Merge "Fix track duration calculation if the start timestamp is non-zero" into gingerbread
diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index ba1e218..e6c2f7e 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -1541,20 +1541,52 @@
int32_t isSync = false;
meta_data->findInt32(kKeyIsSyncFrame, &isSync);
+ /*
+ * The original timestamp found in the data buffer will be modified as below:
+ *
+ * There is a playback offset into this track if the track's start time
+ * is not the same as the movie start time, which will be recorded in edst
+ * box of the output file. The playback offset is to make sure that the
+ * starting time of the audio/video tracks are synchronized. Although the
+ * track's media timestamp may be subject to various modifications
+ * as outlined below, the track's playback offset time remains unchanged
+ * once the first data buffer of the track is received.
+ *
+ * The media time stamp will be calculated by subtracting the playback offset
+ * (and potential pause durations) from the original timestamp in the buffer.
+ *
+ * If this track is a video track for a real-time recording application with
+ * both audio and video tracks, its media timestamp will subject to further
+ * modification based on the media clock of the audio track. This modification
+ * is needed for the purpose of maintaining good audio/video synchronization.
+ *
+ * If the recording session is paused and resumed multiple times, the track
+ * media timestamp will be modified as if the recording session had never been
+ * paused at all during playback of the recorded output file. In other words,
+ * the output file will have no memory of pause/resume durations.
+ *
+ */
CHECK(meta_data->findInt64(kKeyTime, ×tampUs));
+ LOGV("%s timestampUs: %lld", mIsAudio? "Audio": "Video", timestampUs);
////////////////////////////////////////////////////////////////////////////////
if (mSampleSizes.empty()) {
mStartTimestampUs = timestampUs;
mOwner->setStartTimestampUs(mStartTimestampUs);
+ previousPausedDurationUs = mStartTimestampUs;
}
if (mResumed) {
- previousPausedDurationUs += (timestampUs - mTrackDurationUs - lastDurationUs);
+ int64_t durExcludingEarlierPausesUs = timestampUs - previousPausedDurationUs;
+ CHECK(durExcludingEarlierPausesUs >= 0);
+ int64_t pausedDurationUs = durExcludingEarlierPausesUs - mTrackDurationUs;
+ CHECK(pausedDurationUs >= lastDurationUs);
+ previousPausedDurationUs += pausedDurationUs - lastDurationUs;
mResumed = false;
}
timestampUs -= previousPausedDurationUs;
+ CHECK(timestampUs >= 0);
if (mIsRealTimeRecording && !mIsAudio) {
// The minor adjustment on the timestamp is heuristic/experimental
// We are adjusting the timestamp to reduce the fluctuation of the duration
@@ -1590,8 +1622,8 @@
}
}
- LOGV("time stamp: %lld and previous paused duration %lld",
- timestampUs, previousPausedDurationUs);
+ LOGV("%s media time stamp: %lld and previous paused duration %lld",
+ mIsAudio? "Audio": "Video", timestampUs, previousPausedDurationUs);
if (timestampUs > mTrackDurationUs) {
mTrackDurationUs = timestampUs;
}
@@ -1873,6 +1905,7 @@
// First elst entry: specify the starting time offset
int64_t offsetUs = mStartTimestampUs - moovStartTimeUs;
+ LOGV("OffsetUs: %lld", offsetUs);
int32_t seg = (offsetUs * mvhdTimeScale + 5E5) / 1E6;
mOwner->writeInt32(seg); // in mvhd timecale
mOwner->writeInt32(-1); // starting time offset