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"

Classes
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 struct HuffReader	HuffReader
typedef struct ImageContext	ImageContext
typedef struct WebPContext	WebPContext
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 }
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 }

Variables
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:

• Animation
• XMP metadata

Macro Definition Documentation

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)

Variable Documentation

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),
    .decode         = webp_decode_frame,
    .close          = webp_decode_close,
    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
}