Utility variables¶

This are enum values which avoid the nuisance of remembering codes and IDs.

Limits for different features¶

enumerator BLOSC_MIN_HEADER_LENGTH¶: Minimum header length (Blosc1)

enumerator BLOSC_EXTENDED_HEADER_LENGTH¶: Extended header length (Blosc2, see README_HEADER)

enumerator BLOSC2_MAX_OVERHEAD¶

The maximum overhead during compression in bytes.

This equals to BLOSC_EXTENDED_HEADER_LENGTH now, but can be higher in future implementations.

enumerator BLOSC_MIN_BUFFERSIZE¶: Minimum buffer size to be compressed.

enumerator BLOSC2_MAX_BUFFERSIZE¶: Maximum source buffer size to be compressed.

enumerator BLOSC_MAX_TYPESIZE¶

Maximum typesize before considering source buffer as a stream of bytes.

Cannot be larger than 255.

enumerator BLOSC2_MAX_FILTERS¶: Maximum number of filters in the filter pipeline.

Codes for filters¶

enumerator BLOSC_NOSHUFFLE¶: No shuffle (for compatibility with Blosc1).

enumerator BLOSC_NOFILTER¶: No filter.

enumerator BLOSC_SHUFFLE¶: Byte-wise shuffle. filters_meta does not have any effect here.

enumerator BLOSC_BITSHUFFLE¶: Bit-wise shuffle. filters_meta does not have any effect here.

enumerator BLOSC_DELTA¶: Delta filter. filters_meta does not have any effect here.

enumerator BLOSC_TRUNC_PREC¶

Truncate mantissa precision.

Positive values in filters_meta will keep bits; negative values will zero bits.

enumerator BLOSC_FILTER_NDCELL¶

Simple filter for grouping NDim cell data together.

See https://github.com/Blosc/c-blosc2/blob/main/plugins/filters/ndcell/README.md

enumerator BLOSC_FILTER_NDMEAN¶

Simple filter for replacing content of a NDim cell with its mean value.

See https://github.com/Blosc/c-blosc2/blob/main/plugins/filters/ndmean/README.md

enumerator BLOSC_FILTER_BYTEDELTA¶

Byteshuffle + delta.

The typesize should be specified in the filters_meta slot. Sometimes this can represent an advantage over BLOSC_SHUFFLE or BLOSC_BITSHUFFLE. See https://www.blosc.org/posts/bytedelta-enhance-compression-toolset/

enumerator BLOSC_FILTER_INT_TRUNC¶

Truncate int precision; positive values in filters_meta slot will keep bits; negative values will remove (set to zero) bits.

This is similar to BLOSC_TRUNC_PREC, but for integers instead of floating point data.

Compressor codecs¶

enumerator BLOSC_BLOSCLZ¶

enumerator BLOSC_LZ4¶

enumerator BLOSC_LZ4HC¶

enumerator BLOSC_ZLIB¶

enumerator BLOSC_ZSTD¶

enumerator BLOSC_CODEC_NDLZ¶: Simple Lempel-Ziv compressor for NDim data. Experimental, mainly for teaching purposes.

enumerator BLOSC_CODEC_ZFP_FIXED_ACCURACY¶

ZFP compressor for fixed accuracy mode.

The desired accuracy is set in compcode_meta. See https://github.com/Blosc/c-blosc2/blob/main/plugins/codecs/zfp/README.md

enumerator BLOSC_CODEC_ZFP_FIXED_PRECISION¶

ZFP compressor for fixed precision.

The desired precision is set in compcode_meta. See https://github.com/Blosc/c-blosc2/blob/main/plugins/codecs/zfp/README.md

enumerator BLOSC_CODEC_ZFP_FIXED_RATE¶

ZFP compressor for fixed precision.

The desired rate is set in compcode_meta. See https://github.com/Blosc/c-blosc2/blob/main/plugins/codecs/zfp/README.md

enumerator BLOSC_CODEC_OPENHTJ2K¶

OpenHTJ2K compressor for JPEG 2000 HT.

See https://github.com/Blosc/blosc2_openhtj2k

enumerator BLOSC_CODEC_GROK¶

Grok compressor for JPEG 2000.

See https://github.com/Blosc/blosc2_grok

Compressor names¶

BLOSC_BLOSCLZ_COMPNAME "blosclz"¶

BLOSC_LZ4_COMPNAME "lz4"¶

BLOSC_LZ4HC_COMPNAME "lz4hc"¶

BLOSC_ZLIB_COMPNAME "zlib"¶

BLOSC_ZSTD_COMPNAME "zstd"¶

Internal flags (blosc1_cbuffer_metainfo)¶

enumerator BLOSC_DOSHUFFLE¶: byte-wise shuffle

enumerator BLOSC_MEMCPYED¶: plain copy

enumerator BLOSC_DOBITSHUFFLE¶: bit-wise shuffle

enumerator BLOSC_DODELTA¶: delta coding

C-Blosc2 API

Utility functions