liblzma (XZ Utils) 5.4.2

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lzma_filter Struct Reference

Filter options. More...

`#include <filter.h>`

## Data Fields
lzma_vli | id
| Filter ID.
void * | options
| Pointer to filter-specific options structure.

## Detailed Description

Filter options.

This structure is used to pass a Filter ID and a pointer to the filter's options to liblzma. A few functions work with a single lzma_filter structure, while most functions expect a filter chain.

A filter chain is indicated with an array of lzma_filter structures. The array is terminated with .id = LZMA_VLI_UNKNOWN. Thus, the filter array must have LZMA_FILTERS_MAX + 1 elements (that is, five) to be able to hold any arbitrary filter chain. This is important when using lzma_block_header_decode() from block.h, because a filter array that is too small would make liblzma write past the end of the array.

## Field Documentation

## ◆ id

lzma_vli lzma_filter::id

Filter ID.

Use constants whose name begin with `LZMA_FILTER_' to specify different filters. In an array of lzma_filter structures, use LZMA_VLI_UNKNOWN to indicate end of filters.

Note
  This is not an enum, because on some systems enums cannot be 64-bit.

## ◆ options

void* lzma_filter::options

Pointer to filter-specific options structure.

If the filter doesn't need options, set this to NULL. If id is set to LZMA_VLI_UNKNOWN, options is ignored, and thus doesn't need be initialized.

The documentation for this struct was generated from the following file:

- lzma/filter.h