-vf eq2, LUT-based brightness/contrast/gamma correction (Y-only)

by Hampa Hug <hhug@student.ethz.ch>


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7518 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 236 insertions, 0 deletions

diff --git a/libmpcodecs/vf_eq2.c b/libmpcodecs/vf_eq2.c
new file mode 100644
index 0000000000..3f16273ad8
--- /dev/null
+++ b/libmpcodecs/vf_eq2.c
@@ -0,0 +1,236 @@
+/*
+ * vf_eq2.c
+ *
+ * Extended software equalizer (brightness, contrast, gamma)
+ *
+ * Hampa Hug <hhug@student.ethz.ch>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#include "../config.h"
+#include "../mp_msg.h"
+
+#include "img_format.h"
+#include "mp_image.h"
+#include "vf.h"
+
+
+typedef struct vf_priv_s {
+  unsigned char *buf;
+  int           buf_w;
+  int           buf_h;
+
+  double        contrast;
+  double        bright;
+  double        gamma;
+
+  unsigned char lut[256];
+} vf_eq2_t;
+
+
+static
+void create_lut (vf_eq2_t *eq2)
+{
+  unsigned i;
+  double   c, b, g;
+  double   v;
+
+  c = eq2->contrast;
+  b = eq2->bright;
+  g = eq2->gamma;
+
+  if ((g < 0.001) || (g > 1000.0)) {
+    g = 1.0;
+  }
+
+  fprintf (stderr, "vf_eq2: c=%.2f b=%.2f g=%.4f\n", c, b, g);
+
+  g = 1.0 / g;
+
+  for (i = 0; i < 256; i++) {
+    v = (double) i / 255.0;
+    v = c * (v - 0.5) + 0.5 + b;
+
+    if (v <= 0.0) {
+      eq2->lut[i] = 0;
+    }
+    else {
+      v = pow (v, g);
+
+      if (v >= 1.0) {
+        eq2->lut[i] = 255;
+      }
+      else {
+        eq2->lut[i] = (unsigned char) (256.0 * v);
+      }
+    }
+  }
+}
+
+/* could inline this */
+static
+void process (unsigned char *dst, int dstride, unsigned char *src, int sstride,
+  int w, int h, unsigned char lut[256])
+{
+  int i, j;
+
+  for (j = 0; j < h; j++) {
+    for (i = 0; i < w; i++) {
+      *(dst++) = lut[*(src++)];
+    }
+
+    src += sstride - w;
+    dst += dstride - w;
+  }
+}
+
+static
+int put_image (vf_instance_t *vf, mp_image_t *src)
+{
+  mp_image_t *dst;
+  vf_eq2_t   *eq2;
+
+  eq2 = vf->priv;
+
+  if ((eq2->buf == NULL) || (eq2->buf_w != src->stride[0]) || (eq2->buf_h != src->h)) {
+    eq2->buf = (unsigned char *) realloc (eq2->buf, src->stride[0] * src->h);
+    eq2->buf_w = src->stride[0];
+    eq2->buf_h = src->h;
+  }
+
+  dst = vf_get_image (vf->next, src->imgfmt, MP_IMGTYPE_EXPORT, 0, src->w, src->h);
+
+  dst->stride[0] = src->stride[0];
+  dst->stride[1] = src->stride[1];
+  dst->stride[2] = src->stride[2];
+  dst->planes[0] = vf->priv->buf;
+  dst->planes[1] = src->planes[1];
+  dst->planes[2] = src->planes[2];
+
+  process (
+    dst->planes[0], dst->stride[0], src->planes[0], src->stride[0],
+    src->w, src->h, eq2->lut
+  );
+
+  return vf_next_put_image (vf, dst);
+}
+
+static
+int control (vf_instance_t *vf, int request, void *data)
+{
+  vf_equalizer_t *eq;
+
+  switch (request) {
+    case VFCTRL_SET_EQUALIZER:
+      eq = (vf_equalizer_t *) data;
+
+      if (strcmp (eq->item, "gamma") == 0) {
+        vf->priv->gamma = exp (log (8.0) * eq->value / 100.0);
+        create_lut (vf->priv);
+        return CONTROL_TRUE;
+      }
+      else if (strcmp (eq->item, "contrast") == 0) {
+        vf->priv->contrast = (1.0 / 100.0) * (eq->value + 100);
+        create_lut (vf->priv);
+        return CONTROL_TRUE;
+      }
+      else if (strcmp (eq->item, "brightness") == 0) {
+        vf->priv->bright = (1.0 / 100.0) * eq->value;
+        create_lut (vf->priv);
+        return CONTROL_TRUE;
+      }
+      break;
+
+    case VFCTRL_GET_EQUALIZER:
+      eq = (vf_equalizer_t *) data;
+      if (strcmp (eq->item, "gamma") == 0) {
+        eq->value = (int) (100.0 * log (vf->priv->gamma) / log (8.0));
+        return CONTROL_TRUE;
+      }
+      else if (strcmp (eq->item, "contrast") == 0) {
+        eq->value = (int) (100.0 * vf->priv->contrast) - 100;
+        return CONTROL_TRUE;
+      }
+      else if (strcmp (eq->item, "brightness") == 0) {
+        eq->value = (int) (100.0 * vf->priv->bright);
+        return CONTROL_TRUE;
+      }
+      break;
+  }
+
+  return vf_next_control (vf, request, data);
+}
+
+static
+int query_format (vf_instance_t *vf, unsigned fmt)
+{
+  switch (fmt) {
+    case IMGFMT_YVU9:
+    case IMGFMT_IF09:
+    case IMGFMT_YV12:
+    case IMGFMT_I420:
+    case IMGFMT_IYUV:
+    case IMGFMT_CLPL:
+    case IMGFMT_Y800:
+    case IMGFMT_Y8:
+    case IMGFMT_NV12:
+    case IMGFMT_444P:
+    case IMGFMT_422P:
+    case IMGFMT_411P:
+      return vf_next_query_format (vf, fmt);
+  }
+
+  return 0;
+}
+
+static
+void uninit (vf_instance_t *vf)
+{
+  if (vf->priv != NULL) {
+    free (vf->priv->buf);
+    free (vf->priv);
+  }
+}
+
+static
+int open (vf_instance_t *vf, char *args)
+{
+  vf_eq2_t *eq2;
+
+  vf->control = control;
+  vf->query_format = query_format;
+  vf->put_image = put_image;
+  vf->uninit = uninit;
+
+  vf->priv = (vf_eq2_t *) malloc (sizeof (vf_eq2_t));
+  eq2 = vf->priv;
+
+  eq2->buf = NULL;
+  eq2->buf_w = 0;
+  eq2->buf_h = 0;
+
+  eq2->gamma = 1.0;
+  eq2->contrast = 1.0;
+  eq2->bright = 0.0;
+
+  if (args != NULL) {
+    sscanf (args, "%lf:%lf:%lf", &eq2->gamma, &eq2->contrast, &eq2->bright);
+  }
+
+  create_lut (eq2);
+
+  return 1;
+}
+
+vf_info_t vf_info_eq2 = {
+  "extended software equalizer",
+  "eq2",
+  "Hampa Hug",
+  "",
+  &open
+};