signature_lookup.c File Reference

MPEG-7 video signature calculation and lookup filter. More...

#include "signature.h"

Go to the source code of this file.

Macros
#define	HOUGH_MAX_OFFSET   90
#define	MAX_FRAMERATE   60
#define	DIR_PREV   0
#define	DIR_NEXT   1
#define	DIR_PREV_END   2
#define	DIR_NEXT_END   3
#define	STATUS_NULL   0
#define	STATUS_END_REACHED   1
#define	STATUS_BEGIN_REACHED   2

Functions
static void	fill_l1distlut (uint8_t lut[])
static unsigned int	intersection_word (const uint8_t *first, const uint8_t *second)
static unsigned int	union_word (const uint8_t *first, const uint8_t *second)
static unsigned int	get_l1dist (AVFilterContext *ctx, SignatureContext *sc, const uint8_t *first, const uint8_t *second)
static int	get_jaccarddist (SignatureContext *sc, CoarseSignature *first, CoarseSignature *second)
	calculates the jaccard distance and evaluates a pair of coarse signatures as good More...
static int	find_next_coarsecandidate (SignatureContext *sc, CoarseSignature *secondstart, CoarseSignature **first, CoarseSignature **second, int start)
	step through the coarsesignatures as long as a good candidate is found More...
static MatchingInfo *	get_matching_parameters (AVFilterContext *ctx, SignatureContext *sc, FineSignature *first, FineSignature *second)
	compares framesignatures and sorts out signatures with a l1 distance above a given threshold. More...
static int	iterate_frame (double frr, FineSignature **a, FineSignature **b, int fcount, int *bcount, int dir)
static MatchingInfo	evaluate_parameters (AVFilterContext *ctx, SignatureContext *sc, MatchingInfo *infos, MatchingInfo bestmatch, int mode)
static void	sll_free (MatchingInfo *sll)
static MatchingInfo	lookup_signatures (AVFilterContext *ctx, SignatureContext *sc, StreamContext *first, StreamContext *second, int mode)

Detailed Description

MPEG-7 video signature calculation and lookup filter.

Definition in file signature_lookup.c.

Macro Definition Documentation

HOUGH_MAX_OFFSET

#define HOUGH_MAX_OFFSET   90

Definition at line 28 of file signature_lookup.c.

Referenced by get_matching_parameters().

MAX_FRAMERATE

#define MAX_FRAMERATE   60

Definition at line 29 of file signature_lookup.c.

Referenced by get_matching_parameters().

DIR_PREV

#define DIR_PREV   0

Definition at line 31 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

DIR_NEXT

#define DIR_NEXT   1

Definition at line 32 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

DIR_PREV_END

#define DIR_PREV_END   2

Definition at line 33 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

DIR_NEXT_END

#define DIR_NEXT_END   3

Definition at line 34 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

STATUS_NULL

#define STATUS_NULL   0

Definition at line 36 of file signature_lookup.c.

Referenced by evaluate_parameters().

STATUS_END_REACHED

#define STATUS_END_REACHED   1

Definition at line 37 of file signature_lookup.c.

Referenced by evaluate_parameters().

STATUS_BEGIN_REACHED

#define STATUS_BEGIN_REACHED   2

Definition at line 38 of file signature_lookup.c.

Referenced by evaluate_parameters().

Function Documentation

fill_l1distlut()

static void fill_l1distlut ( uint8_t  lut[] )

static

Definition at line 40 of file signature_lookup.c.

Referenced by lookup_signatures().

intersection_word()

static unsigned int intersection_word ( const uint8_t *  first, const uint8_t *  second  )

static

Definition at line 60 of file signature_lookup.c.

Referenced by get_jaccarddist().

union_word()

static unsigned int union_word ( const uint8_t *  first, const uint8_t *  second  )

static

Definition at line 75 of file signature_lookup.c.

Referenced by get_jaccarddist().

get_l1dist()

static unsigned int get_l1dist ( AVFilterContext *  ctx, SignatureContext *  sc, const uint8_t *  first, const uint8_t *  second  )

static

Definition at line 90 of file signature_lookup.c.

Referenced by evaluate_parameters(), and get_matching_parameters().

get_jaccarddist()

static int get_jaccarddist ( SignatureContext *  sc, CoarseSignature *  first, CoarseSignature *  second  )

static

calculates the jaccard distance and evaluates a pair of coarse signatures as good

Returns

0 if pair is bad, 1 otherwise

Definition at line 115 of file signature_lookup.c.

Referenced by find_next_coarsecandidate().

find_next_coarsecandidate()

static int find_next_coarsecandidate ( SignatureContext *  sc, CoarseSignature *  secondstart, CoarseSignature **  first, CoarseSignature **  second, int  start  )

static

step through the coarsesignatures as long as a good candidate is found

Returns

0 if no candidate is found, 1 otherwise

Definition at line 140 of file signature_lookup.c.

Referenced by lookup_signatures().

get_matching_parameters()

static MatchingInfo* get_matching_parameters ( AVFilterContext *  ctx, SignatureContext *  sc, FineSignature *  first, FineSignature *  second  )

static

compares framesignatures and sorts out signatures with a l1 distance above a given threshold.

Then tries to find out offset and differences between framerates with a hough transformation

Definition at line 174 of file signature_lookup.c.

Referenced by lookup_signatures().

iterate_frame()

static int iterate_frame ( double  frr, FineSignature **  a, FineSignature **  b, int  fcount, int *  bcount, int  dir  )

static

Definition at line 315 of file signature_lookup.c.

Referenced by evaluate_parameters().

evaluate_parameters()

static MatchingInfo evaluate_parameters ( AVFilterContext *  ctx, SignatureContext *  sc, MatchingInfo *  infos, MatchingInfo  bestmatch, int  mode  )

static

Definition at line 418 of file signature_lookup.c.

Referenced by lookup_signatures().

sll_free()

static void sll_free ( MatchingInfo *  sll )

static

Definition at line 523 of file signature_lookup.c.

Referenced by lookup_signatures().

lookup_signatures()

static MatchingInfo lookup_signatures ( AVFilterContext *  ctx, SignatureContext *  sc, StreamContext *  first, StreamContext *  second, int  mode  )

static

Definition at line 533 of file signature_lookup.c.

Referenced by request_frame().