/*
* Copyright (C) 2010 Georg Martius <georg.martius@web.de>
* Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* 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.
*/
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#include "libavutil/common.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/qsort.h"
#include "deshake.h"
#define OFFSET(x) offsetof(DeshakeContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption deshake_options[] = {
{ "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, "edge"},
{ "blank", "fill zeroes at blank locations", 0, AV_OPT_TYPE_CONST, {.i64=FILL_BLANK}, INT_MIN, INT_MAX, FLAGS, "edge" },
{ "original", "original image at blank locations", 0, AV_OPT_TYPE_CONST, {.i64=FILL_ORIGINAL}, INT_MIN, INT_MAX, FLAGS, "edge" },
{ "clamp", "extruded edge value at blank locations", 0, AV_OPT_TYPE_CONST, {.i64=FILL_CLAMP}, INT_MIN, INT_MAX, FLAGS, "edge" },
{ "mirror", "mirrored edge at blank locations", 0, AV_OPT_TYPE_CONST, {.i64=FILL_MIRROR}, INT_MIN, INT_MAX, FLAGS, "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, "smode" },
{ "exhaustive", "exhaustive search", 0, AV_OPT_TYPE_CONST, {.i64=EXHAUSTIVE}, INT_MIN, INT_MAX, FLAGS, "smode" },
{ "less", "less exhaustive search", 0, AV_OPT_TYPE_CONST, {.i64=SMART_EXHAUSTIVE}, INT_MIN, INT_MAX, FLAGS, "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 }
};
AVFILTER_DEFINE_CLASS(deshake);
static int cmp(const void *a, const void *b)
{
return FFDIFFSIGN(*(const double *)a, *(const double *)b);
}
/**
* Cleaned mean (cuts off 20% of values to remove outliers and then averages)
*/
static double clean_mean(double *values, int count)
{
double mean = 0;
int cut = count / 5;
int x;
AV_QSORT(values, count, double, cmp);
for (x = cut; x < count - cut; x++) {
mean += values[x];
}
return mean / (count - cut * 2);
}
/**
* 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.
*/
static void find_block_motion(DeshakeContext *deshake, uint8_t *src1,
uint8_t *src2, int cx, int cy, int stride,
IntMotionVector *mv)
{
int x, y;
int diff;
int smallest = INT_MAX;
int tmp, tmp2;
#define CMP(i, j) deshake->sad(src1 + cy * stride + cx, stride,\
src2 + (j) * stride + (i), stride)
if (deshake->search == EXHAUSTIVE) {
// Compare every possible position - this is sloooow!
for (y = -deshake->ry; y <= deshake->ry; y++) {
for (x = -deshake->rx; x <= deshake->rx; x++) {
diff = CMP(cx - x, cy - y);
if (diff < smallest) {
smallest = diff;
mv->x = x;
mv->y = y;
}
}
}
} else if (deshake->search == SMART_EXHAUSTIVE) {
// Compare every other possible position and find the best match
for (y = -deshake->ry + 1; y < deshake->ry; y += 2) {
for (x = -deshake->rx + 1; x < deshake->rx; x += 2) {
diff = CMP(cx - x, cy - y);
if (diff < smallest) {
smallest = diff;
mv->x = x;
mv->y = y;
}
}
}
// Hone in on the specific best match around the match we found above
tmp = mv->x;
tmp2 = mv->y;
for (y = tmp2 - 1; y <= tmp2 + 1; y++) {
for (x = tmp - 1; x <= tmp + 1; x++) {
if (x == tmp && y == tmp2)
continue;
diff = CMP(cx - x, cy - y);
if (diff < smallest) {
smallest = diff;
mv->x = x;
mv->y = y;
}
}
}
}
if (smallest > 512) {
mv->x = -1;
mv->y = -1;
}
emms_c();
//av_log(NULL, AV_LOG_ERROR, "%d\n", smallest);
//av_log(NULL, AV_LOG_ERROR, "Final: (%d, %d) = %d x %d\n", cx, cy, mv->x, mv->y);
}
/**
* 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.
*/
static int block_contrast(uint8_t *src, int x, int y, int stride, int blocksize)
{
int highest = 0;
int lowest = 255;
int i, j, pos;
for (i = 0; i <= blocksize * 2; i++) {
// We use a width of 16 here to match the sad function
for (j = 0; j <= 15; j++) {
pos = (y - i) * stride + (x - j);
if (src[pos] < lowest)
lowest = src[pos];
else if (src[pos] > highest) {
highest = src[pos];
}
}
}
return highest - lowest;
}
/**
* Find the rotation for a given block.
*/
static double block_angle(int x, int y, int cx, int cy, IntMotionVector *shift)
{
double a1, a2, diff;
a1 = atan2(y - cy, x - cx);
a2 = atan2(y - cy + shift->y, x - cx + shift->x);
diff = a2 - a1;
return (diff > M_PI) ? diff - 2 * M_PI :
(diff < -M_PI) ? diff + 2 * M_PI :
diff;
}
/**
* 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).
*/
static void find_motion(DeshakeContext *deshake, uint8_t *src1, uint8_t *src2,
int width, int height, int stride, Transform *t)
{
int x, y;
IntMotionVector mv = {0, 0};
int count_max_value = 0;
int contrast;
int pos;
int center_x = 0, center_y = 0;
double p_x, p_y;
av_fast_malloc(&deshake->angles, &deshake->angles_size, width * height / (16 * deshake->blocksize) * sizeof(*deshake->angles));
// Reset counts to zero
for (x = 0; x < deshake->rx * 2 + 1; x++) {
for (y = 0; y < deshake->ry * 2 + 1; y++) {
deshake->counts[x][y] = 0;
}
}
pos = 0;
// Find motion for every block and store the motion vector in the counts
for (y = deshake->ry; y < height - deshake->ry - (deshake->blocksize * 2); y += deshake->blocksize * 2) {
// We use a width of 16 here to match the sad function
for (x = deshake->rx; x < width - deshake->rx - 16; x += 16) {
// If the contrast is too low, just skip this block as it probably
// won't be very useful to us.
contrast = block_contrast(src2, x, y, stride, deshake->blocksize);
if (contrast > deshake->contrast) {
//av_log(NULL, AV_LOG_ERROR, "%d\n", contrast);
find_block_motion(deshake, src1, src2, x, y, stride, &mv);
if (mv.x != -1 && mv.y != -1) {
deshake->counts[mv.x + deshake->rx][mv.y + deshake->ry] += 1;
if (x > deshake->rx && y > deshake->ry)
deshake->angles[pos++] = block_angle(x, y, 0, 0, &mv);
center_x += mv.x;
center_y += mv.y;
}
}
}
}
if (pos) {
center_x /= pos;
center_y /= pos;
t->angle = clean_mean(deshake->angles, pos);
if (t->angle < 0.001)
t->angle = 0;
} else {
t->angle = 0;
}
// Find the most common motion vector in the frame and use it as the gmv
for (y = deshake->ry * 2; y >= 0; y--) {
for (x = 0; x < deshake->rx * 2 + 1; x++) {
//av_log(NULL, AV_LOG_ERROR, "%5d ", deshake->counts[x][y]);
if (deshake->counts[x][y] > count_max_value) {
t->vec.x = x - deshake->rx;
t->vec.y = y - deshake->ry;
count_max_value = deshake->counts[x][y];
}
}
//av_log(NULL, AV_LOG_ERROR, "\n");
}
p_x = (center_x - width / 2.0);
p_y = (center_y - height / 2.0);
t->vec.x += (cos(t->angle)-1)*p_x - sin(t->angle)*p_y;
t->vec.y += sin(t->angle)*p_x + (cos(t->angle)-1)*p_y;
// Clamp max shift & rotation?
t->vec.x = av_clipf(t->vec.x, -deshake->rx * 2, deshake->rx * 2);
t->vec.y = av_clipf(t->vec.y, -deshake->ry * 2, deshake->ry * 2);
t->angle = av_clipf(t->angle, -0.1, 0.1);
//av_log(NULL, AV_LOG_ERROR, "%d x %d\n", avg->x, avg->y);
}
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)
{
int i = 0, ret = 0;
const float *matrixs[3];
int plane_w[3], plane_h[3];
matrixs[0] = matrix_y;
matrixs[1] = matrixs[2] = matrix_uv;
plane_w[0] = width;
plane_w[1] = plane_w[2] = cw;
plane_h[0] = height;
plane_h[1] = plane_h[2] = ch;
for (i = 0; i < 3; i++) {
// Transform the luma and chroma planes
ret = avfilter_transform(in->data[i], out->data[i], in->linesize[i], out->linesize[i],
plane_w[i], plane_h[i], matrixs[i], interpolate, fill);
if (ret < 0)
return ret;
}
return ret;
}
static av_cold int init(AVFilterContext *ctx)
{
DeshakeContext *deshake = ctx->priv;
deshake->sad = av_pixelutils_get_sad_fn(4, 4, 1, deshake); // 16x16, 2nd source unaligned
if (!deshake->sad)
return AVERROR(EINVAL);
deshake->refcount = 20; // XXX: add to options?
deshake->blocksize /= 2;
deshake->blocksize = av_clip(deshake->blocksize, 4, 128);
if (deshake->rx % 16) {
av_log(ctx, AV_LOG_ERROR, "rx must be a multiple of 16\n");
return AVERROR_PATCHWELCOME;
}
if (deshake->filename)
deshake->fp = fopen(deshake->filename, "w");
if (deshake->fp)
fwrite("Ori x, Avg x, Fin x, Ori y, Avg y, Fin y, Ori angle, Avg angle, Fin angle, Ori zoom, Avg zoom, Fin zoom\n", sizeof(char), 104, deshake->fp);
// Quadword align left edge of box for MMX code, adjust width if necessary
// to keep right margin
if (deshake->cx > 0) {
deshake->cw += deshake->cx - (deshake->cx & ~15);
deshake->cx &= ~15;
}
deshake->transform = deshake_transform_c;
av_log(ctx, AV_LOG_VERBOSE, "cx: %d, cy: %d, cw: %d, ch: %d, rx: %d, ry: %d, edge: %d blocksize: %d contrast: %d search: %d\n",
deshake->cx, deshake->cy, deshake->cw, deshake->ch,
deshake->rx, deshake->ry, deshake->edge, deshake->blocksize * 2, deshake->contrast, deshake->search);
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
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
};
AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
if (!fmts_list)
return AVERROR(ENOMEM);
return ff_set_common_formats(ctx, fmts_list);
}
static int config_props(AVFilterLink *link)
{
DeshakeContext *deshake = link->dst->priv;
deshake->ref = NULL;
deshake->last.vec.x = 0;
deshake->last.vec.y = 0;
deshake->last.angle = 0;
deshake->last.zoom = 0;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
DeshakeContext *deshake = ctx->priv;
av_frame_free(&deshake->ref);
av_freep(&deshake->angles);
deshake->angles_size = 0;
if (deshake->fp)
fclose(deshake->fp);
}
static int filter_frame(AVFilterLink *link, AVFrame *in)
{
DeshakeContext *deshake = link->dst->priv;
AVFilterLink *outlink = link->dst->outputs[0];
AVFrame *out;
Transform t = {{0},0}, orig = {{0},0};
float matrix_y[9], matrix_uv[9];
float alpha = 2.0 / deshake->refcount;
char tmp[256];
int ret = 0;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
const int chroma_width = AV_CEIL_RSHIFT(link->w, desc->log2_chroma_w);
const int chroma_height = AV_CEIL_RSHIFT(link->h, desc->log2_chroma_h);
out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
if (deshake->cx < 0 || deshake->cy < 0 || deshake->cw < 0 || deshake->ch < 0) {
// Find the most likely global motion for the current frame
find_motion(deshake, (deshake->ref == NULL) ? in->data[0] : deshake->ref->data[0], in->data[0], link->w, link->h, in->linesize[0], &t);
} else {
uint8_t *src1 = (deshake->ref == NULL) ? in->data[0] : deshake->ref->data[0];
uint8_t *src2 = in->data[0];
deshake->cx = FFMIN(deshake->cx, link->w);
deshake->cy = FFMIN(deshake->cy, link->h);
if ((unsigned)deshake->cx + (unsigned)deshake->cw > link->w) deshake->cw = link->w - deshake->cx;
if ((unsigned)deshake->cy + (unsigned)deshake->ch > link->h) deshake->ch = link->h - deshake->cy;
// Quadword align right margin
deshake->cw &= ~15;
src1 += deshake->cy * in->linesize[0] + deshake->cx;
src2 += deshake->cy * in->linesize[0] + deshake->cx;
find_motion(deshake, src1, src2, deshake->cw, deshake->ch, in->linesize[0], &t);
}
// Copy transform so we can output it later to compare to the smoothed value
orig.vec.x = t.vec.x;
orig.vec.y = t.vec.y;
orig.angle = t.angle;
orig.zoom = t.zoom;
// Generate a one-sided moving exponential average
deshake->avg.vec.x = alpha * t.vec.x + (1.0 - alpha) * deshake->avg.vec.x;
deshake->avg.vec.y = alpha * t.vec.y + (1.0 - alpha) * deshake->avg.vec.y;
deshake->avg.angle = alpha * t.angle + (1.0 - alpha) * deshake->avg.angle;
deshake->avg.zoom = alpha * t.zoom + (1.0 - alpha) * deshake->avg.zoom;
// Remove the average from the current motion to detect the motion that
// is not on purpose, just as jitter from bumping the camera
t.vec.x -= deshake->avg.vec.x;
t.vec.y -= deshake->avg.vec.y;
t.angle -= deshake->avg.angle;
t.zoom -= deshake->avg.zoom;
// Invert the motion to undo it
t.vec.x *= -1;
t.vec.y *= -1;
t.angle *= -1;
// Write statistics to file
if (deshake->fp) {
snprintf(tmp, 256, "%f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f\n", orig.vec.x, deshake->avg.vec.x, t.vec.x, orig.vec.y, deshake->avg.vec.y, t.vec.y, orig.angle, deshake->avg.angle, t.angle, orig.zoom, deshake->avg.zoom, t.zoom);
fwrite(tmp, sizeof(char), strlen(tmp), deshake->fp);
}
// Turn relative current frame motion into absolute by adding it to the
// last absolute motion
t.vec.x += deshake->last.vec.x;
t.vec.y += deshake->last.vec.y;
t.angle += deshake->last.angle;
t.zoom += deshake->last.zoom;
// Shrink motion by 10% to keep things centered in the camera frame
t.vec.x *= 0.9;
t.vec.y *= 0.9;
t.angle *= 0.9;
// Store the last absolute motion information
deshake->last.vec.x = t.vec.x;
deshake->last.vec.y = t.vec.y;
deshake->last.angle = t.angle;
deshake->last.zoom = t.zoom;
// Generate a luma transformation matrix
avfilter_get_matrix(t.vec.x, t.vec.y, t.angle, 1.0 + t.zoom / 100.0, matrix_y);
// Generate a chroma transformation matrix
avfilter_get_matrix(t.vec.x / (link->w / chroma_width), t.vec.y / (link->h / chroma_height), t.angle, 1.0 + t.zoom / 100.0, matrix_uv);
// Transform the luma and chroma planes
ret = deshake->transform(link->dst, link->w, link->h, chroma_width, chroma_height,
matrix_y, matrix_uv, INTERPOLATE_BILINEAR, deshake->edge, in, out);
// Cleanup the old reference frame
av_frame_free(&deshake->ref);
if (ret < 0)
goto fail;
// Store the current frame as the reference frame for calculating the
// motion of the next frame
deshake->ref = in;
return ff_filter_frame(outlink, out);
fail:
av_frame_free(&out);
return ret;
}
static const AVFilterPad deshake_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_props,
},
{ NULL }
};
static const AVFilterPad deshake_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
{ NULL }
};
AVFilter ff_vf_deshake = {
.name = "deshake",
.description = NULL_IF_CONFIG_SMALL("Stabilize shaky video."),
.priv_size = sizeof(DeshakeContext),
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = deshake_inputs,
.outputs = deshake_outputs,
.priv_class = &deshake_class,
};