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32 #define SUB_PIXEL_BITS 8
33 #define SUB_PIXELS (1 << SUB_PIXEL_BITS)
54 void *
arg,
int job,
int nb_jobs);
57 #define OFFSET(x) offsetof(PerspectiveContext, x)
58 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
84 {
"source",
"specify locations in source to send to corners in destination",
86 {
"destination",
"specify locations in destination to send corners of source",
119 coeff = (1.0 - (
A + 3.0) * d * d + (
A + 2.0) * d * d * d);
121 coeff = (-4.0 *
A + 8.0 *
A * d - 5.0 *
A * d * d +
A * d * d * d);
135 double (*
ref)[2] =
s->ref;
142 double x0, x1, x2, x3, x4, x5, x6, x7, x8, q;
146 for (
i = 0;
i < 4;
i++) {
147 for (j = 0; j < 2; j++) {
148 if (!
s->expr_str[
i][j])
169 q = (
ref[1][0] -
ref[3][0]) * (
ref[2][1] -
ref[3][1]) -
172 x0 = q * (
ref[1][0] -
ref[0][0]) *
h + x6 *
ref[1][0];
173 x1 = q * (
ref[2][0] -
ref[0][0]) *
w + x7 *
ref[2][0];
174 x2 = q *
ref[0][0] *
w *
h;
175 x3 = q * (
ref[1][1] -
ref[0][1]) *
h + x6 *
ref[1][1];
176 x4 = q * (
ref[2][1] -
ref[0][1]) *
w + x7 *
ref[2][1];
177 x5 = q *
ref[0][1] *
w *
h;
211 for (y = 0; y <
h; y++){
212 for (x = 0; x <
w; x++){
216 (x6 * x + x7 * y + x8));
218 (x6 * x + x7 * y + x8));
220 s->pv[x + y *
w][0] =
u;
221 s->pv[x + y *
w][1] = v;
236 s->hsub =
desc->log2_chroma_w;
237 s->vsub =
desc->log2_chroma_h;
243 s->height[0] =
s->height[3] =
inlink->h;
260 for (j = 0; j < 4; j++)
263 for (j = 0; j < 4; j++)
266 for (j = 0; j < 4; j++)
283 int job,
int nb_jobs)
288 int dst_linesize =
td->dst_linesize;
290 int src_linesize =
td->src_linesize;
295 int start = (
h * job) / nb_jobs;
296 int end = (
h * (job+1)) / nb_jobs;
297 const int linesize =
s->linesize[0];
300 for (y = start; y < end; y++) {
302 for (x = 0; x <
w; x++) {
303 int u, v, subU, subV, sum, sx;
306 u =
s->pv[sx + sy * linesize][0] >>
hsub;
307 v =
s->pv[sx + sy * linesize][1] >> vsub;
313 if (
u > 0 && v > 0 &&
u <
w - 2 && v <
h - 2){
314 const int index =
u + v*src_linesize;
315 const int a =
s->coeff[subU][0];
316 const int b =
s->coeff[subU][1];
317 const int c =
s->coeff[subU][2];
318 const int d =
s->coeff[subU][3];
320 sum =
s->coeff[subV][0] * (
a *
src[
index - 1 - src_linesize] +
b *
src[
index - 0 - src_linesize] +
324 s->coeff[subV][2] * (
a *
src[
index - 1 + src_linesize] +
b *
src[
index - 0 + src_linesize] +
326 s->coeff[subV][3] * (
a *
src[
index - 1 + 2 * src_linesize] +
b *
src[
index - 0 + 2 * src_linesize] +
333 for (dy = 0; dy < 4; dy++) {
340 for (dx = 0; dx < 4; dx++) {
348 sum +=
s->coeff[subU][dx] *
s->coeff[subV][dy] *
src[ ix + iy * src_linesize];
355 dst[x + y * dst_linesize] = sum;
362 int job,
int nb_jobs)
367 int dst_linesize =
td->dst_linesize;
369 int src_linesize =
td->src_linesize;
374 int start = (
h * job) / nb_jobs;
375 int end = (
h * (job+1)) / nb_jobs;
376 const int linesize =
s->linesize[0];
379 for (y = start; y < end; y++){
381 for (x = 0; x <
w; x++){
382 int u, v, subU, subV, sum, sx,
index, subUI, subVI;
385 u =
s->pv[sx + sy * linesize][0] >>
hsub;
386 v =
s->pv[sx + sy * linesize][1] >> vsub;
392 index =
u + v * src_linesize;
396 if ((
unsigned)
u < (unsigned)(
w - 1)){
397 if((
unsigned)v < (unsigned)(
h - 1)){
399 subV * (subUI *
src[
index + src_linesize] + subU *
src[
index + src_linesize + 1]);
406 index =
u + v * src_linesize;
415 if ((
unsigned)v < (unsigned)(
h - 1)){
416 index =
u + v * src_linesize;
424 index =
u + v * src_linesize;
430 dst[x + y * dst_linesize] = sum;
440 switch (
s->interpolation) {
471 for (plane = 0; plane <
s->nb_planes; plane++) {
472 int hsub = plane == 1 || plane == 2 ?
s->hsub : 0;
473 int vsub = plane == 1 || plane == 2 ?
s->vsub : 0;
475 .dst_linesize =
out->linesize[plane],
476 .src =
frame->data[plane],
477 .src_linesize =
frame->linesize[plane],
478 .w =
s->linesize[plane],
479 .h =
s->height[plane],
515 .
name =
"perspective",
523 .priv_class = &perspective_class,
static double get_coeff(double d)
AVFilter ff_vf_perspective
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
int32_t coeff[SUB_PIXELS][4]
AVPixelFormat
Pixel format.
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
#define u(width, name, range_min, range_max)
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
int(* perspective)(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
This structure describes decoded (raw) audio or video data.
static int calc_persp_luts(AVFilterContext *ctx, AVFilterLink *inlink)
@ AV_PIX_FMT_YUV440P
planar YUV 4:4:0 (1 Cr & Cb sample per 1x2 Y samples)
const char * name
Filter name.
AVFormatInternal * internal
An opaque field for libavformat internal usage.
A link between two filters.
@ PERSPECTIVE_SENSE_SOURCE
coordinates give locations in source of corners of destination.
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
A filter pad used for either input or output.
@ AV_PIX_FMT_YUVJ411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples) full scale (JPEG), deprecated in favor ...
static av_cold int init(AVFilterContext *ctx)
@ AV_PIX_FMT_YUVJ422P
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
static int resample_linear(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
int av_image_fill_linesizes(int linesizes[4], enum AVPixelFormat pix_fmt, int width)
Fill plane linesizes for an image with pixel format pix_fmt and width width.
@ AV_PIX_FMT_YUVA420P
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
#define AV_CEIL_RSHIFT(a, b)
#define av_assert0(cond)
assert() equivalent, that is always enabled.
static const AVFilterPad outputs[]
static enum AVPixelFormat pix_fmts[]
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
@ AV_PIX_FMT_YUVJ444P
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV444P and setting col...
#define av_realloc_f(p, o, n)
static const AVOption perspective_options[]
static const AVFilterPad perspective_inputs[]
Describe the class of an AVClass context structure.
static __device__ float fabs(float a)
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
@ AV_PIX_FMT_YUVJ420P
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
static const AVFilterPad perspective_outputs[]
@ PERSPECTIVE_SENSE_DESTINATION
coordinates give locations in destination of corners of source.
AVFILTER_DEFINE_CLASS(perspective)
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
@ AV_PIX_FMT_YUVA444P
planar YUV 4:4:4 32bpp, (1 Cr & Cb sample per 1x1 Y & A samples)
static int interpolation(DeclickChannel *c, const double *src, int ar_order, double *acoefficients, int *index, int nb_errors, double *auxiliary, double *interpolated)
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
int w
agreed upon image width
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
Used for passing data between threads.
static int config_input(AVFilterLink *inlink)
@ AV_PIX_FMT_YUVJ440P
planar YUV 4:4:0 full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV440P and setting color_range
const char * name
Pad name.
static av_cold void uninit(AVFilterContext *ctx)
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
static int resample_cubic(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
int h
agreed upon image height
static const char *const var_names[]
static int query_formats(AVFilterContext *ctx)
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return values
static int ref[MAX_W *MAX_W]
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
#define AVFILTER_FLAG_SLICE_THREADS
The filter supports multithreading by splitting frames into multiple parts and processing them concur...
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
int64_t frame_count_in
Number of past frames sent through the link.
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
@ AV_PIX_FMT_YUV411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
#define flags(name, subs,...)
@ AV_PIX_FMT_YUV410P
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
static const double coeff[2][5]
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
@ AV_PIX_FMT_YUVA422P
planar YUV 4:2:2 24bpp, (1 Cr & Cb sample per 2x1 Y & A samples)