Is your feature request related to a problem? Please specify.

I'm trying to setup tests to verify full cram support in a tool that accepts bam and cram inputs. I assumed samtools view would enable conversion of bam to cram with some type of bzip2 or lzma option but I can't find any mechanism to do this.

Describe the solution you would like.

I would like some path to test and verify our level of cram support. Either options to control block codecs when creating cram or a simple set of small test cram files in samtools' own test/ resources (or any other approach that meets the above test goal).