Cap pts gap between adjacent frames to specified value

- In the scenario of cast mirroring, encoding could be suspended
  for prolonged periods. Limiting the pts gap to workaround the
  problem where encoder's rate control logic produces huge frames
  after a long period of suspension.

- Repeat last frame a couple more times to get better quality
  on static scenes.

- Fix the timestamp on repeat frames (it was not set)

Bug: 11971963
Change-Id: I1d68ab3d269874bf3921aa429a985c5f63e428c7
diff --git a/include/media/IOMX.h b/include/media/IOMX.h
index 9c8451c..6643736 100644
--- a/include/media/IOMX.h
+++ b/include/media/IOMX.h
@@ -142,6 +142,7 @@
     enum InternalOptionType {
         INTERNAL_OPTION_SUSPEND,  // data is a bool
         INTERNAL_OPTION_REPEAT_PREVIOUS_FRAME_DELAY,  // data is an int64_t
+        INTERNAL_OPTION_MAX_TIMESTAMP_GAP, // data is int64_t
     };
     virtual status_t setInternalOption(
             node_id node,
diff --git a/include/media/stagefright/ACodec.h b/include/media/stagefright/ACodec.h
index f1636e6..bc391fc 100644
--- a/include/media/stagefright/ACodec.h
+++ b/include/media/stagefright/ACodec.h
@@ -202,6 +202,7 @@
     int32_t mMetaDataBuffersToSubmit;
 
     int64_t mRepeatFrameDelayUs;
+    int64_t mMaxPtsGapUs;
 
     status_t setCyclicIntraMacroblockRefresh(const sp<AMessage> &msg, int32_t mode);
     status_t allocateBuffersOnPort(OMX_U32 portIndex);