Calculate audio media drift time from AudioSource
The problem was that the time to receive an output buffer
from an audio encoder is different because the encoder does not
need to read from the source for all output buffers. This leads
to large fluctuation in terms of wall clock duration between two
neighboring audio sample outputs from the audio encoder. As a
result, the media time for the video track after adjustment using
the drifting changes wildly sometimes.
This patch addresses this issue by only updating the media drift
time when an audio source input buffer is read. the wall clock
for the audio track is also calculated at the same time when
the input audio buffer is read at AudioSource.
bug - 2959800
Change-Id: I3174aa182f744784b540f0a7198524d4eee8bd7b
diff --git a/include/media/stagefright/AudioSource.h b/include/media/stagefright/AudioSource.h
index 1af4254..a5cec78 100644
--- a/include/media/stagefright/AudioSource.h
+++ b/include/media/stagefright/AudioSource.h
@@ -72,6 +72,7 @@
int64_t mPrevSampleTimeUs;
int64_t mTotalLostFrames;
int64_t mPrevLostBytes;
+ int64_t mInitialReadTimeUs;
MediaBufferGroup *mGroup;
diff --git a/include/media/stagefright/MPEG4Writer.h b/include/media/stagefright/MPEG4Writer.h
index 2412f6a..9716e98 100644
--- a/include/media/stagefright/MPEG4Writer.h
+++ b/include/media/stagefright/MPEG4Writer.h
@@ -132,7 +132,7 @@
// Adjust other track media clock (presumably wall clock)
// based on audio track media clock with the drift time.
int64_t mDriftTimeUs;
- void addDriftTimeUs(int64_t driftTimeUs);
+ void setDriftTimeUs(int64_t driftTimeUs);
int64_t getDriftTimeUs();
void lock();
diff --git a/include/media/stagefright/MetaData.h b/include/media/stagefright/MetaData.h
index 43354c2..3b31e68 100644
--- a/include/media/stagefright/MetaData.h
+++ b/include/media/stagefright/MetaData.h
@@ -48,6 +48,7 @@
kKeyTime = 'time', // int64_t (usecs)
kKeyNTPTime = 'ntpT', // uint64_t (ntp-timestamp)
kKeyTargetTime = 'tarT', // int64_t (usecs)
+ kKeyDriftTime = 'dftT', // int64_t (usecs)
kKeyDuration = 'dura', // int64_t (usecs)
kKeyColorFormat = 'colf',
kKeyPlatformPrivate = 'priv', // pointer
diff --git a/media/libstagefright/AudioSource.cpp b/media/libstagefright/AudioSource.cpp
index bcae913..c2f79e8 100644
--- a/media/libstagefright/AudioSource.cpp
+++ b/media/libstagefright/AudioSource.cpp
@@ -84,6 +84,7 @@
mTrackMaxAmplitude = false;
mMaxAmplitude = 0;
+ mInitialReadTimeUs = 0;
mStartTimeUs = 0;
int64_t startTimeUs;
if (params && params->findInt64(kKeyTime, &startTimeUs)) {
@@ -210,6 +211,7 @@
return NO_INIT;
}
+ int64_t readTimeUs = systemTime() / 1000;
*out = NULL;
MediaBuffer *buffer;
@@ -223,9 +225,10 @@
if (numFramesRecorded == 0 && mPrevSampleTimeUs == 0) {
+ mInitialReadTimeUs = readTimeUs;
// Initial delay
if (mStartTimeUs > 0) {
- mStartTimeUs = systemTime() / 1000 - mStartTimeUs;
+ mStartTimeUs = readTimeUs - mStartTimeUs;
} else {
// Assume latency is constant.
mStartTimeUs += mRecord->latency() * 1000;
@@ -271,7 +274,10 @@
}
memset(buffer->data(), 0, numLostBytes);
buffer->set_range(0, numLostBytes);
- buffer->meta_data()->setInt64(kKeyTime, mPrevSampleTimeUs);
+ if (numFramesRecorded == 0) {
+ buffer->meta_data()->setInt64(kKeyTime, mStartTimeUs);
+ }
+ buffer->meta_data()->setInt64(kKeyDriftTime, readTimeUs - mInitialReadTimeUs);
mPrevSampleTimeUs = timestampUs;
*out = buffer;
return OK;
@@ -309,7 +315,10 @@
trackMaxAmplitude((int16_t *) buffer->data(), n >> 1);
}
- buffer->meta_data()->setInt64(kKeyTime, mPrevSampleTimeUs);
+ if (numFramesRecorded == 0) {
+ buffer->meta_data()->setInt64(kKeyTime, mStartTimeUs);
+ }
+ buffer->meta_data()->setInt64(kKeyDriftTime, readTimeUs - mInitialReadTimeUs);
CHECK(timestampUs > mPrevSampleTimeUs);
mPrevSampleTimeUs = timestampUs;
LOGV("initial delay: %lld, sample rate: %d, timestamp: %lld",
diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index a15b84e..af2b4c4 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -1430,9 +1430,6 @@
int64_t previousPausedDurationUs = 0;
int64_t timestampUs;
- int64_t wallClockTimeUs = 0;
- int64_t lastWallClockTimeUs = 0;
-
sp<MetaData> meta_data;
bool collectStats = collectStatisticalData();
@@ -1542,14 +1539,15 @@
// of neighboring samples. This in turn helps reduce the track header size,
// especially, the number of entries in the "stts" box.
if (mNumSamples > 1) {
- int64_t durationUs = timestampUs + mOwner->getDriftTimeUs() - lastTimestampUs;
+ int64_t currDriftTimeUs = mOwner->getDriftTimeUs();
+ int64_t durationUs = timestampUs + currDriftTimeUs - lastTimestampUs;
int64_t diffUs = (durationUs > lastDurationUs)
? durationUs - lastDurationUs
: lastDurationUs - durationUs;
if (diffUs <= 5000) { // XXX: Magic number 5ms
timestampUs = lastTimestampUs + lastDurationUs;
} else {
- timestampUs += mOwner->getDriftTimeUs();
+ timestampUs += currDriftTimeUs;
}
}
}
@@ -1557,12 +1555,6 @@
if (mNumSamples > 1) {
if (timestampUs <= lastTimestampUs) {
LOGW("Frame arrives too late!");
-#if 0
- // Drop the late frame.
- copy->release();
- copy = NULL;
- continue;
-#else
// Don't drop the late frame, since dropping a frame may cause
// problems later during playback
@@ -1573,7 +1565,6 @@
} else {
timestampUs = lastTimestampUs + (1000000LL + (mTimeScale >> 1)) / mTimeScale;
}
-#endif
}
}
@@ -1613,12 +1604,10 @@
lastDurationTicks = currDurationTicks;
lastTimestampUs = timestampUs;
if (mIsRealTimeRecording && mIsAudio) {
- wallClockTimeUs = systemTime() / 1000;
- int64_t wallClockDurationUs = wallClockTimeUs - lastWallClockTimeUs;
- if (mNumSamples > 2) {
- mOwner->addDriftTimeUs(lastDurationUs - wallClockDurationUs);
+ int64_t driftTimeUs = 0;
+ if (meta_data->findInt64(kKeyDriftTime, &driftTimeUs)) {
+ mOwner->setDriftTimeUs(driftTimeUs);
}
- lastWallClockTimeUs = wallClockTimeUs;
}
if (isSync != 0) {
@@ -1851,10 +1840,10 @@
}
}
-void MPEG4Writer::addDriftTimeUs(int64_t driftTimeUs) {
- LOGV("addDriftTimeUs: %lld us", driftTimeUs);
+void MPEG4Writer::setDriftTimeUs(int64_t driftTimeUs) {
+ LOGV("setDriftTimeUs: %lld us", driftTimeUs);
Mutex::Autolock autolock(mLock);
- mDriftTimeUs += driftTimeUs;
+ mDriftTimeUs = driftTimeUs;
}
int64_t MPEG4Writer::getDriftTimeUs() {
diff --git a/media/libstagefright/codecs/aacenc/AACEncoder.cpp b/media/libstagefright/codecs/aacenc/AACEncoder.cpp
index 052c354..c05e3e5 100644
--- a/media/libstagefright/codecs/aacenc/AACEncoder.cpp
+++ b/media/libstagefright/codecs/aacenc/AACEncoder.cpp
@@ -208,6 +208,8 @@
MediaBuffer *buffer;
CHECK_EQ(mBufferGroup->acquire_buffer(&buffer), OK);
uint8_t *outPtr = (uint8_t *)buffer->data();
+ bool readFromSource = false;
+ int64_t wallClockTimeUs = 0;
if (mFrameCount == 0) {
memcpy(outPtr, mAudioSpecificConfigData, 2);
@@ -238,9 +240,14 @@
CHECK_EQ(align, 0);
int64_t timeUs;
+ CHECK(mInputBuffer->meta_data()->findInt64(kKeyDriftTime, &timeUs));
+ wallClockTimeUs = timeUs;
if (mInputBuffer->meta_data()->findInt64(kKeyTime, &timeUs)) {
mAnchorTimeUs = timeUs;
}
+ readFromSource = true;
+ } else {
+ readFromSource = false;
}
size_t copy =
(kNumSamplesPerFrame - mNumInputSamples) * sizeof(int16_t);
@@ -288,9 +295,13 @@
CHECK(outputData.Length != 0);
buffer->set_range(0, outputData.Length);
- int64_t timestampUs = ((mFrameCount - 1) * 1000000LL * kNumSamplesPerFrame) / mSampleRate;
+ int64_t mediaTimeUs =
+ ((mFrameCount - 1) * 1000000LL * kNumSamplesPerFrame) / mSampleRate;
+ buffer->meta_data()->setInt64(kKeyTime, mAnchorTimeUs + mediaTimeUs);
+ if (readFromSource) {
+ buffer->meta_data()->setInt64(kKeyDriftTime, mediaTimeUs - wallClockTimeUs);
+ }
++mFrameCount;
- buffer->meta_data()->setInt64(kKeyTime, timestampUs);
*out = buffer;
return OK;
diff --git a/media/libstagefright/codecs/amrnb/enc/AMRNBEncoder.cpp b/media/libstagefright/codecs/amrnb/enc/AMRNBEncoder.cpp
index c875426..dab1390 100644
--- a/media/libstagefright/codecs/amrnb/enc/AMRNBEncoder.cpp
+++ b/media/libstagefright/codecs/amrnb/enc/AMRNBEncoder.cpp
@@ -147,6 +147,8 @@
int64_t seekTimeUs;
ReadOptions::SeekMode mode;
CHECK(options == NULL || !options->getSeekTo(&seekTimeUs, &mode));
+ bool readFromSource = false;
+ int64_t wallClockTimeUs = 0;
while (mNumInputSamples < kNumSamplesPerFrame) {
if (mInputBuffer == NULL) {
@@ -166,12 +168,16 @@
size_t align = mInputBuffer->range_length() % sizeof(int16_t);
CHECK_EQ(align, 0);
+ readFromSource = true;
int64_t timeUs;
+ CHECK(mInputBuffer->meta_data()->findInt64(kKeyDriftTime, &timeUs));
+ wallClockTimeUs = timeUs;
if (mInputBuffer->meta_data()->findInt64(kKeyTime, &timeUs)) {
mAnchorTimeUs = timeUs;
- mNumFramesOutput = 0;
}
+ } else {
+ readFromSource = false;
}
size_t copy =
@@ -217,8 +223,14 @@
buffer->set_range(0, res);
// Each frame of 160 samples is 20ms long.
+ int64_t mediaTimeUs = mNumFramesOutput * 20000LL;
buffer->meta_data()->setInt64(
- kKeyTime, mAnchorTimeUs + mNumFramesOutput * 20000);
+ kKeyTime, mAnchorTimeUs + mediaTimeUs);
+
+ if (readFromSource) {
+ buffer->meta_data()->setInt64(kKeyDriftTime,
+ mediaTimeUs - wallClockTimeUs);
+ }
++mNumFramesOutput;
diff --git a/media/libstagefright/codecs/amrwbenc/AMRWBEncoder.cpp b/media/libstagefright/codecs/amrwbenc/AMRWBEncoder.cpp
index 93304d0..b62eb5b 100644
--- a/media/libstagefright/codecs/amrwbenc/AMRWBEncoder.cpp
+++ b/media/libstagefright/codecs/amrwbenc/AMRWBEncoder.cpp
@@ -198,6 +198,8 @@
int64_t seekTimeUs;
ReadOptions::SeekMode mode;
CHECK(options == NULL || !options->getSeekTo(&seekTimeUs, &mode));
+ bool readFromSource = false;
+ int64_t wallClockTimeUs = 0;
while (mNumInputSamples < kNumSamplesPerFrame) {
if (mInputBuffer == NULL) {
@@ -219,9 +221,14 @@
CHECK_EQ(align, 0);
int64_t timeUs;
+ CHECK(mInputBuffer->meta_data()->findInt64(kKeyDriftTime, &timeUs));
+ wallClockTimeUs = timeUs;
if (mInputBuffer->meta_data()->findInt64(kKeyTime, &timeUs)) {
mAnchorTimeUs = timeUs;
}
+ readFromSource = true;
+ } else {
+ readFromSource = false;
}
size_t copy =
@@ -276,10 +283,11 @@
buffer->set_range(0, outputData.Length);
++mNumFramesOutput;
- // XXX: fix timestamp calculation
- int64_t timestampUs = mNumFramesOutput * 20000LL;
-
- buffer->meta_data()->setInt64(kKeyTime, timestampUs);
+ int64_t mediaTimeUs = mNumFramesOutput * 20000LL;
+ buffer->meta_data()->setInt64(kKeyTime, mAnchorTimeUs + mediaTimeUs);
+ if (readFromSource) {
+ buffer->meta_data()->setInt64(kKeyDriftTime, mediaTimeUs - wallClockTimeUs);
+ }
*out = buffer;
return OK;