#include <inttypes.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "libavutil/error.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"
#include "libavutil/macros.h"
#include "libavutil/mem.h"
#include "libavutil/qsort.h"
#include "libavutil/reverse.h"
#include "vlc.h"

Data Structures
struct	VLCcode

Macros
#define	GET_DATA(v, table, i, wrap, size)

#define	LOCALBUF_ELEMS 1500

#define	COPY(condition)

Functions
static int	alloc_table (VLC *vlc, int size, int use_static)

static av_always_inline uint32_t	bitswap_32 (uint32_t x)

static int	vlc_common_init (VLC vlc, int nb_bits, int nb_codes, VLCcode *buf, int flags)

static int	compare_vlcspec (const void a, const void b)

static int	build_table (VLC vlc, int table_nb_bits, int nb_codes, VLCcode codes, int flags)
	Build VLC decoding tables suitable for use with get_vlc().

static int	vlc_common_end (VLC vlc, int nb_bits, int nb_codes, VLCcode codes, int flags, VLCcode localbuf[LOCALBUF_ELEMS])

int	ff_vlc_init_sparse (VLC vlc, int nb_bits, int nb_codes, const void bits, int bits_wrap, int bits_size, const void codes, int codes_wrap, int codes_size, const void symbols, int symbols_wrap, int symbols_size, int flags)
	Build VLC decoding tables suitable for use with get_vlc2().

int	ff_vlc_init_from_lengths (VLC vlc, int nb_bits, int nb_codes, const int8_t lens, int lens_wrap, const void symbols, int symbols_wrap, int symbols_size, int offset, int flags, void logctx)
	Build VLC decoding tables suitable for use with get_vlc2()

av_cold void	ff_vlc_init_table_from_lengths (VLCElem table[], int table_size, int nb_bits, int nb_codes, const int8_t lens, int lens_wrap, const void symbols, int symbols_wrap, int symbols_size, int offset, int flags)

av_cold const VLCElem *	ff_vlc_init_tables_from_lengths (VLCInitState state, int nb_bits, int nb_codes, const int8_t lens, int lens_wrap, const void *symbols, int symbols_wrap, int symbols_size, int offset, int flags)

av_cold void	ff_vlc_init_table_sparse (VLCElem table[], int table_size, int nb_bits, int nb_codes, const void bits, int bits_wrap, int bits_size, const void codes, int codes_wrap, int codes_size, const void *symbols, int symbols_wrap, int symbols_size, int flags)

av_cold const VLCElem *	ff_vlc_init_tables_sparse (VLCInitState state, int nb_bits, int nb_codes, const void bits, int bits_wrap, int bits_size, const void codes, int codes_wrap, int codes_size, const void symbols, int symbols_wrap, int symbols_size, int flags)

static void	add_level (VLC_MULTI_ELEM table, const int is16bit, const int num, const int numbits, const VLCcode buf, uint32_t curcode, int curlen, int curlimit, int curlevel, const int minlen, const int max, unsigned *levelcnt, VLC_MULTI_ELEM info)

static int	vlc_multi_gen (VLC_MULTI_ELEM table, const VLC single, const int is16bit, const int nb_codes, const int numbits, VLCcode buf, void logctx)

int	ff_vlc_init_multi_from_lengths (VLC vlc, VLC_MULTI multi, int nb_bits, int nb_elems, int nb_codes, const int8_t lens, int lens_wrap, const void symbols, int symbols_wrap, int symbols_size, int offset, int flags, void *logctx)
	Build VLC decoding tables suitable for use with get_vlc_multi()

void	ff_vlc_free_multi (VLC_MULTI *vlc)

void	ff_vlc_free (VLC *vlc)

Macro Definition Documentation

◆ GET_DATA

#define GET_DATA	(	v,
		table,
		i,
		wrap,
		size )

Value:

{                                                           \
    const uint8_t *ptr = (const uint8_t *)table + i * wrap; \
    switch(size) {                                          \
    default:                                                \
        av_unreachable("Only uint8/16/32_t are used");      \
    case 1:                                                 \
        v = *(const uint8_t *)ptr;                          \
        break;                                              \
    case 2:                                                 \
        v = *(const uint16_t *)ptr;                         \
        break;                                              \
    case 4:                                                 \
        v = *(const uint32_t *)ptr;                         \
        break;                                              \
    }                                                       \
}

Definition at line 41 of file vlc.c.

Referenced by ff_vlc_init_from_lengths(), and ff_vlc_init_multi_from_lengths().

◆ LOCALBUF_ELEMS

#define LOCALBUF_ELEMS 1500

Definition at line 80 of file vlc.c.

Referenced by ff_vlc_init_from_lengths(), ff_vlc_init_multi_from_lengths(), ff_vlc_init_sparse(), vlc_common_end(), and vlc_common_init().

◆ COPY

#define COPY ( condition )

Value:

    for (int i = 0; i < nb_codes; i++) {                                    \
        unsigned len;                                                       \
        GET_DATA(len, bits, i, bits_wrap, bits_size);                       \
        if (!(condition))                                                   \
            continue;                                                       \
        if (len > 3*nb_bits || len > 32) {                                  \
            av_log(NULL, AV_LOG_ERROR, "Too long VLC (%u) in vlc_init\n", len);\
            if (buf != localbuf)                                            \
                av_free(buf);                                               \
            return AVERROR(EINVAL);                                         \
        }                                                                   \
        buf[j].bits = len;                                                  \
        GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size);            \
        if (buf[j].code >= (1LL<<buf[j].bits)) {                            \
            av_log(NULL, AV_LOG_ERROR, "Invalid code %"PRIx32" for %d in "  \
                   "vlc_init\n", buf[j].code, i);                           \
            if (buf != localbuf)                                            \
                av_free(buf);                                               \
            return AVERROR(EINVAL);                                         \
        }                                                                   \
        if (flags & VLC_INIT_INPUT_LE)                                      \
            buf[j].code = bitswap_32(buf[j].code);                          \
        else                                                                \
            buf[j].code <<= 32 - buf[j].bits;                               \
        if (symbols)                                                        \
            GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size) \
        else                                                                \
            buf[j].symbol = i;                                              \
        j++;                                                                \
    }

Referenced by ff_vlc_init_sparse().

Function Documentation

◆ alloc_table()

static int alloc_table	(	VLC *	vlc,
		int	size,
		int	use_static )

static

Definition at line 60 of file vlc.c.

Referenced by build_table(), and mp_decode_layer2().

◆ bitswap_32()

static av_always_inline uint32_t bitswap_32 ( uint32_t x )

static

Definition at line 82 of file vlc.c.

Referenced by build_table().

◆ vlc_common_init()

static int vlc_common_init	(	VLC *	vlc,
		int	nb_bits,
		int	nb_codes,
		VLCcode **	buf,
		int	flags )

static

Definition at line 98 of file vlc.c.

Referenced by ff_vlc_init_from_lengths(), ff_vlc_init_multi_from_lengths(), and ff_vlc_init_sparse().

◆ compare_vlcspec()

static int compare_vlcspec	(	const void *	a,
		const void *	b )

static

Definition at line 118 of file vlc.c.

Referenced by ff_vlc_init_sparse().

◆ build_table()

static int build_table	(	VLC *	vlc,
		int	table_nb_bits,
		int	nb_codes,
		VLCcode *	codes,
		int	flags )

static

Build VLC decoding tables suitable for use with get_vlc().

Parameters

vlc	the context to be initialized
table_nb_bits	max length of vlc codes to store directly in this table (Longer codes are delegated to subtables.)
nb_codes	number of elements in codes[]
codes	descriptions of the vlc codes These must be ordered such that codes going into the same subtable are contiguous. Sorting by VLCcode.code is sufficient, though not necessary.

Definition at line 138 of file vlc.c.

Referenced by build_table(), and vlc_common_end().

◆ vlc_common_end()

static int vlc_common_end	(	VLC *	vlc,
		int	nb_bits,
		int	nb_codes,
		VLCcode *	codes,
		int	flags,
		VLCcode	localbuf[LOCALBUF_ELEMS] )

static

Definition at line 229 of file vlc.c.

Referenced by ff_vlc_init_from_lengths(), ff_vlc_init_multi_from_lengths(), and ff_vlc_init_sparse().

◆ ff_vlc_init_sparse()

int ff_vlc_init_sparse	(	VLC *	vlc,
		int	nb_bits,
		int	nb_codes,
		const void *	bits,
		int	bits_wrap,
		int	bits_size,
		const void *	codes,
		int	codes_wrap,
		int	codes_size,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	flags )

Build VLC decoding tables suitable for use with get_vlc2().

Parameters

[in,out]	vlc	The VLC to be initialized; table and table_allocated must have been set when initializing a static VLC, otherwise this will be treated as uninitialized.
[in]	nb_bits	The number of bits to use for the VLC table; higher values take up more memory and cache, but allow to read codes with fewer reads. Corresponds to the `bits` parameter of get_vlc2().
[in]	nb_codes	The number of provided bits, codes and (if supplied) symbol entries.
[in]	bits	The lengths (in bits) of the codes. Entries > 0 correspond to valid codes; entries == 0 will be skipped.
[in]	bits_wrap	Stride (in bytes) of the bits table.
[in]	codes_size	Size of the bits. 1, 2 and 4 are supported.
[in]	codes	Table which gives the bit pattern of of each vlc code.
[in]	codes_wrap	Stride (in bytes) of the codes table.
[in]	codes_size	Size of the codes. 1, 2 and 4 are supported.
[in]	symbols	The symbols, i.e. what is returned from get_vlc2() when the corresponding code is encountered. May be NULL, then 0, 1, 2, 3, 4,... will be used.
[in]	symbols_wrap	Stride (in bytes) of the symbols table.
[in]	symbols_size	Size of the symbols. 1 and 2 are supported.
[in]	flags	A combination of the VLC_INIT_* flags.

'wrap' and 'size' make it possible to use any memory configuration and types (byte/word/int) to store the 'bits', 'codes', and 'symbols' tables.

Definition at line 250 of file vlc.c.

Referenced by build_huff(), build_vlc(), build_vlc(), dnxhd_init_vlc(), ff_vlc_init_table_sparse(), ff_vlc_init_tables_sparse(), generate_joint_tables(), huf_build_dec_table(), init_ralf_vlc(), read_hufftable(), and rv34_gen_vlc_ext().

◆ ff_vlc_init_from_lengths()

int ff_vlc_init_from_lengths	(	VLC *	vlc,
		int	nb_bits,
		int	nb_codes,
		const int8_t *	lens,
		int	lens_wrap,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	offset,
		int	flags,
		void *	logctx )

Build VLC decoding tables suitable for use with get_vlc2()

This function takes lengths and symbols and calculates the codes from them. For this the input lengths and symbols have to be sorted according to "left nodes in the corresponding tree first".

Parameters

[in,out]	vlc	The VLC to be initialized; table and table_allocated must have been set when initializing a static VLC, otherwise this will be treated as uninitialized.
[in]	nb_bits	The number of bits to use for the VLC table; higher values take up more memory and cache, but allow to read codes with fewer reads.
[in]	nb_codes	The number of provided length and (if supplied) symbol entries.
[in]	lens	The lengths of the codes. Entries > 0 correspond to valid codes; entries == 0 will be skipped and entries with len < 0 indicate that the tree is incomplete and has an open end of length -len at this position.
[in]	lens_wrap	Stride (in bytes) of the lengths.
[in]	symbols	The symbols, i.e. what is returned from get_vlc2() when the corresponding code is encountered. May be NULL, then 0, 1, 2, 3, 4,... will be used.
[in]	symbols_wrap	Stride (in bytes) of the symbols.
[in]	symbols_size	Size of the symbols. 1 and 2 are supported.
[in]	offset	An offset to apply to all the valid symbols.
[in]	flags	A combination of the VLC_INIT_* flags; notice that VLC_INIT_INPUT_LE is pointless and ignored.

Definition at line 306 of file vlc.c.

Referenced by atrac3_init_static_data(), build_canonical_huff(), build_huff_tree(), build_vlc(), build_vlc(), build_vlc(), build_vlc(), cfhd_init_vlc(), dv_init_static(), ff_mjpeg_build_vlc(), ff_vlc_init_table_from_lengths(), ff_vlc_init_tables_from_lengths(), huff_reader_build_canonical(), mp_decode_frame(), mss4_init_vlc(), on2avc_decode_init(), qdmc_init_static_data(), read_code_table(), read_simple_vlc_prefix(), read_vlc_prefix(), smacker_decode_header_tree(), smka_decode_frame(), tm2_build_huff_table(), tscc2_init_vlc(), vp3_decode_init(), and wma_decode_init().

◆ ff_vlc_init_table_from_lengths()

av_cold void ff_vlc_init_table_from_lengths	(	VLCElem	table[],
		int	table_size,
		int	nb_bits,
		int	nb_codes,
		const int8_t *	lens,
		int	lens_wrap,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	offset,
		int	flags )

Definition at line 353 of file vlc.c.

Referenced by rv10_build_vlc().

◆ ff_vlc_init_tables_from_lengths()

av_cold const VLCElem * ff_vlc_init_tables_from_lengths	(	VLCInitState *	state,
		int	nb_bits,
		int	nb_codes,
		const int8_t *	lens,
		int	lens_wrap,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	offset,
		int	flags )

Definition at line 366 of file vlc.c.

Referenced by atrac9_init_vlc(), build_vlc(), clv_init_static(), decode_init_static(), hqx_init_static(), imc_init_static(), init_sbr_tables(), init_tables_once(), mobiclip_init_static(), mpc7_init_static(), mpegaudiodec_common_init_static(), msmpeg4_decode_init_static(), rv40_init_table(), rv40_init_tables(), and x8_init_vlc().

◆ ff_vlc_init_table_sparse()

av_cold void ff_vlc_init_table_sparse	(	VLCElem	table[],
		int	table_size,
		int	nb_bits,
		int	nb_codes,
		const void *	bits,
		int	bits_wrap,
		int	bits_size,
		const void *	codes,
		int	codes_wrap,
		int	codes_size,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	flags )

Definition at line 384 of file vlc.c.

Referenced by ff_init_2d_vlc_rl(), ff_rl_init_vlc(), and init_vlcs().

◆ ff_vlc_init_tables_sparse()

av_cold const VLCElem * ff_vlc_init_tables_sparse	(	VLCInitState *	state,
		int	nb_bits,
		int	nb_codes,
		const void *	bits,
		int	bits_wrap,
		int	bits_size,
		const void *	codes,
		int	codes_wrap,
		int	codes_size,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	flags )

Definition at line 400 of file vlc.c.

Referenced by ccitt_unpack_init(), ff_vlc_init_tables(), init_base_tables(), and msmpeg4_decode_init_static().

◆ add_level()

static void add_level	(	VLC_MULTI_ELEM *	table,
		const int	is16bit,
		const int	num,
		const int	numbits,
		const VLCcode *	buf,
		uint32_t	curcode,
		int	curlen,
		int	curlimit,
		int	curlevel,
		const int	minlen,
		const int	max,
		unsigned *	levelcnt,
		VLC_MULTI_ELEM	info )

static

Definition at line 421 of file vlc.c.

Referenced by add_level(), and vlc_multi_gen().

◆ vlc_multi_gen()

static int vlc_multi_gen	(	VLC_MULTI_ELEM *	table,
		const VLC *	single,
		const int	is16bit,
		const int	nb_codes,
		const int	numbits,
		VLCcode *	buf,
		void *	logctx )

static

Definition at line 465 of file vlc.c.

Referenced by ff_vlc_init_multi_from_lengths().

◆ ff_vlc_init_multi_from_lengths()

int ff_vlc_init_multi_from_lengths	(	VLC *	vlc,
		VLC_MULTI *	multi,
		int	nb_bits,
		int	nb_elems,
		int	nb_codes,
		const int8_t *	lens,
		int	lens_wrap,
		const void *	symbols,
		int	symbols_wrap,
		int	symbols_size,
		int	offset,
		int	flags,
		void *	logctx )

Build VLC decoding tables suitable for use with get_vlc_multi()

This function takes lengths and symbols and calculates the codes from them. For this the input lengths and symbols have to be sorted according to "left nodes in the corresponding tree first".

Parameters

[in,out]	vlc	The VLC to be initialized; table and table_allocated must have been set when initializing a static VLC, otherwise this will be treated as uninitialized.
[in,out]	multi	The VLC_MULTI to be initialized; table and table_allocated must have been set when initializing a static VLC, otherwise this will be treated as uninitialized.
[in]	nb_bits	The number of bits to use for the VLC table; higher values take up more memory and cache, but allow to read codes with fewer reads.
[in]	nb_elems	The max possible number of elements.
[in]	nb_codes	The number of provided length and (if supplied) symbol entries.
[in]	lens	The lengths of the codes. Entries > 0 correspond to valid codes; entries == 0 will be skipped and entries with len < 0 indicate that the tree is incomplete and has an open end of length -len at this position.
[in]	lens_wrap	Stride (in bytes) of the lengths.
[in]	symbols	The symbols, i.e. what is returned from get_vlc2() when the corresponding code is encountered. May be NULL, then 0, 1, 2, 3, 4,... will be used.
[in]	symbols_wrap	Stride (in bytes) of the symbols.
[in]	symbols_size	Size of the symbols. 1 and 2 are supported.
[in]	offset	An offset to apply to all the valid symbols.
[in]	flags	A combination of the VLC_INIT_* flags; notice that VLC_INIT_INPUT_LE is pointless and ignored.

Definition at line 517 of file vlc.c.

Referenced by build_huff(), and huff_build().

◆ ff_vlc_free_multi()

void ff_vlc_free_multi ( VLC_MULTI * vlc )

Definition at line 575 of file vlc.c.

Referenced by decode_plane(), decode_plane10(), ff_vlc_init_multi_from_lengths(), huff_build(), and magy_decode_end().

◆ ff_vlc_free()

void ff_vlc_free ( VLC * vlc )

Definition at line 580 of file vlc.c.

Referenced by build_huff(), build_vlc(), build_vlc(), build_vlc(), cfhd_init_vlc(), cook_decode_close(), decode_argb_frame(), decode_close(), decode_close(), decode_close(), decode_end(), decode_end(), decode_end(), decode_end(), decode_end(), decode_plane(), decode_plane10(), decode_rgb24_frame(), decode_rle(), decode_yuv_frame(), dist_bundle_close(), dnxhd_decode_close(), dnxhd_init_vlc(), ff_ivi_dec_huff_desc(), ff_ivi_decode_close(), ff_mjpeg_decode_dht(), ff_mjpeg_decode_end(), ff_wma_end(), fraps2_decode_plane(), free_vlc_tables(), generate_joint_tables(), hqx_decode_close(), huf_build_dec_table(), huff_build(), image_ctx_free(), init_default_huffman_tables(), ivi_free_buffers(), jpg_free_context(), magy_decode_end(), mp_decode_frame(), on2avc_free_vlcs(), photocd_decode_close(), read_huffman_code_normal(), read_huffman_tables(), read_huffman_tables(), read_hufftable(), read_old_huffman_tables(), read_vlc_prefix(), smacker_decode_header_tree(), smka_decode_frame(), tm2_free_codes(), vorbis_free(), vp6_build_huff_tree(), and vp6_decode_free_context().

Data Structures

Macros

Functions

Macro Definition Documentation

◆ GET_DATA

◆ LOCALBUF_ELEMS

◆ COPY

Function Documentation

◆ alloc_table()

◆ bitswap_32()

◆ vlc_common_init()

◆ compare_vlcspec()

◆ build_table()

◆ vlc_common_end()

◆ ff_vlc_init_sparse()

◆ ff_vlc_init_from_lengths()

◆ ff_vlc_init_table_from_lengths()

◆ ff_vlc_init_tables_from_lengths()

◆ ff_vlc_init_table_sparse()

◆ ff_vlc_init_tables_sparse()

◆ add_level()

◆ vlc_multi_gen()

◆ ff_vlc_init_multi_from_lengths()

◆ ff_vlc_free_multi()

◆ ff_vlc_free()