0,0 → 1,580 |
/* |
* 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 "libavcodec/dsputil.h" |
|
#include "deshake.h" |
#include "deshake_opencl.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) |
|
#define OFFSET(x) offsetof(DeshakeContext, x) |
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
|
#define MAX_R 64 |
|
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", "use OpenCL filtering capabilities", OFFSET(opencl), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, .flags = FLAGS }, |
{ NULL } |
}; |
|
AVFILTER_DEFINE_CLASS(deshake); |
|
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; 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 libavcodec sad functions |
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 counts[2*MAX_R+1][2*MAX_R+1]; |
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 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) |
{ |
int ret; |
DeshakeContext *deshake = ctx->priv; |
|
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; |
if (!CONFIG_OPENCL && deshake->opencl) { |
av_log(ctx, AV_LOG_ERROR, "OpenCL support was not enabled in this build, cannot be selected\n"); |
return AVERROR(EINVAL); |
} |
|
if (CONFIG_OPENCL && deshake->opencl) { |
deshake->transform = ff_opencl_transform; |
ret = ff_opencl_deshake_init(ctx); |
if (ret < 0) |
return ret; |
} |
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); |
avpriv_dsputil_init(&deshake->c, deshake->avctx); |
|
return 0; |
} |
|
static av_cold void uninit(AVFilterContext *ctx) |
{ |
DeshakeContext *deshake = ctx->priv; |
if (CONFIG_OPENCL && deshake->opencl) { |
ff_opencl_deshake_uninit(ctx); |
} |
av_frame_free(&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, 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; |
|
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 (CONFIG_OPENCL && deshake->opencl) { |
ret = ff_opencl_deshake_process_inout_buf(link->dst,in, out); |
if (ret < 0) |
return ret; |
} |
|
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_y); |
// 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_uv); |
// Transform the luma and chroma planes |
ret = deshake->transform(link->dst, link->w, link->h, CHROMA_WIDTH(link), CHROMA_HEIGHT(link), |
matrix_y, matrix_uv, INTERPOLATE_BILINEAR, deshake->edge, in, out); |
|
// Cleanup the old reference frame |
av_frame_free(&deshake->ref); |
|
if (ret < 0) |
return ret; |
|
// 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, |
}, |
{ 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, |
.priv_class = &deshake_class, |
}; |