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scramble(1)			 Staden	io_lib			   scramble(1)

NAME
       scramble	- Converts between the SAM, BAM	and CRAM file formats.

SYNOPSIS
       scramble	 [options] [input_file [output_file]]

DESCRIPTION
       scramble	 converts  between  various next-gen sequencing	alignment file
       formats,	including SAM, BAM and CRAM. It	can either act as a pipe read-
       ing stdin and writing to	stdout,	or on named files.

       When operating as a pipe	the input type defaults	to SAM or BAM, requir-
       ing the -I cram option to indicate input	is in CRAM format is appropri-
       ate. The	output defaults	to BAM,	but can	be adjusted by	using  the  -O
       format option. When given filenames the file type is automatically cho-
       sen based on the	filename suffix.

OPTIONS
       -I format
	      Selects  the  input  format,  where format is one	of sam,	bam or
	      cram.  Use this when reading via a pipe to avoid input bytes be-
	      ing consumed when	attempting to detect if	the input is in	SAM or
	      BAM format.

       -O format
	      Selects the output format, where format is one of	 sam,  bam  or
	      cram.

       -1 to -9
	      Sets  the	 compression level from	1 (low compression, fast) to 9
	      (high compression, slow) when writing in	BAM  or	 CRAM  format.
	      This is only used	during writing.

       -0 or -u
	      Writes  uncompressed  data. In BAM this still uses BGZF contain-
	      ers, but with no internal	compression. In	CRAM it	stores	blocks
	      in RAW format instead. The option	has no effect on SAM output.

       -j     CRAM  encoding only.  Add	bzip2 to the list of compression codes
	      potentially used during CRAM creation.

       -Z     CRAM encoding only.  Add lzma to the list	of  compression	 codes
	      potentially  used	during CRAM creation.  Given the slow compres-
	      sion speed of lzma, this may only	be used	where it gives a  sig-
	      nificant	advantage over zlib or bzip2, but with higher compres-
	      sion levels (-7) this weighting is ignored as LZMA decompression
	      speed is acceptable, albeit still	slower than zlib.

       -m     CRAM decoding only. Generate MD:Z: and  NM:I:  auxiliary	fields
	      based on the reference-based compression.

       -M     CRAM  encoding only.  Forcibly pack sequences from multiple ref-
	      erences into the same slice.  Normally CRAM  will	 start	a  new
	      slice  when  changing  from  one	reference to another, but will
	      still automatically switch to multi-reference slices if the num-
	      ber of sequences per slice becomes too small.

       -R range
	      Currently	for CRAM input only, but SAM/BAM support  is  pending.
	      This  indicates a	reference sequence name	and optionally a start
	      and  end	location  within  that	reference,  using  the	syntax
	      ref_name or ref_name:start-end. For efficient operation the CRAM
	      file needs a .crai format	index (built using the cram_index pro-
	      gram).

       -r ref.fa
	      CRAM  encoding  only.   Use  this	to specify the reference fasta
	      file.  Note that if the input SAM	or BAM file a file:  or	 local
	      file system based	URI specified in the @SQ headers then this op-
	      tion may not be necessary.

       -s number
	      CRAM  encoding  only.   Specifies	 the  number  of sequecnes per
	      slice.  Defaults to 10000.

       -S number
	      CRAM encoding only.   Specifies the number of  slices  per  con-
	      tainer.  Defaults	to 1.

       -t     BAM  and	CRAM only.  Specifies the number of compression	or de-
	      compression threads, adaptively shared between both encoding and
	      decoding.	 Defaults to 1 (no threading).

       -V version_string
	      CRAM encoding only.  Sets	the CRAM  file	format	version.  Sup-
	      ported values are	"2.0", "2.1" and "3.0".

       -e     CRAM  encoding only. Embed snippets of the reference sequence in
	      every slice.  This means the files can be	decoded	without	 need-
	      ing to specify the reference fasta file.

       -x     CRAM  encoding  only.   Omit reference based compression and in-
	      stead store details of every base	verbatim.

       -B     Experimental, encoding only.  When storing quality  values,  bin
	      into 8 discrete values (plus 0), as typically used by modern Il-
	      lumina  instruments.   (Note  that the bins may not be precisely
	      the same ranges.)

       -!     CRAM v3.0	and above decoding only. Do not	check CRCs.  This  op-
	      tion  should only	be used	when attempting	to recover from	a data
	      corruption.

       -q     Do not append @PG	header lines with the  scramble	 program  name
	      and arguments.

EXAMPLES
       To  convert  a  BAM  file from stdin to CRAM on stdout, using reference
       MT.fa.

	   some_command	| scramble -I bam -O cram -r MT.fa | some_command

       The default CRAM	output format is version 3.0, so no version  needs  to
       be  specified  when converting from 2.1 to 3.0.	To perform the reverse
       use:

	   scramble -V 2.1 in.cram out.cram

AUTHOR
       James Bonfield, Wellcome	Trust Sanger Institute

				 March 19 2013			   scramble(1)

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