[FFmpeg-cvslog] libavfilter: add deshake filter
danielgtaylor
git at videolan.org
Tue Oct 4 02:29:51 CEST 2011
ffmpeg | branch: master | danielgtaylor <dan at programmer-art.org> | Tue Oct 4 01:31:18 2011 +0200| [0cc2ed4a206551d3c1def87e6b40c67bc1caf294] | committer: Michael Niedermayer
libavfilter: add deshake filter
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0cc2ed4a206551d3c1def87e6b40c67bc1caf294
---
libavfilter/Makefile | 4 +-
libavfilter/allfilters.c | 1 +
libavfilter/vf_deshake.c | 521 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 525 insertions(+), 1 deletions(-)
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5fc0e48..d35020f 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -18,7 +18,8 @@ OBJS = allfilters.o \
defaults.o \
drawutils.o \
formats.o \
- graphparser.o \
+ graphparser.o \
+ transform.o \
OBJS-$(CONFIG_AVCODEC) += avcodec.o
@@ -41,6 +42,7 @@ OBJS-$(CONFIG_COPY_FILTER) += vf_copy.o
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_CROPDETECT_FILTER) += vf_cropdetect.o
OBJS-$(CONFIG_DELOGO_FILTER) += vf_delogo.o
+OBJS-$(CONFIG_DESHAKE_FILTER) += vf_deshake.o
OBJS-$(CONFIG_DRAWBOX_FILTER) += vf_drawbox.o
OBJS-$(CONFIG_DRAWTEXT_FILTER) += vf_drawtext.o
OBJS-$(CONFIG_FADE_FILTER) += vf_fade.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index dcabb68..2bb42a1 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -53,6 +53,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (CROP, crop, vf);
REGISTER_FILTER (CROPDETECT, cropdetect, vf);
REGISTER_FILTER (DELOGO, delogo, vf);
+ REGISTER_FILTER (DESHAKE, deshake, vf);
REGISTER_FILTER (DRAWBOX, drawbox, vf);
REGISTER_FILTER (DRAWTEXT, drawtext, vf);
REGISTER_FILTER (FADE, fade, vf);
diff --git a/libavfilter/vf_deshake.c b/libavfilter/vf_deshake.c
new file mode 100644
index 0000000..838a28a
--- /dev/null
+++ b/libavfilter/vf_deshake.c
@@ -0,0 +1,521 @@
+/*
+ * Copyright (C) 2010 Georg Martius <georg.martius at web.de>
+ * Copyright (C) 2010 Daniel G. Taylor <dan at 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 libavfilter/vf_deshake.c
+ * 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 "libavutil/common.h"
+#include "libavutil/mem.h"
+#include "libavutil/pixdesc.h"
+#include "libavcodec/dsputil.h"
+
+#include "transform.h"
+
+#define CHROMA_WIDTH(link) -((-link->w) >> av_pix_fmt_descriptors[link->format].log2_chroma_w)
+#define CHROMA_HEIGHT(link) -((-link->h) >> av_pix_fmt_descriptors[link->format].log2_chroma_h)
+
+enum SearchMethod {
+ EXHAUSTIVE, //< Search all possible positions
+ SMART_EXHAUSTIVE, //< Search most possible positions (faster)
+ SEARCH_COUNT
+};
+
+typedef struct {
+ double x; //< Horizontal shift
+ double y; //< Vertical shift
+} MotionVector;
+
+typedef struct {
+ MotionVector vector; //< Motion vector
+ double angle; //< Angle of rotation
+ double zoom; //< Zoom percentage
+} Transform;
+
+typedef struct {
+ AVFilterBufferRef *ref; //< Previous frame
+ int rx; //< Maximum horizontal shift
+ int ry; //< Maximum vertical shift
+ enum FillMethod edge; //< Edge fill method
+ int blocksize; //< Size of blocks to compare
+ int contrast; //< Contrast threshold
+ enum SearchMethod search; //< Motion search method
+ AVCodecContext *avctx;
+ DSPContext c; //< Context providing optimized SAD methods
+ Transform last; //< Transform from last frame
+ int refcount; //< Number of reference frames (defines averaging window)
+ FILE *fp;
+} DeshakeContext;
+
+static int cmp(void const *ca, void const *cb)
+{
+ double *a = (double *) ca;
+ double *b = (double *) cb;
+ return *a < *b ? -1 : ( *a > *b ? 1 : 0 );
+}
+
+/**
+ * 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;
+
+ qsort(values, count, sizeof(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,
+ MotionVector *mv)
+{
+ int x, y;
+ int diff;
+ int smallest = INT_MAX;
+ int tmp, tmp2;
+
+ #define CMP(i, j) deshake->c.sad[0](deshake, src1 + cy * stride + cx, \
+ src2 + (j) * stride + (i), stride, \
+ deshake->blocksize)
+
+ 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 - 2; y += 2) {
+ for (x = -deshake->rx + 1; x < deshake->rx - 2; 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 = 0;
+ int i, j, pos;
+
+ for (i = 0; i <= blocksize * 2; i++) {
+ // We use a width of 16 here to match the libavcodec sad functions
+ for (j = 0; i <= 15; i++) {
+ 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, MotionVector *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;
+ MotionVector mv = {0, 0};
+ int counts[128][128];
+ int count_max_value = 0;
+ int contrast;
+
+ int pos;
+ double angles[1200];
+ double totalangles = 0;
+
+ int center_x = 0, center_y = 0;
+ double p_x, p_y;
+
+ // Reset counts to zero
+ for (x = 0; x < deshake->rx * 2 + 1; x++) {
+ for (y = 0; y < deshake->ry * 2 + 1; y++) {
+ 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 libavcodec sad functions
+ 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) {
+ counts[(int)(mv.x + deshake->rx)][(int)(mv.y + deshake->ry)] += 1;
+ if (x > deshake->rx && y > deshake->ry)
+ angles[pos++] = block_angle(x, y, 0, 0, &mv);
+
+ center_x += mv.x;
+ center_y += mv.y;
+ }
+ }
+ }
+ }
+
+ pos = FFMAX(1, pos);
+
+ center_x /= pos;
+ center_y /= pos;
+
+ for (x = 0; x < pos; x++) {
+ totalangles += angles[x];
+ }
+
+ //av_log(NULL, AV_LOG_ERROR, "Angle: %lf\n", totalangles / (pos - 1));
+ t->angle = totalangles / (pos - 1);
+
+ t->angle = clean_mean(angles, pos);
+ if (t->angle < 0.001)
+ 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 ", counts[x][y]);
+ if (counts[x][y] > count_max_value) {
+ t->vector.x = x - deshake->rx;
+ t->vector.y = y - deshake->ry;
+ count_max_value = counts[x][y];
+ }
+ }
+ //av_log(NULL, AV_LOG_ERROR, "\n");
+ }
+
+ p_x = (center_x - width / 2);
+ p_y = (center_y - height / 2);
+ t->vector.x += (cos(t->angle)-1)*p_x - sin(t->angle)*p_y;
+ t->vector.y += sin(t->angle)*p_x + (cos(t->angle)-1)*p_y;
+
+ // Clamp max shift & rotation?
+ t->vector.x = av_clipf(t->vector.x, -deshake->rx * 2, deshake->rx * 2);
+ t->vector.y = av_clipf(t->vector.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 av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+ DeshakeContext *deshake = ctx->priv;
+
+ deshake->rx = 16;
+ deshake->ry = 16;
+ deshake->edge = FILL_BLANK;
+ deshake->blocksize = 8;
+ deshake->contrast = 125;
+ deshake->search = EXHAUSTIVE;
+ deshake->refcount = 20;
+ deshake->fp = fopen("stats.txt", "w");
+ 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);
+
+ if (args) {
+ sscanf(args, "%d:%d:%d:%d:%d:%d", &deshake->rx, &deshake->ry, (int *)&deshake->edge,
+ &deshake->blocksize, &deshake->contrast, (int *)&deshake->search);
+
+ deshake->blocksize /= 2;
+
+ deshake->rx = av_clip(deshake->rx, 0, 64);
+ deshake->ry = av_clip(deshake->ry, 0, 64);
+ deshake->edge = av_clip(deshake->edge, FILL_BLANK, FILL_COUNT - 1);
+ deshake->blocksize = av_clip(deshake->blocksize, 4, 128);
+ deshake->contrast = av_clip(deshake->contrast, 1, 255);
+ deshake->search = av_clip(deshake->search, EXHAUSTIVE, SEARCH_COUNT - 1);
+ }
+
+ av_log(ctx, AV_LOG_INFO, "rx: %d, ry: %d, edge: %d blocksize: %d contrast: %d search: %d\n",
+ deshake->rx, deshake->ry, deshake->edge, deshake->blocksize * 2, deshake->contrast, deshake->search);
+
+ return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ enum PixelFormat pix_fmts[] = {
+ PIX_FMT_YUV420P, PIX_FMT_YUV422P, PIX_FMT_YUV444P, PIX_FMT_YUV410P,
+ PIX_FMT_YUV411P, PIX_FMT_YUV440P, PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P,
+ PIX_FMT_YUVJ444P, PIX_FMT_YUVJ440P, PIX_FMT_NONE
+ };
+
+ avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
+
+ return 0;
+}
+
+static int config_props(AVFilterLink *link)
+{
+ DeshakeContext *deshake = link->dst->priv;
+
+ deshake->ref = NULL;
+ deshake->last.vector.x = 0;
+ deshake->last.vector.y = 0;
+ deshake->last.angle = 0;
+ deshake->last.zoom = 0;
+
+ deshake->avctx= avcodec_alloc_context3(NULL);
+ dsputil_init(&deshake->c, deshake->avctx);
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ DeshakeContext *deshake = ctx->priv;
+
+ avfilter_unref_buffer(deshake->ref);
+ fclose(deshake->fp);
+}
+
+static void end_frame(AVFilterLink *link)
+{
+ DeshakeContext *deshake = link->dst->priv;
+ AVFilterBufferRef *in = link->cur_buf;
+ AVFilterBufferRef *out = link->dst->outputs[0]->out_buf;
+ Transform t;
+ static float matrix[9];
+ static Transform avg = {
+ .vector = {
+ .x = 0,
+ .y = 0
+ },
+ .angle = 0,
+ .zoom = 0.0f
+ };
+ float alpha = 2.0 / deshake->refcount;
+ char tmp[256];
+ Transform orig;
+
+ // 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);
+
+ // Copy transform so we can output it later to compare to the smoothed value
+ orig.vector.x = t.vector.x;
+ orig.vector.y = t.vector.y;
+ orig.angle = t.angle;
+ orig.zoom = t.zoom;
+
+ // Generate a one-sided moving exponential average
+ avg.vector.x = alpha * t.vector.x + (1.0 - alpha) * avg.vector.x;
+ avg.vector.y = alpha * t.vector.y + (1.0 - alpha) * avg.vector.y;
+ avg.angle = alpha * t.angle + (1.0 - alpha) * avg.angle;
+ avg.zoom = alpha * t.zoom + (1.0 - alpha) * 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.vector.x -= avg.vector.x;
+ t.vector.y -= avg.vector.y;
+ t.angle -= avg.angle;
+ t.zoom -= avg.zoom;
+
+ // Invert the motion to undo it
+ t.vector.x *= -1;
+ t.vector.y *= -1;
+ t.angle *= -1;
+
+ // Write statistics to file
+ snprintf(tmp, 256, "%f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f\n", orig.vector.x, avg.vector.x, t.vector.x, orig.vector.y, avg.vector.y, t.vector.y, orig.angle, avg.angle, t.angle, orig.zoom, 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.vector.x += deshake->last.vector.x;
+ t.vector.y += deshake->last.vector.y;
+ t.angle += deshake->last.angle;
+ t.zoom += deshake->last.zoom;
+
+ // Shrink motion by 10% to keep things centered in the camera frame
+ t.vector.x *= 0.9;
+ t.vector.y *= 0.9;
+ t.angle *= 0.9;
+
+ // Store the last absolute motion information
+ deshake->last.vector.x = t.vector.x;
+ deshake->last.vector.y = t.vector.y;
+ deshake->last.angle = t.angle;
+ deshake->last.zoom = t.zoom;
+
+ // Generate a luma transformation matrix
+ avfilter_get_matrix(t.vector.x, t.vector.y, t.angle, 1.0 + t.zoom / 100.0, matrix);
+
+ // Transform the luma plane
+ avfilter_transform(in->data[0], out->data[0], in->linesize[0], out->linesize[0], link->w, link->h, matrix, INTERPOLATE_BILINEAR, deshake->edge);
+
+ // Generate a chroma transformation matrix
+ avfilter_get_matrix(t.vector.x / (link->w / CHROMA_WIDTH(link)), t.vector.y / (link->h / CHROMA_HEIGHT(link)), t.angle, 1.0 + t.zoom / 100.0, matrix);
+
+ // Transform the chroma planes
+ avfilter_transform(in->data[1], out->data[1], in->linesize[1], out->linesize[1], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), matrix, INTERPOLATE_BILINEAR, deshake->edge);
+ avfilter_transform(in->data[2], out->data[2], in->linesize[2], out->linesize[2], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), matrix, INTERPOLATE_BILINEAR, deshake->edge);
+
+ // Store the current frame as the reference frame for calculating the
+ // motion of the next frame
+ if (deshake->ref != NULL)
+ avfilter_unref_buffer(deshake->ref);
+
+ // Cleanup the old reference frame
+ deshake->ref = in;
+
+ // Draw the transformed frame information
+ avfilter_draw_slice(link->dst->outputs[0], 0, link->h, 1);
+ avfilter_end_frame(link->dst->outputs[0]);
+ avfilter_unref_buffer(out);
+}
+
+static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
+{
+}
+
+AVFilter avfilter_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 = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .draw_slice = draw_slice,
+ .end_frame = end_frame,
+ .config_props = config_props,
+ .min_perms = AV_PERM_READ, },
+ { .name = NULL}},
+
+ .outputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO, },
+ { .name = NULL}},
+};
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