Added gamma cap. f.

Makefile.in

@@ -103,6 +103,7 @@ COMMON_OBJS     = \
 		src/capture_filter.o \
 		src/capture_filter/every.o \
 		src/capture_filter/flip.o \
+		src/capture_filter/gamma.o \
 		src/capture_filter/grayscale.o \
 		src/capture_filter/logo.o \
 		src/capture_filter/matrix.o \

src/capture_filter/gamma.c

@@ -0,0 +1,119 @@
+/**
+ * @file   capture_filter/gamma.c
+ * @author Martin Pulec     <pulec@cesnet.cz>
+ */
+/*
+ * Copyright (c) 2020 CESNET, z. s. p. o.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, is permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of CESNET nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#include "config_unix.h"
+#include "config_win32.h"
+#endif /* HAVE_CONFIG_H */
+
+#include "capture_filter.h"
+#include "debug.h"
+#include "lib_common.h"
+#include "utils/color_out.h"
+#include "video.h"
+#include "video_codec.h"
+
+#define MOD_NAME "[gamma cap. f.] "
+
+struct state_capture_filter_gamma {
+        unsigned char lut[256];
+};
+
+static int init(struct module *parent, const char *cfg, void **state)
+{
+        UNUSED(parent);
+
+        if (!cfg || strcmp(cfg, "help") == 0) {
+                printf("Performs gamma transformation.\n\n"
+                       "usage:\n");
+                color_out(COLOR_OUT_BOLD, "\t--capture-filter gamma:value\n");
+                return 1;
+        }
+        double gamma = atof(cfg);
+
+        if (gamma <= 0.0) {
+                log_msg(LOG_LEVEL_WARNING, MOD_NAME "Using gamma value %lf\n", gamma);
+        }
+
+        struct state_capture_filter_gamma *s = calloc(1, sizeof(struct state_capture_filter_gamma));
+
+        for (int i = 0; i < 256; ++i) {
+                s->lut[i] = pow((double) i / 255, gamma) * 255;
+        }
+
+        *state = s;
+        return 0;
+}
+
+static void done(void *state)
+{
+        free(state);
+}
+
+static struct video_frame *filter(void *state, struct video_frame *in)
+{
+        struct state_capture_filter_gamma *s = state;
+        struct video_desc desc = video_desc_from_frame(in);
+        if (get_bits_per_component(desc.color_spec) != 8) {
+                log_msg(LOG_LEVEL_ERROR, MOD_NAME "Only 8-bit codecs are currently supported!\n");
+                return NULL;
+        }
+        struct video_frame *out = vf_alloc_desc_data(desc);
+        out->callbacks.dispose = vf_free;
+
+        unsigned char *in_data = (unsigned char *) in->tiles[0].data;
+        unsigned char *out_data = (unsigned char *) out->tiles[0].data;
+
+        for (unsigned int i = 0; i < in->tiles[0].data_len; i += 1) {
+                *out_data++ = s->lut[*in_data++];
+        }
+
+        VIDEO_FRAME_DISPOSE(in);
+
+        return out;
+}
+
+static const struct capture_filter_info capture_filter_matrix = {
+        .init = init,
+        .done = done,
+        .filter = filter,
+};
+
+REGISTER_MODULE(gamma, &capture_filter_matrix, LIBRARY_CLASS_CAPTURE_FILTER, CAPTURE_FILTER_ABI_VERSION);
+
+/* vim: set expandtab sw=8: */