FFmpeg/libavfilter/vf_perspective.c
Andreas Rheinhardt b4f5201967 avfilter: Replace query_formats callback with union of list and callback
If one looks at the many query_formats callbacks in existence,
one will immediately recognize that there is one type of default
callback for video and a slightly different default callback for
audio: It is "return ff_set_common_formats_from_list(ctx, pix_fmts);"
for video with a filter-specific pix_fmts list. For audio, it is
the same with a filter-specific sample_fmts list together with
ff_set_common_all_samplerates() and ff_set_common_all_channel_counts().

This commit allows to remove the boilerplate query_formats callbacks
by replacing said callback with a union consisting the old callback
and pointers for pixel and sample format arrays. For the not uncommon
case in which these lists only contain a single entry (besides the
sentinel) enum AVPixelFormat and enum AVSampleFormat fields are also
added to the union to store them directly in the AVFilter,
thereby avoiding a relocation.

The state of said union will be contained in a new, dedicated AVFilter
field (the nb_inputs and nb_outputs fields have been shrunk to uint8_t
in order to create a hole for this new field; this is no problem, as
the maximum of all the nb_inputs is four; for nb_outputs it is only
two).

The state's default value coincides with the earlier default of
query_formats being unset, namely that the filter accepts all formats
(and also sample rates and channel counts/layouts for audio)
provided that these properties agree coincide for all inputs and
outputs.

By using different union members for audio and video filters
the type-unsafety of using the same functions for audio and video
lists will furthermore be more confined to formats.c than before.

When the new fields are used, they will also avoid allocations:
Currently something nearly equivalent to ff_default_query_formats()
is called after every successful call to a query_formats callback;
yet in the common case that the newly allocated AVFilterFormats
are not used at all (namely if there are no free links) these newly
allocated AVFilterFormats are freed again without ever being used.
Filters no longer using the callback will not exhibit this any more.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2021-10-05 17:48:25 +02:00

522 lines
19 KiB
C

/*
* Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
* Copyright (c) 2013 Paul B Mahol
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU 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
*/
#include "libavutil/avassert.h"
#include "libavutil/eval.h"
#include "libavutil/imgutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#define SUB_PIXEL_BITS 8
#define SUB_PIXELS (1 << SUB_PIXEL_BITS)
#define COEFF_BITS 11
#define LINEAR 0
#define CUBIC 1
typedef struct PerspectiveContext {
const AVClass *class;
char *expr_str[4][2];
double ref[4][2];
int32_t (*pv)[2];
int32_t coeff[SUB_PIXELS][4];
int interpolation;
int linesize[4];
int height[4];
int hsub, vsub;
int nb_planes;
int sense;
int eval_mode;
int (*perspective)(AVFilterContext *ctx,
void *arg, int job, int nb_jobs);
} PerspectiveContext;
#define OFFSET(x) offsetof(PerspectiveContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
enum PERSPECTIVESense {
PERSPECTIVE_SENSE_SOURCE = 0, ///< coordinates give locations in source of corners of destination.
PERSPECTIVE_SENSE_DESTINATION = 1, ///< coordinates give locations in destination of corners of source.
};
enum EvalMode {
EVAL_MODE_INIT,
EVAL_MODE_FRAME,
EVAL_MODE_NB
};
static const AVOption perspective_options[] = {
{ "x0", "set top left x coordinate", OFFSET(expr_str[0][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
{ "y0", "set top left y coordinate", OFFSET(expr_str[0][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
{ "x1", "set top right x coordinate", OFFSET(expr_str[1][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
{ "y1", "set top right y coordinate", OFFSET(expr_str[1][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
{ "x2", "set bottom left x coordinate", OFFSET(expr_str[2][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
{ "y2", "set bottom left y coordinate", OFFSET(expr_str[2][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
{ "x3", "set bottom right x coordinate", OFFSET(expr_str[3][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
{ "y3", "set bottom right y coordinate", OFFSET(expr_str[3][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
{ "interpolation", "set interpolation", OFFSET(interpolation), AV_OPT_TYPE_INT, {.i64=LINEAR}, 0, 1, FLAGS, "interpolation" },
{ "linear", "", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "interpolation" },
{ "cubic", "", 0, AV_OPT_TYPE_CONST, {.i64=CUBIC}, 0, 0, FLAGS, "interpolation" },
{ "sense", "specify the sense of the coordinates", OFFSET(sense), AV_OPT_TYPE_INT, {.i64=PERSPECTIVE_SENSE_SOURCE}, 0, 1, FLAGS, "sense"},
{ "source", "specify locations in source to send to corners in destination",
0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE_SENSE_SOURCE}, 0, 0, FLAGS, "sense"},
{ "destination", "specify locations in destination to send corners of source",
0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE_SENSE_DESTINATION}, 0, 0, FLAGS, "sense"},
{ "eval", "specify when to evaluate expressions", OFFSET(eval_mode), AV_OPT_TYPE_INT, {.i64 = EVAL_MODE_INIT}, 0, EVAL_MODE_NB-1, FLAGS, "eval" },
{ "init", "eval expressions once during initialization", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_INIT}, .flags = FLAGS, .unit = "eval" },
{ "frame", "eval expressions per-frame", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_FRAME}, .flags = FLAGS, .unit = "eval" },
{ NULL }
};
AVFILTER_DEFINE_CLASS(perspective);
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
};
return ff_set_common_formats_from_list(ctx, pix_fmts);
}
static inline double get_coeff(double d)
{
double coeff, A = -0.60;
d = fabs(d);
if (d < 1.0)
coeff = (1.0 - (A + 3.0) * d * d + (A + 2.0) * d * d * d);
else if (d < 2.0)
coeff = (-4.0 * A + 8.0 * A * d - 5.0 * A * d * d + A * d * d * d);
else
coeff = 0.0;
return coeff;
}
static const char *const var_names[] = { "W", "H", "in", "on", NULL };
enum { VAR_W, VAR_H, VAR_IN, VAR_ON, VAR_VARS_NB };
static int calc_persp_luts(AVFilterContext *ctx, AVFilterLink *inlink)
{
PerspectiveContext *s = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
double (*ref)[2] = s->ref;
double values[VAR_VARS_NB] = { [VAR_W] = inlink->w, [VAR_H] = inlink->h,
[VAR_IN] = inlink->frame_count_out + 1,
[VAR_ON] = outlink->frame_count_in + 1 };
const int h = values[VAR_H];
const int w = values[VAR_W];
double x0, x1, x2, x3, x4, x5, x6, x7, x8, q;
double t0, t1, t2, t3;
int x, y, i, j, ret;
for (i = 0; i < 4; i++) {
for (j = 0; j < 2; j++) {
if (!s->expr_str[i][j])
return AVERROR(EINVAL);
ret = av_expr_parse_and_eval(&s->ref[i][j], s->expr_str[i][j],
var_names, &values[0],
NULL, NULL, NULL, NULL,
0, 0, ctx);
if (ret < 0)
return ret;
}
}
switch (s->sense) {
case PERSPECTIVE_SENSE_SOURCE:
x6 = ((ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
(ref[2][1] - ref[3][1]) -
( ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
(ref[2][0] - ref[3][0])) * h;
x7 = ((ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
(ref[1][0] - ref[3][0]) -
( ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
(ref[1][1] - ref[3][1])) * w;
q = ( ref[1][0] - ref[3][0]) * (ref[2][1] - ref[3][1]) -
( ref[2][0] - ref[3][0]) * (ref[1][1] - ref[3][1]);
x0 = q * (ref[1][0] - ref[0][0]) * h + x6 * ref[1][0];
x1 = q * (ref[2][0] - ref[0][0]) * w + x7 * ref[2][0];
x2 = q * ref[0][0] * w * h;
x3 = q * (ref[1][1] - ref[0][1]) * h + x6 * ref[1][1];
x4 = q * (ref[2][1] - ref[0][1]) * w + x7 * ref[2][1];
x5 = q * ref[0][1] * w * h;
x8 = q * w * h;
break;
case PERSPECTIVE_SENSE_DESTINATION:
t0 = ref[0][0] * (ref[3][1] - ref[1][1]) +
ref[1][0] * (ref[0][1] - ref[3][1]) +
ref[3][0] * (ref[1][1] - ref[0][1]);
t1 = ref[1][0] * (ref[2][1] - ref[3][1]) +
ref[2][0] * (ref[3][1] - ref[1][1]) +
ref[3][0] * (ref[1][1] - ref[2][1]);
t2 = ref[0][0] * (ref[3][1] - ref[2][1]) +
ref[2][0] * (ref[0][1] - ref[3][1]) +
ref[3][0] * (ref[2][1] - ref[0][1]);
t3 = ref[0][0] * (ref[1][1] - ref[2][1]) +
ref[1][0] * (ref[2][1] - ref[0][1]) +
ref[2][0] * (ref[0][1] - ref[1][1]);
x0 = t0 * t1 * w * (ref[2][1] - ref[0][1]);
x1 = t0 * t1 * w * (ref[0][0] - ref[2][0]);
x2 = t0 * t1 * w * (ref[0][1] * ref[2][0] - ref[0][0] * ref[2][1]);
x3 = t1 * t2 * h * (ref[1][1] - ref[0][1]);
x4 = t1 * t2 * h * (ref[0][0] - ref[1][0]);
x5 = t1 * t2 * h * (ref[0][1] * ref[1][0] - ref[0][0] * ref[1][1]);
x6 = t1 * t2 * (ref[1][1] - ref[0][1]) +
t0 * t3 * (ref[2][1] - ref[3][1]);
x7 = t1 * t2 * (ref[0][0] - ref[1][0]) +
t0 * t3 * (ref[3][0] - ref[2][0]);
x8 = t1 * t2 * (ref[0][1] * ref[1][0] - ref[0][0] * ref[1][1]) +
t0 * t3 * (ref[2][0] * ref[3][1] - ref[2][1] * ref[3][0]);
break;
default:
av_assert0(0);
}
for (y = 0; y < h; y++){
for (x = 0; x < w; x++){
int u, v;
u = lrint(SUB_PIXELS * (x0 * x + x1 * y + x2) /
(x6 * x + x7 * y + x8));
v = lrint(SUB_PIXELS * (x3 * x + x4 * y + x5) /
(x6 * x + x7 * y + x8));
s->pv[x + y * w][0] = u;
s->pv[x + y * w][1] = v;
}
}
return 0;
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
PerspectiveContext *s = ctx->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
int h = inlink->h;
int w = inlink->w;
int i, j, ret;
s->hsub = desc->log2_chroma_w;
s->vsub = desc->log2_chroma_h;
s->nb_planes = av_pix_fmt_count_planes(inlink->format);
if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
return ret;
s->height[1] = s->height[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
s->height[0] = s->height[3] = inlink->h;
s->pv = av_realloc_f(s->pv, w * h, 2 * sizeof(*s->pv));
if (!s->pv)
return AVERROR(ENOMEM);
if (s->eval_mode == EVAL_MODE_INIT) {
if ((ret = calc_persp_luts(ctx, inlink)) < 0) {
return ret;
}
}
for (i = 0; i < SUB_PIXELS; i++){
double d = i / (double)SUB_PIXELS;
double temp[4];
double sum = 0;
for (j = 0; j < 4; j++)
temp[j] = get_coeff(j - d - 1);
for (j = 0; j < 4; j++)
sum += temp[j];
for (j = 0; j < 4; j++)
s->coeff[i][j] = lrint((1 << COEFF_BITS) * temp[j] / sum);
}
return 0;
}
typedef struct ThreadData {
uint8_t *dst;
int dst_linesize;
uint8_t *src;
int src_linesize;
int w, h;
int hsub, vsub;
} ThreadData;
static int resample_cubic(AVFilterContext *ctx, void *arg,
int job, int nb_jobs)
{
PerspectiveContext *s = ctx->priv;
ThreadData *td = arg;
uint8_t *dst = td->dst;
int dst_linesize = td->dst_linesize;
uint8_t *src = td->src;
int src_linesize = td->src_linesize;
int w = td->w;
int h = td->h;
int hsub = td->hsub;
int vsub = td->vsub;
int start = (h * job) / nb_jobs;
int end = (h * (job+1)) / nb_jobs;
const int linesize = s->linesize[0];
int x, y;
for (y = start; y < end; y++) {
int sy = y << vsub;
for (x = 0; x < w; x++) {
int u, v, subU, subV, sum, sx;
sx = x << hsub;
u = s->pv[sx + sy * linesize][0] >> hsub;
v = s->pv[sx + sy * linesize][1] >> vsub;
subU = u & (SUB_PIXELS - 1);
subV = v & (SUB_PIXELS - 1);
u >>= SUB_PIXEL_BITS;
v >>= SUB_PIXEL_BITS;
if (u > 0 && v > 0 && u < w - 2 && v < h - 2){
const int index = u + v*src_linesize;
const int a = s->coeff[subU][0];
const int b = s->coeff[subU][1];
const int c = s->coeff[subU][2];
const int d = s->coeff[subU][3];
sum = s->coeff[subV][0] * (a * src[index - 1 - src_linesize] + b * src[index - 0 - src_linesize] +
c * src[index + 1 - src_linesize] + d * src[index + 2 - src_linesize]) +
s->coeff[subV][1] * (a * src[index - 1 ] + b * src[index - 0 ] +
c * src[index + 1 ] + d * src[index + 2 ]) +
s->coeff[subV][2] * (a * src[index - 1 + src_linesize] + b * src[index - 0 + src_linesize] +
c * src[index + 1 + src_linesize] + d * src[index + 2 + src_linesize]) +
s->coeff[subV][3] * (a * src[index - 1 + 2 * src_linesize] + b * src[index - 0 + 2 * src_linesize] +
c * src[index + 1 + 2 * src_linesize] + d * src[index + 2 + 2 * src_linesize]);
} else {
int dx, dy;
sum = 0;
for (dy = 0; dy < 4; dy++) {
int iy = v + dy - 1;
if (iy < 0)
iy = 0;
else if (iy >= h)
iy = h-1;
for (dx = 0; dx < 4; dx++) {
int ix = u + dx - 1;
if (ix < 0)
ix = 0;
else if (ix >= w)
ix = w - 1;
sum += s->coeff[subU][dx] * s->coeff[subV][dy] * src[ ix + iy * src_linesize];
}
}
}
sum = (sum + (1<<(COEFF_BITS * 2 - 1))) >> (COEFF_BITS * 2);
sum = av_clip_uint8(sum);
dst[x + y * dst_linesize] = sum;
}
}
return 0;
}
static int resample_linear(AVFilterContext *ctx, void *arg,
int job, int nb_jobs)
{
PerspectiveContext *s = ctx->priv;
ThreadData *td = arg;
uint8_t *dst = td->dst;
int dst_linesize = td->dst_linesize;
uint8_t *src = td->src;
int src_linesize = td->src_linesize;
int w = td->w;
int h = td->h;
int hsub = td->hsub;
int vsub = td->vsub;
int start = (h * job) / nb_jobs;
int end = (h * (job+1)) / nb_jobs;
const int linesize = s->linesize[0];
int x, y;
for (y = start; y < end; y++){
int sy = y << vsub;
for (x = 0; x < w; x++){
int u, v, subU, subV, sum, sx, index, subUI, subVI;
sx = x << hsub;
u = s->pv[sx + sy * linesize][0] >> hsub;
v = s->pv[sx + sy * linesize][1] >> vsub;
subU = u & (SUB_PIXELS - 1);
subV = v & (SUB_PIXELS - 1);
u >>= SUB_PIXEL_BITS;
v >>= SUB_PIXEL_BITS;
index = u + v * src_linesize;
subUI = SUB_PIXELS - subU;
subVI = SUB_PIXELS - subV;
if ((unsigned)u < (unsigned)(w - 1)){
if((unsigned)v < (unsigned)(h - 1)){
sum = subVI * (subUI * src[index] + subU * src[index + 1]) +
subV * (subUI * src[index + src_linesize] + subU * src[index + src_linesize + 1]);
sum = (sum + (1 << (SUB_PIXEL_BITS * 2 - 1)))>> (SUB_PIXEL_BITS * 2);
} else {
if (v < 0)
v = 0;
else
v = h - 1;
index = u + v * src_linesize;
sum = subUI * src[index] + subU * src[index + 1];
sum = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
}
} else {
if (u < 0)
u = 0;
else
u = w - 1;
if ((unsigned)v < (unsigned)(h - 1)){
index = u + v * src_linesize;
sum = subVI * src[index] + subV * src[index + src_linesize];
sum = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
} else {
if (v < 0)
v = 0;
else
v = h - 1;
index = u + v * src_linesize;
sum = src[index];
}
}
sum = av_clip_uint8(sum);
dst[x + y * dst_linesize] = sum;
}
}
return 0;
}
static av_cold int init(AVFilterContext *ctx)
{
PerspectiveContext *s = ctx->priv;
switch (s->interpolation) {
case LINEAR: s->perspective = resample_linear; break;
case CUBIC: s->perspective = resample_cubic; break;
}
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
PerspectiveContext *s = ctx->priv;
AVFrame *out;
int plane;
int ret;
out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!out) {
av_frame_free(&frame);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, frame);
if (s->eval_mode == EVAL_MODE_FRAME) {
if ((ret = calc_persp_luts(ctx, inlink)) < 0) {
av_frame_free(&out);
return ret;
}
}
for (plane = 0; plane < s->nb_planes; plane++) {
int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
ThreadData td = {.dst = out->data[plane],
.dst_linesize = out->linesize[plane],
.src = frame->data[plane],
.src_linesize = frame->linesize[plane],
.w = s->linesize[plane],
.h = s->height[plane],
.hsub = hsub,
.vsub = vsub };
ff_filter_execute(ctx, s->perspective, &td, NULL,
FFMIN(td.h, ff_filter_get_nb_threads(ctx)));
}
av_frame_free(&frame);
return ff_filter_frame(outlink, out);
}
static av_cold void uninit(AVFilterContext *ctx)
{
PerspectiveContext *s = ctx->priv;
av_freep(&s->pv);
}
static const AVFilterPad perspective_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input,
},
};
static const AVFilterPad perspective_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
};
const AVFilter ff_vf_perspective = {
.name = "perspective",
.description = NULL_IF_CONFIG_SMALL("Correct the perspective of video."),
.priv_size = sizeof(PerspectiveContext),
.init = init,
.uninit = uninit,
FILTER_INPUTS(perspective_inputs),
FILTER_OUTPUTS(perspective_outputs),
FILTER_QUERY_FUNC(query_formats),
.priv_class = &perspective_class,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
};