THPDFLoadedStreamOptimizationInfo Record
ScannedStreamCount, CandidateStreamCount, RewrittenStreamCount, UnsupportedStreamCount and DecodeFailureCount track scan and rewrite coverage
BytesBefore, BytesAfter, and BytesSaved report the byte reduction
FilterStatistics nests decode statistics and RecompressionMode records the selected Flate recompression mode
CompressionTrialCount and the Zopfli* counters measure recompression trials, completions, selections, budget exceedances, input bytes, savings over baseline and elapsed time