PLI: handle picture loss rtcp packet

src/include/com/amazonaws/kinesis/video/webrtcclient/Include.h

@@ -621,6 +621,17 @@ typedef VOID (*RtcOnFrame)(UINT64, PFrame);
  */
 typedef VOID (*RtcOnBandwidthEstimation)(UINT64, DOUBLE);
 
+/**
+ * @brief RtcOnPictureLoss is fired everytime a Picture Loss Indication (PLI)
+ * feedback message is received. Receiving such message normally indicates that
+ * you sent a video frame which receiver could not decode.
+ * It may happen either because of packet loss or for any other reason.
+ * Generating an intra frame (aka keyframe, aka I-frame) in response to such message is considered a good strategy.
+ *
+ * See https://tools.ietf.org/html/rfc4585#section-6.3 for more details
+ */
+typedef VOID (*RtcOnPictureLoss)(UINT64);
+
 
 /**
  * @brief RtcOnMessage is fired when a message is received for the DataChannel

src/source/PeerConnection/Rtcp.c

@@ -20,8 +20,13 @@ STATUS onRtcpPacket(PKvsPeerConnection pKvsPeerConnection, PBYTE pBuff, UINT32 b
                    isRembPacket(rtcpPacket.payload, rtcpPacket.payloadLength) == STATUS_SUCCESS)
         {
             CHK_STATUS(onRtcpRembPacket(&rtcpPacket, pKvsPeerConnection));
+        } else if (rtcpPacket.header.packetType == RTCP_PACKET_TYPE_PAYLOAD_SPECIFIC_FEEDBACK &&
+                   rtcpPacket.header.receptionReportCount == RTCP_PSFB_PLI)
+        {
+            CHK_STATUS(onRtcpPLIPacket(&rtcpPacket, pKvsPeerConnection));
         }
 
+
         currentOffset += (rtcpPacket.payloadLength + RTCP_PACKET_HEADER_LEN);
     }
 
@@ -70,3 +75,37 @@ STATUS onRtcpRembPacket(PRtcpPacket pRtcpPacket, PKvsPeerConnection pKvsPeerConn
 
     return retStatus;
 }
+
+STATUS onRtcpPLIPacket(PRtcpPacket pRtcpPacket, PKvsPeerConnection pKvsPeerConnection)
+{
+    STATUS retStatus = STATUS_SUCCESS;
+    UINT32 mediaSSRC = 0;
+    PDoubleListNode pCurNode = NULL;
+    PKvsRtpTransceiver pTransceiver = NULL;
+    UINT64 item;
+
+    CHK(pKvsPeerConnection != NULL && pRtcpPacket != NULL, STATUS_NULL_ARG);
+    mediaSSRC = getInt32(*(PUINT32) (pRtcpPacket->payload + (SIZEOF(UINT32))));
+
+    CHK_STATUS(doubleListGetHeadNode(pKvsPeerConnection->pTransceievers, &pCurNode));
+    while(pCurNode != NULL && pTransceiver == NULL) {
+        CHK_STATUS(doubleListGetNodeData(pCurNode, &item));
+        CHK(item != 0, STATUS_INTERNAL_ERROR);
+
+        pTransceiver = (PKvsRtpTransceiver) item;
+        if (pTransceiver->sender.ssrc != mediaSSRC && pTransceiver->sender.rtxSsrc != mediaSSRC) {
+            pTransceiver = NULL;
+        }
+
+        pCurNode = pCurNode->pNext;
+    }
+
+    CHK_ERR(pTransceiver != NULL, STATUS_RTCP_INPUT_SSRC_INVALID, "Received PLI for non existing ssrcs: ssrc %lu", mediaSSRC);
+    if (pTransceiver->onPictureLoss != NULL) {
+        pTransceiver->onPictureLoss(pTransceiver->onPictureLossCustomData);
+    }
+
+CleanUp:
+
+    return retStatus;
+}

src/source/PeerConnection/Rtcp.h

@@ -9,6 +9,7 @@ extern "C" {
 
 STATUS onRtcpPacket(PKvsPeerConnection, PBYTE, UINT32);
 STATUS onRtcpRembPacket(PRtcpPacket, PKvsPeerConnection);
+STATUS onRtcpPLIPacket(PRtcpPacket, PKvsPeerConnection);
 
 #ifdef  __cplusplus
 }

src/source/PeerConnection/Rtp.h

@@ -42,6 +42,8 @@ typedef struct {
 
     UINT64 onBandwidthEstimationCustomData;
     RtcOnBandwidthEstimation onBandwidthEstimation;
+    UINT64 onPictureLossCustomData;
+    RtcOnPictureLoss onPictureLoss;
 
     PBYTE peerFrameBuffer;
     UINT32 peerFrameBufferSize;

src/source/Rtcp/RtcpPacket.h

@@ -35,6 +35,7 @@ typedef enum {
 
 typedef enum {
     RTCP_FEEDBACK_MESSAGE_TYPE_NACK = 1,
+    RTCP_PSFB_PLI = 1, //https://tools.ietf.org/html/rfc4585#section-6.3
     RTCP_FEEDBACK_MESSAGE_TYPE_APPLICATION_LAYER_FEEDBACK = 15,
 } RTCP_FEEDBACK_MESSAGE_TYPE;
 

tst/RtcpFunctionalityTest.cpp

@@ -175,6 +175,30 @@ TEST_F(RtcpFunctionalityTest, rembValueGet) {
     EXPECT_EQ(STATUS_RTCP_INPUT_REMB_INVALID, rembValueGet(invalidSSRCLength, SIZEOF(invalidSSRCLength), &maximumBitRate, ssrcList, &ssrcListLen));
 }
 
+static void on_PLI_callback(UINT64 opaque) {
+    *(PBOOL) opaque = TRUE;
+}
+
+TEST_F(RtcpFunctionalityTest, onpli) {
+    initializeEndianness();
+    BYTE rawRtcpPacket[] = {0x81, 0xCE, 0x00, 0x02, 0x00, 0x00, 0x00, 0x01, 0x1D, 0xC8, 0x69, 0x91};
+    RtcpPacket rtcpPacket = {0};
+    EXPECT_EQ(STATUS_SUCCESS, setRtcpPacketFromBytes(rawRtcpPacket, SIZEOF(rawRtcpPacket), &rtcpPacket));
+    ASSERT_TRUE(rtcpPacket.header.packetType == RTCP_PACKET_TYPE_PAYLOAD_SPECIFIC_FEEDBACK &&
+                rtcpPacket.header.receptionReportCount == RTCP_PSFB_PLI);
+    KvsPeerConnection kpc = {0};
+    doubleListCreate(&kpc.pTransceievers);
+    KvsRtpTransceiver kvsRtpTransceiver;
+    MEMSET(&kvsRtpTransceiver, 0, sizeof(KvsRtpTransceiver));
+    kvsRtpTransceiver.sender.ssrc =  0x1DC86991;
+    BOOL on_picture_loss_called = FALSE;
+    kvsRtpTransceiver.onPictureLossCustomData = (UINT64) &on_picture_loss_called;
+    kvsRtpTransceiver.onPictureLoss = on_PLI_callback;
+    doubleListInsertItemHead(kpc.pTransceievers, (UINT64) &kvsRtpTransceiver);
+    onRtcpPLIPacket(&rtcpPacket, &kpc);
+    ASSERT_TRUE(on_picture_loss_called);
+}
+
 }
 }
 }