示例#1
0
void WebMBufferedState::NotifyDataArrived(const unsigned char* aBuffer, uint32_t aLength, int64_t aOffset)
{
  uint32_t idx = mRangeParsers.IndexOfFirstElementGt(aOffset - 1);
  if (idx == 0 || !(mRangeParsers[idx-1] == aOffset)) {
    // If the incoming data overlaps an already parsed range, adjust the
    // buffer so that we only reparse the new data.  It's also possible to
    // have an overlap where the end of the incoming data is within an
    // already parsed range, but we don't bother handling that other than by
    // avoiding storing duplicate timecodes when the parser runs.
    if (idx != mRangeParsers.Length() && mRangeParsers[idx].mStartOffset <= aOffset) {
      // Complete overlap, skip parsing.
      if (aOffset + aLength <= mRangeParsers[idx].mCurrentOffset) {
        return;
      }

      // Partial overlap, adjust the buffer to parse only the new data.
      int64_t adjust = mRangeParsers[idx].mCurrentOffset - aOffset;
      NS_ASSERTION(adjust >= 0, "Overlap detection bug.");
      aBuffer += adjust;
      aLength -= uint32_t(adjust);
    } else {
      mRangeParsers.InsertElementAt(idx, WebMBufferedParser(aOffset));
      if (idx != 0) {
        mRangeParsers[idx].SetTimecodeScale(mRangeParsers[0].GetTimecodeScale());
      }
    }
  }

  mRangeParsers[idx].Append(aBuffer,
                            aLength,
                            mTimeMapping,
                            mReentrantMonitor);

  // Merge parsers with overlapping regions and clean up the remnants.
  uint32_t i = 0;
  while (i + 1 < mRangeParsers.Length()) {
    if (mRangeParsers[i].mCurrentOffset >= mRangeParsers[i + 1].mStartOffset) {
      mRangeParsers[i + 1].mStartOffset = mRangeParsers[i].mStartOffset;
      mRangeParsers[i + 1].mInitEndOffset = mRangeParsers[i].mInitEndOffset;
      mRangeParsers.RemoveElementAt(i);
    } else {
      i += 1;
    }
  }

  if (mRangeParsers.IsEmpty()) {
    return;
  }

  ReentrantMonitorAutoEnter mon(mReentrantMonitor);
  mLastBlockOffset = mRangeParsers.LastElement().mBlockEndOffset;
}
示例#2
0
void WebMBufferedState::UpdateIndex(const MediaByteRangeSet& aRanges, MediaResource* aResource)
{
  for (uint32_t index = 0; index < aRanges.Length(); index++) {
    const MediaByteRange& range = aRanges[index];
    int64_t offset = range.mStart;
    uint32_t length = range.mEnd - range.mStart;

    uint32_t idx = mRangeParsers.IndexOfFirstElementGt(offset - 1);
    if (!idx || !(mRangeParsers[idx-1] == offset)) {
      // If the incoming data overlaps an already parsed range, adjust the
      // buffer so that we only reparse the new data.  It's also possible to
      // have an overlap where the end of the incoming data is within an
      // already parsed range, but we don't bother handling that other than by
      // avoiding storing duplicate timecodes when the parser runs.
      if (idx != mRangeParsers.Length() && mRangeParsers[idx].mStartOffset <= offset) {
        // Complete overlap, skip parsing.
        if (offset + length <= mRangeParsers[idx].mCurrentOffset) {
          continue;
        }

        // Partial overlap, adjust the buffer to parse only the new data.
        int64_t adjust = mRangeParsers[idx].mCurrentOffset - offset;
        NS_ASSERTION(adjust >= 0, "Overlap detection bug.");
        offset += adjust;
        length -= uint32_t(adjust);
      } else {
        mRangeParsers.InsertElementAt(idx, WebMBufferedParser(offset));
        if (idx) {
          mRangeParsers[idx].SetTimecodeScale(mRangeParsers[0].GetTimecodeScale());
        }
      }
    }

    MediaResourceIndex res(aResource);
    while (length > 0) {
      static const uint32_t BLOCK_SIZE = 1048576;
      uint32_t block = std::min(length, BLOCK_SIZE);
      RefPtr<MediaByteBuffer> bytes = res.CachedMediaReadAt(offset, block);
      if (!bytes) {
        break;
      }
      NotifyDataArrived(bytes->Elements(), bytes->Length(), offset);
      length -= bytes->Length();
      offset += bytes->Length();
    }
  }
}
示例#3
0
  bool ParseStartAndEndTimestamps(MediaLargeByteBuffer* aData,
                                  int64_t& aStart, int64_t& aEnd)
  {
    bool initSegment = IsInitSegmentPresent(aData);
    if (initSegment) {
      mOffset = 0;
      mParser = WebMBufferedParser(0);
      mOverlappedMapping.Clear();
      mInitData = new MediaLargeByteBuffer();
      mResource = new SourceBufferResource(NS_LITERAL_CSTRING("video/webm"));
    }

    // XXX if it only adds new mappings, overlapped but not available
    // (e.g. overlap < 0) frames are "lost" from the reported mappings here.
    nsTArray<WebMTimeDataOffset> mapping;
    mapping.AppendElements(mOverlappedMapping);
    mOverlappedMapping.Clear();
    ReentrantMonitor dummy("dummy");
    mParser.Append(aData->Elements(), aData->Length(), mapping, dummy);
    if (mResource) {
      mResource->AppendData(aData);
    }

    // XXX This is a bit of a hack.  Assume if there are no timecodes
    // present and it's an init segment that it's _just_ an init segment.
    // We should be more precise.
    if (initSegment || !HasCompleteInitData()) {
      if (mParser.mInitEndOffset > 0) {
        MOZ_ASSERT(mParser.mInitEndOffset <= mResource->GetLength());
        if (!mInitData->SetLength(mParser.mInitEndOffset)) {
          // Super unlikely OOM
          return false;
        }
        char* buffer = reinterpret_cast<char*>(mInitData->Elements());
        mResource->ReadFromCache(buffer, 0, mParser.mInitEndOffset);
        MSE_DEBUG(WebMContainerParser, "Stashed init of %u bytes.",
                  mParser.mInitEndOffset);
        mResource = nullptr;
      } else {
        MSE_DEBUG(WebMContainerParser, "Incomplete init found.");
      }
      mHasInitData = true;
    }
    mOffset += aData->Length();

    if (mapping.IsEmpty()) {
      return false;
    }

    // Exclude frames that we don't enough data to cover the end of.
    uint32_t endIdx = mapping.Length() - 1;
    while (mOffset < mapping[endIdx].mEndOffset && endIdx > 0) {
      endIdx -= 1;
    }

    if (endIdx == 0) {
      return false;
    }

    uint64_t frameDuration = mapping[endIdx].mTimecode - mapping[endIdx - 1].mTimecode;
    aStart = mapping[0].mTimecode / NS_PER_USEC;
    aEnd = (mapping[endIdx].mTimecode + frameDuration) / NS_PER_USEC;

    MSE_DEBUG(WebMContainerParser, "[%lld, %lld] [fso=%lld, leo=%lld, l=%u endIdx=%u]",
              aStart, aEnd, mapping[0].mSyncOffset, mapping[endIdx].mEndOffset, mapping.Length(), endIdx);

    mapping.RemoveElementsAt(0, endIdx + 1);
    mOverlappedMapping.AppendElements(mapping);

    return true;
  }