File writer size estimation improvement
o Do not count the reserved space for moov if the meta data size is small
o Do not count the extra 1KB disturbing small file estimation.
o Reduce the default minimum reserved space from 4 KB to 3 KB.
o Estimate the moov size based on both duration AND file size limit is set
and set it to the smaller estimated value.
low risk change
bug - 3111983
Change-Id: I6ac2adb979d8cc12d6b4f1813d000c989add0199
diff --git a/include/media/stagefright/MPEG4Writer.h b/include/media/stagefright/MPEG4Writer.h
index cff38b2..bb469e5 100644
--- a/include/media/stagefright/MPEG4Writer.h
+++ b/include/media/stagefright/MPEG4Writer.h
@@ -152,6 +152,7 @@
bool exceedsFileSizeLimit();
bool use32BitFileOffset() const;
bool exceedsFileDurationLimit();
+ bool isFileStreamable() const;
void trackProgressStatus(const Track* track, int64_t timeUs, status_t err = OK);
MPEG4Writer(const MPEG4Writer &);
diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index e53b0a0..90b104a 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -309,11 +309,10 @@
//
// Statistical analysis shows that metadata usually accounts
// for a small portion of the total file size, usually < 0.6%.
- // Currently, lets set to 0.4% for now.
- // The default MIN_MOOV_BOX_SIZE is set to 0.4% x 1MB,
+ // The default MIN_MOOV_BOX_SIZE is set to 0.6% x 1MB / 2,
// where 1MB is the common file size limit for MMS application.
- // The default MAX _MOOV_BOX_SIZE value is based on about 4
+ // The default MAX _MOOV_BOX_SIZE value is based on about 3
// minute video recording with a bit rate about 3 Mbps, because
// statistics also show that most of the video captured are going
// to be less than 3 minutes.
@@ -321,20 +320,33 @@
// If the estimation is wrong, we will pay the price of wasting
// some reserved space. This should not happen so often statistically.
static const int32_t factor = mUse32BitOffset? 1: 2;
- static const int64_t MIN_MOOV_BOX_SIZE = 4 * 1024; // 4 KB
+ static const int64_t MIN_MOOV_BOX_SIZE = 3 * 1024; // 3 KB
static const int64_t MAX_MOOV_BOX_SIZE = (180 * 3000000 * 6LL / 8000);
int64_t size = MIN_MOOV_BOX_SIZE;
+ // Max file size limit is set
if (mMaxFileSizeLimitBytes != 0 && mIsFileSizeLimitExplicitlyRequested) {
- size = mMaxFileSizeLimitBytes * 4 / 1000;
- } else if (mMaxFileDurationLimitUs != 0) {
- if (bitRate <= 0) {
- // We could not estimate the file size since bitRate is not set.
- size = MIN_MOOV_BOX_SIZE;
- } else {
- size = ((mMaxFileDurationLimitUs * bitRate * 4) / 1000 / 8000000);
+ size = mMaxFileSizeLimitBytes * 6 / 1000;
+ }
+
+ // Max file duration limit is set
+ if (mMaxFileDurationLimitUs != 0) {
+ if (bitRate > 0) {
+ int64_t size2 =
+ ((mMaxFileDurationLimitUs * bitRate * 6) / 1000 / 8000000);
+ if (mMaxFileSizeLimitBytes != 0 && mIsFileSizeLimitExplicitlyRequested) {
+ // When both file size and duration limits are set,
+ // we use the smaller limit of the two.
+ if (size > size2) {
+ size = size2;
+ }
+ } else {
+ // Only max file duration limit is set
+ size = size2;
+ }
}
}
+
if (size < MIN_MOOV_BOX_SIZE) {
size = MIN_MOOV_BOX_SIZE;
}
@@ -787,6 +799,10 @@
write(data, 1, size, mFile);
}
+bool MPEG4Writer::isFileStreamable() const {
+ return mStreamableFile;
+}
+
bool MPEG4Writer::exceedsFileSizeLimit() {
// No limit
if (mMaxFileSizeLimitBytes == 0) {
@@ -799,7 +815,7 @@
nTotalBytesEstimate += (*it)->getEstimatedTrackSizeBytes();
}
- return (nTotalBytesEstimate + 1024 >= mMaxFileSizeLimitBytes);
+ return (nTotalBytesEstimate >= mMaxFileSizeLimitBytes);
}
bool MPEG4Writer::exceedsFileDurationLimit() {
@@ -887,12 +903,16 @@
int64_t stszBoxSizeBytes = mSamplesHaveSameSize? 4: (mNumSamples * 4);
- mEstimatedTrackSizeBytes = mMdatSizeBytes + // media data size
- mNumStscTableEntries * 12 + // stsc box size
- mNumStssTableEntries * 4 + // stss box size
- mNumSttsTableEntries * 8 + // stts box size
- stcoBoxSizeBytes + // stco box size
- stszBoxSizeBytes; // stsz box size
+ mEstimatedTrackSizeBytes = mMdatSizeBytes; // media data size
+ if (!mOwner->isFileStreamable()) {
+ // Reserved free space is not large enough to hold
+ // all meta data and thus wasted.
+ mEstimatedTrackSizeBytes += mNumStscTableEntries * 12 + // stsc box size
+ mNumStssTableEntries * 4 + // stss box size
+ mNumSttsTableEntries * 8 + // stts box size
+ stcoBoxSizeBytes + // stco box size
+ stszBoxSizeBytes; // stsz box size
+ }
}
void MPEG4Writer::Track::addOneStscTableEntry(
