vf_mcdeint.c File Reference

Motion Compensation Deinterlacer Ported from MPlayer libmpcodecs/vf_mcdeint.c. More...

#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavcodec/avcodec.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"

Classes
struct	MCDeintContext

Macros
#define	OFFSET(x)   offsetof(MCDeintContext, x)
#define	FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
#define	CONST(name, help, val, unit)   { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, INT_MIN, INT_MAX, FLAGS, unit }
#define	DELTA(j)   av_clip(j, -x, w-1-x)
#define	GET_SCORE_EDGE(j)
#define	GET_SCORE(j)
#define	CHECK_EDGE(j)
#define	CHECK(j)

Typedefs
typedef struct MCDeintContext	MCDeintContext

Enumerations
enum	MCDeintMode {   MODE_FAST = 0, MODE_MEDIUM, MODE_SLOW, MODE_EXTRA_SLOW,   MODE_NB }
enum	MCDeintParity { PARITY_TFF = 0, PARITY_BFF = 1 }

Functions
	AVFILTER_DEFINE_CLASS (mcdeint)
	CHECK (-1) CHECK(-2) }} }} CHECK(1) CHECK(2) }} }} } if(diff0+diff1 > 0) temp -
	for (y=0;y< h;y++)
	if (ret< 0)
return	ff_filter_frame (outlink, outpic)

Variables
	else
else	temp = (diff0 + diff1 + FFABS(FFABS(diff0) - FFABS(diff1)) / 2) / 2
*	filp = *dstp = temp > 255U ? ~(temp>>31) : temp
mcdeint	parity = 1
end	__pad0__
av_frame_free &	inpic
AVFilter	ff_vf_mcdeint

Detailed Description

Motion Compensation Deinterlacer Ported from MPlayer libmpcodecs/vf_mcdeint.c.

Known Issues:

The motion estimation is somewhat at the mercy of the input, if the input frames are created purely based on spatial interpolation then for example a thin black line or another random and not interpolateable pattern will cause problems. Note: completely ignoring the "unavailable" lines during motion estimation did not look any better, so the most obvious solution would be to improve tfields or penalize problematic motion vectors.

If non iterative ME is used then snow currently ignores the OBMC window and as a result sometimes creates artifacts.

Only past frames are used, we should ideally use future frames too, something like filtering the whole movie in forward and then backward direction seems like an interesting idea but the current filter framework is FAR from supporting such things.

Combining the motion compensated image with the input image also is not as trivial as it seems, simple blindly taking even lines from one and odd ones from the other does not work at all as ME/MC sometimes has nothing in the previous frames which matches the current. The current algorithm has been found by trial and error and almost certainly can be improved...

Macro Definition Documentation

CHECK

#define CHECK

(

j

)

Value:

{   int score = GET_SCORE(j);\
        if (score < spatial_score){\
            spatial_score= score;\
            diff0 = filp[-fils+(j)] - srcp[-srcs+(j)];\
            diff1 = filp[+fils-(j)] - srcp[+srcs-(j)];\

CHECK_EDGE

#define CHECK_EDGE

(

j

)

Value:

{   int score = GET_SCORE_EDGE(j);\
        if (score < spatial_score){\
            spatial_score = score;\
            diff0 = filp[-fils+DELTA(j)]    - srcp[-srcs+DELTA(j)];\
            diff1 = filp[+fils+DELTA(-(j))] - srcp[+srcs+DELTA(-(j))];\

GET_SCORE

#define GET_SCORE

(

j

)

Value:

FFABS(srcp[-srcs-1+(j)] - srcp[+srcs-1-(j)])+\
   FFABS(srcp[-srcs  +(j)] - srcp[+srcs  -(j)])+\
   FFABS(srcp[-srcs+1+(j)] - srcp[+srcs+1-(j)])

GET_SCORE_EDGE

#define GET_SCORE_EDGE

(

j

)

Value:

FFABS(srcp[-srcs+DELTA(-1+(j))] - srcp[+srcs+DELTA(-1-(j))])+\
   FFABS(srcp[-srcs+DELTA(j)     ] - srcp[+srcs+DELTA(  -(j))])+\
   FFABS(srcp[-srcs+DELTA(1+(j)) ] - srcp[+srcs+DELTA( 1-(j))])

Enumeration Type Documentation

MCDeintParity

enum MCDeintParity

Enumerator
PARITY_TFF	top field first
PARITY_BFF	bottom field first

Variable Documentation

else

else

Initial value:

{
                            int spatial_score = GET_SCORE(0) - 1

ff_vf_mcdeint

AVFilter ff_vf_mcdeint

Initial value:

= {
    .name          = "mcdeint",
    .description   = NULL_IF_CONFIG_SMALL("Apply motion compensating deinterlacing."),
    .priv_size     = sizeof(MCDeintContext),
    .uninit        = uninit,
    .query_formats = query_formats,
    .inputs        = mcdeint_inputs,
    .outputs       = mcdeint_outputs,
    .priv_class    = &mcdeint_class,
}