Reduce the frequency of IDR frames and add intra-fresh mode support for WiFi display

The time interval between periodic neighboring IDR frames is increased from 1 second to 15 seconds.

o related-to-bug: 7524791

Change-Id: Ic32f37448f952f329549eda5e73637ee3b02f046

1 files changed, 18 insertions, 1 deletions

diff --git a/media/libstagefright/wifi-display/source/Converter.cpp b/media/libstagefright/wifi-display/source/Converter.cpp
index 82c98b9..7a87444 100644
--- a/media/libstagefright/wifi-display/source/Converter.cpp
+++ b/media/libstagefright/wifi-display/source/Converter.cpp
@@ -161,7 +161,24 @@ status_t Converter::initEncoder() {
         mOutputFormat->setInt32("bitrate", videoBitrate);
         mOutputFormat->setInt32("bitrate-mode", OMX_Video_ControlRateConstant);
         mOutputFormat->setInt32("frame-rate", 30);
-        mOutputFormat->setInt32("i-frame-interval", 1);  // Iframes every 1 secs
+        mOutputFormat->setInt32("i-frame-interval", 15);  // Iframes every 15 secs
+
+        // Configure encoder to use intra macroblock refresh mode
+        mOutputFormat->setInt32("intra-refresh-mode", OMX_VIDEO_IntraRefreshCyclic);
+
+        int width, height, mbs;
+        if (!mOutputFormat->findInt32("width", &width)
+                || !mOutputFormat->findInt32("height", &height)) {
+            return ERROR_UNSUPPORTED;
+        }
+
+        // Update macroblocks in a cyclic fashion with 10% of all MBs within
+        // frame gets updated at one time. It takes about 10 frames to
+        // completely update a whole video frame. If the frame rate is 30,
+        // it takes about 333 ms in the best case (if next frame is not an IDR)
+        // to recover from a lost/corrupted packet.
+        mbs = (((width + 15) / 16) * ((height + 15) / 16) * 10) / 100;
+        mOutputFormat->setInt32("intra-refresh-CIR-mbs", mbs);
     }
 
     ALOGV("output format is '%s'", mOutputFormat->debugString(0).c_str());