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author | Andreas Huber <andih@google.com> | 2011-09-19 12:18:47 -0700 |
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committer | Andreas Huber <andih@google.com> | 2011-09-19 12:21:33 -0700 |
commit | 89aa8fe4cb00d2f24260005b008602232d678684 (patch) | |
tree | 06d871b702884809f45f70ed71b19917cc93fd3d /media/libstagefright/SampleTable.cpp | |
parent | 84ada693b87f4d9344578e750a506b7789c13eb9 (diff) | |
download | frameworks_av-89aa8fe4cb00d2f24260005b008602232d678684.zip frameworks_av-89aa8fe4cb00d2f24260005b008602232d678684.tar.gz frameworks_av-89aa8fe4cb00d2f24260005b008602232d678684.tar.bz2 |
Remove an O(n^2) algorithm in MPEG4Extractor.cpp to speed up seeks in long streams
containing B-frames.
Change-Id: Ie4dc734d2c2d5a5ce84674bb883f4b27e2278642
related-to-bug: 5336497
Diffstat (limited to 'media/libstagefright/SampleTable.cpp')
-rw-r--r-- | media/libstagefright/SampleTable.cpp | 101 |
1 files changed, 80 insertions, 21 deletions
diff --git a/media/libstagefright/SampleTable.cpp b/media/libstagefright/SampleTable.cpp index 2b9d99b..ebad321 100644 --- a/media/libstagefright/SampleTable.cpp +++ b/media/libstagefright/SampleTable.cpp @@ -23,8 +23,8 @@ #include <arpa/inet.h> +#include <media/stagefright/foundation/ADebug.h> #include <media/stagefright/DataSource.h> -#include <media/stagefright/MediaDebug.h> #include <media/stagefright/Utils.h> namespace android { @@ -40,6 +40,71 @@ const uint32_t SampleTable::kSampleSizeTypeCompact = FOURCC('s', 't', 'z', '2'); //////////////////////////////////////////////////////////////////////////////// +struct SampleTable::CompositionDeltaLookup { + CompositionDeltaLookup(); + + void setEntries( + const uint32_t *deltaEntries, size_t numDeltaEntries); + + uint32_t getCompositionTimeOffset(uint32_t sampleIndex); + +private: + Mutex mLock; + + const uint32_t *mDeltaEntries; + size_t mNumDeltaEntries; + + size_t mCurrentDeltaEntry; + size_t mCurrentEntrySampleIndex; + + DISALLOW_EVIL_CONSTRUCTORS(CompositionDeltaLookup); +}; + +SampleTable::CompositionDeltaLookup::CompositionDeltaLookup() + : mDeltaEntries(NULL), + mNumDeltaEntries(0), + mCurrentDeltaEntry(0), + mCurrentEntrySampleIndex(0) { +} + +void SampleTable::CompositionDeltaLookup::setEntries( + const uint32_t *deltaEntries, size_t numDeltaEntries) { + Mutex::Autolock autolock(mLock); + + mDeltaEntries = deltaEntries; + mNumDeltaEntries = numDeltaEntries; + mCurrentDeltaEntry = 0; + mCurrentEntrySampleIndex = 0; +} + +uint32_t SampleTable::CompositionDeltaLookup::getCompositionTimeOffset( + uint32_t sampleIndex) { + Mutex::Autolock autolock(mLock); + + if (mDeltaEntries == NULL) { + return 0; + } + + if (sampleIndex < mCurrentEntrySampleIndex) { + mCurrentDeltaEntry = 0; + mCurrentEntrySampleIndex = 0; + } + + while (mCurrentDeltaEntry < mNumDeltaEntries) { + uint32_t sampleCount = mDeltaEntries[2 * mCurrentDeltaEntry]; + if (sampleIndex < mCurrentEntrySampleIndex + sampleCount) { + return mDeltaEntries[2 * mCurrentDeltaEntry + 1]; + } + + mCurrentEntrySampleIndex += sampleCount; + ++mCurrentDeltaEntry; + } + + return 0; +} + +//////////////////////////////////////////////////////////////////////////////// + SampleTable::SampleTable(const sp<DataSource> &source) : mDataSource(source), mChunkOffsetOffset(-1), @@ -56,6 +121,7 @@ SampleTable::SampleTable(const sp<DataSource> &source) mSampleTimeEntries(NULL), mCompositionTimeDeltaEntries(NULL), mNumCompositionTimeDeltaEntries(0), + mCompositionDeltaLookup(new CompositionDeltaLookup), mSyncSampleOffset(-1), mNumSyncSamples(0), mSyncSamples(NULL), @@ -71,6 +137,9 @@ SampleTable::~SampleTable() { delete[] mSyncSamples; mSyncSamples = NULL; + delete mCompositionDeltaLookup; + mCompositionDeltaLookup = NULL; + delete[] mCompositionTimeDeltaEntries; mCompositionTimeDeltaEntries = NULL; @@ -318,6 +387,9 @@ status_t SampleTable::setCompositionTimeToSampleParams( mCompositionTimeDeltaEntries[i] = ntohl(mCompositionTimeDeltaEntries[i]); } + mCompositionDeltaLookup->setEntries( + mCompositionTimeDeltaEntries, mNumCompositionTimeDeltaEntries); + return OK; } @@ -430,8 +502,12 @@ void SampleTable::buildSampleEntriesTable() { mSampleTimeEntries[sampleIndex].mSampleIndex = sampleIndex; + uint32_t compTimeDelta = + mCompositionDeltaLookup->getCompositionTimeOffset( + sampleIndex); + mSampleTimeEntries[sampleIndex].mCompositionTime = - sampleTime + getCompositionTimeOffset(sampleIndex); + sampleTime + compTimeDelta; } ++sampleIndex; @@ -739,25 +815,8 @@ status_t SampleTable::getMetaDataForSample( return OK; } -uint32_t SampleTable::getCompositionTimeOffset(uint32_t sampleIndex) const { - if (mCompositionTimeDeltaEntries == NULL) { - return 0; - } - - uint32_t curSample = 0; - for (size_t i = 0; i < mNumCompositionTimeDeltaEntries; ++i) { - uint32_t sampleCount = mCompositionTimeDeltaEntries[2 * i]; - - if (sampleIndex < curSample + sampleCount) { - uint32_t sampleDelta = mCompositionTimeDeltaEntries[2 * i + 1]; - - return sampleDelta; - } - - curSample += sampleCount; - } - - return 0; +uint32_t SampleTable::getCompositionTimeOffset(uint32_t sampleIndex) { + return mCompositionDeltaLookup->getCompositionTimeOffset(sampleIndex); } } // namespace android |