Low-Level C API

The low-level C API provides functionality for compressing individual d-dimensional blocks of up to 4^d values. If a block is not complete, i.e., contains fewer than 4^d values, then zfp’s partial block support should be favored over padding the block with, say, zeros or other fill values. The blocks (de)compressed need not be contiguous and can be gathered from or scattered to a larger array by setting appropriate strides.

The following topics are available:

• Stream Manipulation
• Encoder
  • 1D Data
  • 2D Data
  • 3D Data
  • 4D Data
• Decoder
  • 1D Data
  • 2D Data
  • 3D Data
  • 4D Data
• Utility Functions

Stream Manipulation

size_t zfp_stream_flush(zfp_stream* stream)

Flush bit stream to write out any buffered bits. This function must be must be called after the last encode call. The bit stream is aligned on a stream word boundary following this call. The number of zero-bits written, if any, is returned.

size_t zfp_stream_align(zfp_stream* stream)

Align bit stream on next word boundary. This function is analogous to zfp_stream_flush(), but for decoding. That is, wherever the encoder flushes the stream, the decoder should align it to ensure synchronization between encoder and decoder. The number of bits skipped, if any, is returned.

Encoder

A function is available for encoding whole or partial blocks of each scalar type and dimensionality. These functions return the number of bits of compressed storage for the block being encoded, or zero upon failure.

1D Data

uint zfp_encode_block_int32_1(zfp_stream* stream, const int32* block)

uint zfp_encode_block_int64_1(zfp_stream* stream, const int64* block)

uint zfp_encode_block_float_1(zfp_stream* stream, const float* block)

uint zfp_encode_block_double_1(zfp_stream* stream, const double* block)

Encode 1D contiguous block of 4 values.

uint zfp_encode_block_strided_int32_1(zfp_stream* stream, const int32* p, int sx)

uint zfp_encode_block_strided_int64_1(zfp_stream* stream, const int64* p, int sx)

uint zfp_encode_block_strided_float_1(zfp_stream* stream, const float* p, int sx)

uint zfp_encode_block_strided_double_1(zfp_stream* stream, const double* p, int sx)

Encode 1D complete block from strided array with stride sx.

uint zfp_encode_partial_block_strided_int32_1(zfp_stream* stream, const int32* p, uint nx, int sx)

uint zfp_encode_partial_block_strided_int64_1(zfp_stream* stream, const int64* p, uint nx, int sx)

uint zfp_encode_partial_block_strided_float_1(zfp_stream* stream, const float* p, uint nx, int sx)

uint zfp_encode_partial_block_strided_double_1(zfp_stream* stream, const double* p, uint nx, int sx)

Encode 1D partial block of size nx from strided array with stride sx.

2D Data

uint zfp_encode_block_int32_2(zfp_stream* stream, const int32* block)

uint zfp_encode_block_int64_2(zfp_stream* stream, const int64* block)

uint zfp_encode_block_float_2(zfp_stream* stream, const float* block)

uint zfp_encode_block_double_2(zfp_stream* stream, const double* block)

Encode 2D contiguous block of 4 × 4 values.

uint zfp_encode_block_strided_int32_2(zfp_stream* stream, const int32* p, int sx, int sy)

uint zfp_encode_block_strided_int64_2(zfp_stream* stream, const int64* p, int sx, int sy)

uint zfp_encode_block_strided_float_2(zfp_stream* stream, const float* p, int sx, int sy)

uint zfp_encode_block_strided_double_2(zfp_stream* stream, const double* p, int sx, int sy)

Encode 2D complete block from strided array with strides sx and sy.

uint zfp_encode_partial_block_strided_int32_2(zfp_stream* stream, const int32* p, uint nx, uint ny, int sx, int sy)

uint zfp_encode_partial_block_strided_int64_2(zfp_stream* stream, const int64* p, uint nx, uint ny, int sx, int sy)

uint zfp_encode_partial_block_strided_float_2(zfp_stream* stream, const float* p, uint nx, uint ny, int sx, int sy)

uint zfp_encode_partial_block_strided_double_2(zfp_stream* stream, const double* p, uint nx, uint ny, int sx, int sy)

Encode 2D partial block of size nx × ny from strided array with strides sx and sy.

3D Data

uint zfp_encode_block_int32_3(zfp_stream* stream, const int32* block)

uint zfp_encode_block_int64_3(zfp_stream* stream, const int64* block)

uint zfp_encode_block_float_3(zfp_stream* stream, const float* block)

uint zfp_encode_block_double_3(zfp_stream* stream, const double* block)

Encode 3D contiguous block of 4 × 4 × 4 values.

uint zfp_encode_block_strided_int32_3(zfp_stream* stream, const int32* p, int sx, int sy, int sz)

uint zfp_encode_block_strided_int64_3(zfp_stream* stream, const int64* p, int sx, int sy, int sz)

uint zfp_encode_block_strided_float_3(zfp_stream* stream, const float* p, int sx, int sy, int sz)

uint zfp_encode_block_strided_double_3(zfp_stream* stream, const double* p, int sx, int sy, int sz)

Encode 3D complete block from strided array with strides sx, sy, and sz.

uint zfp_encode_partial_block_strided_int32_3(zfp_stream* stream, const int32* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

uint zfp_encode_partial_block_strided_int64_3(zfp_stream* stream, const int64* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

uint zfp_encode_partial_block_strided_float_3(zfp_stream* stream, const float* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

uint zfp_encode_partial_block_strided_double_3(zfp_stream* stream, const double* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

Encode 3D partial block of size nx × ny × nz from strided array with strides sx, sy, and sz.

4D Data

uint zfp_encode_block_int32_4(zfp_stream* stream, const int32* block)

uint zfp_encode_block_int64_4(zfp_stream* stream, const int64* block)

uint zfp_encode_block_float_4(zfp_stream* stream, const float* block)

uint zfp_encode_block_double_4(zfp_stream* stream, const double* block)

Encode 4D contiguous block of 4 × 4 × 4 × 4 values.

uint zfp_encode_block_strided_int32_4(zfp_stream* stream, const int32* p, int sx, int sy, int sz, int sw)

uint zfp_encode_block_strided_int64_4(zfp_stream* stream, const int64* p, int sx, int sy, int sz, int sw)

uint zfp_encode_block_strided_float_4(zfp_stream* stream, const float* p, int sx, int sy, int sz, int sw)

uint zfp_encode_block_strided_double_4(zfp_stream* stream, const double* p, int sx, int sy, int sz, int sw)

Encode 4D complete block from strided array with strides sx, sy, sz, and sw.

uint zfp_encode_partial_block_strided_int32_4(zfp_stream* stream, const int32* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

uint zfp_encode_partial_block_strided_int64_4(zfp_stream* stream, const int64* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

uint zfp_encode_partial_block_strided_float_4(zfp_stream* stream, const float* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

uint zfp_encode_partial_block_strided_double_4(zfp_stream* stream, const double* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

Encode 4D partial block of size nx × ny × nz × nw from strided array with strides sx, sy, sz, and sw.

Decoder

Each function below decompresses a single block and returns the number of bits of compressed storage consumed. See corresponding encoder functions above for further details.

1D Data

uint zfp_decode_block_int32_1(zfp_stream* stream, int32* block)

uint zfp_decode_block_int64_1(zfp_stream* stream, int64* block)

uint zfp_decode_block_float_1(zfp_stream* stream, float* block)

uint zfp_decode_block_double_1(zfp_stream* stream, double* block)

Decode 1D contiguous block of 4 values.

uint zfp_decode_block_strided_int32_1(zfp_stream* stream, int32* p, int sx)

uint zfp_decode_block_strided_int64_1(zfp_stream* stream, int64* p, int sx)

uint zfp_decode_block_strided_float_1(zfp_stream* stream, float* p, int sx)

uint zfp_decode_block_strided_double_1(zfp_stream* stream, double* p, int sx)

Decode 1D complete block to strided array with stride sx.

uint zfp_decode_partial_block_strided_int32_1(zfp_stream* stream, int32* p, uint nx, int sx)

uint zfp_decode_partial_block_strided_int64_1(zfp_stream* stream, int64* p, uint nx, int sx)

uint zfp_decode_partial_block_strided_float_1(zfp_stream* stream, float* p, uint nx, int sx)

uint zfp_decode_partial_block_strided_double_1(zfp_stream* stream, double* p, uint nx, int sx)

Decode 1D partial block of size nx to strided array with stride sx.

2D Data

uint zfp_decode_block_int32_2(zfp_stream* stream, int32* block)

uint zfp_decode_block_int64_2(zfp_stream* stream, int64* block)

uint zfp_decode_block_float_2(zfp_stream* stream, float* block)

uint zfp_decode_block_double_2(zfp_stream* stream, double* block)

Decode 2D contiguous block of 4 × 4 values.

uint zfp_decode_block_strided_int32_2(zfp_stream* stream, int32* p, int sx, int sy)

uint zfp_decode_block_strided_int64_2(zfp_stream* stream, int64* p, int sx, int sy)

uint zfp_decode_block_strided_float_2(zfp_stream* stream, float* p, int sx, int sy)

uint zfp_decode_block_strided_double_2(zfp_stream* stream, double* p, int sx, int sy)

Decode 2D complete block to strided array with strides sx and sy.

uint zfp_decode_partial_block_strided_int32_2(zfp_stream* stream, int32* p, uint nx, uint ny, int sx, int sy)

uint zfp_decode_partial_block_strided_int64_2(zfp_stream* stream, int64* p, uint nx, uint ny, int sx, int sy)

uint zfp_decode_partial_block_strided_float_2(zfp_stream* stream, float* p, uint nx, uint ny, int sx, int sy)

uint zfp_decode_partial_block_strided_double_2(zfp_stream* stream, double* p, uint nx, uint ny, int sx, int sy)

Decode 2D partial block of size nx × ny to strided array with strides sx and sy.

3D Data

uint zfp_decode_block_int32_3(zfp_stream* stream, int32* block)

uint zfp_decode_block_int64_3(zfp_stream* stream, int64* block)

uint zfp_decode_block_float_3(zfp_stream* stream, float* block)

uint zfp_decode_block_double_3(zfp_stream* stream, double* block)

Decode 3D contiguous block of 4 × 4 × 4 values.

uint zfp_decode_block_strided_int32_3(zfp_stream* stream, int32* p, int sx, int sy, int sz)

uint zfp_decode_block_strided_int64_3(zfp_stream* stream, int64* p, int sx, int sy, int sz)

uint zfp_decode_block_strided_float_3(zfp_stream* stream, float* p, int sx, int sy, int sz)

uint zfp_decode_block_strided_double_3(zfp_stream* stream, double* p, int sx, int sy, int sz)

Decode 3D complete block to strided array with strides sx, sy, and sz.

uint zfp_decode_partial_block_strided_int32_3(zfp_stream* stream, int32* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

uint zfp_decode_partial_block_strided_int64_3(zfp_stream* stream, int64* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

uint zfp_decode_partial_block_strided_float_3(zfp_stream* stream, float* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

uint zfp_decode_partial_block_strided_double_3(zfp_stream* stream, double* p, uint nx, uint ny, uint nz, int sx, int sy, int sz)

Decode 3D partial block of size nx × ny × nz to strided array with strides sx, sy, and sz.

4D Data

uint zfp_decode_block_int32_4(zfp_stream* stream, int32* block)

uint zfp_decode_block_int64_4(zfp_stream* stream, int64* block)

uint zfp_decode_block_float_4(zfp_stream* stream, float* block)

uint zfp_decode_block_double_4(zfp_stream* stream, double* block)

Decode 4D contiguous block of 4 × 4 × 4 × 4 values.

uint zfp_decode_block_strided_int32_4(zfp_stream* stream, int32* p, int sx, int sy, int sz, int sw)

uint zfp_decode_block_strided_int64_4(zfp_stream* stream, int64* p, int sx, int sy, int sz, int sw)

uint zfp_decode_block_strided_float_4(zfp_stream* stream, float* p, int sx, int sy, int sz, int sw)

uint zfp_decode_block_strided_double_4(zfp_stream* stream, double* p, int sx, int sy, int sz, int sw)

Decode 4D complete block to strided array with strides sx, sy, sz, and sw.

uint zfp_decode_partial_block_strided_int32_4(zfp_stream* stream, int32* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

uint zfp_decode_partial_block_strided_int64_4(zfp_stream* stream, int64* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

uint zfp_decode_partial_block_strided_float_4(zfp_stream* stream, float* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

uint zfp_decode_partial_block_strided_double_4(zfp_stream* stream, double* p, uint nx, uint ny, uint nz, uint nw, int sx, int sy, int sz, int sw)

Decode 4D partial block of size nx × ny × nz × nw to strided array with strides sx, sy, sz, and sw.

Utility Functions

These functions convert 8- and 16-bit signed and unsigned integer data to (by promoting) and from (by demoting) 32-bit integers that can be (de)compressed by zfp’s int32 functions. These conversion functions are preferred over simple casting since they eliminate the redundant leading zeros that would otherwise have to be compressed, and they apply the appropriate bias for unsigned integer data.

void zfp_promote_int8_to_int32(int32* oblock, const int8* iblock, uint dims)

void zfp_promote_uint8_to_int32(int32* oblock, const uint8* iblock, uint dims)

void zfp_promote_int16_to_int32(int32* oblock, const int16* iblock, uint dims)

void zfp_promote_uint16_to_int32(int32* oblock, const uint16* iblock, uint dims)

Convert dims-dimensional contiguous block to 32-bit integer type.

void zfp_demote_int32_to_int8(int8* oblock, const int32* iblock, uint dims)

void zfp_demote_int32_to_uint8(uint8* oblock, const int32* iblock, uint dims)

void zfp_demote_int32_to_int16(int16* oblock, const int32* iblock, uint dims)

void zfp_demote_int32_to_uint16(uint16* oblock, const int32* iblock, uint dims)

Convert dims-dimensional contiguous block from 32-bit integer type.