/* * 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/pixdesc.h" #include "libavcodec/dsputil.h" #include "transform.h" #define CHROMA_WIDTH(link) -((-link->w) >> av_pix_fmt_desc_get(link->format)->log2_chroma_w) #define CHROMA_HEIGHT(link) -((-link->h) >> av_pix_fmt_desc_get(link->format)->log2_chroma_h) enum SearchMethod { EXHAUSTIVE, ///< Search all possible positions SMART_EXHAUSTIVE, ///< Search most possible positions (faster) SEARCH_COUNT }; typedef struct { int x; ///< Horizontal shift int y; ///< Vertical shift } IntMotionVector; 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 { AVClass av_class; AVFilterBufferRef *ref; ///< Previous frame int rx; ///< Maximum horizontal shift int ry; ///< Maximum vertical shift int edge; ///< Edge fill method int blocksize; ///< Size of blocks to compare int contrast; ///< Contrast threshold int 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; Transform avg; int cw; ///< Crop motion search to this box int ch; int cx; int cy; } DeshakeContext; static int cmp(const double *a, const double *b) { 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), (void*)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->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, 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 counts[128][128]; int count_max_value = 0; int contrast; int pos; double *angles = av_malloc(sizeof(*angles) * width * height / (16 * deshake->blocksize)); 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[mv.x + deshake->rx][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; } } } } if (pos) { center_x /= pos; center_y /= pos; t->angle = clean_mean(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 ", 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); av_free(angles); } static av_cold int init(AVFilterContext *ctx, const char *args) { DeshakeContext *deshake = ctx->priv; char filename[256] = {0}; deshake->rx = 16; deshake->ry = 16; deshake->edge = FILL_MIRROR; deshake->blocksize = 8; deshake->contrast = 125; deshake->search = EXHAUSTIVE; deshake->refcount = 20; deshake->cw = -1; deshake->ch = -1; deshake->cx = -1; deshake->cy = -1; if (args) { sscanf(args, "%d:%d:%d:%d:%d:%d:%d:%d:%d:%d:%255s", &deshake->cx, &deshake->cy, &deshake->cw, &deshake->ch, &deshake->rx, &deshake->ry, &deshake->edge, &deshake->blocksize, &deshake->contrast, &deshake->search, filename); 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); } if (*filename) deshake->fp = fopen(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; } 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 }; ff_set_common_formats(ctx, ff_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); if (deshake->fp) fclose(deshake->fp); if (deshake->avctx) avcodec_close(deshake->avctx); av_freep(&deshake->avctx); } static int filter_frame(AVFilterLink *link, AVFilterBufferRef *in) { DeshakeContext *deshake = link->dst->priv; AVFilterLink *outlink = link->dst->outputs[0]; AVFilterBufferRef *out; Transform t = {{0},0}, orig = {{0},0}; float matrix[9]; float alpha = 2.0 / deshake->refcount; char tmp[256]; out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h); if (!out) { avfilter_unref_bufferp(&in); return AVERROR(ENOMEM); } avfilter_copy_buffer_ref_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.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 deshake->avg.vector.x = alpha * t.vector.x + (1.0 - alpha) * deshake->avg.vector.x; deshake->avg.vector.y = alpha * t.vector.y + (1.0 - alpha) * deshake->avg.vector.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.vector.x -= deshake->avg.vector.x; t.vector.y -= deshake->avg.vector.y; t.angle -= deshake->avg.angle; t.zoom -= deshake->avg.zoom; // Invert the motion to undo it t.vector.x *= -1; t.vector.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.vector.x, deshake->avg.vector.x, t.vector.x, orig.vector.y, deshake->avg.vector.y, t.vector.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.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); // Cleanup the old reference frame avfilter_unref_buffer(deshake->ref); // 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); } static const AVFilterPad deshake_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .filter_frame = filter_frame, .config_props = config_props, .min_perms = AV_PERM_READ | AV_PERM_PRESERVE, }, { NULL } }; static const AVFilterPad deshake_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, }, { NULL } }; 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 = deshake_inputs, .outputs = deshake_outputs, };