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/*
* Copyright (c) 2007 Bobby Bingham
*
* 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
* video crop filter
*/
/* #define DEBUG */
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#include "libavutil/eval.h"
#include "libavutil/avstring.h"
#include "libavutil/libm.h"
#include "libavutil/imgutils.h"
#include "libavutil/mathematics.h"
static const char *const var_names[] = {
"in_w", "iw", ///< width of the input video
"in_h", "ih", ///< height of the input video
"out_w", "ow", ///< width of the cropped video
"out_h", "oh", ///< height of the cropped video
"a",
"sar",
"dar",
"hsub",
"vsub",
"x",
"y",
"n", ///< number of frame
"pos", ///< position in the file
"t", ///< timestamp expressed in seconds
NULL
};
enum var_name {
VAR_IN_W, VAR_IW,
VAR_IN_H, VAR_IH,
VAR_OUT_W, VAR_OW,
VAR_OUT_H, VAR_OH,
VAR_A,
VAR_SAR,
VAR_DAR,
VAR_HSUB,
VAR_VSUB,
VAR_X,
VAR_Y,
VAR_N,
VAR_POS,
VAR_T,
VAR_VARS_NB
};
typedef struct {
int x; ///< x offset of the non-cropped area with respect to the input area
int y; ///< y offset of the non-cropped area with respect to the input area
int w; ///< width of the cropped area
int h; ///< height of the cropped area
AVRational out_sar; ///< output sample aspect ratio
int keep_aspect; ///< keep display aspect ratio when cropping
int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
int hsub, vsub; ///< chroma subsampling
char x_expr[256], y_expr[256], ow_expr[256], oh_expr[256];
AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
double var_values[VAR_VARS_NB];
} CropContext;
static int query_formats(AVFilterContext *ctx)
{
static const enum PixelFormat pix_fmts[] = {
PIX_FMT_RGB48BE, PIX_FMT_RGB48LE,
PIX_FMT_BGR48BE, PIX_FMT_BGR48LE,
PIX_FMT_ARGB, PIX_FMT_RGBA,
PIX_FMT_ABGR, PIX_FMT_BGRA,
PIX_FMT_RGB24, PIX_FMT_BGR24,
PIX_FMT_RGB565BE, PIX_FMT_RGB565LE,
PIX_FMT_RGB555BE, PIX_FMT_RGB555LE,
PIX_FMT_BGR565BE, PIX_FMT_BGR565LE,
PIX_FMT_BGR555BE, PIX_FMT_BGR555LE,
PIX_FMT_GRAY16BE, PIX_FMT_GRAY16LE,
PIX_FMT_YUV420P16LE, PIX_FMT_YUV420P16BE,
PIX_FMT_YUV422P16LE, PIX_FMT_YUV422P16BE,
PIX_FMT_YUV444P16LE, PIX_FMT_YUV444P16BE,
PIX_FMT_YUV444P, PIX_FMT_YUV422P,
PIX_FMT_YUV420P, PIX_FMT_YUV411P,
PIX_FMT_YUV410P, PIX_FMT_YUV440P,
PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P,
PIX_FMT_YUVJ420P, PIX_FMT_YUVJ440P,
PIX_FMT_YUVA420P,
PIX_FMT_RGB8, PIX_FMT_BGR8,
PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE,
PIX_FMT_PAL8, PIX_FMT_GRAY8,
PIX_FMT_NONE
};
ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
return 0;
}
static av_cold int init(AVFilterContext *ctx, const char *args)
{
CropContext *crop = ctx->priv;
av_strlcpy(crop->ow_expr, "iw", sizeof(crop->ow_expr));
av_strlcpy(crop->oh_expr, "ih", sizeof(crop->oh_expr));
av_strlcpy(crop->x_expr, "(in_w-out_w)/2", sizeof(crop->x_expr));
av_strlcpy(crop->y_expr, "(in_h-out_h)/2", sizeof(crop->y_expr));
if (args)
sscanf(args, "%255[^:]:%255[^:]:%255[^:]:%255[^:]:%d", crop->ow_expr, crop->oh_expr, crop->x_expr, crop->y_expr, &crop->keep_aspect);
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
CropContext *crop = ctx->priv;
av_expr_free(crop->x_pexpr); crop->x_pexpr = NULL;
av_expr_free(crop->y_pexpr); crop->y_pexpr = NULL;
}
static inline int normalize_double(int *n, double d)
{
int ret = 0;
if (isnan(d)) {
ret = AVERROR(EINVAL);
} else if (d > INT_MAX || d < INT_MIN) {
*n = d > INT_MAX ? INT_MAX : INT_MIN;
ret = AVERROR(EINVAL);
} else
*n = round(d);
return ret;
}
static int config_input(AVFilterLink *link)
{
AVFilterContext *ctx = link->dst;
CropContext *crop = ctx->priv;
const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[link->format];
int ret;
const char *expr;
double res;
crop->var_values[VAR_IN_W] = crop->var_values[VAR_IW] = ctx->inputs[0]->w;
crop->var_values[VAR_IN_H] = crop->var_values[VAR_IH] = ctx->inputs[0]->h;
crop->var_values[VAR_A] = (float) link->w / link->h;
crop->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
crop->var_values[VAR_DAR] = crop->var_values[VAR_A] * crop->var_values[VAR_SAR];
crop->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
crop->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
crop->var_values[VAR_X] = NAN;
crop->var_values[VAR_Y] = NAN;
crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = NAN;
crop->var_values[VAR_OUT_H] = crop->var_values[VAR_OH] = NAN;
crop->var_values[VAR_N] = 0;
crop->var_values[VAR_T] = NAN;
crop->var_values[VAR_POS] = NAN;
av_image_fill_max_pixsteps(crop->max_step, NULL, pix_desc);
crop->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
crop->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
if ((ret = av_expr_parse_and_eval(&res, (expr = crop->ow_expr),
var_names, crop->var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = res;
if ((ret = av_expr_parse_and_eval(&res, (expr = crop->oh_expr),
var_names, crop->var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
crop->var_values[VAR_OUT_H] = crop->var_values[VAR_OH] = res;
/* evaluate again ow as it may depend on oh */
if ((ret = av_expr_parse_and_eval(&res, (expr = crop->ow_expr),
var_names, crop->var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) goto fail_expr;
crop->var_values[VAR_OUT_W] = crop->var_values[VAR_OW] = res;
if (normalize_double(&crop->w, crop->var_values[VAR_OUT_W]) < 0 ||
normalize_double(&crop->h, crop->var_values[VAR_OUT_H]) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Too big value or invalid expression for out_w/ow or out_h/oh. "
"Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
crop->ow_expr, crop->oh_expr);
return AVERROR(EINVAL);
}
crop->w &= ~((1 << crop->hsub) - 1);
crop->h &= ~((1 << crop->vsub) - 1);
if ((ret = av_expr_parse(&crop->x_pexpr, crop->x_expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
(ret = av_expr_parse(&crop->y_pexpr, crop->y_expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0)
return AVERROR(EINVAL);
if (crop->keep_aspect) {
AVRational dar = av_mul_q(link->sample_aspect_ratio,
(AVRational){ link->w, link->h });
av_reduce(&crop->out_sar.num, &crop->out_sar.den,
dar.num * crop->h, dar.den * crop->w, INT_MAX);
} else
crop->out_sar = link->sample_aspect_ratio;
av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
crop->w, crop->h, crop->out_sar.num, crop->out_sar.den);
if (crop->w <= 0 || crop->h <= 0 ||
crop->w > link->w || crop->h > link->h) {
av_log(ctx, AV_LOG_ERROR,
"Invalid too big or non positive size for width '%d' or height '%d'\n",
crop->w, crop->h);
return AVERROR(EINVAL);
}
/* set default, required in the case the first computed value for x/y is NAN */
crop->x = (link->w - crop->w) / 2;
crop->y = (link->h - crop->h) / 2;
crop->x &= ~((1 << crop->hsub) - 1);
crop->y &= ~((1 << crop->vsub) - 1);
return 0;
fail_expr:
av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
return ret;
}
static int config_output(AVFilterLink *link)
{
CropContext *crop = link->src->priv;
link->w = crop->w;
link->h = crop->h;
link->sample_aspect_ratio = crop->out_sar;
return 0;
}
static int start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
{
AVFilterContext *ctx = link->dst;
CropContext *crop = ctx->priv;
AVFilterBufferRef *ref2;
int i;
ref2 = avfilter_ref_buffer(picref, ~0);
if (!ref2)
return AVERROR(ENOMEM);
ref2->video->w = crop->w;
ref2->video->h = crop->h;
crop->var_values[VAR_T] = picref->pts == AV_NOPTS_VALUE ?
NAN : picref->pts * av_q2d(link->time_base);
crop->var_values[VAR_POS] = picref->pos == -1 ? NAN : picref->pos;
crop->var_values[VAR_X] = av_expr_eval(crop->x_pexpr, crop->var_values, NULL);
crop->var_values[VAR_Y] = av_expr_eval(crop->y_pexpr, crop->var_values, NULL);
crop->var_values[VAR_X] = av_expr_eval(crop->x_pexpr, crop->var_values, NULL);
normalize_double(&crop->x, crop->var_values[VAR_X]);
normalize_double(&crop->y, crop->var_values[VAR_Y]);
if (crop->x < 0) crop->x = 0;
if (crop->y < 0) crop->y = 0;
if ((unsigned)crop->x + (unsigned)crop->w > link->w) crop->x = link->w - crop->w;
if ((unsigned)crop->y + (unsigned)crop->h > link->h) crop->y = link->h - crop->h;
crop->x &= ~((1 << crop->hsub) - 1);
crop->y &= ~((1 << crop->vsub) - 1);
av_dlog(ctx, "n:%d t:%f x:%d y:%d x+w:%d y+h:%d\n",
(int)crop->var_values[VAR_N], crop->var_values[VAR_T], crop->x,
crop->y, crop->x+crop->w, crop->y+crop->h);
ref2->data[0] += crop->y * ref2->linesize[0];
ref2->data[0] += crop->x * crop->max_step[0];
if (!(av_pix_fmt_descriptors[link->format].flags & PIX_FMT_PAL ||
av_pix_fmt_descriptors[link->format].flags & PIX_FMT_PSEUDOPAL)) {
for (i = 1; i < 3; i ++) {
if (ref2->data[i]) {
ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
ref2->data[i] += (crop->x * crop->max_step[i]) >> crop->hsub;
}
}
}
/* alpha plane */
if (ref2->data[3]) {
ref2->data[3] += crop->y * ref2->linesize[3];
ref2->data[3] += crop->x * crop->max_step[3];
}
return ff_start_frame(link->dst->outputs[0], ref2);
}
static int draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
{
AVFilterContext *ctx = link->dst;
CropContext *crop = ctx->priv;
if (y >= crop->y + crop->h || y + h <= crop->y)
return 0;
if (y < crop->y) {
h -= crop->y - y;
y = crop->y;
}
if (y + h > crop->y + crop->h)
h = crop->y + crop->h - y;
return ff_draw_slice(ctx->outputs[0], y - crop->y, h, slice_dir);
}
static int end_frame(AVFilterLink *link)
{
CropContext *crop = link->dst->priv;
crop->var_values[VAR_N] += 1.0;
return ff_end_frame(link->dst->outputs[0]);
}
AVFilter avfilter_vf_crop = {
.name = "crop",
.description = NULL_IF_CONFIG_SMALL("Crop the input video to width:height:x:y."),
.priv_size = sizeof(CropContext),
.query_formats = query_formats,
.init = init,
.uninit = uninit,
.inputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.start_frame = start_frame,
.draw_slice = draw_slice,
.end_frame = end_frame,
.get_video_buffer = ff_null_get_video_buffer,
.config_props = config_input, },
{ .name = NULL}},
.outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output, },
{ .name = NULL}},
};
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