Move registry to interp and add support for functions and filesystems.
This will be used later for allow formats to add own functions and fq code.
Add gojqextra function helpers to have more comfortable API to add functions.
Takes care of argument type casting and JQValue:s and some more things.
Refactor interp package to use new function helper and registry. Probably
fixes a bunch of JQValue bugs and other type errors.
Refactor out some mpeg nal things to mpeg format.
Refactor interp jq code into display.q and init.jq.
Remove undocumented aes_ctr funciton, was a test. Hopefully will add more crypto things laster.
Decode API design is that Try* returns error non-Try panics.
Also rename Must* as they should panic and introduce some new Try* functions
that were missing.
PSSH decoding probably got broken in some refactoring. system id is 16 bytes,
also scalar mapper should use cloned reader to not affect reader which in the case
broke reading system id bytes.
Add test with playread and widevine pssh boxes
Related to #282
Rename s/interface{}/any/g
Preparation for using generics in decode API and native jq funcations etc
Remove some unused linter ignores as linter has been fixed
Remove bitio.Buffer layer. bitio.Buffer was a kitchen sink layer with helpers
now it's just a buffer and most functions have been moved to decode instead.
bitio package now only have primitive types and functions simialar to standard
library io and bytes packages.
Make nearly eveything internally use bitio.Bit* interfaces so that slicing work
correctly this will also make it possible to start experimenting with more
complicated silcing helpers, ex things like:
breplace(.header.bitrate; 123) to get a new buffer with bitrate changed.
Move scalar into own package.
Split scalar code into decode related scalar code (that reads etc) and
scalar code that just transform the scalar value.
Use a scalar.Mapper interface instead of just a function.
Make mappers, assert and validat impement the interface.
