diff options
Diffstat (limited to 'src/lzw.c')
| -rw-r--r-- | src/lzw.c | 6 |
1 files changed, 6 insertions, 0 deletions
@@ -58,6 +58,7 @@ struct lzw_read_ctx { struct lzw_table_entry { uint8_t value; /**< Last value for record ending at entry. */ uint8_t first; /**< First value in entry's entire record. */ + uint16_t count; /**< Count of values in this entry's record. */ uint16_t extends; /**< Offset in table to previous entry. */ }; @@ -69,6 +70,7 @@ struct lzw_ctx { uint32_t prev_code; /**< Code read from input previously. */ uint32_t prev_code_first; /**< First value of previous code. */ + uint32_t prev_code_count; /**< Total values for previous code. */ uint32_t initial_code_size; /**< Starting LZW code size. */ @@ -253,6 +255,7 @@ static lzw_result lzw__clear_codes( /* Record this initial code as "previous" code, needed during decode. */ ctx->prev_code = code; ctx->prev_code_first = code; + ctx->prev_code_count = 1; /* Reset the stack, and add first non-clear code added as first item. */ stack_pos = ctx->stack_base; @@ -297,6 +300,7 @@ lzw_result lzw_decode_init( for (uint32_t i = 0; i < ctx->clear_code; ++i) { table[i].first = i; table[i].value = i; + table[i].count = 1; } *stack_base_out = ctx->stack_base; @@ -317,6 +321,7 @@ static inline void lzw__table_add_entry( entry->value = code; entry->first = ctx->prev_code_first; + entry->count = ctx->prev_code_count + 1; entry->extends = ctx->prev_code; ctx->table_size++; @@ -392,6 +397,7 @@ lzw_result lzw_decode(struct lzw_ctx *ctx, /* Store details of this code as "previous code" to the context. */ ctx->prev_code_first = ctx->table[code].first; + ctx->prev_code_count = ctx->table[code].count; ctx->prev_code = code; lzw__write_pixels(ctx, code, stack_pos_out); |