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  1. /*
  2.  * Copyright (C) 2010 Georg Martius <georg.martius@web.de>
  3.  * Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
  4.  *
  5.  * This file is part of FFmpeg.
  6.  *
  7.  * FFmpeg is free software; you can redistribute it and/or
  8.  * modify it under the terms of the GNU Lesser General Public
  9.  * License as published by the Free Software Foundation; either
  10.  * version 2.1 of the License, or (at your option) any later version.
  11.  *
  12.  * FFmpeg is distributed in the hope that it will be useful,
  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15.  * Lesser General Public License for more details.
  16.  *
  17.  * You should have received a copy of the GNU Lesser General Public
  18.  * License along with FFmpeg; if not, write to the Free Software
  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20.  */
  21.  
  22. /**
  23.  * @file
  24.  * fast deshake / depan video filter
  25.  *
  26.  * SAD block-matching motion compensation to fix small changes in
  27.  * horizontal and/or vertical shift. This filter helps remove camera shake
  28.  * from hand-holding a camera, bumping a tripod, moving on a vehicle, etc.
  29.  *
  30.  * Algorithm:
  31.  *   - For each frame with one previous reference frame
  32.  *       - For each block in the frame
  33.  *           - If contrast > threshold then find likely motion vector
  34.  *       - For all found motion vectors
  35.  *           - Find most common, store as global motion vector
  36.  *       - Find most likely rotation angle
  37.  *       - Transform image along global motion
  38.  *
  39.  * TODO:
  40.  *   - Fill frame edges based on previous/next reference frames
  41.  *   - Fill frame edges by stretching image near the edges?
  42.  *       - Can this be done quickly and look decent?
  43.  *
  44.  * Dark Shikari links to http://wiki.videolan.org/SoC_x264_2010#GPU_Motion_Estimation_2
  45.  * for an algorithm similar to what could be used here to get the gmv
  46.  * It requires only a couple diamond searches + fast downscaling
  47.  *
  48.  * Special thanks to Jason Kotenko for his help with the algorithm and my
  49.  * inability to see simple errors in C code.
  50.  */
  51.  
  52. #include "avfilter.h"
  53. #include "formats.h"
  54. #include "internal.h"
  55. #include "video.h"
  56. #include "libavutil/common.h"
  57. #include "libavutil/mem.h"
  58. #include "libavutil/opt.h"
  59. #include "libavutil/pixdesc.h"
  60.  
  61. #include "deshake.h"
  62. #include "deshake_opencl.h"
  63.  
  64. #define CHROMA_WIDTH(link)  (-((-(link)->w) >> av_pix_fmt_desc_get((link)->format)->log2_chroma_w))
  65. #define CHROMA_HEIGHT(link) (-((-(link)->h) >> av_pix_fmt_desc_get((link)->format)->log2_chroma_h))
  66.  
  67. #define OFFSET(x) offsetof(DeshakeContext, x)
  68. #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
  69.  
  70. static const AVOption deshake_options[] = {
  71.     { "x", "set x for the rectangular search area",      OFFSET(cx), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
  72.     { "y", "set y for the rectangular search area",      OFFSET(cy), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
  73.     { "w", "set width for the rectangular search area",  OFFSET(cw), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
  74.     { "h", "set height for the rectangular search area", OFFSET(ch), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
  75.     { "rx", "set x for the rectangular search area",     OFFSET(rx), AV_OPT_TYPE_INT, {.i64=16}, 0, MAX_R, .flags = FLAGS },
  76.     { "ry", "set y for the rectangular search area",     OFFSET(ry), AV_OPT_TYPE_INT, {.i64=16}, 0, MAX_R, .flags = FLAGS },
  77.     { "edge", "set edge mode", OFFSET(edge), AV_OPT_TYPE_INT, {.i64=FILL_MIRROR}, FILL_BLANK, FILL_COUNT-1, FLAGS, "edge"},
  78.         { "blank",    "fill zeroes at blank locations",         0, AV_OPT_TYPE_CONST, {.i64=FILL_BLANK},    INT_MIN, INT_MAX, FLAGS, "edge" },
  79.         { "original", "original image at blank locations",      0, AV_OPT_TYPE_CONST, {.i64=FILL_ORIGINAL}, INT_MIN, INT_MAX, FLAGS, "edge" },
  80.         { "clamp",    "extruded edge value at blank locations", 0, AV_OPT_TYPE_CONST, {.i64=FILL_CLAMP},    INT_MIN, INT_MAX, FLAGS, "edge" },
  81.         { "mirror",   "mirrored edge at blank locations",       0, AV_OPT_TYPE_CONST, {.i64=FILL_MIRROR},   INT_MIN, INT_MAX, FLAGS, "edge" },
  82.     { "blocksize", "set motion search blocksize",       OFFSET(blocksize), AV_OPT_TYPE_INT, {.i64=8},   4, 128, .flags = FLAGS },
  83.     { "contrast",  "set contrast threshold for blocks", OFFSET(contrast),  AV_OPT_TYPE_INT, {.i64=125}, 1, 255, .flags = FLAGS },
  84.     { "search",  "set search strategy", OFFSET(search), AV_OPT_TYPE_INT, {.i64=EXHAUSTIVE}, EXHAUSTIVE, SEARCH_COUNT-1, FLAGS, "smode" },
  85.         { "exhaustive", "exhaustive search",      0, AV_OPT_TYPE_CONST, {.i64=EXHAUSTIVE},       INT_MIN, INT_MAX, FLAGS, "smode" },
  86.         { "less",       "less exhaustive search", 0, AV_OPT_TYPE_CONST, {.i64=SMART_EXHAUSTIVE}, INT_MIN, INT_MAX, FLAGS, "smode" },
  87.     { "filename", "set motion search detailed log file name", OFFSET(filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
  88.     { "opencl", "use OpenCL filtering capabilities", OFFSET(opencl), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, .flags = FLAGS },
  89.     { NULL }
  90. };
  91.  
  92. AVFILTER_DEFINE_CLASS(deshake);
  93.  
  94. static int cmp(const double *a, const double *b)
  95. {
  96.     return *a < *b ? -1 : ( *a > *b ? 1 : 0 );
  97. }
  98.  
  99. /**
  100.  * Cleaned mean (cuts off 20% of values to remove outliers and then averages)
  101.  */
  102. static double clean_mean(double *values, int count)
  103. {
  104.     double mean = 0;
  105.     int cut = count / 5;
  106.     int x;
  107.  
  108.     qsort(values, count, sizeof(double), (void*)cmp);
  109.  
  110.     for (x = cut; x < count - cut; x++) {
  111.         mean += values[x];
  112.     }
  113.  
  114.     return mean / (count - cut * 2);
  115. }
  116.  
  117. /**
  118.  * Find the most likely shift in motion between two frames for a given
  119.  * macroblock. Test each block against several shifts given by the rx
  120.  * and ry attributes. Searches using a simple matrix of those shifts and
  121.  * chooses the most likely shift by the smallest difference in blocks.
  122.  */
  123. static void find_block_motion(DeshakeContext *deshake, uint8_t *src1,
  124.                               uint8_t *src2, int cx, int cy, int stride,
  125.                               IntMotionVector *mv)
  126. {
  127.     int x, y;
  128.     int diff;
  129.     int smallest = INT_MAX;
  130.     int tmp, tmp2;
  131.  
  132.     #define CMP(i, j) deshake->sad(src1 + cy  * stride + cx,  stride,\
  133.                                    src2 + (j) * stride + (i), stride)
  134.  
  135.     if (deshake->search == EXHAUSTIVE) {
  136.         // Compare every possible position - this is sloooow!
  137.         for (y = -deshake->ry; y <= deshake->ry; y++) {
  138.             for (x = -deshake->rx; x <= deshake->rx; x++) {
  139.                 diff = CMP(cx - x, cy - y);
  140.                 if (diff < smallest) {
  141.                     smallest = diff;
  142.                     mv->x = x;
  143.                     mv->y = y;
  144.                 }
  145.             }
  146.         }
  147.     } else if (deshake->search == SMART_EXHAUSTIVE) {
  148.         // Compare every other possible position and find the best match
  149.         for (y = -deshake->ry + 1; y < deshake->ry; y += 2) {
  150.             for (x = -deshake->rx + 1; x < deshake->rx; x += 2) {
  151.                 diff = CMP(cx - x, cy - y);
  152.                 if (diff < smallest) {
  153.                     smallest = diff;
  154.                     mv->x = x;
  155.                     mv->y = y;
  156.                 }
  157.             }
  158.         }
  159.  
  160.         // Hone in on the specific best match around the match we found above
  161.         tmp = mv->x;
  162.         tmp2 = mv->y;
  163.  
  164.         for (y = tmp2 - 1; y <= tmp2 + 1; y++) {
  165.             for (x = tmp - 1; x <= tmp + 1; x++) {
  166.                 if (x == tmp && y == tmp2)
  167.                     continue;
  168.  
  169.                 diff = CMP(cx - x, cy - y);
  170.                 if (diff < smallest) {
  171.                     smallest = diff;
  172.                     mv->x = x;
  173.                     mv->y = y;
  174.                 }
  175.             }
  176.         }
  177.     }
  178.  
  179.     if (smallest > 512) {
  180.         mv->x = -1;
  181.         mv->y = -1;
  182.     }
  183.     emms_c();
  184.     //av_log(NULL, AV_LOG_ERROR, "%d\n", smallest);
  185.     //av_log(NULL, AV_LOG_ERROR, "Final: (%d, %d) = %d x %d\n", cx, cy, mv->x, mv->y);
  186. }
  187.  
  188. /**
  189.  * Find the contrast of a given block. When searching for global motion we
  190.  * really only care about the high contrast blocks, so using this method we
  191.  * can actually skip blocks we don't care much about.
  192.  */
  193. static int block_contrast(uint8_t *src, int x, int y, int stride, int blocksize)
  194. {
  195.     int highest = 0;
  196.     int lowest = 255;
  197.     int i, j, pos;
  198.  
  199.     for (i = 0; i <= blocksize * 2; i++) {
  200.         // We use a width of 16 here to match the sad function
  201.         for (j = 0; j <= 15; j++) {
  202.             pos = (y - i) * stride + (x - j);
  203.             if (src[pos] < lowest)
  204.                 lowest = src[pos];
  205.             else if (src[pos] > highest) {
  206.                 highest = src[pos];
  207.             }
  208.         }
  209.     }
  210.  
  211.     return highest - lowest;
  212. }
  213.  
  214. /**
  215.  * Find the rotation for a given block.
  216.  */
  217. static double block_angle(int x, int y, int cx, int cy, IntMotionVector *shift)
  218. {
  219.     double a1, a2, diff;
  220.  
  221.     a1 = atan2(y - cy, x - cx);
  222.     a2 = atan2(y - cy + shift->y, x - cx + shift->x);
  223.  
  224.     diff = a2 - a1;
  225.  
  226.     return (diff > M_PI)  ? diff - 2 * M_PI :
  227.            (diff < -M_PI) ? diff + 2 * M_PI :
  228.            diff;
  229. }
  230.  
  231. /**
  232.  * Find the estimated global motion for a scene given the most likely shift
  233.  * for each block in the frame. The global motion is estimated to be the
  234.  * same as the motion from most blocks in the frame, so if most blocks
  235.  * move one pixel to the right and two pixels down, this would yield a
  236.  * motion vector (1, -2).
  237.  */
  238. static void find_motion(DeshakeContext *deshake, uint8_t *src1, uint8_t *src2,
  239.                         int width, int height, int stride, Transform *t)
  240. {
  241.     int x, y;
  242.     IntMotionVector mv = {0, 0};
  243.     int count_max_value = 0;
  244.     int contrast;
  245.  
  246.     int pos;
  247.     int center_x = 0, center_y = 0;
  248.     double p_x, p_y;
  249.  
  250.     av_fast_malloc(&deshake->angles, &deshake->angles_size, width * height / (16 * deshake->blocksize) * sizeof(*deshake->angles));
  251.  
  252.     // Reset counts to zero
  253.     for (x = 0; x < deshake->rx * 2 + 1; x++) {
  254.         for (y = 0; y < deshake->ry * 2 + 1; y++) {
  255.             deshake->counts[x][y] = 0;
  256.         }
  257.     }
  258.  
  259.     pos = 0;
  260.     // Find motion for every block and store the motion vector in the counts
  261.     for (y = deshake->ry; y < height - deshake->ry - (deshake->blocksize * 2); y += deshake->blocksize * 2) {
  262.         // We use a width of 16 here to match the sad function
  263.         for (x = deshake->rx; x < width - deshake->rx - 16; x += 16) {
  264.             // If the contrast is too low, just skip this block as it probably
  265.             // won't be very useful to us.
  266.             contrast = block_contrast(src2, x, y, stride, deshake->blocksize);
  267.             if (contrast > deshake->contrast) {
  268.                 //av_log(NULL, AV_LOG_ERROR, "%d\n", contrast);
  269.                 find_block_motion(deshake, src1, src2, x, y, stride, &mv);
  270.                 if (mv.x != -1 && mv.y != -1) {
  271.                     deshake->counts[mv.x + deshake->rx][mv.y + deshake->ry] += 1;
  272.                     if (x > deshake->rx && y > deshake->ry)
  273.                         deshake->angles[pos++] = block_angle(x, y, 0, 0, &mv);
  274.  
  275.                     center_x += mv.x;
  276.                     center_y += mv.y;
  277.                 }
  278.             }
  279.         }
  280.     }
  281.  
  282.     if (pos) {
  283.          center_x /= pos;
  284.          center_y /= pos;
  285.          t->angle = clean_mean(deshake->angles, pos);
  286.          if (t->angle < 0.001)
  287.               t->angle = 0;
  288.     } else {
  289.          t->angle = 0;
  290.     }
  291.  
  292.     // Find the most common motion vector in the frame and use it as the gmv
  293.     for (y = deshake->ry * 2; y >= 0; y--) {
  294.         for (x = 0; x < deshake->rx * 2 + 1; x++) {
  295.             //av_log(NULL, AV_LOG_ERROR, "%5d ", deshake->counts[x][y]);
  296.             if (deshake->counts[x][y] > count_max_value) {
  297.                 t->vec.x = x - deshake->rx;
  298.                 t->vec.y = y - deshake->ry;
  299.                 count_max_value = deshake->counts[x][y];
  300.             }
  301.         }
  302.         //av_log(NULL, AV_LOG_ERROR, "\n");
  303.     }
  304.  
  305.     p_x = (center_x - width / 2.0);
  306.     p_y = (center_y - height / 2.0);
  307.     t->vec.x += (cos(t->angle)-1)*p_x  - sin(t->angle)*p_y;
  308.     t->vec.y += sin(t->angle)*p_x  + (cos(t->angle)-1)*p_y;
  309.  
  310.     // Clamp max shift & rotation?
  311.     t->vec.x = av_clipf(t->vec.x, -deshake->rx * 2, deshake->rx * 2);
  312.     t->vec.y = av_clipf(t->vec.y, -deshake->ry * 2, deshake->ry * 2);
  313.     t->angle = av_clipf(t->angle, -0.1, 0.1);
  314.  
  315.     //av_log(NULL, AV_LOG_ERROR, "%d x %d\n", avg->x, avg->y);
  316. }
  317.  
  318. static int deshake_transform_c(AVFilterContext *ctx,
  319.                                     int width, int height, int cw, int ch,
  320.                                     const float *matrix_y, const float *matrix_uv,
  321.                                     enum InterpolateMethod interpolate,
  322.                                     enum FillMethod fill, AVFrame *in, AVFrame *out)
  323. {
  324.     int i = 0, ret = 0;
  325.     const float *matrixs[3];
  326.     int plane_w[3], plane_h[3];
  327.     matrixs[0] = matrix_y;
  328.     matrixs[1] =  matrixs[2] = matrix_uv;
  329.     plane_w[0] = width;
  330.     plane_w[1] = plane_w[2] = cw;
  331.     plane_h[0] = height;
  332.     plane_h[1] = plane_h[2] = ch;
  333.  
  334.     for (i = 0; i < 3; i++) {
  335.         // Transform the luma and chroma planes
  336.         ret = avfilter_transform(in->data[i], out->data[i], in->linesize[i], out->linesize[i],
  337.                                  plane_w[i], plane_h[i], matrixs[i], interpolate, fill);
  338.         if (ret < 0)
  339.             return ret;
  340.     }
  341.     return ret;
  342. }
  343.  
  344. static av_cold int init(AVFilterContext *ctx)
  345. {
  346.     int ret;
  347.     DeshakeContext *deshake = ctx->priv;
  348.  
  349.     deshake->sad = av_pixelutils_get_sad_fn(4, 4, 1, deshake); // 16x16, 2nd source unaligned
  350.     if (!deshake->sad)
  351.         return AVERROR(EINVAL);
  352.  
  353.     deshake->refcount = 20; // XXX: add to options?
  354.     deshake->blocksize /= 2;
  355.     deshake->blocksize = av_clip(deshake->blocksize, 4, 128);
  356.  
  357.     if (deshake->rx % 16) {
  358.         av_log(ctx, AV_LOG_ERROR, "rx must be a multiple of 16\n");
  359.         return AVERROR_PATCHWELCOME;
  360.     }
  361.  
  362.     if (deshake->filename)
  363.         deshake->fp = fopen(deshake->filename, "w");
  364.     if (deshake->fp)
  365.         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);
  366.  
  367.     // Quadword align left edge of box for MMX code, adjust width if necessary
  368.     // to keep right margin
  369.     if (deshake->cx > 0) {
  370.         deshake->cw += deshake->cx - (deshake->cx & ~15);
  371.         deshake->cx &= ~15;
  372.     }
  373.     deshake->transform = deshake_transform_c;
  374.     if (!CONFIG_OPENCL && deshake->opencl) {
  375.         av_log(ctx, AV_LOG_ERROR, "OpenCL support was not enabled in this build, cannot be selected\n");
  376.         return AVERROR(EINVAL);
  377.     }
  378.  
  379.     if (CONFIG_OPENCL && deshake->opencl) {
  380.         deshake->transform = ff_opencl_transform;
  381.         ret = ff_opencl_deshake_init(ctx);
  382.         if (ret < 0)
  383.             return ret;
  384.     }
  385.     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",
  386.            deshake->cx, deshake->cy, deshake->cw, deshake->ch,
  387.            deshake->rx, deshake->ry, deshake->edge, deshake->blocksize * 2, deshake->contrast, deshake->search);
  388.  
  389.     return 0;
  390. }
  391.  
  392. static int query_formats(AVFilterContext *ctx)
  393. {
  394.     static const enum AVPixelFormat pix_fmts[] = {
  395.         AV_PIX_FMT_YUV420P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV410P,
  396.         AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
  397.         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE
  398.     };
  399.     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
  400.     if (!fmts_list)
  401.         return AVERROR(ENOMEM);
  402.     return ff_set_common_formats(ctx, fmts_list);
  403. }
  404.  
  405. static int config_props(AVFilterLink *link)
  406. {
  407.     DeshakeContext *deshake = link->dst->priv;
  408.  
  409.     deshake->ref = NULL;
  410.     deshake->last.vec.x = 0;
  411.     deshake->last.vec.y = 0;
  412.     deshake->last.angle = 0;
  413.     deshake->last.zoom = 0;
  414.  
  415.     return 0;
  416. }
  417.  
  418. static av_cold void uninit(AVFilterContext *ctx)
  419. {
  420.     DeshakeContext *deshake = ctx->priv;
  421.     if (CONFIG_OPENCL && deshake->opencl) {
  422.         ff_opencl_deshake_uninit(ctx);
  423.     }
  424.     av_frame_free(&deshake->ref);
  425.     av_freep(&deshake->angles);
  426.     deshake->angles_size = 0;
  427.     if (deshake->fp)
  428.         fclose(deshake->fp);
  429. }
  430.  
  431. static int filter_frame(AVFilterLink *link, AVFrame *in)
  432. {
  433.     DeshakeContext *deshake = link->dst->priv;
  434.     AVFilterLink *outlink = link->dst->outputs[0];
  435.     AVFrame *out;
  436.     Transform t = {{0},0}, orig = {{0},0};
  437.     float matrix_y[9], matrix_uv[9];
  438.     float alpha = 2.0 / deshake->refcount;
  439.     char tmp[256];
  440.     int ret = 0;
  441.  
  442.     out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
  443.     if (!out) {
  444.         av_frame_free(&in);
  445.         return AVERROR(ENOMEM);
  446.     }
  447.     av_frame_copy_props(out, in);
  448.  
  449.     if (CONFIG_OPENCL && deshake->opencl) {
  450.         ret = ff_opencl_deshake_process_inout_buf(link->dst,in, out);
  451.         if (ret < 0)
  452.             return ret;
  453.     }
  454.  
  455.     if (deshake->cx < 0 || deshake->cy < 0 || deshake->cw < 0 || deshake->ch < 0) {
  456.         // Find the most likely global motion for the current frame
  457.         find_motion(deshake, (deshake->ref == NULL) ? in->data[0] : deshake->ref->data[0], in->data[0], link->w, link->h, in->linesize[0], &t);
  458.     } else {
  459.         uint8_t *src1 = (deshake->ref == NULL) ? in->data[0] : deshake->ref->data[0];
  460.         uint8_t *src2 = in->data[0];
  461.  
  462.         deshake->cx = FFMIN(deshake->cx, link->w);
  463.         deshake->cy = FFMIN(deshake->cy, link->h);
  464.  
  465.         if ((unsigned)deshake->cx + (unsigned)deshake->cw > link->w) deshake->cw = link->w - deshake->cx;
  466.         if ((unsigned)deshake->cy + (unsigned)deshake->ch > link->h) deshake->ch = link->h - deshake->cy;
  467.  
  468.         // Quadword align right margin
  469.         deshake->cw &= ~15;
  470.  
  471.         src1 += deshake->cy * in->linesize[0] + deshake->cx;
  472.         src2 += deshake->cy * in->linesize[0] + deshake->cx;
  473.  
  474.         find_motion(deshake, src1, src2, deshake->cw, deshake->ch, in->linesize[0], &t);
  475.     }
  476.  
  477.  
  478.     // Copy transform so we can output it later to compare to the smoothed value
  479.     orig.vec.x = t.vec.x;
  480.     orig.vec.y = t.vec.y;
  481.     orig.angle = t.angle;
  482.     orig.zoom = t.zoom;
  483.  
  484.     // Generate a one-sided moving exponential average
  485.     deshake->avg.vec.x = alpha * t.vec.x + (1.0 - alpha) * deshake->avg.vec.x;
  486.     deshake->avg.vec.y = alpha * t.vec.y + (1.0 - alpha) * deshake->avg.vec.y;
  487.     deshake->avg.angle = alpha * t.angle + (1.0 - alpha) * deshake->avg.angle;
  488.     deshake->avg.zoom = alpha * t.zoom + (1.0 - alpha) * deshake->avg.zoom;
  489.  
  490.     // Remove the average from the current motion to detect the motion that
  491.     // is not on purpose, just as jitter from bumping the camera
  492.     t.vec.x -= deshake->avg.vec.x;
  493.     t.vec.y -= deshake->avg.vec.y;
  494.     t.angle -= deshake->avg.angle;
  495.     t.zoom -= deshake->avg.zoom;
  496.  
  497.     // Invert the motion to undo it
  498.     t.vec.x *= -1;
  499.     t.vec.y *= -1;
  500.     t.angle *= -1;
  501.  
  502.     // Write statistics to file
  503.     if (deshake->fp) {
  504.         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);
  505.         fwrite(tmp, sizeof(char), strlen(tmp), deshake->fp);
  506.     }
  507.  
  508.     // Turn relative current frame motion into absolute by adding it to the
  509.     // last absolute motion
  510.     t.vec.x += deshake->last.vec.x;
  511.     t.vec.y += deshake->last.vec.y;
  512.     t.angle += deshake->last.angle;
  513.     t.zoom += deshake->last.zoom;
  514.  
  515.     // Shrink motion by 10% to keep things centered in the camera frame
  516.     t.vec.x *= 0.9;
  517.     t.vec.y *= 0.9;
  518.     t.angle *= 0.9;
  519.  
  520.     // Store the last absolute motion information
  521.     deshake->last.vec.x = t.vec.x;
  522.     deshake->last.vec.y = t.vec.y;
  523.     deshake->last.angle = t.angle;
  524.     deshake->last.zoom = t.zoom;
  525.  
  526.     // Generate a luma transformation matrix
  527.     avfilter_get_matrix(t.vec.x, t.vec.y, t.angle, 1.0 + t.zoom / 100.0, matrix_y);
  528.     // Generate a chroma transformation matrix
  529.     avfilter_get_matrix(t.vec.x / (link->w / CHROMA_WIDTH(link)), t.vec.y / (link->h / CHROMA_HEIGHT(link)), t.angle, 1.0 + t.zoom / 100.0, matrix_uv);
  530.     // Transform the luma and chroma planes
  531.     ret = deshake->transform(link->dst, link->w, link->h, CHROMA_WIDTH(link), CHROMA_HEIGHT(link),
  532.                              matrix_y, matrix_uv, INTERPOLATE_BILINEAR, deshake->edge, in, out);
  533.  
  534.     // Cleanup the old reference frame
  535.     av_frame_free(&deshake->ref);
  536.  
  537.     if (ret < 0)
  538.         return ret;
  539.  
  540.     // Store the current frame as the reference frame for calculating the
  541.     // motion of the next frame
  542.     deshake->ref = in;
  543.  
  544.     return ff_filter_frame(outlink, out);
  545. }
  546.  
  547. static const AVFilterPad deshake_inputs[] = {
  548.     {
  549.         .name         = "default",
  550.         .type         = AVMEDIA_TYPE_VIDEO,
  551.         .filter_frame = filter_frame,
  552.         .config_props = config_props,
  553.     },
  554.     { NULL }
  555. };
  556.  
  557. static const AVFilterPad deshake_outputs[] = {
  558.     {
  559.         .name = "default",
  560.         .type = AVMEDIA_TYPE_VIDEO,
  561.     },
  562.     { NULL }
  563. };
  564.  
  565. AVFilter ff_vf_deshake = {
  566.     .name          = "deshake",
  567.     .description   = NULL_IF_CONFIG_SMALL("Stabilize shaky video."),
  568.     .priv_size     = sizeof(DeshakeContext),
  569.     .init          = init,
  570.     .uninit        = uninit,
  571.     .query_formats = query_formats,
  572.     .inputs        = deshake_inputs,
  573.     .outputs       = deshake_outputs,
  574.     .priv_class    = &deshake_class,
  575. };
  576.