| /* |
| * 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 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) |
| { |
| AVFilterFormats *formats = NULL; |
| int fmt, ret; |
| |
| for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) { |
| const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt); |
| if (!(desc->flags & (AV_PIX_FMT_FLAG_HWACCEL | AV_PIX_FMT_FLAG_BITSTREAM)) && |
| !((desc->log2_chroma_w || desc->log2_chroma_h) && !(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) && |
| (ret = ff_add_format(&formats, fmt)) < 0) |
| return ret; |
| } |
| |
| return ff_set_common_formats(ctx, formats); |
| } |
| |
| 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); |
| s->hsub = pix_desc->log2_chroma_w; |
| s->vsub = pix_desc->log2_chroma_h; |
| |
| 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 ((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); |
| } |
| 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; |
| s->x &= ~((1 << s->hsub) - 1); |
| s->y &= ~((1 << s->vsub) - 1); |
| return 0; |
| |
| fail_expr: |
| av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr); |
| return ret; |
| } |
| |
| static int config_output(AVFilterLink *link) |
| { |
| CropContext *s = link->src->priv; |
| |
| 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; |
| |
| frame->width = s->w; |
| frame->height = s->h; |
| |
| s->var_values[VAR_N] = link->frame_count; |
| s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ? |
| NAN : frame->pts * av_q2d(link->time_base); |
| s->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ? |
| NAN : av_frame_get_pkt_pos(frame); |
| 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); |
| 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; |
| 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); |
| |
| 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 || desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL)) { |
| 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 |
| |
| static const AVOption crop_options[] = { |
| { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| { "x", "set the x crop area expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| { "y", "set the y crop area expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), 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, |
| }, |
| { NULL } |
| }; |
| |
| static const AVFilterPad avfilter_vf_crop_outputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .config_props = config_output, |
| }, |
| { NULL } |
| }; |
| |
| AVFilter ff_vf_crop = { |
| .name = "crop", |
| .description = NULL_IF_CONFIG_SMALL("Crop the input video."), |
| .priv_size = sizeof(CropContext), |
| .priv_class = &crop_class, |
| .query_formats = query_formats, |
| .uninit = uninit, |
| .inputs = avfilter_vf_crop_inputs, |
| .outputs = avfilter_vf_crop_outputs, |
| .process_command = process_command, |
| }; |