Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 712 insertions, 0 deletions

diff --git a/dom/media/mp4/SampleIterator.cpp b/dom/media/mp4/SampleIterator.cpp
new file mode 100644
index 0000000000..95fc8af457
--- /dev/null
+++ b/dom/media/mp4/SampleIterator.cpp
@@ -0,0 +1,712 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SampleIterator.h"
+
+#include <algorithm>
+#include <limits>
+
+#include "BufferReader.h"
+#include "mozilla/RefPtr.h"
+#include "MP4Interval.h"
+#include "MP4Metadata.h"
+#include "SinfParser.h"
+
+using namespace mozilla::media;
+
+namespace mozilla {
+
+class MOZ_STACK_CLASS RangeFinder {
+ public:
+  // Given that we're processing this in order we don't use a binary search
+  // to find the apropriate time range. Instead we search linearly from the
+  // last used point.
+  explicit RangeFinder(const MediaByteRangeSet& ranges)
+      : mRanges(ranges), mIndex(0) {
+    // Ranges must be normalised for this to work
+  }
+
+  bool Contains(const MediaByteRange& aByteRange);
+
+ private:
+  const MediaByteRangeSet& mRanges;
+  size_t mIndex;
+};
+
+bool RangeFinder::Contains(const MediaByteRange& aByteRange) {
+  if (mRanges.IsEmpty()) {
+    return false;
+  }
+
+  if (mRanges[mIndex].ContainsStrict(aByteRange)) {
+    return true;
+  }
+
+  if (aByteRange.mStart < mRanges[mIndex].mStart) {
+    // Search backwards
+    do {
+      if (!mIndex) {
+        return false;
+      }
+      --mIndex;
+      if (mRanges[mIndex].ContainsStrict(aByteRange)) {
+        return true;
+      }
+    } while (aByteRange.mStart < mRanges[mIndex].mStart);
+
+    return false;
+  }
+
+  while (aByteRange.mEnd > mRanges[mIndex].mEnd) {
+    if (mIndex == mRanges.Length() - 1) {
+      return false;
+    }
+    ++mIndex;
+    if (mRanges[mIndex].ContainsStrict(aByteRange)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+SampleIterator::SampleIterator(MP4SampleIndex* aIndex)
+    : mIndex(aIndex), mCurrentMoof(0), mCurrentSample(0) {
+  mIndex->RegisterIterator(this);
+}
+
+SampleIterator::~SampleIterator() { mIndex->UnregisterIterator(this); }
+
+bool SampleIterator::HasNext() { return !!Get(); }
+
+already_AddRefed<MediaRawData> SampleIterator::GetNext() {
+  Sample* s(Get());
+  if (!s) {
+    return nullptr;
+  }
+
+  int64_t length = std::numeric_limits<int64_t>::max();
+  mIndex->mSource->Length(&length);
+  if (s->mByteRange.mEnd > length) {
+    // We don't have this complete sample.
+    return nullptr;
+  }
+
+  RefPtr<MediaRawData> sample = new MediaRawData();
+  sample->mTimecode = s->mDecodeTime;
+  sample->mTime = s->mCompositionRange.start;
+  sample->mDuration = s->mCompositionRange.Length();
+  sample->mOffset = s->mByteRange.mStart;
+  sample->mKeyframe = s->mSync;
+
+  UniquePtr<MediaRawDataWriter> writer(sample->CreateWriter());
+  // Do the blocking read
+  if (!writer->SetSize(s->mByteRange.Length())) {
+    return nullptr;
+  }
+
+  size_t bytesRead;
+  if (!mIndex->mSource->ReadAt(sample->mOffset, writer->Data(), sample->Size(),
+                               &bytesRead) ||
+      bytesRead != sample->Size()) {
+    return nullptr;
+  }
+
+  MoofParser* moofParser = mIndex->mMoofParser.get();
+  if (!moofParser) {
+    // File is not fragmented, we can't have crypto, just early return.
+    Next();
+    return sample.forget();
+  }
+
+  // We need to check if this moof has init data the CDM expects us to surface.
+  // This should happen when handling the first sample, even if that sample
+  // isn't encrypted (samples later in the moof may be).
+  if (mCurrentSample == 0) {
+    const nsTArray<Moof>& moofs = moofParser->Moofs();
+    const Moof* currentMoof = &moofs[mCurrentMoof];
+    if (!currentMoof->mPsshes.IsEmpty()) {
+      // This Moof contained crypto init data. Report that. We only report
+      // the init data on the Moof's first sample, to avoid reporting it more
+      // than once per Moof.
+      writer->mCrypto.mInitDatas.AppendElements(currentMoof->mPsshes);
+      writer->mCrypto.mInitDataType = u"cenc"_ns;
+    }
+  }
+
+  auto cryptoSchemeResult = GetEncryptionScheme();
+  if (cryptoSchemeResult.isErr()) {
+    // Log the error here in future.
+    return nullptr;
+  }
+  CryptoScheme cryptoScheme = cryptoSchemeResult.unwrap();
+  if (cryptoScheme == CryptoScheme::None) {
+    // No crypto to handle, early return.
+    Next();
+    return sample.forget();
+  }
+
+  writer->mCrypto.mCryptoScheme = cryptoScheme;
+  MOZ_ASSERT(writer->mCrypto.mCryptoScheme != CryptoScheme::None,
+             "Should have early returned if we don't have a crypto scheme!");
+  MOZ_ASSERT(writer->mCrypto.mKeyId.IsEmpty(),
+             "Sample should not already have a key ID");
+  MOZ_ASSERT(writer->mCrypto.mConstantIV.IsEmpty(),
+             "Sample should not already have a constant IV");
+  CencSampleEncryptionInfoEntry* sampleInfo = GetSampleEncryptionEntry();
+  if (sampleInfo) {
+    // Use sample group information if present, this supersedes track level
+    // information.
+    writer->mCrypto.mKeyId.AppendElements(sampleInfo->mKeyId);
+    writer->mCrypto.mIVSize = sampleInfo->mIVSize;
+    writer->mCrypto.mCryptByteBlock = sampleInfo->mCryptByteBlock;
+    writer->mCrypto.mSkipByteBlock = sampleInfo->mSkipByteBlock;
+    writer->mCrypto.mConstantIV.AppendElements(sampleInfo->mConsantIV);
+  } else {
+    // Use the crypto info from track metadata
+    writer->mCrypto.mKeyId.AppendElements(moofParser->mSinf.mDefaultKeyID, 16);
+    writer->mCrypto.mIVSize = moofParser->mSinf.mDefaultIVSize;
+    writer->mCrypto.mCryptByteBlock = moofParser->mSinf.mDefaultCryptByteBlock;
+    writer->mCrypto.mSkipByteBlock = moofParser->mSinf.mDefaultSkipByteBlock;
+    writer->mCrypto.mConstantIV.AppendElements(
+        moofParser->mSinf.mDefaultConstantIV);
+  }
+
+  if ((writer->mCrypto.mIVSize == 0 && writer->mCrypto.mConstantIV.IsEmpty()) ||
+      (writer->mCrypto.mIVSize != 0 && s->mCencRange.IsEmpty())) {
+    // If mIVSize == 0, this indicates that a constant IV is in use, thus we
+    // should have a non empty constant IV. Alternatively if IV size is non
+    // zero, we should have an IV for this sample, which we need to look up
+    // in mCencRange (which must then be non empty). If neither of these are
+    // true we have bad crypto data, so bail.
+    return nullptr;
+  }
+  // Parse auxiliary information if present
+  if (!s->mCencRange.IsEmpty()) {
+    // The size comes from an 8 bit field
+    AutoTArray<uint8_t, 256> cencAuxInfo;
+    cencAuxInfo.SetLength(s->mCencRange.Length());
+    if (!mIndex->mSource->ReadAt(s->mCencRange.mStart, cencAuxInfo.Elements(),
+                                 cencAuxInfo.Length(), &bytesRead) ||
+        bytesRead != cencAuxInfo.Length()) {
+      return nullptr;
+    }
+    BufferReader reader(cencAuxInfo);
+    if (!reader.ReadArray(writer->mCrypto.mIV, writer->mCrypto.mIVSize)) {
+      return nullptr;
+    }
+
+    // Parse the auxiliary information for subsample information
+    auto res = reader.ReadU16();
+    if (res.isOk() && res.unwrap() > 0) {
+      uint16_t count = res.unwrap();
+
+      if (reader.Remaining() < count * 6) {
+        return nullptr;
+      }
+
+      for (size_t i = 0; i < count; i++) {
+        auto res_16 = reader.ReadU16();
+        auto res_32 = reader.ReadU32();
+        if (res_16.isErr() || res_32.isErr()) {
+          return nullptr;
+        }
+        writer->mCrypto.mPlainSizes.AppendElement(res_16.unwrap());
+        writer->mCrypto.mEncryptedSizes.AppendElement(res_32.unwrap());
+      }
+    } else {
+      // No subsample information means the entire sample is encrypted.
+      writer->mCrypto.mPlainSizes.AppendElement(0);
+      writer->mCrypto.mEncryptedSizes.AppendElement(sample->Size());
+    }
+  }
+
+  Next();
+
+  return sample.forget();
+}
+
+SampleDescriptionEntry* SampleIterator::GetSampleDescriptionEntry() {
+  nsTArray<Moof>& moofs = mIndex->mMoofParser->Moofs();
+  Moof& currentMoof = moofs[mCurrentMoof];
+  uint32_t sampleDescriptionIndex =
+      currentMoof.mTfhd.mDefaultSampleDescriptionIndex;
+  // Mp4 indices start at 1, shift down 1 so we index our array correctly.
+  sampleDescriptionIndex--;
+  FallibleTArray<SampleDescriptionEntry>& sampleDescriptions =
+      mIndex->mMoofParser->mSampleDescriptions;
+  if (sampleDescriptionIndex >= sampleDescriptions.Length()) {
+    // The sample description index is invalid, the mp4 is malformed. Bail out.
+    return nullptr;
+  }
+  return &sampleDescriptions[sampleDescriptionIndex];
+}
+
+CencSampleEncryptionInfoEntry* SampleIterator::GetSampleEncryptionEntry() {
+  nsTArray<Moof>& moofs = mIndex->mMoofParser->Moofs();
+  Moof* currentMoof = &moofs[mCurrentMoof];
+  SampleToGroupEntry* sampleToGroupEntry = nullptr;
+
+  // Default to using the sample to group entries for the fragment, otherwise
+  // fall back to the sample to group entries for the track.
+  FallibleTArray<SampleToGroupEntry>* sampleToGroupEntries =
+      currentMoof->mFragmentSampleToGroupEntries.Length() != 0
+          ? &currentMoof->mFragmentSampleToGroupEntries
+          : &mIndex->mMoofParser->mTrackSampleToGroupEntries;
+
+  uint32_t seen = 0;
+
+  for (SampleToGroupEntry& entry : *sampleToGroupEntries) {
+    if (seen + entry.mSampleCount > mCurrentSample) {
+      sampleToGroupEntry = &entry;
+      break;
+    }
+    seen += entry.mSampleCount;
+  }
+
+  // ISO-14496-12 Section 8.9.2.3 and 8.9.4 : group description index
+  // (1) ranges from 1 to the number of sample group entries in the track
+  // level SampleGroupDescription Box, or (2) takes the value 0 to
+  // indicate that this sample is a member of no group, in this case, the
+  // sample is associated with the default values specified in
+  // TrackEncryption Box, or (3) starts at 0x10001, i.e. the index value
+  // 1, with the value 1 in the top 16 bits, to reference fragment-local
+  // SampleGroupDescription Box.
+
+  // According to the spec, ISO-14496-12, the sum of the sample counts in this
+  // box should be equal to the total number of samples, and, if less, the
+  // reader should behave as if an extra SampleToGroupEntry existed, with
+  // groupDescriptionIndex 0.
+
+  if (!sampleToGroupEntry || sampleToGroupEntry->mGroupDescriptionIndex == 0) {
+    return nullptr;
+  }
+
+  FallibleTArray<CencSampleEncryptionInfoEntry>* entries =
+      &mIndex->mMoofParser->mTrackSampleEncryptionInfoEntries;
+
+  uint32_t groupIndex = sampleToGroupEntry->mGroupDescriptionIndex;
+
+  // If the first bit is set to a one, then we should use the sample group
+  // descriptions from the fragment.
+  if (groupIndex > SampleToGroupEntry::kFragmentGroupDescriptionIndexBase) {
+    groupIndex -= SampleToGroupEntry::kFragmentGroupDescriptionIndexBase;
+    entries = &currentMoof->mFragmentSampleEncryptionInfoEntries;
+  }
+
+  // The group_index is one based.
+  return groupIndex > entries->Length() ? nullptr
+                                        : &entries->ElementAt(groupIndex - 1);
+}
+
+Result<CryptoScheme, nsCString> SampleIterator::GetEncryptionScheme() {
+  // See ISO/IEC 23001-7 for information on the metadata being checked.
+  MoofParser* moofParser = mIndex->mMoofParser.get();
+  if (!moofParser) {
+    // This mp4 isn't fragmented so it can't be encrypted.
+    return CryptoScheme::None;
+  }
+
+  SampleDescriptionEntry* sampleDescriptionEntry = GetSampleDescriptionEntry();
+  if (!sampleDescriptionEntry) {
+    // For the file to be valid the tfhd must reference a sample description
+    // entry.
+    // If we encounter this error often, we may consider using the first
+    // sample description entry if the index is out of bounds.
+    return mozilla::Err(nsLiteralCString(
+        "Could not determine encryption scheme due to bad index for sample "
+        "description entry."));
+  }
+
+  if (!sampleDescriptionEntry->mIsEncryptedEntry) {
+    return CryptoScheme::None;
+  }
+
+  if (!moofParser->mSinf.IsValid()) {
+    // The sample description entry says this sample is encrypted, but we
+    // don't have a valid sinf box. This shouldn't happen as the sinf box is
+    // part of the sample description entry. Suggests a malformed file, bail.
+    return mozilla::Err(nsLiteralCString(
+        "Could not determine encryption scheme. Sample description entry "
+        "indicates encryption, but could not find associated sinf box."));
+  }
+
+  CencSampleEncryptionInfoEntry* sampleInfo = GetSampleEncryptionEntry();
+  if (sampleInfo && !sampleInfo->mIsEncrypted) {
+    // May not have sample encryption info, but if we do, it should match other
+    // metadata.
+    return mozilla::Err(nsLiteralCString(
+        "Could not determine encryption scheme. Sample description entry "
+        "indicates encryption, but sample encryption entry indicates sample is "
+        "not encrypted. These should be consistent."));
+  }
+
+  if (moofParser->mSinf.mDefaultEncryptionType == AtomType("cenc")) {
+    return CryptoScheme::Cenc;
+  } else if (moofParser->mSinf.mDefaultEncryptionType == AtomType("cbcs")) {
+    return CryptoScheme::Cbcs;
+  }
+  return mozilla::Err(nsLiteralCString(
+      "Could not determine encryption scheme. Sample description entry "
+      "reports sample is encrypted, but no scheme, or an unsupported scheme "
+      "is in use."));
+}
+
+Sample* SampleIterator::Get() {
+  if (!mIndex->mMoofParser) {
+    MOZ_ASSERT(!mCurrentMoof);
+    return mCurrentSample < mIndex->mIndex.Length()
+               ? &mIndex->mIndex[mCurrentSample]
+               : nullptr;
+  }
+
+  nsTArray<Moof>& moofs = mIndex->mMoofParser->Moofs();
+  while (true) {
+    if (mCurrentMoof == moofs.Length()) {
+      if (!mIndex->mMoofParser->BlockingReadNextMoof()) {
+        return nullptr;
+      }
+      MOZ_ASSERT(mCurrentMoof < moofs.Length());
+    }
+    if (mCurrentSample < moofs[mCurrentMoof].mIndex.Length()) {
+      break;
+    }
+    mCurrentSample = 0;
+    ++mCurrentMoof;
+  }
+  return &moofs[mCurrentMoof].mIndex[mCurrentSample];
+}
+
+void SampleIterator::Next() { ++mCurrentSample; }
+
+void SampleIterator::Seek(const TimeUnit& aTime) {
+  size_t syncMoof = 0;
+  size_t syncSample = 0;
+  mCurrentMoof = 0;
+  mCurrentSample = 0;
+  Sample* sample;
+  while (!!(sample = Get())) {
+    if (sample->mCompositionRange.start > aTime) {
+      break;
+    }
+    if (sample->mSync) {
+      syncMoof = mCurrentMoof;
+      syncSample = mCurrentSample;
+    }
+    if (sample->mCompositionRange.start == aTime) {
+      break;
+    }
+    Next();
+  }
+  mCurrentMoof = syncMoof;
+  mCurrentSample = syncSample;
+}
+
+TimeUnit SampleIterator::GetNextKeyframeTime() {
+  SampleIterator itr(*this);
+  Sample* sample;
+  while (!!(sample = itr.Get())) {
+    if (sample->mSync) {
+      return sample->mCompositionRange.start;
+    }
+    itr.Next();
+  }
+  return TimeUnit::Invalid();
+}
+
+MP4SampleIndex::MP4SampleIndex(const IndiceWrapper& aIndices,
+                               ByteStream* aSource, uint32_t aTrackId,
+                               bool aIsAudio, uint32_t aTimeScale)
+    : mSource(aSource), mIsAudio(aIsAudio) {
+  if (!aIndices.Length()) {
+    mMoofParser =
+        MakeUnique<MoofParser>(aSource, AsVariant(aTrackId), aIsAudio);
+  } else {
+    if (!mIndex.SetCapacity(aIndices.Length(), fallible)) {
+      // OOM.
+      return;
+    }
+    media::IntervalSet<TimeUnit> intervalTime;
+    MediaByteRange intervalRange;
+    bool haveSync = false;
+    bool progressive = true;
+    int64_t lastOffset = 0;
+    for (size_t i = 0; i < aIndices.Length(); i++) {
+      Indice indice{};
+      int64_t timescale =
+          mMoofParser ? AssertedCast<int64_t>(mMoofParser->mMvhd.mTimescale)
+                      : aTimeScale;
+      if (!aIndices.GetIndice(i, indice)) {
+        // Out of index?
+        return;
+      }
+      if (indice.sync || mIsAudio) {
+        haveSync = true;
+      }
+      if (!haveSync) {
+        continue;
+      }
+      Sample sample;
+      sample.mByteRange =
+          MediaByteRange(indice.start_offset, indice.end_offset);
+      sample.mCompositionRange = MP4Interval<media::TimeUnit>(
+          TimeUnit(indice.start_composition, timescale),
+          TimeUnit(indice.end_composition, timescale));
+      sample.mDecodeTime = TimeUnit(indice.start_decode, timescale);
+      sample.mSync = indice.sync || mIsAudio;
+      // FIXME: Make this infallible after bug 968520 is done.
+      MOZ_ALWAYS_TRUE(mIndex.AppendElement(sample, fallible));
+      if (indice.start_offset < lastOffset) {
+        NS_WARNING("Chunks in MP4 out of order, expect slow down");
+        progressive = false;
+      }
+      lastOffset = indice.end_offset;
+
+      // Pack audio samples in group of 128.
+      if (sample.mSync && progressive && (!mIsAudio || !(i % 128))) {
+        if (mDataOffset.Length()) {
+          auto& last = mDataOffset.LastElement();
+          last.mEndOffset = intervalRange.mEnd;
+          NS_ASSERTION(intervalTime.Length() == 1,
+                       "Discontinuous samples between keyframes");
+          last.mTime.start = intervalTime.GetStart();
+          last.mTime.end = intervalTime.GetEnd();
+        }
+        if (!mDataOffset.AppendElement(
+                MP4DataOffset(mIndex.Length() - 1, indice.start_offset),
+                fallible)) {
+          // OOM.
+          return;
+        }
+        intervalTime = media::IntervalSet<TimeUnit>();
+        intervalRange = MediaByteRange();
+      }
+      intervalTime += media::Interval<TimeUnit>(sample.mCompositionRange.start,
+                                                sample.mCompositionRange.end);
+      intervalRange = intervalRange.Span(sample.mByteRange);
+    }
+
+    if (mDataOffset.Length() && progressive) {
+      Indice indice;
+      if (!aIndices.GetIndice(aIndices.Length() - 1, indice)) {
+        return;
+      }
+      auto& last = mDataOffset.LastElement();
+      last.mEndOffset = indice.end_offset;
+      last.mTime =
+          MP4Interval<TimeUnit>(intervalTime.GetStart(), intervalTime.GetEnd());
+    } else {
+      mDataOffset.Clear();
+    }
+  }
+}
+
+MP4SampleIndex::~MP4SampleIndex() = default;
+
+void MP4SampleIndex::UpdateMoofIndex(const MediaByteRangeSet& aByteRanges) {
+  UpdateMoofIndex(aByteRanges, false);
+}
+
+void MP4SampleIndex::UpdateMoofIndex(const MediaByteRangeSet& aByteRanges,
+                                     bool aCanEvict) {
+  if (!mMoofParser) {
+    return;
+  }
+  size_t moofs = mMoofParser->Moofs().Length();
+  bool canEvict = aCanEvict && moofs > 1;
+  if (canEvict) {
+    // Check that we can trim the mMoofParser. We can only do so if all
+    // iterators have demuxed all possible samples.
+    for (const SampleIterator* iterator : mIterators) {
+      if ((iterator->mCurrentSample == 0 && iterator->mCurrentMoof == moofs) ||
+          iterator->mCurrentMoof == moofs - 1) {
+        continue;
+      }
+      canEvict = false;
+      break;
+    }
+  }
+  mMoofParser->RebuildFragmentedIndex(aByteRanges, &canEvict);
+  if (canEvict) {
+    // The moofparser got trimmed. Adjust all registered iterators.
+    for (SampleIterator* iterator : mIterators) {
+      iterator->mCurrentMoof -= moofs - 1;
+    }
+  }
+}
+
+TimeUnit MP4SampleIndex::GetEndCompositionIfBuffered(
+    const MediaByteRangeSet& aByteRanges) {
+  FallibleTArray<Sample>* index;
+  if (mMoofParser) {
+    int64_t base = mMoofParser->mMdhd.mTimescale;
+    if (!mMoofParser->ReachedEnd() || mMoofParser->Moofs().IsEmpty()) {
+      return TimeUnit::Zero(base);
+    }
+    index = &mMoofParser->Moofs().LastElement().mIndex;
+  } else {
+    index = &mIndex;
+  }
+
+  int64_t base = mMoofParser->mMdhd.mTimescale;
+  media::TimeUnit lastComposition = TimeUnit::Zero(base);
+  RangeFinder rangeFinder(aByteRanges);
+  for (size_t i = index->Length(); i--;) {
+    const Sample& sample = (*index)[i];
+    if (!rangeFinder.Contains(sample.mByteRange)) {
+      return TimeUnit::Zero(base);
+    }
+    lastComposition = std::max(lastComposition, sample.mCompositionRange.end);
+    if (sample.mSync) {
+      return lastComposition;
+    }
+  }
+  return TimeUnit::Zero(base);
+}
+
+TimeIntervals MP4SampleIndex::ConvertByteRangesToTimeRanges(
+    const MediaByteRangeSet& aByteRanges) {
+  if (aByteRanges == mLastCachedRanges) {
+    return mLastBufferedRanges;
+  }
+  mLastCachedRanges = aByteRanges;
+
+  if (mDataOffset.Length()) {
+    TimeIntervals timeRanges;
+    for (const auto& range : aByteRanges) {
+      uint32_t start = mDataOffset.IndexOfFirstElementGt(range.mStart - 1);
+      if (!mIsAudio && start == mDataOffset.Length()) {
+        continue;
+      }
+      uint32_t end = mDataOffset.IndexOfFirstElementGt(
+          range.mEnd, MP4DataOffset::EndOffsetComparator());
+      if (!mIsAudio && end < start) {
+        continue;
+      }
+      if (mIsAudio && start &&
+          range.Intersects(MediaByteRange(mDataOffset[start - 1].mStartOffset,
+                                          mDataOffset[start - 1].mEndOffset))) {
+        // Check if previous audio data block contains some available samples.
+        for (size_t i = mDataOffset[start - 1].mIndex; i < mIndex.Length();
+             i++) {
+          if (range.ContainsStrict(mIndex[i].mByteRange)) {
+            timeRanges += TimeInterval(mIndex[i].mCompositionRange.start,
+                                       mIndex[i].mCompositionRange.end);
+          }
+        }
+      }
+      if (end > start) {
+        for (uint32_t i = start; i < end; i++) {
+          timeRanges += TimeInterval(mDataOffset[i].mTime.start,
+                                     mDataOffset[i].mTime.end);
+        }
+      }
+      if (end < mDataOffset.Length()) {
+        // Find samples in partial block contained in the byte range.
+        for (size_t i = mDataOffset[end].mIndex;
+             i < mIndex.Length() && range.ContainsStrict(mIndex[i].mByteRange);
+             i++) {
+          timeRanges += TimeInterval(mIndex[i].mCompositionRange.start,
+                                     mIndex[i].mCompositionRange.end);
+        }
+      }
+    }
+    mLastBufferedRanges = timeRanges;
+    return timeRanges;
+  }
+
+  RangeFinder rangeFinder(aByteRanges);
+  nsTArray<MP4Interval<media::TimeUnit>> timeRanges;
+  nsTArray<FallibleTArray<Sample>*> indexes;
+  if (mMoofParser) {
+    // We take the index out of the moof parser and move it into a local
+    // variable so we don't get concurrency issues. It gets freed when we
+    // exit this function.
+    for (int i = 0; i < mMoofParser->Moofs().Length(); i++) {
+      Moof& moof = mMoofParser->Moofs()[i];
+
+      // We need the entire moof in order to play anything
+      if (rangeFinder.Contains(moof.mRange)) {
+        if (rangeFinder.Contains(moof.mMdatRange)) {
+          MP4Interval<media::TimeUnit>::SemiNormalAppend(timeRanges,
+                                                         moof.mTimeRange);
+        } else {
+          indexes.AppendElement(&moof.mIndex);
+        }
+      }
+    }
+  } else {
+    indexes.AppendElement(&mIndex);
+  }
+
+  bool hasSync = false;
+  for (size_t i = 0; i < indexes.Length(); i++) {
+    FallibleTArray<Sample>* index = indexes[i];
+    for (size_t j = 0; j < index->Length(); j++) {
+      const Sample& sample = (*index)[j];
+      if (!rangeFinder.Contains(sample.mByteRange)) {
+        // We process the index in decode order so we clear hasSync when we hit
+        // a range that isn't buffered.
+        hasSync = false;
+        continue;
+      }
+
+      hasSync |= sample.mSync;
+      if (!hasSync) {
+        continue;
+      }
+
+      MP4Interval<media::TimeUnit>::SemiNormalAppend(timeRanges,
+                                                     sample.mCompositionRange);
+    }
+  }
+
+  // This fixes up when the compositon order differs from the byte range order
+  nsTArray<MP4Interval<TimeUnit>> timeRangesNormalized;
+  MP4Interval<media::TimeUnit>::Normalize(timeRanges, &timeRangesNormalized);
+  // convert timeRanges.
+  media::TimeIntervals ranges;
+  for (size_t i = 0; i < timeRangesNormalized.Length(); i++) {
+    ranges += media::TimeInterval(timeRangesNormalized[i].start,
+                                  timeRangesNormalized[i].end);
+  }
+  mLastBufferedRanges = ranges;
+  return ranges;
+}
+
+uint64_t MP4SampleIndex::GetEvictionOffset(const TimeUnit& aTime) {
+  uint64_t offset = std::numeric_limits<uint64_t>::max();
+  if (mMoofParser) {
+    // We need to keep the whole moof if we're keeping any of it because the
+    // parser doesn't keep parsed moofs.
+    for (int i = 0; i < mMoofParser->Moofs().Length(); i++) {
+      Moof& moof = mMoofParser->Moofs()[i];
+
+      if (!moof.mTimeRange.Length().IsZero() && moof.mTimeRange.end > aTime) {
+        offset = std::min(offset, uint64_t(std::min(moof.mRange.mStart,
+                                                    moof.mMdatRange.mStart)));
+      }
+    }
+  } else {
+    // We've already parsed and stored the moov so we don't need to keep it.
+    // All we need to keep is the sample data itself.
+    for (size_t i = 0; i < mIndex.Length(); i++) {
+      const Sample& sample = mIndex[i];
+      if (aTime >= sample.mCompositionRange.end) {
+        offset = std::min(offset, uint64_t(sample.mByteRange.mEnd));
+      }
+    }
+  }
+  return offset;
+}
+
+void MP4SampleIndex::RegisterIterator(SampleIterator* aIterator) {
+  mIterators.AppendElement(aIterator);
+}
+
+void MP4SampleIndex::UnregisterIterator(SampleIterator* aIterator) {
+  mIterators.RemoveElement(aIterator);
+}
+
+}  // namespace mozilla