gstalpha.c 15.1 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 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
/* 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>

#include <string.h>

#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))
#define GST_IS_ALPHA_CLASS(obj) \
  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ALPHA))

typedef struct _GstAlpha GstAlpha;
typedef struct _GstAlphaClass GstAlphaClass;

typedef enum
{
  ALPHA_METHOD_ADD,
  ALPHA_METHOD_GREEN,
  ALPHA_METHOD_BLUE,
47
  ALPHA_METHOD_BLACK,
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146
}
GstAlphaMethod;

#define DEFAULT_METHOD ALPHA_METHOD_ADD
#define DEFAULT_ALPHA 1.0
#define DEFAULT_TARGET_CR 116
#define DEFAULT_TARGET_CB 116

struct _GstAlpha
{
  GstElement element;

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

  /* caps */
  gint in_width, in_height;
  gint out_width, out_height;

  gdouble alpha;

  guint target_cr, target_cb;

  GstAlphaMethod method;
};

struct _GstAlphaClass
{
  GstElementClass parent_class;
};

/* elementfactory information */
static GstElementDetails gst_alpha_details =
GST_ELEMENT_DETAILS ("alpha filter",
    "Filter/Effect/Video",
    "Adds an alpha channel to video",
    "Wim Taymans <wim@fluendo.com>");


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

enum
{
  ARG_0,
  ARG_METHOD,
  ARG_ALPHA,
  ARG_TARGET_CR,
  ARG_TARGET_CB,
  /* 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 =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
    );


static void gst_alpha_base_init (gpointer g_class);
static void gst_alpha_class_init (GstAlphaClass * klass);
static void gst_alpha_init (GstAlpha * alpha);

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);

static GstPadLinkReturn
gst_alpha_sink_link (GstPad * pad, const GstCaps * caps);
static void gst_alpha_chain (GstPad * pad, GstData * _data);

static GstElementStateReturn gst_alpha_change_state (GstElement * element);


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;
  static GEnumValue alpha_method[] = {
    {ALPHA_METHOD_ADD, "0", "Add alpha channel"},
    {ALPHA_METHOD_GREEN, "1", "Chroma Key green"},
    {ALPHA_METHOD_BLUE, "2", "Chroma Key blue"},
147
    {ALPHA_METHOD_BLACK, "3", "Chroma Key black"},
148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331
    {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;

  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);

  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",
          0.0, 1.0, DEFAULT_ALPHA, (GParamFlags) G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_CR,
      g_param_spec_uint ("target_cr", "Target Red", "The Red Chroma target", 0,
          255, 116, (GParamFlags) G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_CB,
      g_param_spec_uint ("target_cb", "Target Blue", "The Blue Chroma target",
          0, 255, 116, (GParamFlags) G_PARAM_READWRITE));

  gobject_class->set_property = gst_alpha_set_property;
  gobject_class->get_property = gst_alpha_get_property;

  gstelement_class->change_state = gst_alpha_change_state;
}

static void
gst_alpha_init (GstAlpha * alpha)
{
  /* create the sink and src pads */
  alpha->sinkpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&gst_alpha_sink_template), "sink");
  gst_element_add_pad (GST_ELEMENT (alpha), alpha->sinkpad);
  gst_pad_set_chain_function (alpha->sinkpad, gst_alpha_chain);
  gst_pad_set_link_function (alpha->sinkpad, gst_alpha_sink_link);

  alpha->srcpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&gst_alpha_src_template), "src");
  gst_element_add_pad (GST_ELEMENT (alpha), alpha->srcpad);

  alpha->alpha = DEFAULT_ALPHA;
  alpha->method = DEFAULT_METHOD;
  alpha->target_cr = DEFAULT_TARGET_CR;
  alpha->target_cb = DEFAULT_TARGET_CB;

  GST_FLAG_SET (alpha, GST_ELEMENT_EVENT_AWARE);
}

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

  /* it's not null if we got it, but it might not be ours */
  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);
      break;
    case ARG_ALPHA:
      alpha->alpha = g_value_get_double (value);
      break;
    case ARG_TARGET_CB:
      alpha->target_cb = g_value_get_uint (value);
      break;
    case ARG_TARGET_CR:
      alpha->target_cr = g_value_get_uint (value);
      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;

  /* it's not null if we got it, but it might not be ours */
  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;
    case ARG_TARGET_CR:
      g_value_set_uint (value, alpha->target_cr);
      break;
    case ARG_TARGET_CB:
      g_value_set_uint (value, alpha->target_cb);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstPadLinkReturn
gst_alpha_sink_link (GstPad * pad, const GstCaps * caps)
{
  GstAlpha *alpha;
  GstStructure *structure;
  gboolean ret;

  alpha = GST_ALPHA (gst_pad_get_parent (pad));
  structure = gst_caps_get_structure (caps, 0);

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

  return GST_PAD_LINK_OK;
}

/*
static int yuv_colors_Y[] = {  16, 150,  29 };
static int yuv_colors_U[] = { 128,  46, 255 };
static int yuv_colors_V[] = { 128,  21, 107 };
*/

332 333
#define ROUND_UP_4(x) (((x) + 3) & ~3)

334 335 336 337 338 339 340 341 342
static void
gst_alpha_add (guint8 * src, guint8 * dest, gint width, gint height,
    gdouble alpha)
{
  gint b_alpha = (gint) (alpha * 255);
  guint8 *srcY;
  guint8 *srcU;
  guint8 *srcV;
  gint i, j;
343 344 345 346 347 348 349 350 351 352 353
  gint w2, h2;
  gint size, size2;
  gint stride, stride2;
  gint wrap, wrap2;

  stride = ROUND_UP_4 (width);
  size = stride * height;
  w2 = (width + 1) >> 1;
  stride2 = ROUND_UP_4 (w2);
  h2 = (height + 1) >> 1;
  size2 = stride2 * h2;
354

355 356
  wrap = stride - 2 * (width / 2);
  wrap2 = stride2 - width / 2;
357 358 359

  srcY = src;
  srcU = srcY + size;
360
  srcV = srcU + size2;
361 362 363 364 365 366 367 368 369 370 371 372 373

  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) {
374 375 376 377 378
      srcU -= width / 2;
      srcV -= width / 2;
    } else {
      srcU += wrap2;
      srcV += wrap2;
379
    }
380
    srcY += wrap;
381 382 383
  }
}

384 385 386
#define ROUND_UP_4(x) (((x) + 3) & ~3)
#define ROUND_UP_2(x) (((x) + 1) & ~1)

387 388 389 390 391 392 393 394 395 396 397
static void
gst_alpha_chroma_key (gchar * src, gchar * dest, gint width, gint height,
    gboolean soft, gint target_u, gint target_v, gfloat edge_factor,
    gdouble alpha)
{
  gint b_alpha;
  gint f_alpha = (gint) (alpha * 255);
  guint8 *srcY1, *srcY2, *srcU, *srcV;
  guint8 *dest1, *dest2;
  gint i, j;
  gint x, z, u, v;
398 399 400 401 402 403 404 405 406 407 408
  gint w2, h2;
  gint size, size2;
  gint stride, stride2;
  gint wrap, wrap2, wrap3;

  stride = ROUND_UP_4 (width);
  size = stride * height;
  w2 = (width + 1) >> 1;
  stride2 = ROUND_UP_4 (w2);
  h2 = (height + 1) >> 1;
  size2 = stride2 * h2;
409 410

  srcY1 = src;
411
  srcY2 = src + stride;
412
  srcU = srcY1 + size;
413
  srcV = srcU + size2;
414 415 416 417

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

418 419 420 421
  wrap = 2 * stride - 2 * (width / 2);
  wrap2 = stride2 - width / 2;
  wrap3 = 8 * width - 8 * (ROUND_UP_2 (width) / 2);

422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475
  for (i = 0; i < height / 2; i++) {
    for (j = 0; j < width / 2; j++) {
      u = *srcU++;
      v = *srcV++;

      x = target_u - u;
      z = target_v - v;

      // only filter if in top left square
      if ((x > 0) && (z > 0)) {
        // only calculate lot of stuff if we'll use soft edges
        if (soft) {
          gint ds = (x > z) ? z : x;

          gfloat df = (gfloat) (ds) / edge_factor;

          if (df > 1.0)
            df = 1.0;

          // suppress foreground
          if (x > z) {
            u += z;
            v += z;
          } else {
            u += x;
            v += x;
          }
          b_alpha = (int) (f_alpha * (1.0 - df));
        } else {
          // kill color and alpha
          b_alpha = 0;
        }
      } else {
        // do nothing;
        b_alpha = f_alpha;
      }

      *dest1++ = b_alpha;
      *dest1++ = *srcY1++;
      *dest1++ = u;
      *dest1++ = v;
      *dest1++ = b_alpha;
      *dest1++ = *srcY1++;
      *dest1++ = u;
      *dest1++ = v;
      *dest2++ = b_alpha;
      *dest2++ = *srcY2++;
      *dest2++ = u;
      *dest2++ = v;
      *dest2++ = b_alpha;
      *dest2++ = *srcY2++;
      *dest2++ = u;
      *dest2++ = v;
    }
476 477 478 479 480 481
    dest1 += wrap3;
    dest2 += wrap3;
    srcY1 += wrap;
    srcY2 += wrap;
    srcU += wrap2;
    srcV += wrap2;
482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541
  }
}

static void
gst_alpha_chain (GstPad * pad, GstData * _data)
{
  GstBuffer *buffer;
  GstAlpha *alpha;
  GstBuffer *outbuf;
  gint new_width, new_height;

  alpha = GST_ALPHA (gst_pad_get_parent (pad));

  if (GST_IS_EVENT (_data)) {
    GstEvent *event = GST_EVENT (_data);

    switch (GST_EVENT_TYPE (event)) {
      default:
        gst_pad_event_default (pad, event);
        break;
    }
    return;
  }

  buffer = GST_BUFFER (_data);

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

  if (new_width != alpha->out_width ||
      new_height != alpha->out_height || !GST_PAD_CAPS (alpha->srcpad)) {
    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);

    if (!gst_pad_try_set_caps (alpha->srcpad, newcaps)) {
      GST_ELEMENT_ERROR (alpha, CORE, NEGOTIATION, (NULL), (NULL));
      return;
    }

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

  outbuf = gst_buffer_new_and_alloc (new_width * new_height * 4);
  GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
  GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);

  switch (alpha->method) {
    case ALPHA_METHOD_ADD:
      gst_alpha_add (GST_BUFFER_DATA (buffer),
          GST_BUFFER_DATA (outbuf), new_width, new_height, alpha->alpha);
      break;
    case ALPHA_METHOD_GREEN:
      gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
          GST_BUFFER_DATA (outbuf),
          new_width, new_height,
542
          FALSE, alpha->target_cr, alpha->target_cb, 1.0, alpha->alpha);
543 544 545 546 547 548
      break;
    case ALPHA_METHOD_BLUE:
      gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
          GST_BUFFER_DATA (outbuf),
          new_width, new_height, TRUE, 100, 100, 1.0, alpha->alpha);
      break;
549 550 551 552 553 554 555
    case ALPHA_METHOD_BLACK:
      gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
          GST_BUFFER_DATA (outbuf),
          new_width, new_height, TRUE, 129, 129, 1.0, alpha->alpha);
      break;
    default:
      break;
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
  }

  gst_buffer_unref (buffer);

  gst_pad_push (alpha->srcpad, GST_DATA (outbuf));
}

static GstElementStateReturn
gst_alpha_change_state (GstElement * element)
{
  GstAlpha *alpha;

  alpha = GST_ALPHA (element);

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_NULL_TO_READY:
      break;
    case GST_STATE_READY_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_PLAYING:
      break;
    case GST_STATE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_READY:
      break;
    case GST_STATE_READY_TO_NULL:
      break;
  }

  parent_class->change_state (element);

  return GST_STATE_SUCCESS;
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  return gst_element_register (plugin, "alpha", GST_RANK_NONE, GST_TYPE_ALPHA);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "alpha",
    "resizes a video by adding borders or cropping",
    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)