gstalpha.c 26.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/video/video.h>
25
#include <gst/controller/gstcontroller.h>
26

27
#include <stdlib.h>
28
#include <string.h>
29
#include <math.h>
30

31 32 33 34
#ifndef M_PI
#define M_PI  3.14159265358979323846
#endif

35 36 37 38 39 40 41 42
#define GST_TYPE_ALPHA \
  (gst_alpha_get_type())
#define GST_ALPHA(obj) \
  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ALPHA,GstAlpha))
#define GST_ALPHA_CLASS(klass) \
  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ALPHA,GstAlphaClass))
#define GST_IS_ALPHA(obj) \
  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ALPHA))
Stefan Kost's avatar
Stefan Kost committed
43
#define GST_IS_ALPHA_CLASS(klass) \
44 45 46 47 48 49 50
  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ALPHA))

typedef struct _GstAlpha GstAlpha;
typedef struct _GstAlphaClass GstAlphaClass;

typedef enum
{
51
  ALPHA_METHOD_SET,
52 53
  ALPHA_METHOD_GREEN,
  ALPHA_METHOD_BLUE,
54
  ALPHA_METHOD_CUSTOM,
55 56 57
}
GstAlphaMethod;

58
#define ROUND_UP_2(x) (((x) + 1) & ~1)
Wim Taymans's avatar
Wim Taymans committed
59 60
#define ROUND_UP_4(x) (((x) + 3) & ~3)
#define ROUND_UP_8(x) (((x) + 7) & ~7)
61

62 63 64
#define GST_CAT_DEFAULT gst_alpha_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

65 66 67 68 69 70 71 72 73 74 75
struct _GstAlpha
{
  GstElement element;

  /* pads */
  GstPad *sinkpad;
  GstPad *srcpad;

  /* caps */
  gint in_width, in_height;
  gint out_width, out_height;
76
  gboolean ayuv;
77 78 79

  gdouble alpha;

80 81 82
  guint target_r;
  guint target_g;
  guint target_b;
83 84

  GstAlphaMethod method;
85 86 87 88 89 90 91 92 93 94 95 96 97

  gfloat angle;
  gfloat noise_level;

  gfloat y;                     /* chroma color */
  gint8 cb, cr;
  gint8 kg;
  gfloat accept_angle_cos;
  gfloat accept_angle_sin;
  guint8 accept_angle_tg;
  guint8 accept_angle_ctg;
  guint8 one_over_kc;
  guint8 kfgy_scale;
98 99

  GstSegment segment;
100 101 102 103 104 105 106 107
};

struct _GstAlphaClass
{
  GstElementClass parent_class;
};

/* elementfactory information */
108
static const GstElementDetails gst_alpha_details =
Wim Taymans's avatar
Wim Taymans committed
109
GST_ELEMENT_DETAILS ("Alpha filter",
110 111 112 113 114 115 116 117 118 119 120 121
    "Filter/Effect/Video",
    "Adds an alpha channel to video",
    "Wim Taymans <wim@fluendo.com>");


/* Alpha signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

122
#define DEFAULT_METHOD ALPHA_METHOD_SET
123 124 125 126 127 128 129
#define DEFAULT_ALPHA 1.0
#define DEFAULT_TARGET_R 0
#define DEFAULT_TARGET_G 255
#define DEFAULT_TARGET_B 0
#define DEFAULT_ANGLE 20.0
#define DEFAULT_NOISE_LEVEL 2.0

130 131 132 133 134
enum
{
  ARG_0,
  ARG_METHOD,
  ARG_ALPHA,
135 136 137 138 139
  ARG_TARGET_R,
  ARG_TARGET_G,
  ARG_TARGET_B,
  ARG_ANGLE,
  ARG_NOISE_LEVEL,
140 141 142 143 144 145 146 147 148 149 150
  /* FILL ME */
};

static GstStaticPadTemplate gst_alpha_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV"))
    );

static GstStaticPadTemplate gst_alpha_sink_template =
151
    GST_STATIC_PAD_TEMPLATE ("sink",
152 153
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
154 155 156
    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV")
        ";" GST_VIDEO_CAPS_YUV ("I420")
    )
157 158 159 160 161 162
    );


static void gst_alpha_base_init (gpointer g_class);
static void gst_alpha_class_init (GstAlphaClass * klass);
static void gst_alpha_init (GstAlpha * alpha);
163
static void gst_alpha_init_params (GstAlpha * alpha);
164 165 166 167 168 169

static void gst_alpha_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_alpha_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

170 171
static gboolean gst_alpha_sink_setcaps (GstPad * pad, GstCaps * caps);
static GstFlowReturn gst_alpha_chain (GstPad * pad, GstBuffer * buffer);
172
static gboolean gst_alpha_sink_event (GstPad * pad, GstEvent * event);
173

174 175
static GstStateChangeReturn gst_alpha_change_state (GstElement * element,
    GstStateChange transition);
176 177 178 179 180 181 182 183 184


static GstElementClass *parent_class = NULL;

#define GST_TYPE_ALPHA_METHOD (gst_alpha_method_get_type())
static GType
gst_alpha_method_get_type (void)
{
  static GType alpha_method_type = 0;
185
  static const GEnumValue alpha_method[] = {
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
186 187 188 189
    {ALPHA_METHOD_SET, "Set/adjust alpha channel", "set"},
    {ALPHA_METHOD_GREEN, "Chroma Key green", "green"},
    {ALPHA_METHOD_BLUE, "Chroma Key blue", "blue"},
    {ALPHA_METHOD_CUSTOM, "Chroma Key on target_r/g/b", "custom"},
190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245
    {0, NULL, NULL},
  };

  if (!alpha_method_type) {
    alpha_method_type = g_enum_register_static ("GstAlphaMethod", alpha_method);
  }
  return alpha_method_type;
}

/* static guint gst_alpha_signals[LAST_SIGNAL] = { 0 }; */

GType
gst_alpha_get_type (void)
{
  static GType alpha_type = 0;

  if (!alpha_type) {
    static const GTypeInfo alpha_info = {
      sizeof (GstAlphaClass),
      gst_alpha_base_init,
      NULL,
      (GClassInitFunc) gst_alpha_class_init,
      NULL,
      NULL,
      sizeof (GstAlpha),
      0,
      (GInstanceInitFunc) gst_alpha_init,
    };

    alpha_type =
        g_type_register_static (GST_TYPE_ELEMENT, "GstAlpha", &alpha_info, 0);
  }
  return alpha_type;
}

static void
gst_alpha_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_set_details (element_class, &gst_alpha_details);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_alpha_sink_template));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_alpha_src_template));
}
static void
gst_alpha_class_init (GstAlphaClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

246
  parent_class = g_type_class_peek_parent (klass);
247

248 249 250
  gobject_class->set_property = gst_alpha_set_property;
  gobject_class->get_property = gst_alpha_get_property;

251 252 253 254 255 256
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_METHOD,
      g_param_spec_enum ("method", "Method",
          "How the alpha channels should be created", GST_TYPE_ALPHA_METHOD,
          DEFAULT_METHOD, (GParamFlags) G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_ALPHA,
      g_param_spec_double ("alpha", "Alpha", "The value for the alpha channel",
257 258
          0.0, 1.0, DEFAULT_ALPHA,
          (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
259
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_R,
260 261 262
      g_param_spec_uint ("target_r", "Target Red", "The Red target", 0, 255,
          DEFAULT_TARGET_R,
          (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
263
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_G,
264 265 266
      g_param_spec_uint ("target_g", "Target Green", "The Green target", 0, 255,
          DEFAULT_TARGET_G,
          (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
267
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_B,
268 269 270
      g_param_spec_uint ("target_b", "Target Blue", "The Blue target", 0, 255,
          DEFAULT_TARGET_B,
          (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
271 272
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_ANGLE,
      g_param_spec_float ("angle", "Angle", "Size of the colorcube to change",
273 274
          0.0, 90.0, DEFAULT_ANGLE,
          (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
275 276
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_NOISE_LEVEL,
      g_param_spec_float ("noise_level", "Noise Level", "Size of noise radius",
277 278
          0.0, 64.0, DEFAULT_NOISE_LEVEL,
          (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
279 280 281 282 283 284 285 286 287

  gstelement_class->change_state = gst_alpha_change_state;
}

static void
gst_alpha_init (GstAlpha * alpha)
{
  /* create the sink and src pads */
  alpha->sinkpad =
288
      gst_pad_new_from_static_template (&gst_alpha_sink_template, "sink");
289 290
  gst_element_add_pad (GST_ELEMENT (alpha), alpha->sinkpad);
  gst_pad_set_chain_function (alpha->sinkpad, gst_alpha_chain);
291
  gst_pad_set_setcaps_function (alpha->sinkpad, gst_alpha_sink_setcaps);
292
  gst_pad_set_event_function (alpha->sinkpad, gst_alpha_sink_event);
293 294

  alpha->srcpad =
295
      gst_pad_new_from_static_template (&gst_alpha_src_template, "src");
296 297 298 299
  gst_element_add_pad (GST_ELEMENT (alpha), alpha->srcpad);

  alpha->alpha = DEFAULT_ALPHA;
  alpha->method = DEFAULT_METHOD;
300 301 302 303 304
  alpha->target_r = DEFAULT_TARGET_R;
  alpha->target_g = DEFAULT_TARGET_G;
  alpha->target_b = DEFAULT_TARGET_B;
  alpha->angle = DEFAULT_ANGLE;
  alpha->noise_level = DEFAULT_NOISE_LEVEL;
305 306

  GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "alpha", 0, "Alpha adding element");
307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322
}

/* do we need this function? */
static void
gst_alpha_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstAlpha *alpha;

  g_return_if_fail (GST_IS_ALPHA (object));

  alpha = GST_ALPHA (object);

  switch (prop_id) {
    case ARG_METHOD:
      alpha->method = g_value_get_enum (value);
323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
      switch (alpha->method) {
        case ALPHA_METHOD_GREEN:
          alpha->target_r = 0;
          alpha->target_g = 255;
          alpha->target_b = 0;
          break;
        case ALPHA_METHOD_BLUE:
          alpha->target_r = 0;
          alpha->target_g = 0;
          alpha->target_b = 255;
          break;
        default:
          break;
      }
      gst_alpha_init_params (alpha);
338 339 340 341
      break;
    case ARG_ALPHA:
      alpha->alpha = g_value_get_double (value);
      break;
342 343 344 345 346 347 348 349 350 351 352
    case ARG_TARGET_R:
      alpha->target_r = g_value_get_uint (value);
      gst_alpha_init_params (alpha);
      break;
    case ARG_TARGET_G:
      alpha->target_g = g_value_get_uint (value);
      gst_alpha_init_params (alpha);
      break;
    case ARG_TARGET_B:
      alpha->target_b = g_value_get_uint (value);
      gst_alpha_init_params (alpha);
353
      break;
354 355 356 357 358 359 360
    case ARG_ANGLE:
      alpha->angle = g_value_get_float (value);
      gst_alpha_init_params (alpha);
      break;
    case ARG_NOISE_LEVEL:
      alpha->noise_level = g_value_get_float (value);
      gst_alpha_init_params (alpha);
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}
static void
gst_alpha_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstAlpha *alpha;

  g_return_if_fail (GST_IS_ALPHA (object));

  alpha = GST_ALPHA (object);

  switch (prop_id) {
    case ARG_METHOD:
      g_value_set_enum (value, alpha->method);
      break;
    case ARG_ALPHA:
      g_value_set_double (value, alpha->alpha);
      break;
384 385 386 387 388 389 390 391
    case ARG_TARGET_R:
      g_value_set_uint (value, alpha->target_r);
      break;
    case ARG_TARGET_G:
      g_value_set_uint (value, alpha->target_g);
      break;
    case ARG_TARGET_B:
      g_value_set_uint (value, alpha->target_b);
392
      break;
393 394 395 396 397
    case ARG_ANGLE:
      g_value_set_float (value, alpha->angle);
      break;
    case ARG_NOISE_LEVEL:
      g_value_set_float (value, alpha->noise_level);
398 399 400 401 402 403 404
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

405 406
static gboolean
gst_alpha_sink_setcaps (GstPad * pad, GstCaps * caps)
407 408 409 410
{
  GstAlpha *alpha;
  GstStructure *structure;
  gboolean ret;
411
  guint32 fourcc;
412

413
  alpha = GST_ALPHA (GST_PAD_PARENT (pad));
414 415
  structure = gst_caps_get_structure (caps, 0);

416 417 418 419 420 421 422 423 424
  if (gst_structure_get_fourcc (structure, "format", &fourcc)) {
    switch (fourcc) {
      case GST_MAKE_FOURCC ('I', '4', '2', '0'):
        alpha->ayuv = FALSE;
        break;
      case GST_MAKE_FOURCC ('A', 'Y', 'U', 'V'):
        alpha->ayuv = TRUE;
        break;
      default:
425
        return FALSE;
426 427
    }
  } else {
428
    return FALSE;
429 430
  }

431 432 433
  ret = gst_structure_get_int (structure, "width", &alpha->in_width);
  ret &= gst_structure_get_int (structure, "height", &alpha->in_height);

434
  return TRUE;
435 436 437
}

static void
438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468
gst_alpha_set_ayuv (guint8 * src, guint8 * dest, gint width, gint height,
    gdouble alpha)
{
  gint b_alpha = (gint) (alpha * 255);
  gint i, j;
  gint size;
  gint stride;
  gint wrap;

  width = ROUND_UP_2 (width);
  height = ROUND_UP_2 (height);

  stride = ROUND_UP_4 (width);
  size = stride * height;

  wrap = stride - width;

  for (i = 0; i < height; i++) {
    for (j = 0; j < width; j++) {
      *dest++ = (*src++ * b_alpha) >> 8;
      *dest++ = *src++;
      *dest++ = *src++;
      *dest++ = *src++;
    }
    src += wrap;
    dest += wrap;
  }
}

static void
gst_alpha_set_i420 (guint8 * src, guint8 * dest, gint width, gint height,
469 470 471 472 473 474 475
    gdouble alpha)
{
  gint b_alpha = (gint) (alpha * 255);
  guint8 *srcY;
  guint8 *srcU;
  guint8 *srcV;
  gint i, j;
476 477 478 479
  gint size, size2;
  gint stride, stride2;
  gint wrap, wrap2;

Wim Taymans's avatar
Wim Taymans committed
480 481 482
  width = ROUND_UP_2 (width);
  height = ROUND_UP_2 (height);

483 484
  stride = ROUND_UP_4 (width);
  size = stride * height;
Wim Taymans's avatar
Wim Taymans committed
485 486
  stride2 = ROUND_UP_8 (width) / 2;
  size2 = stride2 * height / 2;
487

488 489
  wrap = stride - 2 * (width / 2);
  wrap2 = stride2 - width / 2;
490 491 492

  srcY = src;
  srcU = srcY + size;
493
  srcV = srcU + size2;
494 495 496 497 498 499 500 501 502 503 504 505 506

  for (i = 0; i < height; i++) {
    for (j = 0; j < width / 2; j++) {
      *dest++ = b_alpha;
      *dest++ = *srcY++;
      *dest++ = *srcU;
      *dest++ = *srcV;
      *dest++ = b_alpha;
      *dest++ = *srcY++;
      *dest++ = *srcU++;
      *dest++ = *srcV++;
    }
    if (i % 2 == 0) {
507 508 509 510 511
      srcU -= width / 2;
      srcV -= width / 2;
    } else {
      srcU += wrap2;
      srcV += wrap2;
512
    }
513
    srcY += wrap;
514 515 516
  }
}

517
static void
518
gst_alpha_chroma_key_ayuv (guint8 * src, guint8 * dest, gint width, gint height,
519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624
    GstAlpha * alpha)
{
  gint b_alpha;
  guint8 *src1;
  guint8 *dest1;
  gint i, j;
  gint x, z, u, v, y, a;
  gint size;
  gint stride;
  gint wrap;
  gint tmp, tmp1;
  gint x1, y1;

  width = ROUND_UP_2 (width);
  height = ROUND_UP_2 (height);

  stride = ROUND_UP_4 (width);
  size = stride * height;

  src1 = src;
  dest1 = dest;

  wrap = stride - width;

  for (i = 0; i < height; i++) {
    for (j = 0; j < width; j++) {
      a = *src1++ * (alpha->alpha);
      y = *src1++;
      u = *src1++ - 128;
      v = *src1++ - 128;

      /* Convert foreground to XZ coords where X direction is defined by
         the key color */
      tmp = ((short) u * alpha->cb + (short) v * alpha->cr) >> 7;
      x = CLAMP (tmp, -128, 127);
      tmp = ((short) v * alpha->cb - (short) u * alpha->cr) >> 7;
      z = CLAMP (tmp, -128, 127);

      /* WARNING: accept angle should never be set greater than "somewhat less
         than 90 degrees" to avoid dealing with negative/infinite tg. In reality,
         80 degrees should be enough if foreground is reasonable. If this seems
         to be a problem, go to alternative ways of checking point position
         (scalar product or line equations). This angle should not be too small
         either to avoid infinite ctg (used to suppress foreground without use of
         division) */

      tmp = ((short) (x) * alpha->accept_angle_tg) >> 4;
      tmp = MIN (tmp, 127);

      if (abs (z) > tmp) {
        /* keep foreground Kfg = 0 */
        b_alpha = a;
      } else {
        /* Compute Kfg (implicitly) and Kbg, suppress foreground in XZ coord
           according to Kfg */
        tmp = ((short) (z) * alpha->accept_angle_ctg) >> 4;
        tmp = CLAMP (tmp, -128, 127);
        x1 = abs (tmp);
        y1 = z;

        tmp1 = x - x1;
        tmp1 = MAX (tmp1, 0);
        b_alpha = (((unsigned char) (tmp1) *
                (unsigned short) (alpha->one_over_kc)) / 2);
        b_alpha = 255 - CLAMP (b_alpha, 0, 255);
        b_alpha = (a * b_alpha) >> 8;

        tmp = ((unsigned short) (tmp1) * alpha->kfgy_scale) >> 4;
        tmp1 = MIN (tmp, 255);

        tmp = y - tmp1;
        y = MAX (tmp, 0);

        /* Convert suppressed foreground back to CbCr */
        tmp = ((char) (x1) * (short) (alpha->cb) -
            (char) (y1) * (short) (alpha->cr)) >> 7;
        u = CLAMP (tmp, -128, 127);

        tmp = ((char) (x1) * (short) (alpha->cr) +
            (char) (y1) * (short) (alpha->cb)) >> 7;
        v = CLAMP (tmp, -128, 127);

        /* Deal with noise. For now, a circle around the key color with
           radius of noise_level treated as exact key color. Introduces
           sharp transitions.
         */
        tmp = z * (short) (z) + (x - alpha->kg) * (short) (x - alpha->kg);
        tmp = MIN (tmp, 0xffff);

        if (tmp < alpha->noise_level * alpha->noise_level) {
          b_alpha = 0;
        }
      }

      u += 128;
      v += 128;

      *dest1++ = b_alpha;
      *dest1++ = y;
      *dest1++ = u;
      *dest1++ = v;
    }
    dest1 += wrap;
    src1 += wrap;
  }
}
625

626 627
/* based on http://www.cs.utah.edu/~michael/chroma/
 */
628
static void
629
gst_alpha_chroma_key_i420 (guint8 * src, guint8 * dest, gint width, gint height,
630
    GstAlpha * alpha)
631 632 633 634 635
{
  gint b_alpha;
  guint8 *srcY1, *srcY2, *srcU, *srcV;
  guint8 *dest1, *dest2;
  gint i, j;
636
  gint x, z, u, v, y11, y12, y21, y22, a;
637 638 639
  gint size, size2;
  gint stride, stride2;
  gint wrap, wrap2, wrap3;
640 641
  gint tmp, tmp1;
  gint x1, y1;
642

Wim Taymans's avatar
Wim Taymans committed
643 644 645
  width = ROUND_UP_2 (width);
  height = ROUND_UP_2 (height);

646 647
  stride = ROUND_UP_4 (width);
  size = stride * height;
Wim Taymans's avatar
Wim Taymans committed
648 649
  stride2 = ROUND_UP_8 (width) / 2;
  size2 = stride2 * height / 2;
650 651

  srcY1 = src;
652
  srcY2 = src + stride;
653
  srcU = srcY1 + size;
654
  srcV = srcU + size2;
655 656 657 658

  dest1 = dest;
  dest2 = dest + width * 4;

659 660
  wrap = 2 * stride - 2 * (width / 2);
  wrap2 = stride2 - width / 2;
Wim Taymans's avatar
Wim Taymans committed
661
  wrap3 = 8 * width - 8 * (width / 2);
662

663 664
  a = 255 * alpha->alpha;

665 666
  for (i = 0; i < height / 2; i++) {
    for (j = 0; j < width / 2; j++) {
667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707
      y11 = *srcY1++;
      y12 = *srcY1++;
      y21 = *srcY2++;
      y22 = *srcY2++;
      u = *srcU++ - 128;
      v = *srcV++ - 128;

      /* Convert foreground to XZ coords where X direction is defined by
         the key color */
      tmp = ((short) u * alpha->cb + (short) v * alpha->cr) >> 7;
      x = CLAMP (tmp, -128, 127);
      tmp = ((short) v * alpha->cb - (short) u * alpha->cr) >> 7;
      z = CLAMP (tmp, -128, 127);

      /* WARNING: accept angle should never be set greater than "somewhat less
         than 90 degrees" to avoid dealing with negative/infinite tg. In reality,
         80 degrees should be enough if foreground is reasonable. If this seems
         to be a problem, go to alternative ways of checking point position
         (scalar product or line equations). This angle should not be too small
         either to avoid infinite ctg (used to suppress foreground without use of
         division) */

      tmp = ((short) (x) * alpha->accept_angle_tg) >> 4;
      tmp = MIN (tmp, 127);

      if (abs (z) > tmp) {
        /* keep foreground Kfg = 0 */
        b_alpha = 255;
      } else {
        /* Compute Kfg (implicitly) and Kbg, suppress foreground in XZ coord
           according to Kfg */
        tmp = ((short) (z) * alpha->accept_angle_ctg) >> 4;
        tmp = CLAMP (tmp, -128, 127);
        x1 = abs (tmp);
        y1 = z;

        tmp1 = x - x1;
        tmp1 = MAX (tmp1, 0);
        b_alpha = (((unsigned char) (tmp1) *
                (unsigned short) (alpha->one_over_kc)) / 2);
        b_alpha = 255 - CLAMP (b_alpha, 0, 255);
708
        b_alpha = (a * b_alpha) >> 8;
709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739

        tmp = ((unsigned short) (tmp1) * alpha->kfgy_scale) >> 4;
        tmp1 = MIN (tmp, 255);

        tmp = y11 - tmp1;
        y11 = MAX (tmp, 0);
        tmp = y12 - tmp1;
        y12 = MAX (tmp, 0);
        tmp = y21 - tmp1;
        y21 = MAX (tmp, 0);
        tmp = y22 - tmp1;
        y22 = MAX (tmp, 0);

        /* Convert suppressed foreground back to CbCr */
        tmp = ((char) (x1) * (short) (alpha->cb) -
            (char) (y1) * (short) (alpha->cr)) >> 7;
        u = CLAMP (tmp, -128, 127);

        tmp = ((char) (x1) * (short) (alpha->cr) +
            (char) (y1) * (short) (alpha->cb)) >> 7;
        v = CLAMP (tmp, -128, 127);

        /* Deal with noise. For now, a circle around the key color with
           radius of noise_level treated as exact key color. Introduces
           sharp transitions.
         */
        tmp = z * (short) (z) + (x - alpha->kg) * (short) (x - alpha->kg);
        tmp = MIN (tmp, 0xffff);

        if (tmp < alpha->noise_level * alpha->noise_level) {
          /* Uncomment this if you want total suppression within the noise circle */
740 741 742 743
          b_alpha = 0;
        }
      }

744 745 746
      u += 128;
      v += 128;

747
      *dest1++ = b_alpha;
748
      *dest1++ = y11;
749 750 751
      *dest1++ = u;
      *dest1++ = v;
      *dest1++ = b_alpha;
752
      *dest1++ = y12;
753 754 755
      *dest1++ = u;
      *dest1++ = v;
      *dest2++ = b_alpha;
756
      *dest2++ = y21;
757 758 759
      *dest2++ = u;
      *dest2++ = v;
      *dest2++ = b_alpha;
760
      *dest2++ = y22;
761 762 763
      *dest2++ = u;
      *dest2++ = v;
    }
764 765 766 767 768 769
    dest1 += wrap3;
    dest2 += wrap3;
    srcY1 += wrap;
    srcY2 += wrap;
    srcU += wrap2;
    srcV += wrap2;
770 771 772
  }
}

773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808
static void
gst_alpha_init_params (GstAlpha * alpha)
{
  float kgl;
  float tmp;
  float tmp1, tmp2;

  alpha->y =
      0.257 * alpha->target_r + 0.504 * alpha->target_g +
      0.098 * alpha->target_b;
  tmp1 =
      -0.148 * alpha->target_r - 0.291 * alpha->target_g +
      0.439 * alpha->target_b;
  tmp2 =
      0.439 * alpha->target_r - 0.368 * alpha->target_g -
      0.071 * alpha->target_b;
  kgl = sqrt (tmp1 * tmp1 + tmp2 * tmp2);
  alpha->cb = 127 * (tmp1 / kgl);
  alpha->cr = 127 * (tmp2 / kgl);

  alpha->accept_angle_cos = cos (M_PI * alpha->angle / 180);
  alpha->accept_angle_sin = sin (M_PI * alpha->angle / 180);
  tmp = 15 * tan (M_PI * alpha->angle / 180);
  tmp = MIN (tmp, 255);
  alpha->accept_angle_tg = tmp;
  tmp = 15 / tan (M_PI * alpha->angle / 180);
  tmp = MIN (tmp, 255);
  alpha->accept_angle_ctg = tmp;
  tmp = 1 / (kgl);
  alpha->one_over_kc = 255 * 2 * tmp - 255;
  tmp = 15 * (float) (alpha->y) / kgl;
  tmp = MIN (tmp, 255);
  alpha->kfgy_scale = tmp;
  alpha->kg = MIN (kgl, 127);
}

809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842
static gboolean
gst_alpha_sink_event (GstPad * pad, GstEvent * event)
{
  GstAlpha *alpha;
  gboolean ret;

  alpha = GST_ALPHA (GST_PAD_PARENT (pad));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_FLUSH_STOP:
      gst_segment_init (&alpha->segment, GST_FORMAT_UNDEFINED);
      break;
    case GST_EVENT_NEWSEGMENT:{
      GstFormat format;
      gdouble rate, arate;
      gint64 start, stop, time;
      gboolean update;

      gst_event_parse_new_segment_full (event, &update, &rate, &arate, &format,
          &start, &stop, &time);

      gst_segment_set_newsegment_full (&alpha->segment, update, rate, arate,
          format, start, stop, time);
      break;
    }
    default:
      break;
  }

  ret = gst_pad_push_event (alpha->srcpad, event);

  return ret;
}

843 844
static GstFlowReturn
gst_alpha_chain (GstPad * pad, GstBuffer * buffer)
845 846 847 848
{
  GstAlpha *alpha;
  GstBuffer *outbuf;
  gint new_width, new_height;
849
  GstFlowReturn ret;
850
  GstClockTime timestamp;
851

852
  alpha = GST_ALPHA (GST_PAD_PARENT (pad));
853 854 855 856 857

  new_width = alpha->in_width;
  new_height = alpha->in_height;

  if (new_width != alpha->out_width ||
858
      new_height != alpha->out_height || !GST_PAD_CAPS (alpha->srcpad)) {
859 860 861 862 863 864 865
    GstCaps *newcaps;

    newcaps = gst_caps_copy (gst_pad_get_negotiated_caps (alpha->sinkpad));
    gst_caps_set_simple (newcaps,
        "format", GST_TYPE_FOURCC, GST_STR_FOURCC ("AYUV"),
        "width", G_TYPE_INT, new_width, "height", G_TYPE_INT, new_height, NULL);

866
    gst_pad_set_caps (alpha->srcpad, newcaps);
867 868 869 870 871

    alpha->out_width = new_width;
    alpha->out_height = new_height;
  }

Wim Taymans's avatar
Wim Taymans committed
872 873 874
  outbuf =
      gst_buffer_new_and_alloc (ROUND_UP_2 (new_width) *
      ROUND_UP_2 (new_height) * 4);
875
  gst_buffer_set_caps (outbuf, GST_PAD_CAPS (alpha->srcpad));
876 877
  GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
  GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
878 879 880 881 882
  timestamp = gst_segment_to_stream_time (&alpha->segment, GST_FORMAT_TIME,
      GST_BUFFER_TIMESTAMP (buffer));
  GST_LOG ("Got stream time of %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp));
  if (GST_CLOCK_TIME_IS_VALID (timestamp))
    gst_object_sync_values (G_OBJECT (alpha), timestamp);
883 884

  switch (alpha->method) {
885 886 887 888 889 890 891 892
    case ALPHA_METHOD_SET:
      if (alpha->ayuv) {
        gst_alpha_set_ayuv (GST_BUFFER_DATA (buffer),
            GST_BUFFER_DATA (outbuf), new_width, new_height, alpha->alpha);
      } else {
        gst_alpha_set_i420 (GST_BUFFER_DATA (buffer),
            GST_BUFFER_DATA (outbuf), new_width, new_height, alpha->alpha);
      }
893 894 895
      break;
    case ALPHA_METHOD_GREEN:
    case ALPHA_METHOD_BLUE:
896
    case ALPHA_METHOD_CUSTOM:
897 898 899 900 901 902 903
      if (alpha->ayuv) {
        gst_alpha_chroma_key_ayuv (GST_BUFFER_DATA (buffer),
            GST_BUFFER_DATA (outbuf), new_width, new_height, alpha);
      } else {
        gst_alpha_chroma_key_i420 (GST_BUFFER_DATA (buffer),
            GST_BUFFER_DATA (outbuf), new_width, new_height, alpha);
      }
904 905 906
      break;
    default:
      break;
907 908 909 910
  }

  gst_buffer_unref (buffer);

911 912 913 914 915 916 917 918 919 920
  /* Update last stop position in segment */
  if (GST_BUFFER_TIMESTAMP (outbuf) != GST_CLOCK_TIME_NONE) {
    GstClockTime last_stop = GST_BUFFER_TIMESTAMP (outbuf);

    if (GST_BUFFER_DURATION (outbuf) != GST_CLOCK_TIME_NONE)
      last_stop += GST_BUFFER_DURATION (outbuf);

    gst_segment_set_last_stop (&alpha->segment, GST_FORMAT_TIME, last_stop);
  }

921 922 923
  ret = gst_pad_push (alpha->srcpad, outbuf);

  return ret;
924 925
}

926 927
static GstStateChangeReturn
gst_alpha_change_state (GstElement * element, GstStateChange transition)
928
{
929
  GstStateChangeReturn res;
930 931 932 933
  GstAlpha *alpha;

  alpha = GST_ALPHA (element);

934 935
  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
936
      break;
937
    case GST_STATE_CHANGE_READY_TO_PAUSED:
938
      gst_segment_init (&alpha->segment, GST_FORMAT_UNDEFINED);
939
      gst_alpha_init_params (alpha);
940
      break;
941
    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
942
    default:
943
      break;
944 945 946 947 948
  }

  res = parent_class->change_state (element, transition);

  switch (transition) {
949 950 951
    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
    case GST_STATE_CHANGE_PAUSED_TO_READY:
    case GST_STATE_CHANGE_READY_TO_NULL:
952
    default:
953 954 955
      break;
  }

956
  return res;
957 958 959 960 961
}

static gboolean
plugin_init (GstPlugin * plugin)
{
962 963
  gst_controller_init (NULL, NULL);

964 965 966 967 968 969
  return gst_element_register (plugin, "alpha", GST_RANK_NONE, GST_TYPE_ALPHA);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "alpha",
970
    "adds an alpha channel to video",
971
    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)