commit d5523ea59a7c6e85b8ba28f6d92430a64a240e32
author Lajos Molnar <lajos@google.com> Fri Jul 13 14:10:21 2018 -0700
committer Lajos Molnar <lajos@google.com> Fri Jul 13 14:12:52 2018 -0700
tree 770d0d89aa8b7522285866e7af7b380bf56daf30
parent b50a84b3e1626527b0fb904f8e94038ef94b53db

media sync: forcefully limit correction by VideoFrameScheduler.

Don't allow video frame scheduler to correct by more than twice the
correction limit. If this happens, restart the scheduler.

Bug: 79400257
Change-Id: I9c30ee0acf3bbb8ef89ce31672fe5f8055c85e2e

media/libstagefright/VideoFrameScheduler.cpp

diff --git a/media/libstagefright/VideoFrameScheduler.cpp b/media/libstagefright/VideoFrameScheduler.cpp
index 6819bba..9020fc1 100644
--- a/media/libstagefright/VideoFrameScheduler.cpp
+++ b/media/libstagefright/VideoFrameScheduler.cpp
@@ -475,7 +475,16 @@
                 nextVsyncTime += mVsyncPeriod;
                 if (vsyncsForLastFrame < ULONG_MAX)
                     ++vsyncsForLastFrame;
+            } else if (mTimeCorrection < -correctionLimit * 2
+                    || mTimeCorrection > correctionLimit * 2) {
+                ALOGW("correction beyond limit: %lld vs %lld (vsyncs for last frame: %zu, min: %zu)"
+                        " restarting. render=%lld",
+                        (long long)mTimeCorrection, (long long)correctionLimit,
+                        vsyncsForLastFrame, minVsyncsPerFrame, (long long)origRenderTime);
+                restart();
+                return origRenderTime;
             }
+
             ATRACE_INT("FRAME_VSYNCS", vsyncsForLastFrame);
         }
         mLastVsyncTime = nextVsyncTime;