signature_lookup.c File Reference

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

#include "libavutil/mem.h"
#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	sll_free (MatchingInfo **sll)
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
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
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.
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 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 29 of file signature_lookup.c.

Referenced by get_matching_parameters().

MAX_FRAMERATE

#define MAX_FRAMERATE   60

Definition at line 30 of file signature_lookup.c.

Referenced by get_matching_parameters().

DIR_PREV

#define DIR_PREV   0

Definition at line 32 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

DIR_NEXT

#define DIR_NEXT   1

Definition at line 33 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

DIR_PREV_END

#define DIR_PREV_END   2

Definition at line 34 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

DIR_NEXT_END

#define DIR_NEXT_END   3

Definition at line 35 of file signature_lookup.c.

Referenced by evaluate_parameters(), and iterate_frame().

STATUS_NULL

#define STATUS_NULL   0

Definition at line 37 of file signature_lookup.c.

Referenced by evaluate_parameters().

STATUS_END_REACHED

#define STATUS_END_REACHED   1

Definition at line 38 of file signature_lookup.c.

Referenced by evaluate_parameters().

STATUS_BEGIN_REACHED

#define STATUS_BEGIN_REACHED   2

Definition at line 39 of file signature_lookup.c.

Referenced by evaluate_parameters().

Function Documentation

sll_free()

static void sll_free ( MatchingInfo ** sll )

static

Definition at line 41 of file signature_lookup.c.

Referenced by get_matching_parameters(), and lookup_signatures().

fill_l1distlut()

static void fill_l1distlut ( uint8_t lut[] )

static

Definition at line 51 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 71 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 86 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 101 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 126 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 152 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 186 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 327 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 430 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 535 of file signature_lookup.c.

Referenced by request_frame().