avfilter: rename scale.c,h to scale_eval

scale.c is too generic; scale_eval is more representative

1 files changed, 250 insertions, 0 deletions

diff --git a/libavfilter/scale_eval.c b/libavfilter/scale_eval.c
new file mode 100644
index 0000000000..a3439a95e0
--- /dev/null
+++ b/libavfilter/scale_eval.c
@@ -0,0 +1,250 @@
+/*
+ * 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_eval.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 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;
+
+    *ret_w = eval_w;
+    *ret_h = eval_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;
+}
+
+int ff_scale_adjust_dimensions(AVFilterLink *inlink,
+    int *ret_w, int *ret_h,
+    int force_original_aspect_ratio, int force_divisible_by)
+{
+    int w, h;
+    int factor_w, factor_h;
+
+    w = *ret_w;
+    h = *ret_h;
+
+    /* Check if it is requested that the result has to be divisible by 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, 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;
+
+    /* Note that force_original_aspect_ratio may overwrite the previous set
+     * dimensions so that it is not divisible by the set factors anymore
+     * unless force_divisible_by is defined as well */
+    if (force_original_aspect_ratio) {
+        int tmp_w = av_rescale(h, inlink->w, inlink->h);
+        int tmp_h = av_rescale(w, inlink->h, inlink->w);
+
+        if (force_original_aspect_ratio == 1) {
+             w = FFMIN(tmp_w, w);
+             h = FFMIN(tmp_h, h);
+             if (force_divisible_by > 1) {
+                 // round down
+                 w = w / force_divisible_by * force_divisible_by;
+                 h = h / force_divisible_by * force_divisible_by;
+             }
+        } else {
+             w = FFMAX(tmp_w, w);
+             h = FFMAX(tmp_h, h);
+             if (force_divisible_by > 1) {
+                 // round up
+                 w = (w + force_divisible_by - 1) / force_divisible_by * force_divisible_by;
+                 h = (h + force_divisible_by - 1) / force_divisible_by * force_divisible_by;
+             }
+        }
+    }
+
+    *ret_w = w;
+    *ret_h = h;
+
+    return 0;
+}