typedef enum
{
- ALPHA_METHOD_ADD,
+ ALPHA_METHOD_SET,
ALPHA_METHOD_GREEN,
ALPHA_METHOD_BLUE,
ALPHA_METHOD_CUSTOM,
/* caps */
gint in_width, in_height;
gint out_width, out_height;
+ gboolean ayuv;
gdouble alpha;
LAST_SIGNAL
};
-#define DEFAULT_METHOD ALPHA_METHOD_ADD
+#define DEFAULT_METHOD ALPHA_METHOD_SET
#define DEFAULT_ALPHA 1.0
#define DEFAULT_TARGET_R 0
#define DEFAULT_TARGET_G 255
);
static GstStaticPadTemplate gst_alpha_sink_template =
-GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
- GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
+ GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV")
+ ";" GST_VIDEO_CAPS_YUV ("I420")
+ )
);
{
static GType alpha_method_type = 0;
static GEnumValue alpha_method[] = {
- {ALPHA_METHOD_ADD, "0", "Add alpha channel"},
+ {ALPHA_METHOD_SET, "0", "Set/adjust alpha channel"},
{ALPHA_METHOD_GREEN, "1", "Chroma Key green"},
{ALPHA_METHOD_BLUE, "2", "Chroma Key blue"},
{ALPHA_METHOD_CUSTOM, "3", "Chroma Key on target_r/g/b"},
GstAlpha *alpha;
GstStructure *structure;
gboolean ret;
+ guint32 fourcc;
alpha = GST_ALPHA (gst_pad_get_parent (pad));
structure = gst_caps_get_structure (caps, 0);
+ 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:
+ return GST_PAD_LINK_REFUSED;
+ }
+ } else {
+ return GST_PAD_LINK_REFUSED;
+ }
+
ret = gst_structure_get_int (structure, "width", &alpha->in_width);
ret &= gst_structure_get_int (structure, "height", &alpha->in_height);
}
static void
-gst_alpha_add (guint8 * src, guint8 * dest, gint width, gint height,
+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,
gdouble alpha)
{
gint b_alpha = (gint) (alpha * 255);
}
}
+static void
+gst_alpha_chroma_key_ayuv (gchar * src, gchar * dest, gint width, gint height,
+ 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;
+ }
+}
/* based on http://www.cs.utah.edu/~michael/chroma/
*/
static void
-gst_alpha_chroma_key (gchar * src, gchar * dest, gint width, gint height,
+gst_alpha_chroma_key_i420 (gchar * src, gchar * dest, gint width, gint height,
GstAlpha * alpha)
{
gint b_alpha;
guint8 *srcY1, *srcY2, *srcU, *srcV;
guint8 *dest1, *dest2;
gint i, j;
- gint x, z, u, v, y11, y12, y21, y22;
+ gint x, z, u, v, y11, y12, y21, y22, a;
gint size, size2;
gint stride, stride2;
gint wrap, wrap2, wrap3;
wrap2 = stride2 - width / 2;
wrap3 = 8 * width - 8 * (width / 2);
+ a = 255 * alpha->alpha;
+
for (i = 0; i < height / 2; i++) {
for (j = 0; j < width / 2; j++) {
y11 = *srcY1++;
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);
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);
+ 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);
+ }
break;
case ALPHA_METHOD_GREEN:
- gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
- GST_BUFFER_DATA (outbuf), new_width, new_height, alpha);
- break;
case ALPHA_METHOD_BLUE:
- gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
- GST_BUFFER_DATA (outbuf), new_width, new_height, alpha);
- break;
case ALPHA_METHOD_CUSTOM:
- gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
- GST_BUFFER_DATA (outbuf), new_width, new_height, alpha);
+ 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);
+ }
break;
default:
break;