FFmpeg  4.4.6
Data Structures | Macros | Typedefs | Enumerations | Functions | Variables
webp.c File Reference

WebP image decoder. More...

#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "exif.h"
#include "get_bits.h"
#include "internal.h"
#include "thread.h"
#include "vp8.h"

Go to the source code of this file.

Data Structures

struct  HuffReader
 
struct  ImageContext
 
struct  WebPContext
 

Macros

#define BITSTREAM_READER_LE
 
#define VP8X_FLAG_ANIMATION   0x02
 
#define VP8X_FLAG_XMP_METADATA   0x04
 
#define VP8X_FLAG_EXIF_METADATA   0x08
 
#define VP8X_FLAG_ALPHA   0x10
 
#define VP8X_FLAG_ICC   0x20
 
#define MAX_PALETTE_SIZE   256
 
#define MAX_CACHE_BITS   11
 
#define NUM_CODE_LENGTH_CODES   19
 
#define HUFFMAN_CODES_PER_META_CODE   5
 
#define NUM_LITERAL_CODES   256
 
#define NUM_LENGTH_CODES   24
 
#define NUM_DISTANCE_CODES   40
 
#define NUM_SHORT_DISTANCES   120
 
#define MAX_HUFFMAN_CODE_LENGTH   15
 
#define GET_PIXEL(frame, x, y)    ((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x))
 
#define GET_PIXEL_COMP(frame, x, y, c)    (*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c))
 
#define PARSE_BLOCK_SIZE(w, h)
 

Typedefs

typedef void(* inv_predict_func) (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 

Enumerations

enum  AlphaCompression { ALPHA_COMPRESSION_NONE , ALPHA_COMPRESSION_VP8L }
 
enum  AlphaFilter { ALPHA_FILTER_NONE , ALPHA_FILTER_HORIZONTAL , ALPHA_FILTER_VERTICAL , ALPHA_FILTER_GRADIENT }
 
enum  TransformType {
  PREDICTOR_TRANSFORM = 0 , COLOR_TRANSFORM = 1 , SUBTRACT_GREEN = 2 , COLOR_INDEXING_TRANSFORM = 3 ,
  DI , DII , TDII , LATT ,
  NB_TTYPE
}
 
enum  PredictionMode {
  PRED_MODE_BLACK , PRED_MODE_L , PRED_MODE_T , PRED_MODE_TR ,
  PRED_MODE_TL , PRED_MODE_AVG_T_AVG_L_TR , PRED_MODE_AVG_L_TL , PRED_MODE_AVG_L_T ,
  PRED_MODE_AVG_TL_T , PRED_MODE_AVG_T_TR , PRED_MODE_AVG_AVG_L_TL_AVG_T_TR , PRED_MODE_SELECT ,
  PRED_MODE_ADD_SUBTRACT_FULL , PRED_MODE_ADD_SUBTRACT_HALF
}
 
enum  HuffmanIndex {
  HUFF_IDX_GREEN = 0 , HUFF_IDX_RED = 1 , HUFF_IDX_BLUE = 2 , HUFF_IDX_ALPHA = 3 ,
  HUFF_IDX_DIST = 4
}
 
enum  ImageRole {
  IMAGE_ROLE_ARGB , IMAGE_ROLE_ENTROPY , IMAGE_ROLE_PREDICTOR , IMAGE_ROLE_COLOR_TRANSFORM ,
  IMAGE_ROLE_COLOR_INDEXING , IMAGE_ROLE_NB
}
 

Functions

static void image_ctx_free (ImageContext *img)
 
static int huff_reader_get_symbol (HuffReader *r, GetBitContext *gb)
 
static int huff_reader_build_canonical (HuffReader *r, const uint8_t *code_lengths, int alphabet_size)
 
static void read_huffman_code_simple (WebPContext *s, HuffReader *hc)
 
static int read_huffman_code_normal (WebPContext *s, HuffReader *hc, int alphabet_size)
 
static int decode_entropy_coded_image (WebPContext *s, enum ImageRole role, int w, int h)
 
static int decode_entropy_image (WebPContext *s)
 
static int parse_transform_predictor (WebPContext *s)
 
static int parse_transform_color (WebPContext *s)
 
static int parse_transform_color_indexing (WebPContext *s)
 
static HuffReader * get_huffman_group (WebPContext *s, ImageContext *img, int x, int y)
 
static av_always_inline void color_cache_put (ImageContext *img, uint32_t c)
 
static void inv_predict_0 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_1 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_2 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_3 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_4 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_5 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_6 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_7 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_8 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_9 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_10 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_11 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inv_predict_12 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static av_always_inline uint8_t clamp_add_subtract_half (int a, int b, int c)
 
static void inv_predict_13 (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
 
static void inverse_prediction (AVFrame *frame, enum PredictionMode m, int x, int y)
 
static int apply_predictor_transform (WebPContext *s)
 
static av_always_inline uint8_t color_transform_delta (uint8_t color_pred, uint8_t color)
 
static int apply_color_transform (WebPContext *s)
 
static int apply_subtract_green_transform (WebPContext *s)
 
static int apply_color_indexing_transform (WebPContext *s)
 
static void update_canvas_size (AVCodecContext *avctx, int w, int h)
 
static int vp8_lossless_decode_frame (AVCodecContext *avctx, AVFrame *p, int *got_frame, uint8_t *data_start, unsigned int data_size, int is_alpha_chunk)
 
static void alpha_inverse_prediction (AVFrame *frame, enum AlphaFilter m)
 
static int vp8_lossy_decode_alpha (AVCodecContext *avctx, AVFrame *p, uint8_t *data_start, unsigned int data_size)
 
static int vp8_lossy_decode_frame (AVCodecContext *avctx, AVFrame *p, int *got_frame, uint8_t *data_start, unsigned int data_size)
 
static int webp_decode_frame (AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
 
static av_cold int webp_decode_init (AVCodecContext *avctx)
 
static av_cold int webp_decode_close (AVCodecContext *avctx)
 

Variables

static const uint16_t alphabet_sizes [HUFFMAN_CODES_PER_META_CODE]
 
static const uint8_t code_length_code_order [NUM_CODE_LENGTH_CODES]
 
static const int8_t lz77_distance_offsets [NUM_SHORT_DISTANCES][2]
 
static const inv_predict_func inverse_predict [14]
 
AVCodec ff_webp_decoder
 

Detailed Description

WebP image decoder.

Author
Aneesh Dogra anees.nosp@m.h@su.nosp@m.garla.nosp@m.bs.o.nosp@m.rg Container and Lossy decoding
Justin Ruggles justi.nosp@m.n.ru.nosp@m.ggles.nosp@m.@gma.nosp@m.il.co.nosp@m.m Lossless decoder Compressed alpha for lossy
James Almer jamri.nosp@m.al@g.nosp@m.mail..nosp@m.com Exif metadata ICC profile

Unimplemented:

Definition in file webp.c.

Macro Definition Documentation

◆ BITSTREAM_READER_LE

#define BITSTREAM_READER_LE

Definition at line 45 of file webp.c.

◆ VP8X_FLAG_ANIMATION

#define VP8X_FLAG_ANIMATION   0x02

Definition at line 54 of file webp.c.

◆ VP8X_FLAG_XMP_METADATA

#define VP8X_FLAG_XMP_METADATA   0x04

Definition at line 55 of file webp.c.

◆ VP8X_FLAG_EXIF_METADATA

#define VP8X_FLAG_EXIF_METADATA   0x08

Definition at line 56 of file webp.c.

◆ VP8X_FLAG_ALPHA

#define VP8X_FLAG_ALPHA   0x10

Definition at line 57 of file webp.c.

◆ VP8X_FLAG_ICC

#define VP8X_FLAG_ICC   0x20

Definition at line 58 of file webp.c.

◆ MAX_PALETTE_SIZE

#define MAX_PALETTE_SIZE   256

Definition at line 60 of file webp.c.

◆ MAX_CACHE_BITS

#define MAX_CACHE_BITS   11

Definition at line 61 of file webp.c.

◆ NUM_CODE_LENGTH_CODES

#define NUM_CODE_LENGTH_CODES   19

Definition at line 62 of file webp.c.

◆ HUFFMAN_CODES_PER_META_CODE

#define HUFFMAN_CODES_PER_META_CODE   5

Definition at line 63 of file webp.c.

◆ NUM_LITERAL_CODES

#define NUM_LITERAL_CODES   256

Definition at line 64 of file webp.c.

◆ NUM_LENGTH_CODES

#define NUM_LENGTH_CODES   24

Definition at line 65 of file webp.c.

◆ NUM_DISTANCE_CODES

#define NUM_DISTANCE_CODES   40

Definition at line 66 of file webp.c.

◆ NUM_SHORT_DISTANCES

#define NUM_SHORT_DISTANCES   120

Definition at line 67 of file webp.c.

◆ MAX_HUFFMAN_CODE_LENGTH

#define MAX_HUFFMAN_CODE_LENGTH   15

Definition at line 68 of file webp.c.

◆ GET_PIXEL

#define GET_PIXEL (   frame,
  x,
  y 
)     ((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x))

Definition at line 213 of file webp.c.

◆ GET_PIXEL_COMP

#define GET_PIXEL_COMP (   frame,
  x,
  y,
  c 
)     (*((frame)->data[0] + (y) * frame->linesize[0] + 4 * (x) + c))

Definition at line 216 of file webp.c.

◆ PARSE_BLOCK_SIZE

#define PARSE_BLOCK_SIZE (   w,
  h 
)
Value:
do { \
block_bits = get_bits(&s->gb, 3) + 2; \
blocks_w = FFALIGN((w), 1 << block_bits) >> block_bits; \
blocks_h = FFALIGN((h), 1 << block_bits) >> block_bits; \
} while (0)
s
#define s(width, name)
Definition: cbs_vp9.c:257
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
block_bits
static const uint8_t block_bits[]
Definition: imm4.c:103
w
uint8_t w
Definition: llviddspenc.c:39
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:48
h
h
Definition: vp9dsp_template.c:2038

Definition at line 419 of file webp.c.

Typedef Documentation

◆ inv_predict_func

typedef void(* inv_predict_func) (uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)

Definition at line 891 of file webp.c.

Enumeration Type Documentation

◆ AlphaCompression

enum AlphaCompression
Enumerator
ALPHA_COMPRESSION_NONE 
ALPHA_COMPRESSION_VP8L 

Definition at line 98 of file webp.c.

◆ AlphaFilter

enum AlphaFilter
Enumerator
ALPHA_FILTER_NONE 
ALPHA_FILTER_HORIZONTAL 
ALPHA_FILTER_VERTICAL 
ALPHA_FILTER_GRADIENT 

Definition at line 103 of file webp.c.

◆ TransformType

enum TransformType
Enumerator
PREDICTOR_TRANSFORM 
COLOR_TRANSFORM 
SUBTRACT_GREEN 
COLOR_INDEXING_TRANSFORM 
DI 
DII 
TDII 
LATT 
NB_TTYPE 

Definition at line 110 of file webp.c.

◆ PredictionMode

enum PredictionMode
Enumerator
PRED_MODE_BLACK 
PRED_MODE_L 
PRED_MODE_T 
PRED_MODE_TR 
PRED_MODE_TL 
PRED_MODE_AVG_T_AVG_L_TR 
PRED_MODE_AVG_L_TL 
PRED_MODE_AVG_L_T 
PRED_MODE_AVG_TL_T 
PRED_MODE_AVG_T_TR 
PRED_MODE_AVG_AVG_L_TL_AVG_T_TR 
PRED_MODE_SELECT 
PRED_MODE_ADD_SUBTRACT_FULL 
PRED_MODE_ADD_SUBTRACT_HALF 

Definition at line 117 of file webp.c.

◆ HuffmanIndex

enum HuffmanIndex
Enumerator
HUFF_IDX_GREEN 
HUFF_IDX_RED 
HUFF_IDX_BLUE 
HUFF_IDX_ALPHA 
HUFF_IDX_DIST 

Definition at line 134 of file webp.c.

◆ ImageRole

enum ImageRole
Enumerator
IMAGE_ROLE_ARGB 
IMAGE_ROLE_ENTROPY 
IMAGE_ROLE_PREDICTOR 
IMAGE_ROLE_COLOR_TRANSFORM 
IMAGE_ROLE_COLOR_INDEXING 
IMAGE_ROLE_NB 

Definition at line 148 of file webp.c.

Function Documentation

◆ image_ctx_free()

static void image_ctx_free ( ImageContext *  img)
static

Definition at line 219 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ huff_reader_get_symbol()

static int huff_reader_get_symbol ( HuffReader *  r,
GetBitContext *  gb 
)
static

Definition at line 236 of file webp.c.

Referenced by decode_entropy_coded_image(), and read_huffman_code_normal().

◆ huff_reader_build_canonical()

static int huff_reader_build_canonical ( HuffReader *  r,
const uint8_t *  code_lengths,
int  alphabet_size 
)
static

Definition at line 247 of file webp.c.

Referenced by read_huffman_code_normal().

◆ read_huffman_code_simple()

static void read_huffman_code_simple ( WebPContext *  s,
HuffReader *  hc 
)
static

Definition at line 309 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ read_huffman_code_normal()

static int read_huffman_code_normal ( WebPContext *  s,
HuffReader *  hc,
int  alphabet_size 
)
static

Definition at line 324 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ decode_entropy_coded_image()

static int decode_entropy_coded_image ( WebPContext *  s,
enum ImageRole  role,
int  w,
int  h 
)
static

Definition at line 549 of file webp.c.

Referenced by decode_entropy_image(), parse_transform_color(), parse_transform_color_indexing(), parse_transform_predictor(), and vp8_lossless_decode_frame().

◆ decode_entropy_image()

static int decode_entropy_image ( WebPContext *  s)
static

Definition at line 425 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ parse_transform_predictor()

static int parse_transform_predictor ( WebPContext *  s)
static

Definition at line 459 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ parse_transform_color()

static int parse_transform_color ( WebPContext *  s)
static

Definition at line 475 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ parse_transform_color_indexing()

static int parse_transform_color_indexing ( WebPContext *  s)
static

Definition at line 491 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ get_huffman_group()

static HuffReader* get_huffman_group ( WebPContext *  s,
ImageContext *  img,
int  x,
int  y 
)
static

Definition at line 526 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ color_cache_put()

static av_always_inline void color_cache_put ( ImageContext *  img,
uint32_t  c 
)
static

Definition at line 543 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ inv_predict_0()

static void inv_predict_0 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 757 of file webp.c.

◆ inv_predict_1()

static void inv_predict_1 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 764 of file webp.c.

◆ inv_predict_2()

static void inv_predict_2 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 771 of file webp.c.

◆ inv_predict_3()

static void inv_predict_3 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 778 of file webp.c.

◆ inv_predict_4()

static void inv_predict_4 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 785 of file webp.c.

◆ inv_predict_5()

static void inv_predict_5 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 792 of file webp.c.

◆ inv_predict_6()

static void inv_predict_6 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 802 of file webp.c.

◆ inv_predict_7()

static void inv_predict_7 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 812 of file webp.c.

◆ inv_predict_8()

static void inv_predict_8 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 822 of file webp.c.

◆ inv_predict_9()

static void inv_predict_9 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 832 of file webp.c.

◆ inv_predict_10()

static void inv_predict_10 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 842 of file webp.c.

◆ inv_predict_11()

static void inv_predict_11 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 852 of file webp.c.

◆ inv_predict_12()

static void inv_predict_12 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 866 of file webp.c.

◆ clamp_add_subtract_half()

static av_always_inline uint8_t clamp_add_subtract_half ( int  a,
int  b,
int  c 
)
static

Definition at line 875 of file webp.c.

Referenced by inv_predict_13().

◆ inv_predict_13()

static void inv_predict_13 ( uint8_t *  p,
const uint8_t *  p_l,
const uint8_t *  p_tl,
const uint8_t *  p_t,
const uint8_t *  p_tr 
)
static

Definition at line 882 of file webp.c.

◆ inverse_prediction()

static void inverse_prediction ( AVFrame *  frame,
enum PredictionMode  m,
int  x,
int  y 
)
static

Definition at line 902 of file webp.c.

Referenced by apply_predictor_transform().

◆ apply_predictor_transform()

static int apply_predictor_transform ( WebPContext *  s)
static

Definition at line 924 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ color_transform_delta()

static av_always_inline uint8_t color_transform_delta ( uint8_t  color_pred,
uint8_t  color 
)
static

Definition at line 955 of file webp.c.

Referenced by apply_color_transform().

◆ apply_color_transform()

static int apply_color_transform ( WebPContext *  s)
static

Definition at line 961 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ apply_subtract_green_transform()

static int apply_subtract_green_transform ( WebPContext *  s)
static

Definition at line 985 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ apply_color_indexing_transform()

static int apply_color_indexing_transform ( WebPContext *  s)
static

Definition at line 1000 of file webp.c.

Referenced by vp8_lossless_decode_frame().

◆ update_canvas_size()

static void update_canvas_size ( AVCodecContext *  avctx,
int  w,
int  h 
)
static

Definition at line 1071 of file webp.c.

Referenced by vp8_lossless_decode_frame(), and vp8_lossy_decode_frame().

◆ vp8_lossless_decode_frame()

static int vp8_lossless_decode_frame ( AVCodecContext *  avctx,
AVFrame *  p,
int *  got_frame,
uint8_t *  data_start,
unsigned int  data_size,
int  is_alpha_chunk 
)
static

Definition at line 1086 of file webp.c.

Referenced by vp8_lossy_decode_alpha(), and webp_decode_frame().

◆ alpha_inverse_prediction()

static void alpha_inverse_prediction ( AVFrame *  frame,
enum AlphaFilter  m 
)
static

Definition at line 1199 of file webp.c.

Referenced by vp8_lossy_decode_alpha().

◆ vp8_lossy_decode_alpha()

static int vp8_lossy_decode_alpha ( AVCodecContext *  avctx,
AVFrame *  p,
uint8_t *  data_start,
unsigned int  data_size 
)
static

Definition at line 1242 of file webp.c.

Referenced by vp8_lossy_decode_frame().

◆ vp8_lossy_decode_frame()

static int vp8_lossy_decode_frame ( AVCodecContext *  avctx,
AVFrame *  p,
int *  got_frame,
uint8_t *  data_start,
unsigned int  data_size 
)
static

Definition at line 1295 of file webp.c.

Referenced by webp_decode_frame().

◆ webp_decode_frame()

static int webp_decode_frame ( AVCodecContext *  avctx,
void *  data,
int *  got_frame,
AVPacket *  avpkt 
)
static

Definition at line 1337 of file webp.c.

◆ webp_decode_init()

static av_cold int webp_decode_init ( AVCodecContext *  avctx)
static

Definition at line 1536 of file webp.c.

◆ webp_decode_close()

static av_cold int webp_decode_close ( AVCodecContext *  avctx)
static

Definition at line 1547 of file webp.c.

Variable Documentation

◆ alphabet_sizes

const uint16_t alphabet_sizes[HUFFMAN_CODES_PER_META_CODE]
static
Initial value:
= {
NUM_LITERAL_CODES + NUM_LENGTH_CODES,
NUM_LITERAL_CODES, NUM_LITERAL_CODES, NUM_LITERAL_CODES,
NUM_DISTANCE_CODES
}
NUM_LITERAL_CODES
#define NUM_LITERAL_CODES
Definition: webp.c:64
NUM_LENGTH_CODES
#define NUM_LENGTH_CODES
Definition: webp.c:65
NUM_DISTANCE_CODES
#define NUM_DISTANCE_CODES
Definition: webp.c:66

Definition at line 70 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ code_length_code_order

const uint8_t code_length_code_order[NUM_CODE_LENGTH_CODES]
static
Initial value:
= {
17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
}

Definition at line 76 of file webp.c.

Referenced by read_huffman_code_normal().

◆ lz77_distance_offsets

const int8_t lz77_distance_offsets[NUM_SHORT_DISTANCES][2]
static
Initial value:
= {
{ 0, 1 }, { 1, 0 }, { 1, 1 }, { -1, 1 }, { 0, 2 }, { 2, 0 }, { 1, 2 }, { -1, 2 },
{ 2, 1 }, { -2, 1 }, { 2, 2 }, { -2, 2 }, { 0, 3 }, { 3, 0 }, { 1, 3 }, { -1, 3 },
{ 3, 1 }, { -3, 1 }, { 2, 3 }, { -2, 3 }, { 3, 2 }, { -3, 2 }, { 0, 4 }, { 4, 0 },
{ 1, 4 }, { -1, 4 }, { 4, 1 }, { -4, 1 }, { 3, 3 }, { -3, 3 }, { 2, 4 }, { -2, 4 },
{ 4, 2 }, { -4, 2 }, { 0, 5 }, { 3, 4 }, { -3, 4 }, { 4, 3 }, { -4, 3 }, { 5, 0 },
{ 1, 5 }, { -1, 5 }, { 5, 1 }, { -5, 1 }, { 2, 5 }, { -2, 5 }, { 5, 2 }, { -5, 2 },
{ 4, 4 }, { -4, 4 }, { 3, 5 }, { -3, 5 }, { 5, 3 }, { -5, 3 }, { 0, 6 }, { 6, 0 },
{ 1, 6 }, { -1, 6 }, { 6, 1 }, { -6, 1 }, { 2, 6 }, { -2, 6 }, { 6, 2 }, { -6, 2 },
{ 4, 5 }, { -4, 5 }, { 5, 4 }, { -5, 4 }, { 3, 6 }, { -3, 6 }, { 6, 3 }, { -6, 3 },
{ 0, 7 }, { 7, 0 }, { 1, 7 }, { -1, 7 }, { 5, 5 }, { -5, 5 }, { 7, 1 }, { -7, 1 },
{ 4, 6 }, { -4, 6 }, { 6, 4 }, { -6, 4 }, { 2, 7 }, { -2, 7 }, { 7, 2 }, { -7, 2 },
{ 3, 7 }, { -3, 7 }, { 7, 3 }, { -7, 3 }, { 5, 6 }, { -5, 6 }, { 6, 5 }, { -6, 5 },
{ 8, 0 }, { 4, 7 }, { -4, 7 }, { 7, 4 }, { -7, 4 }, { 8, 1 }, { 8, 2 }, { 6, 6 },
{ -6, 6 }, { 8, 3 }, { 5, 7 }, { -5, 7 }, { 7, 5 }, { -7, 5 }, { 8, 4 }, { 6, 7 },
{ -6, 7 }, { 7, 6 }, { -7, 6 }, { 8, 5 }, { 7, 7 }, { -7, 7 }, { 8, 6 }, { 8, 7 }
}

Definition at line 80 of file webp.c.

Referenced by decode_entropy_coded_image().

◆ inverse_predict

const inv_predict_func inverse_predict[14]
static
Initial value:
= {
inv_predict_0, inv_predict_1, inv_predict_2, inv_predict_3,
inv_predict_4, inv_predict_5, inv_predict_6, inv_predict_7,
inv_predict_8, inv_predict_9, inv_predict_10, inv_predict_11,
inv_predict_12, inv_predict_13,
}
inv_predict_10
static void inv_predict_10(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:842
inv_predict_8
static void inv_predict_8(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:822
inv_predict_7
static void inv_predict_7(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:812
inv_predict_4
static void inv_predict_4(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:785
inv_predict_0
static void inv_predict_0(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:757
inv_predict_11
static void inv_predict_11(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:852
inv_predict_9
static void inv_predict_9(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:832
inv_predict_3
static void inv_predict_3(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:778
inv_predict_6
static void inv_predict_6(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:802
inv_predict_2
static void inv_predict_2(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:771
inv_predict_13
static void inv_predict_13(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:882
inv_predict_1
static void inv_predict_1(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:764
inv_predict_12
static void inv_predict_12(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:866
inv_predict_5
static void inv_predict_5(uint8_t *p, const uint8_t *p_l, const uint8_t *p_tl, const uint8_t *p_t, const uint8_t *p_tr)
Definition: webp.c:792

Definition at line 895 of file webp.c.

Referenced by inverse_prediction().

◆ ff_webp_decoder

AVCodec ff_webp_decoder
Initial value:
= {
.name = "webp",
.long_name = NULL_IF_CONFIG_SMALL("WebP image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_WEBP,
.priv_data_size = sizeof(WebPContext),
.init = webp_decode_init,
.decode = webp_decode_frame,
.close = webp_decode_close,
.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
}
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AV_CODEC_CAP_FRAME_THREADS
#define AV_CODEC_CAP_FRAME_THREADS
Codec supports frame-level multithreading.
Definition: codec.h:108
AV_CODEC_ID_WEBP
@ AV_CODEC_ID_WEBP
Definition: codec_id.h:221
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
webp_decode_close
static av_cold int webp_decode_close(AVCodecContext *avctx)
Definition: webp.c:1547
webp_decode_frame
static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: webp.c:1337
webp_decode_init
static av_cold int webp_decode_init(AVCodecContext *avctx)
Definition: webp.c:1536

Definition at line 1559 of file webp.c.

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