diff options
Diffstat (limited to 'include/sqfs/compressor.h')
| -rw-r--r-- | include/sqfs/compressor.h | 69 |
1 files changed, 67 insertions, 2 deletions
diff --git a/include/sqfs/compressor.h b/include/sqfs/compressor.h index 4190c67..af379e7 100644 --- a/include/sqfs/compressor.h +++ b/include/sqfs/compressor.h @@ -199,7 +199,50 @@ struct sqfs_compressor_config_t { */ sqfs_u32 dict_size; - sqfs_u32 padd0[3]; + /** + * @brief Compression level. Maximum 9, default is 6. + */ + sqfs_u8 level; + + /** + * @brief Number of literal context bits. + * + * How many of the highest bits of the previous + * uncompressed byte to take into account when + * predicting the bits of the next byte. + * + * The sum lc + lp must be at MOST 4. Default value of + * lc is 3. + */ + sqfs_u8 lc; + + /** + * @brief Number of literal position bits. + * + * lp affects what kind of alignment in the uncompressed + * data is assumed when encoding bytes. + * See pb below for more information about alignment. + * + * The sum lc + lp must be at MOST 4. Default value of + * lp is 0. + */ + sqfs_u8 lp; + + /** + * @brief Number of position bits. + * + * This is the log2 of the assumed underlying alignment + * of the input data, i.e. pb=0 means single byte + * allignment, pb=1 means 16 bit, 2 means 32 bit. + * + * When the alignment is known, setting pb may reduce + * the file size. + * + * The default value is 2, i.e. 32 bit alignment. + */ + sqfs_u8 pb; + + sqfs_u32 padd0[2]; } xz; sqfs_u64 padd0[2]; @@ -247,7 +290,13 @@ typedef enum { * @brief For LZMA, set this to select the Sparc BCJ filter. */ SQFS_COMP_FLAG_XZ_SPARC = 0x0020, - SQFS_COMP_FLAG_XZ_ALL = 0x003F, + + /** + * @brief Tell the LZMA compressor to try the "extreme" option. + */ + SQFS_COMP_FLAG_XZ_EXTREME = 0x0100, + + SQFS_COMP_FLAG_XZ_ALL = 0x013F, /** * @brief For zlib deflate, set this to try the default strategy. @@ -316,6 +365,22 @@ typedef enum { #define SQFS_GZIP_MIN_WINDOW (8) #define SQFS_GZIP_MAX_WINDOW (15) +#define SQFS_XZ_MIN_LEVEL (0) +#define SQFS_XZ_MAX_LEVEL (9) +#define SQFS_XZ_DEFAULT_LEVEL (6) + +#define SQFS_XZ_MIN_LC 0 +#define SQFS_XZ_MAX_LC 4 +#define SQFS_XZ_DEFAULT_LC 3 + +#define SQFS_XZ_MIN_LP 0 +#define SQFS_XZ_MAX_LP 4 +#define SQFS_XZ_DEFAULT_LP 0 + +#define SQFS_XZ_MIN_PB 0 +#define SQFS_XZ_MAX_PB 4 +#define SQFS_XZ_DEFAULT_PB 2 + #ifdef __cplusplus extern "C" { #endif |