To use this in an Apache Pig you must make sure this library has been added as a dependency.
Simply download the prebuilt library from Maven Central. You can find the latest jar file here: https://search.maven.org/search?q=a:splittablegzip
Then in Pig you need to load this jat file into your job.
REGISTER splittablegzip-*.jar
and then before actually running the job you set the configuration using something like this:
-- Set the compression codecs so that the GZipCodec is removed and the splittable variant is added.
-- In this example we simply remove everything and only have the splittable codec.
SET io.compression.codecs nl.basjes.hadoop.io.compress.SplittableGzipCodec
-- Tune the settings how big the splits should be.
SET mapreduce.input.fileinputformat.split.minsize $splitsize
SET mapreduce.input.fileinputformat.split.maxsize $splitsize
-- Avoid PIG merging multiple splits back to a single mapper.
-- http://stackoverflow.com/q/17054880
SET pig.noSplitCombination true
And after this the actual job is done.