/* * Copyright (c) 2002 Michael Niedermayer * 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 }; AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts); if (!fmts_list) return AVERROR(ENOMEM); return ff_set_common_formats(ctx, fmts_list); } 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 }; ctx->internal->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, }, { NULL } }; static const AVFilterPad perspective_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, }, { NULL } }; AVFilter ff_vf_perspective = { .name = "perspective", .description = NULL_IF_CONFIG_SMALL("Correct the perspective of video."), .priv_size = sizeof(PerspectiveContext), .init = init, .uninit = uninit, .query_formats = query_formats, .inputs = perspective_inputs, .outputs = perspective_outputs, .priv_class = &perspective_class, .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS, };