OpenJPH
Open-source implementation of JPEG2000 Part-15
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VLC decoding tables

Functions

static bool ojph::local::vlc_init_tables ()
 Initializes vlc_tbl0 and vlc_tbl1 tables, from table0.h and table1.h.

Variables

ui16 ojph::local::vlc_tbl0 [1024] = { 0 }
 vlc_tbl0 contains decoding information for initial row of quads
ui16 ojph::local::vlc_tbl1 [1024] = { 0 }
 vlc_tbl1 contains decoding information for non-initial row of quads
static bool ojph::local::vlc_tables_initialized = vlc_init_tables()
 Initializes VLC tables vlc_tbl0 and vlc_tbl1.

Detailed Description

VLC decoding tables used in decoding VLC codewords to these fields:

  • cwd_len : 3bits -> the codeword length of the VLC codeword;
    the VLC cwd is in the LSB of bitstream
  • u_off : 1bit -> u_offset, which is 1 if u value is not 0
  • rho : 4bits -> significant samples within a quad
  • e_1 : 4bits -> EMB e_1
  • e_k : 4bits -> EMB e_k

    The table index is 10 bits and composed of two parts:
    The 7 LSBs contain a codeword which might be shorter than 7 bits;
    this word is the next decodable bits in the bitstream.
    The 3 MSB is the context of for the codeword.

Function Documentation

◆ vlc_init_tables()

bool ojph::local::vlc_init_tables ( )
static

#include </build/openjph/src/OpenJPH-0.24.2/src/core/coding/ojph_block_common.cpp>

Initializes vlc_tbl0 and vlc_tbl1 tables, from table0.h and table1.h.

Definition at line 117 of file ojph_block_common.cpp.

References vlc_tbl0, and vlc_tbl1.

Referenced by initialize_block_encoder_tables().

Variable Documentation

◆ vlc_tables_initialized

bool ojph::local::vlc_tables_initialized = vlc_init_tables()
static

#include </build/openjph/src/OpenJPH-0.24.2/src/core/coding/ojph_block_common.cpp>

Initializes VLC tables vlc_tbl0 and vlc_tbl1.

Definition at line 336 of file ojph_block_common.cpp.

◆ vlc_tbl0

◆ vlc_tbl1