lavfi: Add boxblur_opencl filter

Behaves like existing boxblur filter.

1 files changed, 127 insertions, 0 deletions

diff --git a/libavfilter/boxblur.c b/libavfilter/boxblur.c
new file mode 100644
index 0000000000..4534b456d9
--- /dev/null
+++ b/libavfilter/boxblur.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2011 Stefano Sabatini
+ * Copyright (c) 2018 Danil Iashchenko
+ *
+ * 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 "boxblur.h"
+
+static const char *const var_names[] = {
+    "w",
+    "h",
+    "cw",
+    "ch",
+    "hsub",
+    "vsub",
+    NULL
+};
+
+enum var_name {
+    VAR_W,
+    VAR_H,
+    VAR_CW,
+    VAR_CH,
+    VAR_HSUB,
+    VAR_VSUB,
+    VARS_NB
+};
+
+
+int ff_boxblur_eval_filter_params(AVFilterLink *inlink,
+                                  FilterParam *luma_param,
+                                  FilterParam *chroma_param,
+                                  FilterParam *alpha_param)
+{
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    AVFilterContext *ctx = inlink->dst;
+    int w = inlink->w, h = inlink->h;
+    int cw, ch;
+    double var_values[VARS_NB], res;
+    char *expr;
+    int ret;
+
+    if (!luma_param->radius_expr) {
+        av_log(ctx, AV_LOG_ERROR, "Luma radius expression is not set.\n");
+        return AVERROR(EINVAL);
+    }
+
+    /* fill missing params */
+    if (!chroma_param->radius_expr) {
+        chroma_param->radius_expr = av_strdup(luma_param->radius_expr);
+        if (!chroma_param->radius_expr)
+            return AVERROR(ENOMEM);
+    }
+    if (chroma_param->power < 0)
+        chroma_param->power = luma_param->power;
+
+    if (!alpha_param->radius_expr) {
+        alpha_param->radius_expr = av_strdup(luma_param->radius_expr);
+        if (!alpha_param->radius_expr)
+            return AVERROR(ENOMEM);
+    }
+    if (alpha_param->power < 0)
+        alpha_param->power = luma_param->power;
+
+    var_values[VAR_W]       = inlink->w;
+    var_values[VAR_H]       = inlink->h;
+    var_values[VAR_CW] = cw = w>>(desc->log2_chroma_w);
+    var_values[VAR_CH] = ch = h>>(desc->log2_chroma_h);
+    var_values[VAR_HSUB]    = 1<<(desc->log2_chroma_w);
+    var_values[VAR_VSUB]    = 1<<(desc->log2_chroma_h);
+
+#define EVAL_RADIUS_EXPR(comp)                                          \
+    expr = comp->radius_expr;                                           \
+    ret = av_expr_parse_and_eval(&res, expr, var_names, var_values,     \
+                                 NULL, NULL, NULL, NULL, NULL, 0, ctx); \
+    comp->radius = res;                                                 \
+    if (ret < 0) {                                                      \
+        av_log(NULL, AV_LOG_ERROR,                                      \
+               "Error when evaluating " #comp " radius expression '%s'\n", expr); \
+        return ret;                                                     \
+    }
+
+    EVAL_RADIUS_EXPR(luma_param);
+    EVAL_RADIUS_EXPR(chroma_param);
+    EVAL_RADIUS_EXPR(alpha_param);
+
+    av_log(ctx, AV_LOG_VERBOSE,
+           "luma_radius:%d luma_power:%d "
+           "chroma_radius:%d chroma_power:%d "
+           "alpha_radius:%d alpha_power:%d "
+           "w:%d chroma_w:%d h:%d chroma_h:%d\n",
+           luma_param  ->radius, luma_param  ->power,
+           chroma_param->radius, chroma_param->power,
+           alpha_param ->radius, alpha_param ->power,
+           w, cw, h, ch);
+
+
+#define CHECK_RADIUS_VAL(w_, h_, comp)                                  \
+    if (comp->radius < 0 ||                                   \
+        2*comp->radius > FFMIN(w_, h_)) {                     \
+        av_log(ctx, AV_LOG_ERROR,                                       \
+               "Invalid " #comp " radius value %d, must be >= 0 and <= %d\n", \
+               comp->radius, FFMIN(w_, h_)/2);                \
+        return AVERROR(EINVAL);                                         \
+    }
+    CHECK_RADIUS_VAL(w,  h,  luma_param);
+    CHECK_RADIUS_VAL(cw, ch, chroma_param);
+    CHECK_RADIUS_VAL(w,  h,  alpha_param);
+
+    return 0;
+}