/* * 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 "pos", ///< position in the file "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, VAR_POS, 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; s->var_values[VAR_POS] = NAN; 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); s->var_values[VAR_POS] = frame->pkt_pos == -1 ? NAN : frame->pkt_pos; 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 pos:%f x:%d y:%d x+w:%d y+h:%d\n", (int)s->var_values[VAR_N], s->var_values[VAR_T], s->var_values[VAR_POS], 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, };