b94d5401a15e694f50498093
Gerrit-Change-Number: 32094
Gerrit-PatchSet: 1
Gerrit-Owner: Matan Perelman <matan1...@gmail.com>
Gerrit-MessageType: newchange