am 8ddb8f81: am bc1daf01: Merge "Eliminate the linear cost associated with mSampleSizes.size()" into gingerbread
Merge commit '8ddb8f81902045ec8a53ec14b8fb936fd42517e0'
* commit '8ddb8f81902045ec8a53ec14b8fb936fd42517e0':
Eliminate the linear cost associated with mSampleSizes.size()
diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index 16b1094..baf9f4f 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -66,6 +66,10 @@
pthread_t mThread;
+ // mNumSamples is used to track how many samples in mSampleSizes List.
+ // This is to reduce the cost associated with mSampleSizes.size() call,
+ // since it is O(n). Ideally, the fix should be in List class.
+ size_t mNumSamples;
List<size_t> mSampleSizes;
bool mSamplesHaveSameSize;
@@ -942,6 +946,7 @@
sp<MetaData> meta_data;
bool collectStats = collectStatisticalData();
+ mNumSamples = 0;
status_t err = OK;
MediaBuffer *buffer;
while (!mDone && (err = mSource->read(&buffer)) == OK) {
@@ -1133,7 +1138,8 @@
}
mSampleSizes.push_back(sampleSize);
- if (mSampleSizes.size() > 2) {
+ ++mNumSamples;
+ if (mNumSamples > 2) {
if (lastDurationUs != timestampUs - lastTimestampUs) {
SttsTableEntry sttsEntry(sampleCount, lastDurationUs);
mSttsTableEntries.push_back(sttsEntry);
@@ -1143,7 +1149,7 @@
}
}
if (mSamplesHaveSameSize) {
- if (mSampleSizes.size() >= 2 && previousSampleSize != sampleSize) {
+ if (mNumSamples >= 2 && previousSampleSize != sampleSize) {
mSamplesHaveSameSize = false;
}
previousSampleSize = sampleSize;
@@ -1152,7 +1158,7 @@
lastTimestampUs = timestampUs;
if (isSync != 0) {
- mStssTableEntries.push_back(mSampleSizes.size());
+ mStssTableEntries.push_back(mNumSamples);
}
if (mTrackingProgressStatus) {
@@ -1208,7 +1214,7 @@
// Last chunk
if (mOwner->numTracks() == 1) {
- StscTableEntry stscEntry(1, mSampleSizes.size(), 1);
+ StscTableEntry stscEntry(1, mNumSamples, 1);
mStscTableEntries.push_back(stscEntry);
} else if (!mChunkSamples.empty()) {
++nChunks;
@@ -1220,7 +1226,7 @@
// We don't really know how long the last frame lasts, since
// there is no frame time after it, just repeat the previous
// frame's duration.
- if (mSampleSizes.size() == 1) {
+ if (mNumSamples == 1) {
lastDurationUs = 0; // A single sample's duration
} else {
++sampleCount; // Count for the last sample
@@ -1229,7 +1235,7 @@
mSttsTableEntries.push_back(sttsEntry);
mReachedEOS = true;
LOGI("Received total/0-length (%d/%d) buffers and encoded %d frames - %s",
- count, nZeroLengthFrames, mSampleSizes.size(), is_audio? "audio": "video");
+ count, nZeroLengthFrames, mNumSamples, is_audio? "audio": "video");
logStatisticalData(is_audio);
}
@@ -1292,7 +1298,7 @@
void MPEG4Writer::Track::findMinAvgMaxSampleDurationMs(
int32_t *min, int32_t *avg, int32_t *max) {
CHECK(!mSampleSizes.empty());
- int32_t avgSampleDurationMs = mMaxTimeStampUs / 1000 / mSampleSizes.size();
+ int32_t avgSampleDurationMs = mMaxTimeStampUs / 1000 / mNumSamples;
int32_t minSampleDurationMs = 0x7FFFFFFF;
int32_t maxSampleDurationMs = 0;
for (List<SttsTableEntry>::iterator it = mSttsTableEntries.begin();
@@ -1344,7 +1350,7 @@
if (collectStats) {
LOGI("%s track - duration %lld us, total %d frames",
isAudio? "audio": "video", mMaxTimeStampUs,
- mSampleSizes.size());
+ mNumSamples);
int32_t min, avg, max;
findMinAvgMaxSampleDurationMs(&min, &avg, &max);
LOGI("min/avg/max sample duration (ms): %d/%d/%d", min, avg, max);
@@ -1738,7 +1744,7 @@
} else {
mOwner->writeInt32(0);
}
- mOwner->writeInt32(mSampleSizes.size());
+ mOwner->writeInt32(mNumSamples);
if (!mSamplesHaveSameSize) {
for (List<size_t>::iterator it = mSampleSizes.begin();
it != mSampleSizes.end(); ++it) {