diff options
Diffstat (limited to 'src/liblzma/api/lzma/delta.h')
| -rw-r--r-- | src/liblzma/api/lzma/delta.h | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/src/liblzma/api/lzma/delta.h b/src/liblzma/api/lzma/delta.h index 58afec18..740de97c 100644 --- a/src/liblzma/api/lzma/delta.h +++ b/src/liblzma/api/lzma/delta.h @@ -24,9 +24,21 @@ /** * \brief Filter ID * - * Filter ID of the Delta filter. This is used as lzma_options_filter.id. + * Filter ID of the Delta filter. This is used as lzma_filter.id. */ -#define LZMA_FILTER_DELTA LZMA_VLI_C(0x20) +#define LZMA_FILTER_DELTA LZMA_VLI_C(0x03) + + +/** + * \brief Type of the delta calculation + * + * Currently only byte-wise delta is supported. Other possible types could + * be, for example, delta of 16/32/64-bit little/big endian integers, but + * these are not currently planned since byte-wise delta is almost as good. + */ +typedef enum { + LZMA_DELTA_TYPE_BYTE +} lzma_delta_type; /** @@ -35,8 +47,14 @@ * These options are needed by both encoder and decoder. */ typedef struct { + /** For now, this must always be LZMA_DELTA_TYPE_BYTE. */ + lzma_delta_type type; + /** - * \brief Delta distance as bytes + * \brief Delta distance + * + * With the only currently supported type, LZMA_DELTA_TYPE_BYTE, + * the distance is as bytes. * * Examples: * - 16-bit stereo audio: distance = 4 bytes @@ -46,4 +64,16 @@ typedef struct { # define LZMA_DELTA_DISTANCE_MIN 1 # define LZMA_DELTA_DISTANCE_MAX 256 + /** + * \brief Reserved space for possible future extensions + * + * You should not touch these, because the names of these variables + * may change. These are and will never be used when type is + * LZMA_DELTA_TYPE_BYTE, so it is safe to leave these uninitialized. + */ + uint32_t reserved_int1; + uint32_t reserved_int2; + void *reserved_ptr1; + void *reserved_ptr2; + } lzma_options_delta; |