am fa7a87fb: Merge "File writer size estimation improvement" into gingerbread

Merge commit 'fa7a87fb4b3d25b0b6b0985d65848a144d28df26' into gingerbread-plus-aosp

* commit 'fa7a87fb4b3d25b0b6b0985d65848a144d28df26':
  File writer size estimation improvement
This commit is contained in:
James Dong
2010-10-20 21:28:38 -07:00
committed by Android Git Automerger
2 changed files with 39 additions and 18 deletions

View File

@ -152,6 +152,7 @@ private:
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 &);

View File

@ -309,11 +309,10 @@ int64_t MPEG4Writer::estimateMoovBoxSize(int32_t bitRate) {
//
// 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 @@ int64_t MPEG4Writer::estimateMoovBoxSize(int32_t bitRate) {
// 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;
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 {
size = ((mMaxFileDurationLimitUs * bitRate * 4) / 1000 / 8000000);
// Only max file duration limit is set
size = size2;
}
}
}
if (size < MIN_MOOV_BOX_SIZE) {
size = MIN_MOOV_BOX_SIZE;
}
@ -787,6 +799,10 @@ void MPEG4Writer::write(const void *data, size_t size) {
write(data, 1, size, mFile);
}
bool MPEG4Writer::isFileStreamable() const {
return mStreamableFile;
}
bool MPEG4Writer::exceedsFileSizeLimit() {
// No limit
if (mMaxFileSizeLimitBytes == 0) {
@ -799,7 +815,7 @@ bool MPEG4Writer::exceedsFileSizeLimit() {
nTotalBytesEstimate += (*it)->getEstimatedTrackSizeBytes();
}
return (nTotalBytesEstimate + 1024 >= mMaxFileSizeLimitBytes);
return (nTotalBytesEstimate >= mMaxFileSizeLimitBytes);
}
bool MPEG4Writer::exceedsFileDurationLimit() {
@ -887,12 +903,16 @@ void MPEG4Writer::Track::updateTrackSizeEstimate() {
int64_t stszBoxSizeBytes = mSamplesHaveSameSize? 4: (mNumSamples * 4);
mEstimatedTrackSizeBytes = mMdatSizeBytes + // media data size
mNumStscTableEntries * 12 + // stsc 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(