In "special" mode we now establish a UDP RTCP channel in addition to the

TCP RTP channel and provide feedback on the latency of arriving packets from
the sink back to the source. This information is then used to throttle
video bitrate.

Change-Id: Ic589a3cb65e4893a3ff67de947da6063d32a1c6e

4 files changed, 50 insertions, 13 deletions

diff --git a/media/libstagefright/wifi-display/rtp/RTPReceiver.cpp b/media/libstagefright/wifi-display/rtp/RTPReceiver.cpp
index c55e0be..238fb82 100644
--- a/media/libstagefright/wifi-display/rtp/RTPReceiver.cpp
+++ b/media/libstagefright/wifi-display/rtp/RTPReceiver.cpp
@@ -567,8 +567,18 @@ status_t RTPReceiver::connect(
     return OK;
 }
 
-status_t RTPReceiver::notifyLateness(int64_t latenessUs) {
-    sp<ABuffer> buf = new ABuffer(20);
+status_t RTPReceiver::informSender(const sp<AMessage> &params) {
+    if (!mRTCPConnected) {
+        return INVALID_OPERATION;
+    }
+
+    int64_t avgLatencyUs;
+    CHECK(params->findInt64("avgLatencyUs", &avgLatencyUs));
+
+    int64_t maxLatencyUs;
+    CHECK(params->findInt64("maxLatencyUs", &maxLatencyUs));
+
+    sp<ABuffer> buf = new ABuffer(28);
 
     uint8_t *ptr = buf->data();
     ptr[0] = 0x80 | 0;
@@ -587,14 +597,23 @@ status_t RTPReceiver::notifyLateness(int64_t latenessUs) {
     ptr[10] = 't';
     ptr[11] = 'e';
 
-    ptr[12] = latenessUs >> 56;
-    ptr[13] = (latenessUs >> 48) & 0xff;
-    ptr[14] = (latenessUs >> 40) & 0xff;
-    ptr[15] = (latenessUs >> 32) & 0xff;
-    ptr[16] = (latenessUs >> 24) & 0xff;
-    ptr[17] = (latenessUs >> 16) & 0xff;
-    ptr[18] = (latenessUs >> 8) & 0xff;
-    ptr[19] = latenessUs & 0xff;
+    ptr[12] = avgLatencyUs >> 56;
+    ptr[13] = (avgLatencyUs >> 48) & 0xff;
+    ptr[14] = (avgLatencyUs >> 40) & 0xff;
+    ptr[15] = (avgLatencyUs >> 32) & 0xff;
+    ptr[16] = (avgLatencyUs >> 24) & 0xff;
+    ptr[17] = (avgLatencyUs >> 16) & 0xff;
+    ptr[18] = (avgLatencyUs >> 8) & 0xff;
+    ptr[19] = avgLatencyUs & 0xff;
+
+    ptr[20] = maxLatencyUs >> 56;
+    ptr[21] = (maxLatencyUs >> 48) & 0xff;
+    ptr[22] = (maxLatencyUs >> 40) & 0xff;
+    ptr[23] = (maxLatencyUs >> 32) & 0xff;
+    ptr[24] = (maxLatencyUs >> 24) & 0xff;
+    ptr[25] = (maxLatencyUs >> 16) & 0xff;
+    ptr[26] = (maxLatencyUs >> 8) & 0xff;
+    ptr[27] = maxLatencyUs & 0xff;
 
     mNetSession->sendRequest(mRTCPSessionID, buf->data(), buf->size());
 
diff --git a/media/libstagefright/wifi-display/rtp/RTPReceiver.h b/media/libstagefright/wifi-display/rtp/RTPReceiver.h
index abbe6a8..630bce9 100644
--- a/media/libstagefright/wifi-display/rtp/RTPReceiver.h
+++ b/media/libstagefright/wifi-display/rtp/RTPReceiver.h
@@ -56,7 +56,7 @@ struct RTPReceiver : public RTPBase, public AHandler {
             int32_t remoteRTPPort,
             int32_t remoteRTCPPort);
 
-    status_t notifyLateness(int64_t latenessUs);
+    status_t informSender(const sp<AMessage> &params);
 
 protected:
     virtual ~RTPReceiver();
diff --git a/media/libstagefright/wifi-display/rtp/RTPSender.cpp b/media/libstagefright/wifi-display/rtp/RTPSender.cpp
index c686e01..9eeeabd 100644
--- a/media/libstagefright/wifi-display/rtp/RTPSender.cpp
+++ b/media/libstagefright/wifi-display/rtp/RTPSender.cpp
@@ -91,8 +91,8 @@ status_t RTPSender::initAsync(
     CHECK_NE(rtpMode, TRANSPORT_TCP_INTERLEAVED);
     CHECK_NE(rtcpMode, TRANSPORT_TCP_INTERLEAVED);
 
-    if (rtcpMode == TRANSPORT_NONE && remoteRTCPPort >= 0
-            || rtcpMode != TRANSPORT_NONE && remoteRTCPPort < 0) {
+    if ((rtcpMode == TRANSPORT_NONE && remoteRTCPPort >= 0)
+            || (rtcpMode != TRANSPORT_NONE && remoteRTCPPort < 0)) {
         return INVALID_OPERATION;
     }
 
@@ -616,6 +616,7 @@ status_t RTPSender::onRTCPData(const sp<ABuffer> &buffer) {
                 break;
 
             case 204:  // APP
+                parseAPP(data, headerLength);
                 break;
 
             case 205:  // TSFB (transport layer specific feedback)
@@ -721,6 +722,21 @@ status_t RTPSender::parseTSFB(const uint8_t *data, size_t size) {
     return OK;
 }
 
+status_t RTPSender::parseAPP(const uint8_t *data, size_t size) {
+    if (!memcmp("late", &data[8], 4)) {
+        int64_t avgLatencyUs = (int64_t)U64_AT(&data[12]);
+        int64_t maxLatencyUs = (int64_t)U64_AT(&data[20]);
+
+        sp<AMessage> notify = mNotify->dup();
+        notify->setInt32("what", kWhatInformSender);
+        notify->setInt64("avgLatencyUs", avgLatencyUs);
+        notify->setInt64("maxLatencyUs", maxLatencyUs);
+        notify->post();
+    }
+
+    return OK;
+}
+
 void RTPSender::notifyInitDone(status_t err) {
     sp<AMessage> notify = mNotify->dup();
     notify->setInt32("what", kWhatInitDone);
diff --git a/media/libstagefright/wifi-display/rtp/RTPSender.h b/media/libstagefright/wifi-display/rtp/RTPSender.h
index 8409b8d..3a926ea 100644
--- a/media/libstagefright/wifi-display/rtp/RTPSender.h
+++ b/media/libstagefright/wifi-display/rtp/RTPSender.h
@@ -37,6 +37,7 @@ struct RTPSender : public RTPBase, public AHandler {
         kWhatInitDone,
         kWhatError,
         kWhatNetworkStall,
+        kWhatInformSender,
     };
     RTPSender(
             const sp<ANetworkSession> &netSession,
@@ -105,6 +106,7 @@ private:
     status_t onRTCPData(const sp<ABuffer> &data);
     status_t parseReceiverReport(const uint8_t *data, size_t size);
     status_t parseTSFB(const uint8_t *data, size_t size);
+    status_t parseAPP(const uint8_t *data, size_t size);
 
     void notifyInitDone(status_t err);
     void notifyError(status_t err);