pyktx.ktx_basis_params module

class pyktx.ktx_basis_params.KtxBasisParams(uastc: bool = False, verbose: bool = False, no_sse: bool = False, thread_count: int = 1, compression_level: int = 0, quality_level: int = 0, max_endpoints: int = 0, endpoint_rdo_threshold: int = 0, max_selectors: int = 0, selector_rdo_threshold: int = 0, input_swizzle: bytes = b'\x00\x00\x00\x00', normal_map: bool = False, pre_swizzle: bool = False, separate_rg_to_rgb_a: bool = False, no_endpoint_rdo: bool = False, no_selector_rdo: bool = False, uastc_flags: int = KtxPackUastcFlagBits.FASTEST, uastc_rdo: bool = False, uastc_rdo_quality_scalar: float = 0.0, uastc_rdo_dict_size: int = 0, uastc_rdo_max_smooth_block_error_scale: float = 10.0, uastc_rdo_max_smooth_block_std_dev: float = 18.0, uastc_rdo_dont_favor_simpler_modes: bool = False, uastc_rdo_no_multithreading: bool = False)

Bases: object

Data for passing extended params to KtxTexture2.compressBasis().

compression_level: int = 0

Encoding speed vs. quality tradeoff. Range is [0,5].

Higher values are slower, but give higher quality. There is no default. Callers must explicitly set this value. Callers can use KTX_ETC1S_DEFAULT_COMPRESSION_LEVEL as a default value. Currently this is 2.

endpoint_rdo_threshold: int = 0

Set endpoint RDO quality threshold. The default is 1.25.

Lower is higher quality but less quality per output bit (try [1.0,3.0]. This will override the value chosen by quality_level.

input_swizzle: bytes = b'\x00\x00\x00\x00'

A swizzle to apply before encoding.

It must match the regular expression /^[rgba01]{4}$/. If both this and pre_swizzle are specified KtxTexture2.compressBasis() will raise INVALID_OPERATION.

max_endpoints: int = 0

Manually set the max number of color endpoint clusters.

Range is [1,16128]. Default is 0, unset. If this is set, max_selectors must also be set, otherwise the value will be ignored.

max_selectors: int = 0

Manually set the max number of color selector clusters. Range is [1,16128].

Default is 0, unset. If this is set, max_endpoints must also be set, otherwise the value will be ignored.

no_endpoint_rdo: bool = False

Disable endpoint rate distortion optimizations.

Slightly faster, less noisy output, but lower quality per output bit.

no_selector_rdo: bool = False

Disable selector rate distortion optimizations.

Slightly faster, less noisy output, but lower quality per output bit.

no_sse: bool = False

True to forbid use of the SSE instruction set. Ignored if CPU does not support SSE.

normal_map: bool = False

Tunes codec parameters for better quality on normal maps (no selector RDO, no endpoint RDO) and sets the texture’s DFD appropriately.

Only valid for linear textures.

pre_swizzle: bool = False

If the texture has swizzle metadata, apply it before compressing.

Swizzling, like rabb may yield drastically different error metrics if done after supercompression.

quality_level: int = 0

Compression quality. Range is [1,255].

Lower gives better compression/lower quality/faster. Higher gives less compression/higher quality/slower. This automatically determines values for max_endpoints, max_selectors, endpoint_rdo_threshold, and selector_rdo_threshold for the target quality level. Setting these parameters overrides the values determined by quality_level which defaults to 128 if neither it nor both of max_endpoints and max_selectors have been set.

Both of max_endpoints and max_selectors must be set for them to have any effect. quality_level will only determine values for endpoint_rdo_threshold and selector_rdo_threshold when its value exceeds 128, otherwise their defaults will be used.

selector_rdo_threshold: int = 0

Set selector RDO quality threshold. The default is 1.5.

Lower is higher quality but less quality per output bit (try [1.0,3.0]). This will override the value chosen by @c qualityLevel.

separate_rg_to_rgb_a: bool = False

This was and is a no-op.

2-component inputs have always been automatically separated using an “rrrg” input_swizzle.

thread_count: int = 1

Number of threads used for compression. Default is 1.

uastc: bool = False

True to use UASTC base, false to use ETC1S base.

uastc_flags: int = 0

A set of KtxPackUastcFlagBits controlling UASTC encoding.

The most important value is the level given in the least-significant 4 bits which selects a speed vs quality tradeoff.

uastc_rdo: bool = False

Enable Rate Distortion Optimization (RDO) post-processing.

uastc_rdo_dict_size: int = 0

UASTC RDO dictionary size in bytes. Default is 4096. Lower values=faster, but give less compression. Range is [64,65536].

uastc_rdo_dont_favor_simpler_modes: bool = False

Do not favor simpler UASTC modes in RDO mode.

uastc_rdo_max_smooth_block_error_scale: float = 10.0

UASTC RDO max smooth block error scale. Range is [1,300]. Default is 10.0, 1.0 is disabled. Larger values suppress more artifacts (and allocate more bits) on smooth blocks.

uastc_rdo_max_smooth_block_std_dev: float = 18.0

UASTC RDO max smooth block standard deviation. Range is [.01,65536.0]. Default is 18.0. Larger values expand the range of blocks considered smooth.

uastc_rdo_no_multithreading: bool = False

Disable RDO multithreading (slightly higher compression, deterministic).

uastc_rdo_quality_scalar: float = 0.0

UASTC RDO quality scalar (lambda).

Lower values yield higher quality/larger LZ compressed files, higher values yield lower quality/smaller LZ compressed files. A good range to try is [.2,4]. Full range is [.001,50.0]. Default is 1.0.

verbose: bool = False

If true, prints Basis Universal encoder operation details to stdout. Not recommended for GUI apps.