vf_deshake.c File Reference

fast deshake / depan video filter More...

#include "avfilter.h"
#include "filters.h"
#include "transform.h"
#include "video.h"
#include "libavutil/common.h"
#include "libavutil/file_open.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/pixelutils.h"
#include "libavutil/qsort.h"

Go to the source code of this file.

Data Structures
struct	IntMotionVector
struct	MotionVector
struct	Transform
struct	DeshakeContext

Macros
#define	MAX_R   64
#define	OFFSET(x)
#define	FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
#define	CMP(i, j)

Enumerations
enum	SearchMethod { EXHAUSTIVE , SMART_EXHAUSTIVE , SEARCH_COUNT }

Functions
	AVFILTER_DEFINE_CLASS (deshake)
static int	cmp (const void *a, const void *b)
static double	clean_mean (double *values, int count)
	Cleaned mean (cuts off 20% of values to remove outliers and then averages)
static void	find_block_motion (DeshakeContext *deshake, uint8_t *src1, uint8_t *src2, int cx, int cy, int stride, IntMotionVector *mv)
	Find the most likely shift in motion between two frames for a given macroblock.
static int	block_contrast (uint8_t *src, int x, int y, int stride, int blocksize)
	Find the contrast of a given block.
static double	block_angle (int x, int y, int cx, int cy, IntMotionVector *shift)
	Find the rotation for a given block.
static void	find_motion (DeshakeContext *deshake, uint8_t *src1, uint8_t *src2, int width, int height, int stride, Transform *t)
	Find the estimated global motion for a scene given the most likely shift for each block in the frame.
static int	deshake_transform_c (AVFilterContext *ctx, int width, int height, int cw, int ch, const float *matrix_y, const float *matrix_uv, enum InterpolateMethod interpolate, enum FillMethod fill, AVFrame *in, AVFrame *out)
static av_cold int	init (AVFilterContext *ctx)
static int	config_props (AVFilterLink *link)
static av_cold void	uninit (AVFilterContext *ctx)
static int	filter_frame (AVFilterLink *link, AVFrame *in)

Variables
static const AVOption	deshake_options []
static enum AVPixelFormat	pix_fmts []
static const AVFilterPad	deshake_inputs []
const FFFilter	ff_vf_deshake

Detailed Description

fast deshake / depan video filter

SAD block-matching motion compensation to fix small changes in horizontal and/or vertical shift. This filter helps remove camera shake from hand-holding a camera, bumping a tripod, moving on a vehicle, etc.

Algorithm:

• For each frame with one previous reference frame
  • For each block in the frame
    • If contrast > threshold then find likely motion vector
  • For all found motion vectors
    • Find most common, store as global motion vector
  • Find most likely rotation angle
  • Transform image along global motion

TODO:

• Fill frame edges based on previous/next reference frames
• Fill frame edges by stretching image near the edges?
  • Can this be done quickly and look decent?

Dark Shikari links to http://wiki.videolan.org/SoC_x264_2010#GPU_Motion_Estimation_2 for an algorithm similar to what could be used here to get the gmv It requires only a couple diamond searches + fast downscaling

Special thanks to Jason Kotenko for his help with the algorithm and my inability to see simple errors in C code.

Definition in file vf_deshake.c.

Macro Definition Documentation

MAX_R

#define MAX_R   64

Definition at line 87 of file vf_deshake.c.

OFFSET

#define OFFSET

(

x

)

Value:

offsetof(DeshakeContext, x)

Definition at line 117 of file vf_deshake.c.

FLAGS

#define FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

Definition at line 118 of file vf_deshake.c.

CMP

#define CMP	(		i,
			j )

Value:

                                   deshake->sad(src1 + cy  * stride + cx,  stride,\
                                   src2 + (j) * stride + (i), stride)

Referenced by find_block_motion().

Enumeration Type Documentation

SearchMethod

enum SearchMethod

Enumerator
EXHAUSTIVE	Search all possible positions.
SMART_EXHAUSTIVE	Search most possible positions (faster)
SEARCH_COUNT

Definition at line 65 of file vf_deshake.c.

Function Documentation

AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS

(

deshake

)

cmp()

static int cmp ( const void * a, const void * b )

static

Definition at line 144 of file vf_deshake.c.

clean_mean()

static double clean_mean ( double * values, int count )

static

Cleaned mean (cuts off 20% of values to remove outliers and then averages)

Definition at line 152 of file vf_deshake.c.

Referenced by find_motion().

find_block_motion()

static void find_block_motion ( DeshakeContext * deshake, uint8_t * src1, uint8_t * src2, int cx, int cy, int stride, IntMotionVector * mv )

static

Find the most likely shift in motion between two frames for a given macroblock.

Test each block against several shifts given by the rx and ry attributes. Searches using a simple matrix of those shifts and chooses the most likely shift by the smallest difference in blocks.

Definition at line 173 of file vf_deshake.c.

Referenced by find_motion().

block_contrast()

static int block_contrast ( uint8_t * src, int x, int y, int stride, int blocksize )

static

Find the contrast of a given block.

When searching for global motion we really only care about the high contrast blocks, so using this method we can actually skip blocks we don't care much about.

Definition at line 242 of file vf_deshake.c.

Referenced by find_motion().

block_angle()

static double block_angle ( int x, int y, int cx, int cy, IntMotionVector * shift )

static

Find the rotation for a given block.

Definition at line 266 of file vf_deshake.c.

Referenced by find_motion().

find_motion()

static void find_motion ( DeshakeContext * deshake, uint8_t * src1, uint8_t * src2, int width, int height, int stride, Transform * t )

static

Find the estimated global motion for a scene given the most likely shift for each block in the frame.

The global motion is estimated to be the same as the motion from most blocks in the frame, so if most blocks move one pixel to the right and two pixels down, this would yield a motion vector (1, -2).

Definition at line 287 of file vf_deshake.c.

Referenced by filter_frame().

deshake_transform_c()

static int deshake_transform_c ( AVFilterContext * ctx, int width, int height, int cw, int ch, const float * matrix_y, const float * matrix_uv, enum InterpolateMethod interpolate, enum FillMethod fill, AVFrame * in, AVFrame * out )

static

Definition at line 367 of file vf_deshake.c.

Referenced by init().

init()

static av_cold int init ( AVFilterContext * ctx )

static

Definition at line 394 of file vf_deshake.c.

config_props()

static int config_props ( AVFilterLink * link )

static

Definition at line 433 of file vf_deshake.c.

uninit()

static av_cold void uninit ( AVFilterContext * ctx )

static

Definition at line 446 of file vf_deshake.c.

filter_frame()

static int filter_frame ( AVFilterLink * link, AVFrame * in )

static

Definition at line 456 of file vf_deshake.c.

Variable Documentation

deshake_options

const AVOption deshake_options[]

static

Initial value:

= {
    { "x", "set x for the rectangular search area",      OFFSET(cx), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
    { "y", "set y for the rectangular search area",      OFFSET(cy), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
    { "w", "set width for the rectangular search area",  OFFSET(cw), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
    { "h", "set height for the rectangular search area", OFFSET(ch), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
    { "rx", "set x for the rectangular search area",     OFFSET(rx), AV_OPT_TYPE_INT, {.i64=16}, 0, MAX_R, .flags = FLAGS },
    { "ry", "set y for the rectangular search area",     OFFSET(ry), AV_OPT_TYPE_INT, {.i64=16}, 0, MAX_R, .flags = FLAGS },
    { "edge", "set edge mode", OFFSET(edge), AV_OPT_TYPE_INT, {.i64=FILL_MIRROR}, FILL_BLANK, FILL_COUNT-1, FLAGS, .unit = "edge"},
        { "blank",    "fill zeroes at blank locations",         0, AV_OPT_TYPE_CONST, {.i64=FILL_BLANK},    INT_MIN, INT_MAX, FLAGS, .unit = "edge" },
        { "original", "original image at blank locations",      0, AV_OPT_TYPE_CONST, {.i64=FILL_ORIGINAL}, INT_MIN, INT_MAX, FLAGS, .unit = "edge" },
        { "clamp",    "extruded edge value at blank locations", 0, AV_OPT_TYPE_CONST, {.i64=FILL_CLAMP},    INT_MIN, INT_MAX, FLAGS, .unit = "edge" },
        { "mirror",   "mirrored edge at blank locations",       0, AV_OPT_TYPE_CONST, {.i64=FILL_MIRROR},   INT_MIN, INT_MAX, FLAGS, .unit = "edge" },
    { "blocksize", "set motion search blocksize",       OFFSET(blocksize), AV_OPT_TYPE_INT, {.i64=8},   4, 128, .flags = FLAGS },
    { "contrast",  "set contrast threshold for blocks", OFFSET(contrast),  AV_OPT_TYPE_INT, {.i64=125}, 1, 255, .flags = FLAGS },
    { "search",  "set search strategy", OFFSET(search), AV_OPT_TYPE_INT, {.i64=EXHAUSTIVE}, EXHAUSTIVE, SEARCH_COUNT-1, FLAGS, .unit = "smode" },
        { "exhaustive", "exhaustive search",      0, AV_OPT_TYPE_CONST, {.i64=EXHAUSTIVE},       INT_MIN, INT_MAX, FLAGS, .unit = "smode" },
        { "less",       "less exhaustive search", 0, AV_OPT_TYPE_CONST, {.i64=SMART_EXHAUSTIVE}, INT_MIN, INT_MAX, FLAGS, .unit = "smode" },
    { "filename", "set motion search detailed log file name", OFFSET(filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
    { "opencl", "ignored",                              OFFSET(opencl), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags = FLAGS },
    { NULL }
}

Definition at line 120 of file vf_deshake.c.

pix_fmts

enum AVPixelFormat pix_fmts[]

static

Initial value:

= {
    AV_PIX_FMT_YUV420P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV410P,
    AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
    AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE
}

Definition at line 427 of file vf_deshake.c.

deshake_inputs

const AVFilterPad deshake_inputs[]

static

Initial value:

= {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
        .config_props = config_props,
    },
}

Definition at line 583 of file vf_deshake.c.

ff_vf_deshake

const FFFilter ff_vf_deshake

Initial value:

= {
    .p.name        = "deshake",
    .p.description = NULL_IF_CONFIG_SMALL("Stabilize shaky video."),
    .p.priv_class  = &deshake_class,
    .priv_size     = sizeof(DeshakeContext),
    .init          = init,
    .uninit        = uninit,
    FILTER_INPUTS(deshake_inputs),
    FILTER_OUTPUTS(ff_video_default_filterpad),
    FILTER_PIXFMTS_ARRAY(pix_fmts),
}

Definition at line 592 of file vf_deshake.c.