Allows the authoring engine to skip frame.

This is 1st part of the work to allow audio and video resync if
we found out that audio and video are out of sync during authoring

- also fixed a problem in AACEncoder::read() where the buffer acquired
  from the buffer group does not release when error out at
  reading from source.

Change-Id: I8a2740097fcfdf85e6178869afeb9f3687a99118

1 files changed, 36 insertions, 15 deletions

diff --git a/media/libstagefright/CameraSource.cpp b/media/libstagefright/CameraSource.cpp
index 4cc176a..9c48daf 100644
--- a/media/libstagefright/CameraSource.cpp
+++ b/media/libstagefright/CameraSource.cpp
@@ -277,23 +277,44 @@ status_t CameraSource::read(
 
     {
         Mutex::Autolock autoLock(mLock);
-        while (mStarted && mFramesReceived.empty()) {
-            mFrameAvailableCondition.wait(mLock);
-        }
-        if (!mStarted) {
-            return OK;
-        }
-        frame = *mFramesReceived.begin();
-        mFramesReceived.erase(mFramesReceived.begin());
+        while (mStarted) {
+            while(mFramesReceived.empty()) {
+                mFrameAvailableCondition.wait(mLock);
+            }
+
+            if (!mStarted) {
+                return OK;
+            }
 
-        frameTime = *mFrameTimes.begin();
-        mFrameTimes.erase(mFrameTimes.begin());
+            frame = *mFramesReceived.begin();
+            mFramesReceived.erase(mFramesReceived.begin());
 
-        mFramesBeingEncoded.push_back(frame);
-        *buffer = new MediaBuffer(frame->pointer(), frame->size());
-        (*buffer)->setObserver(this);
-        (*buffer)->add_ref();
-        (*buffer)->meta_data()->setInt64(kKeyTime, frameTime);
+            frameTime = *mFrameTimes.begin();
+            mFrameTimes.erase(mFrameTimes.begin());
+            int64_t skipTimeUs;
+            if (!options || !options->getSkipFrame(&skipTimeUs)) {
+                skipTimeUs = frameTime;
+            }
+            if (skipTimeUs > frameTime) {
+                LOGV("skipTimeUs: %lld us > frameTime: %lld us",
+                    skipTimeUs, frameTime);
+                releaseOneRecordingFrame(frame);
+                ++mNumFramesDropped;
+                // Safeguard against the abuse of the kSkipFrame_Option.
+                if (skipTimeUs - frameTime >= 1E6) {
+                    LOGE("Frame skipping requested is way too long: %lld us",
+                        skipTimeUs - frameTime);
+                    return UNKNOWN_ERROR;
+                }
+            } else {
+                mFramesBeingEncoded.push_back(frame);
+                *buffer = new MediaBuffer(frame->pointer(), frame->size());
+                (*buffer)->setObserver(this);
+                (*buffer)->add_ref();
+                (*buffer)->meta_data()->setInt64(kKeyTime, frameTime);
+                return OK;
+            }
+        }
     }
     return OK;
 }