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FFmpeg/libavfilter/vf_crop.c
Reinhard Tartler 737eb5976f Merge libavcore into libavutil
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
2011-02-15 16:18:21 +01:00

343 lines
12 KiB
C

/*
* 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 "libavutil/eval.h"
#include "libavutil/avstring.h"
#include "libavutil/libm.h"
#include "libavutil/imgutils.h"
static const char *var_names[] = {
"E",
"PHI",
"PI",
"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
"x",
"y",
"n", ///< number of frame
"pos", ///< position in the file
"t", ///< timestamp expressed in seconds
NULL
};
enum var_name {
VAR_E,
VAR_PHI,
VAR_PI,
VAR_IN_W, VAR_IW,
VAR_IN_H, VAR_IH,
VAR_OUT_W, VAR_OW,
VAR_OUT_H, VAR_OH,
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
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_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
};
avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
return 0;
}
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
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[^:]", crop->ow_expr, crop->oh_expr, crop->x_expr, crop->y_expr);
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_E] = M_E;
crop->var_values[VAR_PHI] = M_PHI;
crop->var_values[VAR_PI] = M_PI;
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_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);
av_log(ctx, AV_LOG_INFO, "w:%d h:%d -> w:%d h:%d\n",
link->w, link->h, crop->w, crop->h);
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;
return 0;
}
static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
{
AVFilterContext *ctx = link->dst;
CropContext *crop = ctx->priv;
AVFilterBufferRef *ref2;
int i;
ref2 = avfilter_ref_buffer(picref, ~0);
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);
#ifdef DEBUG
av_log(ctx, AV_LOG_DEBUG,
"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);
#endif
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)) {
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];
}
avfilter_start_frame(link->dst->outputs[0], ref2);
}
static void 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;
if (y < crop->y) {
h -= crop->y - y;
y = crop->y;
}
if (y + h > crop->y + crop->h)
h = crop->y + crop->h - y;
avfilter_draw_slice(ctx->outputs[0], y - crop->y, h, slice_dir);
}
static void end_frame(AVFilterLink *link)
{
CropContext *crop = link->dst->priv;
crop->var_values[VAR_N] += 1.0;
avfilter_unref_buffer(link->cur_buf);
avfilter_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 = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.start_frame = start_frame,
.draw_slice = draw_slice,
.end_frame = end_frame,
.get_video_buffer = avfilter_null_get_video_buffer,
.config_props = config_input, },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output, },
{ .name = NULL}},
};