-i, --in1                                        read1 input file name (string [=])
  -I, --in2                                        read2 input file name (string [=])
  -o, --out1                                       file name to store read1 with on-target sequences (string [=])
  -O, --out2                                       file name to store read2 with on-target sequences (string [=])
  -c, --kmer_collection                            the unique k-mer collection file in fasta format, see an example: http://opengene.org/kmer_collection.fasta (string [=])
  -k, --kmer                                       the unique k-mer file of the detection target in fasta format. data/SARS-CoV-2.kmer.fa will be used if none of k-mer/Genomes/k-mer_Collection file is specified (string [=])
  -g, --genomes                                    the genomes file of the detection target in fasta format. data/SARS-CoV-2.genomes.fa will be used if none of k-mer/Genomes/k-mer_Collection file is specified (string [=])
  -p, --positive_threshold                         the data is considered as POSITIVE, when its mean coverage of unique kmer >= positive_threshold (0.001 ~ 100). 0.1 by default. (float [=0.1])
  -d, --depth_threshold                            For coverage calculation. A region is considered covered when its mean depth >= depth_threshold (0.001 ~ 1000). 1.0 by default. (float [=1])
  -E, --ed_threshold                               If the edit distance of a sequence and a genome region is <=ed_threshold, then consider it a match (0 ~ 50). 8 by default. (int [=8])
      --long_read_threshold                        A read will be considered as long read if its length >= long_read_threshold (100 ~ 10000). 200 by default. (int [=200])
      --read_segment_len                           A long read will be splitted to read segments, with each <= read_segment_len (50 ~ 5000, should be < long_read_threshold). 100 by default. (int [=100])
      --bin_size                                   For coverage calculation. The genome is splitted to many bins, with each bin has a length of bin_size (1 ~ 100000), default 0 means adaptive. (int [=0])
      --kc_coverage_threshold                      For each genome in the k-mer collection FASTA, report it when its coverage > kc_coverage_threshold. Default is 0.01. (double [=0.01])
      --kc_high_confidence_coverage_threshold      For each genome in the k-mer collection FASTA, report it as high confidence when its coverage > kc_high_confidence_coverage_threshold. Default is 0.9. (double [=0.9])
      --kc_high_confidence_median_hit_threshold    For each genome in the k-mer collection FASTA, report it as high confidence when its median hits > kc_high_confidence_median_hit_threshold. Default is 5. (int [=5])
  -j, --json                                       the json format report file name (string [=fastv.json])
  -h, --html                                       the html format report file name (string [=fastv.html])
  -R, --report_title                               should be quoted with ' or ", default is "fastv report" (string [=fastv report])
  -w, --thread                                     worker thread number, default is 4 (int [=4])

  -6, --phred64                       indicate the input is using phred64 scoring (it'll be converted to phred33, so the output will still be phred33)
  -z, --compression                   compression level for gzip output (1 ~ 9). 1 is fastest, 9 is smallest, default is 4. (int [=4])
      --stdin                         input from STDIN. If the STDIN is interleaved paired-end FASTQ, please also add --interleaved_in.
      --stdout                        stream passing-filters reads to STDOUT. This option will result in interleaved FASTQ output for paired-end output. Disabled by default.
      --interleaved_in                indicate that <in1> is an interleaved FASTQ which contains both read1 and read2. Disabled by default.
      --reads_to_process              specify how many reads/pairs to be processed. Default 0 means process all reads. (int [=0])
      --dont_overwrite                don't overwrite existing files. Overwritting is allowed by default.
  -V, --verbose                       output verbose log information (i.e. when every 1M reads are processed).

  -A, --disable_adapter_trimming      adapter trimming is enabled by default. If this option is specified, adapter trimming is disabled
  -a, --adapter_sequence              the adapter for read1. For SE data, if not specified, the adapter will be auto-detected. For PE data, this is used if R1/R2 are found not overlapped. (string [=auto])
      --adapter_sequence_r2           the adapter for read2 (PE data only). This is used if R1/R2 are found not overlapped. If not specified, it will be the same as <adapter_sequence> (string [=auto])
      --adapter_fasta                 specify a FASTA file to trim both read1 and read2 (if PE) by all the sequences in this FASTA file (string [=])
      --detect_adapter_for_pe         by default, the auto-detection for adapter is for SE data input only, turn on this option to enable it for PE data.
  -f, --trim_front1                   trimming how many bases in front for read1, default is 0 (int [=0])
  -t, --trim_tail1                    trimming how many bases in tail for read1, default is 0 (int [=0])
  -b, --max_len1                      if read1 is longer than max_len1, then trim read1 at its tail to make it as long as max_len1. Default 0 means no limitation (int [=0])
  -F, --trim_front2                   trimming how many bases in front for read2. If it's not specified, it will follow read1's settings (int [=0])
  -T, --trim_tail2                    trimming how many bases in tail for read2. If it's not specified, it will follow read1's settings (int [=0])
  -B, --max_len2                      if read2 is longer than max_len2, then trim read2 at its tail to make it as long as max_len2. Default 0 means no limitation. If it's not specified, it will follow read1's settings (int [=0])
      --poly_g_min_len                the minimum length to detect polyG in the read tail. 10 by default. (int [=10])
  -G, --disable_trim_poly_g           disable polyG tail trimming, by default trimming is automatically enabled for Illumina NextSeq/NovaSeq data
  -x, --trim_poly_x                   enable polyX trimming in 3' ends.
      --poly_x_min_len                the minimum length to detect polyX in the read tail. 10 by default. (int [=10])
  -5, --cut_front                     move a sliding window from front (5') to tail, drop the bases in the window if its mean quality < threshold, stop otherwise.
  -3, --cut_tail                      move a sliding window from tail (3') to front, drop the bases in the window if its mean quality < threshold, stop otherwise.
  -r, --cut_right                     move a sliding window from front to tail, if meet one window with mean quality < threshold, drop the bases in the window and the right part, and then stop.
  -W, --cut_window_size               the window size option shared by cut_front, cut_tail or cut_sliding. Range: 1~1000, default: 4 (int [=4])
  -M, --cut_mean_quality              the mean quality requirement option shared by cut_front, cut_tail or cut_sliding. Range: 1~36 default: 20 (Q20) (int [=20])
      --cut_front_window_size         the window size option of cut_front, default to cut_window_size if not specified (int [=4])
      --cut_front_mean_quality        the mean quality requirement option for cut_front, default to cut_mean_quality if not specified (int [=20])
      --cut_tail_window_size          the window size option of cut_tail, default to cut_window_size if not specified (int [=4])
      --cut_tail_mean_quality         the mean quality requirement option for cut_tail, default to cut_mean_quality if not specified (int [=20])
      --cut_right_window_size         the window size option of cut_right, default to cut_window_size if not specified (int [=4])
      --cut_right_mean_quality        the mean quality requirement option for cut_right, default to cut_mean_quality if not specified (int [=20])
  -Q, --disable_quality_filtering     quality filtering is enabled by default. If this option is specified, quality filtering is disabled
  -q, --qualified_quality_phred       the quality value that a base is qualified. Default 15 means phred quality >=Q15 is qualified. (int [=15])
  -u, --unqualified_percent_limit     how many percents of bases are allowed to be unqualified (0~100). Default 40 means 40% (int [=40])
  -n, --n_base_limit                  if one read's number of N base is >n_base_limit, then this read/pair is discarded. Default is 5 (int [=5])
  -e, --average_qual                  if one read's average quality score <avg_qual, then this read/pair is discarded. Default 0 means no requirement (int [=0])
  -L, --disable_length_filtering      length filtering is enabled by default. If this option is specified, length filtering is disabled
  -l, --length_required               reads shorter than length_required will be discarded, default is 15. (int [=15])
      --length_limit                  reads longer than length_limit will be discarded, default 0 means no limitation. (int [=0])
  -y, --low_complexity_filter         enable low complexity filter. The complexity is defined as the percentage of base that is different from its next base (base[i] != base[i+1]).
  -Y, --complexity_threshold          the threshold for low complexity filter (0~100). Default is 30, which means 30% complexity is required. (int [=30])
      --filter_by_index1              specify a file contains a list of barcodes of index1 to be filtered out, one barcode per line (string [=])
      --filter_by_index2              specify a file contains a list of barcodes of index2 to be filtered out, one barcode per line (string [=])
      --filter_by_index_threshold     the allowed difference of index barcode for index filtering, default 0 means completely identical. (int [=0])
  -C, --correction                    enable base correction in overlapped regions (only for PE data), default is disabled
      --overlap_len_require           the minimum length to detect overlapped region of PE reads. This will affect overlap analysis based PE merge, adapter trimming and correction. 30 by default. (int [=30])
      --overlap_diff_limit            the maximum number of mismatched bases to detect overlapped region of PE reads. This will affect overlap analysis based PE merge, adapter trimming and correction. 5 by default. (int [=5])
      --overlap_diff_percent_limit    the maximum percentage of mismatched bases to detect overlapped region of PE reads. This will affect overlap analysis based PE merge, adapter trimming and correction. Default 20 means 20%. (int [=20])
  -U, --umi                           enable unique molecular identifier (UMI) preprocessing
      --umi_loc                       specify the location of UMI, can be (index1/index2/read1/read2/per_index/per_read, default is none (string [=])
      --umi_len                       if the UMI is in read1/read2, its length should be provided (int [=0])
      --umi_prefix                    if specified, an underline will be used to connect prefix and UMI (i.e. prefix=UMI, UMI=AATTCG, final=UMI_AATTCG). No prefix by default (string [=])
      --umi_skip                      if the UMI is in read1/read2, fastv can skip several bases following UMI, default is 0 (int [=0])