| /* |
| * 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 |
| */ |
| |
| #include <stdint.h> |
| #include "scale.h" |
| #include "libavutil/eval.h" |
| #include "libavutil/mathematics.h" |
| #include "libavutil/pixdesc.h" |
| |
| static const char *const var_names[] = { |
| "PI", |
| "PHI", |
| "E", |
| "in_w", "iw", |
| "in_h", "ih", |
| "out_w", "ow", |
| "out_h", "oh", |
| "a", |
| "sar", |
| "dar", |
| "hsub", |
| "vsub", |
| "ohsub", |
| "ovsub", |
| NULL |
| }; |
| |
| enum var_name { |
| VAR_PI, |
| VAR_PHI, |
| VAR_E, |
| 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_OHSUB, |
| VAR_OVSUB, |
| VARS_NB |
| }; |
| |
| /** |
| * This must be kept in sync with var_names so that it is always a |
| * complete list of var_names with the scale2ref specific names |
| * appended. scale2ref values must appear in the order they appear |
| * in the var_name_scale2ref enum but also be below all of the |
| * non-scale2ref specific values. |
| */ |
| static const char *const var_names_scale2ref[] = { |
| "PI", |
| "PHI", |
| "E", |
| "in_w", "iw", |
| "in_h", "ih", |
| "out_w", "ow", |
| "out_h", "oh", |
| "a", |
| "sar", |
| "dar", |
| "hsub", |
| "vsub", |
| "ohsub", |
| "ovsub", |
| "main_w", |
| "main_h", |
| "main_a", |
| "main_sar", |
| "main_dar", "mdar", |
| "main_hsub", |
| "main_vsub", |
| NULL |
| }; |
| |
| enum var_name_scale2ref { |
| VAR_S2R_MAIN_W, |
| VAR_S2R_MAIN_H, |
| VAR_S2R_MAIN_A, |
| VAR_S2R_MAIN_SAR, |
| VAR_S2R_MAIN_DAR, VAR_S2R_MDAR, |
| VAR_S2R_MAIN_HSUB, |
| VAR_S2R_MAIN_VSUB, |
| VARS_S2R_NB |
| }; |
| |
| int ff_scale_eval_dimensions(void *log_ctx, |
| const char *w_expr, const char *h_expr, |
| AVFilterLink *inlink, AVFilterLink *outlink, |
| int *ret_w, int *ret_h) |
| { |
| const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); |
| const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format); |
| const char *expr; |
| int w, h; |
| int factor_w, factor_h; |
| int eval_w, eval_h; |
| int ret; |
| const char scale2ref = outlink->src->nb_inputs == 2 && outlink->src->inputs[1] == inlink; |
| double var_values[VARS_NB + VARS_S2R_NB], res; |
| const AVPixFmtDescriptor *main_desc; |
| const AVFilterLink *main_link; |
| const char *const *names = scale2ref ? var_names_scale2ref : var_names; |
| |
| if (scale2ref) { |
| main_link = outlink->src->inputs[0]; |
| main_desc = av_pix_fmt_desc_get(main_link->format); |
| } |
| |
| var_values[VAR_PI] = M_PI; |
| var_values[VAR_PHI] = M_PHI; |
| var_values[VAR_E] = M_E; |
| var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w; |
| var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h; |
| var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN; |
| var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN; |
| var_values[VAR_A] = (double) inlink->w / inlink->h; |
| var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? |
| (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1; |
| var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR]; |
| var_values[VAR_HSUB] = 1 << desc->log2_chroma_w; |
| var_values[VAR_VSUB] = 1 << desc->log2_chroma_h; |
| var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w; |
| var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h; |
| |
| if (scale2ref) { |
| var_values[VARS_NB + VAR_S2R_MAIN_W] = main_link->w; |
| var_values[VARS_NB + VAR_S2R_MAIN_H] = main_link->h; |
| var_values[VARS_NB + VAR_S2R_MAIN_A] = (double) main_link->w / main_link->h; |
| var_values[VARS_NB + VAR_S2R_MAIN_SAR] = main_link->sample_aspect_ratio.num ? |
| (double) main_link->sample_aspect_ratio.num / main_link->sample_aspect_ratio.den : 1; |
| var_values[VARS_NB + VAR_S2R_MAIN_DAR] = var_values[VARS_NB + VAR_S2R_MDAR] = |
| var_values[VARS_NB + VAR_S2R_MAIN_A] * var_values[VARS_NB + VAR_S2R_MAIN_SAR]; |
| var_values[VARS_NB + VAR_S2R_MAIN_HSUB] = 1 << main_desc->log2_chroma_w; |
| var_values[VARS_NB + VAR_S2R_MAIN_VSUB] = 1 << main_desc->log2_chroma_h; |
| } |
| |
| /* evaluate width and height */ |
| av_expr_parse_and_eval(&res, (expr = w_expr), |
| names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, log_ctx); |
| eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res; |
| |
| if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr), |
| names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0) |
| goto fail; |
| eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res; |
| /* evaluate again the width, as it may depend on the output height */ |
| if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr), |
| names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0) |
| goto fail; |
| eval_w = (int) res == 0 ? inlink->w : (int) res; |
| |
| w = eval_w; |
| h = eval_h; |
| |
| /* Check if it is requested that the result has to be divisible by a some |
| * factor (w or h = -n with n being the factor). */ |
| factor_w = 1; |
| factor_h = 1; |
| if (w < -1) { |
| factor_w = -w; |
| } |
| if (h < -1) { |
| factor_h = -h; |
| } |
| |
| if (w < 0 && h < 0) { |
| w = inlink->w; |
| h = inlink->h; |
| } |
| |
| /* Make sure that the result is divisible by the factor we determined |
| * earlier. If no factor was set, it is nothing will happen as the default |
| * factor is 1 */ |
| if (w < 0) |
| w = av_rescale(h, inlink->w, inlink->h * factor_w) * factor_w; |
| if (h < 0) |
| h = av_rescale(w, inlink->h, inlink->w * factor_h) * factor_h; |
| |
| *ret_w = w; |
| *ret_h = h; |
| |
| return 0; |
| |
| fail: |
| av_log(log_ctx, AV_LOG_ERROR, |
| "Error when evaluating the expression '%s'.\n" |
| "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n", |
| expr, w_expr, h_expr); |
| return ret; |
| } |
