/*
  * 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,

 };