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FFmpeg/libavfilter/vf_crop.c
Anton Khirnov 27f8c9b27b lavu/frame: deprecate AVFrame.pkt_{pos,size}
These fields are supposed to store information about the packet the
frame was decoded from, specifically the byte offset it was stored at
and its size.

However,
- the fields are highly ad-hoc - there is no strong reason why
  specifically those (and not any other) packet properties should have a
  dedicated field in AVFrame; unlike e.g. the timestamps, there is no
  fundamental link between coded packet offset/size and decoded frames
- they only make sense for frames produced by decoding demuxed packets,
  and even then it is not always the case that the encoded data was
  stored in the file as a contiguous sequence of bytes (in order for pos
  to be well-defined)
- pkt_pos was added without much explanation, apparently to allow
  passthrough of this information through lavfi in order to handle byte
  seeking in ffplay. That is now implemented using arbitrary user data
  passthrough in AVFrame.opaque_ref.
- several filters use pkt_pos as a variable available to user-supplied
  expressions, but there seems to be no established motivation for using them.
- pkt_size was added for use in ffprobe, but that too is now handled
  without using this field. Additonally, the values of this field
  produced by libavcodec are flawed, as described in the previous
  ffprobe conversion commit.

In summary - these fields are ill-defined and insufficiently motivated,
so deprecate them.
2023-03-20 10:42:09 +01:00

410 lines
14 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
*/
#include <stdio.h>
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#include "libavutil/eval.h"
#include "libavutil/avstring.h"
#include "libavutil/internal.h"
#include "libavutil/libm.h"
#include "libavutil/imgutils.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.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
#if FF_API_FRAME_PKT
"pos", ///< position in the file
#endif
"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,
#if FF_API_FRAME_PKT
VAR_POS,
#endif
VAR_T,
VAR_VARS_NB
};
typedef struct CropContext {
const AVClass *class;
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 exact; ///< exact cropping, for subsampled formats
int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
int hsub, vsub; ///< chroma subsampling
char *x_expr, *y_expr, *w_expr, *h_expr;
AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
double var_values[VAR_VARS_NB];
} CropContext;
static int query_formats(AVFilterContext *ctx)
{
int reject_flags = AV_PIX_FMT_FLAG_BITSTREAM | FF_PIX_FMT_FLAG_SW_FLAT_SUB;
return ff_set_common_formats(ctx, ff_formats_pixdesc_filter(0, reject_flags));
}
static av_cold void uninit(AVFilterContext *ctx)
{
CropContext *s = ctx->priv;
av_expr_free(s->x_pexpr);
s->x_pexpr = NULL;
av_expr_free(s->y_pexpr);
s->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 = lrint(d);
return ret;
}
static int config_input(AVFilterLink *link)
{
AVFilterContext *ctx = link->dst;
CropContext *s = ctx->priv;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
int ret;
const char *expr;
double res;
s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w;
s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h;
s->var_values[VAR_A] = (float) link->w / link->h;
s->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
s->var_values[VAR_DAR] = s->var_values[VAR_A] * s->var_values[VAR_SAR];
s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
s->var_values[VAR_X] = NAN;
s->var_values[VAR_Y] = NAN;
s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = NAN;
s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = NAN;
s->var_values[VAR_N] = 0;
s->var_values[VAR_T] = NAN;
#if FF_API_FRAME_PKT
s->var_values[VAR_POS] = NAN;
#endif
av_image_fill_max_pixsteps(s->max_step, NULL, pix_desc);
if (pix_desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
s->hsub = 1;
s->vsub = 1;
} else {
s->hsub = pix_desc->log2_chroma_w;
s->vsub = pix_desc->log2_chroma_h;
}
av_expr_parse_and_eval(&res, (expr = s->w_expr),
var_names, s->var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx);
s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
var_names, s->var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail_expr;
s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res;
/* evaluate again ow as it may depend on oh */
if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
var_names, s->var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail_expr;
s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 ||
normalize_double(&s->h, s->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",
s->w_expr, s->h_expr);
return AVERROR(EINVAL);
}
if (!s->exact) {
s->w &= ~((1 << s->hsub) - 1);
s->h &= ~((1 << s->vsub) - 1);
}
av_expr_free(s->x_pexpr);
av_expr_free(s->y_pexpr);
s->x_pexpr = s->y_pexpr = NULL;
if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
(ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0)
return AVERROR(EINVAL);
if (s->keep_aspect) {
AVRational dar = av_mul_q(link->sample_aspect_ratio,
(AVRational){ link->w, link->h });
av_reduce(&s->out_sar.num, &s->out_sar.den,
dar.num * s->h, dar.den * s->w, INT_MAX);
} else
s->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,
s->w, s->h, s->out_sar.num, s->out_sar.den);
if (s->w <= 0 || s->h <= 0 ||
s->w > link->w || s->h > link->h) {
av_log(ctx, AV_LOG_ERROR,
"Invalid too big or non positive size for width '%d' or height '%d'\n",
s->w, s->h);
return AVERROR(EINVAL);
}
/* set default, required in the case the first computed value for x/y is NAN */
s->x = (link->w - s->w) / 2;
s->y = (link->h - s->h) / 2;
if (!s->exact) {
s->x &= ~((1 << s->hsub) - 1);
s->y &= ~((1 << s->vsub) - 1);
}
return 0;
fail_expr:
av_log(ctx, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
return ret;
}
static int config_output(AVFilterLink *link)
{
CropContext *s = link->src->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
// Hardware frames adjust the cropping regions rather than
// changing the frame size.
} else {
link->w = s->w;
link->h = s->h;
}
link->sample_aspect_ratio = s->out_sar;
return 0;
}
static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
AVFilterContext *ctx = link->dst;
CropContext *s = ctx->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
int i;
s->var_values[VAR_N] = link->frame_count_out;
s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
NAN : frame->pts * av_q2d(link->time_base);
#if FF_API_FRAME_PKT
FF_DISABLE_DEPRECATION_WARNINGS
s->var_values[VAR_POS] = frame->pkt_pos == -1 ?
NAN : frame->pkt_pos;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, NULL);
/* It is necessary if x is expressed from y */
s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
normalize_double(&s->x, s->var_values[VAR_X]);
normalize_double(&s->y, s->var_values[VAR_Y]);
if (s->x < 0)
s->x = 0;
if (s->y < 0)
s->y = 0;
if ((unsigned)s->x + (unsigned)s->w > link->w)
s->x = link->w - s->w;
if ((unsigned)s->y + (unsigned)s->h > link->h)
s->y = link->h - s->h;
if (!s->exact) {
s->x &= ~((1 << s->hsub) - 1);
s->y &= ~((1 << s->vsub) - 1);
}
av_log(ctx, AV_LOG_TRACE, "n:%d t:%f x:%d y:%d x+w:%d y+h:%d\n",
(int)s->var_values[VAR_N], s->var_values[VAR_T],
s->x, s->y, s->x+s->w, s->y+s->h);
if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
frame->crop_top += s->y;
frame->crop_left += s->x;
frame->crop_bottom = frame->height - frame->crop_top - frame->crop_bottom - s->h;
frame->crop_right = frame->width - frame->crop_left - frame->crop_right - s->w;
} else {
frame->width = s->w;
frame->height = s->h;
frame->data[0] += s->y * frame->linesize[0];
frame->data[0] += s->x * s->max_step[0];
if (!(desc->flags & AV_PIX_FMT_FLAG_PAL)) {
for (i = 1; i < 3; i ++) {
if (frame->data[i]) {
frame->data[i] += (s->y >> s->vsub) * frame->linesize[i];
frame->data[i] += (s->x * s->max_step[i]) >> s->hsub;
}
}
}
/* alpha plane */
if (frame->data[3]) {
frame->data[3] += s->y * frame->linesize[3];
frame->data[3] += s->x * s->max_step[3];
}
}
return ff_filter_frame(link->dst->outputs[0], frame);
}
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
char *res, int res_len, int flags)
{
CropContext *s = ctx->priv;
int ret;
if ( !strcmp(cmd, "out_w") || !strcmp(cmd, "w")
|| !strcmp(cmd, "out_h") || !strcmp(cmd, "h")
|| !strcmp(cmd, "x") || !strcmp(cmd, "y")) {
int old_x = s->x;
int old_y = s->y;
int old_w = s->w;
int old_h = s->h;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterLink *inlink = ctx->inputs[0];
av_opt_set(s, cmd, args, 0);
if ((ret = config_input(inlink)) < 0) {
s->x = old_x;
s->y = old_y;
s->w = old_w;
s->h = old_h;
return ret;
}
ret = config_output(outlink);
} else
ret = AVERROR(ENOSYS);
return ret;
}
#define OFFSET(x) offsetof(CropContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define TFLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
static const AVOption crop_options[] = {
{ "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, TFLAGS },
{ "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, TFLAGS },
{ "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, TFLAGS },
{ "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, TFLAGS },
{ "x", "set the x crop area expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, 0, 0, TFLAGS },
{ "y", "set the y crop area expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, 0, 0, TFLAGS },
{ "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ "exact", "do exact cropping", OFFSET(exact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(crop);
static const AVFilterPad avfilter_vf_crop_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input,
},
};
static const AVFilterPad avfilter_vf_crop_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output,
},
};
const AVFilter ff_vf_crop = {
.name = "crop",
.description = NULL_IF_CONFIG_SMALL("Crop the input video."),
.priv_size = sizeof(CropContext),
.priv_class = &crop_class,
.uninit = uninit,
FILTER_INPUTS(avfilter_vf_crop_inputs),
FILTER_OUTPUTS(avfilter_vf_crop_outputs),
FILTER_QUERY_FUNC(query_formats),
.process_command = process_command,
};