3 * Copyright (C) 2007 David Schleef <ds@schleef.org>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
21 * Logic enhanced by William Brack <wbrack@mmm.com.hk>
25 * SECTION:element-bayer2rgb
27 * Decodes raw camera bayer (fourcc BA81) to RGB.
31 * In order to guard against my advancing maturity, some extra detailed
32 * information about the logic of the decode is included here. Much of
33 * this was inspired by a technical paper from siliconimaging.com, which
34 * in turn was based upon an article from IEEE,
35 * T. Sakamoto, C. Nakanishi and T. Hase,
36 * “Software pixel interpolation for digital still cameras suitable for
38 * IEEE Trans. Consumer Electronics, vol. 44, no. 4, November 1998.
40 * The code assumes a Bayer matrix of the type produced by the fourcc
41 * BA81 (v4l2 format SBGGR8) of width w and height h which looks like:
51 * We expand this matrix, producing a separate {r, g, b} triple for each
52 * of the individual elements. The algorithm for doing this expansion is
55 * We are designing for speed of transformation, at a slight expense of code.
56 * First, we calculate the appropriate triples for the four corners, the
57 * remainder of the top and bottom rows, and the left and right columns.
58 * The reason for this is that those elements are transformed slightly
59 * differently than all of the remainder of the matrix. Finally, we transform
60 * all of the remainder.
62 * The transformation into the "appropriate triples" is based upon the
63 * "nearest neighbor" principal, with some additional complexity for the
64 * calculation of the "green" element, where an "adaptive" pairing is used.
66 * For purposes of documentation and indentification, each element of the
67 * original array can be put into one of four classes:
70 * GR A green element which is followed by a red one
71 * GB A green element which is followed by a blue one
79 #include <gst/base/gstbasetransform.h>
80 #include <gst/video/video.h>
85 #define GST_CAT_DEFAULT gst_bayer2rgb_debug
86 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
88 #define GST_TYPE_BAYER2RGB (gst_bayer2rgb_get_type())
89 #define GST_BAYER2RGB(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BAYER2RGB,GstBayer2RGB))
90 #define GST_IS_BAYER2RGB(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BAYER2RGB))
91 #define GST_BAYER2RGB_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass) ,GST_TYPE_BAYER2RGB,GstBayer2RGBClass))
92 #define GST_IS_BAYER2RGB_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass) ,GST_TYPE_BAYER2RGB))
93 #define GST_BAYER2RGB_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS((obj) ,GST_TYPE_BAYER2RGB,GstBayer2RGBClass))
94 typedef struct _GstBayer2RGB GstBayer2RGB;
95 typedef struct _GstBayer2RGBClass GstBayer2RGBClass;
97 typedef void (*GstBayer2RGBProcessFunc) (GstBayer2RGB *, guint8 *, guint);
101 GstBaseTransform basetransform;
107 int pixsize; /* bytes per pixel */
108 int r_off; /* offset for red */
109 int g_off; /* offset for green */
110 int b_off; /* offset for blue */
113 struct _GstBayer2RGBClass
115 GstBaseTransformClass parent;
118 static const GstElementDetails element_details =
119 GST_ELEMENT_DETAILS ("Bayer to RGB decoder for cameras",
120 "Filter/Converter/Video",
121 "Converts video/x-raw-bayer to video/x-raw-rgb",
122 "William Brack <wbrack@mmm.com.hk>");
124 //#define SRC_CAPS GST_VIDEO_CAPS_RGBx
126 GST_VIDEO_CAPS_RGBx ";" \
127 GST_VIDEO_CAPS_xRGB ";" \
128 GST_VIDEO_CAPS_BGRx ";" \
129 GST_VIDEO_CAPS_xBGR ";" \
130 GST_VIDEO_CAPS_RGBA ";" \
131 GST_VIDEO_CAPS_ARGB ";" \
132 GST_VIDEO_CAPS_BGRA ";" \
133 GST_VIDEO_CAPS_ABGR ";" \
134 GST_VIDEO_CAPS_RGB ";" \
137 #define SINK_CAPS "video/x-raw-bayer,width=(int)[1,MAX],height=(int)[1,MAX]"
144 #define DEBUG_INIT(bla) \
145 GST_DEBUG_CATEGORY_INIT (gst_bayer2rgb_debug, "bayer2rgb", 0, "bayer2rgb element");
147 GST_BOILERPLATE_FULL (GstBayer2RGB, gst_bayer2rgb, GstBaseTransform,
148 GST_TYPE_BASE_TRANSFORM, DEBUG_INIT);
150 static void gst_bayer2rgb_set_property (GObject * object, guint prop_id,
151 const GValue * value, GParamSpec * pspec);
152 static void gst_bayer2rgb_get_property (GObject * object, guint prop_id,
153 GValue * value, GParamSpec * pspec);
155 static gboolean gst_bayer2rgb_set_caps (GstBaseTransform * filter,
156 GstCaps * incaps, GstCaps * outcaps);
157 static GstFlowReturn gst_bayer2rgb_transform (GstBaseTransform * base,
158 GstBuffer * inbuf, GstBuffer * outbuf);
159 static void gst_bayer2rgb_reset (GstBayer2RGB * filter);
160 static GstCaps *gst_bayer2rgb_transform_caps (GstBaseTransform * base,
161 GstPadDirection direction, GstCaps * caps);
162 static gboolean gst_bayer2rgb_get_unit_size (GstBaseTransform * base,
163 GstCaps * caps, guint * size);
167 gst_bayer2rgb_base_init (gpointer klass)
169 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
171 gst_element_class_set_details (element_class, &element_details);
173 gst_element_class_add_pad_template (element_class,
174 gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
175 gst_caps_from_string (SRC_CAPS)));
176 gst_element_class_add_pad_template (element_class,
177 gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
178 gst_caps_from_string (SINK_CAPS)));
182 gst_bayer2rgb_class_init (GstBayer2RGBClass * klass)
184 GObjectClass *gobject_class;
186 gobject_class = (GObjectClass *) klass;
187 gobject_class->set_property = gst_bayer2rgb_set_property;
188 gobject_class->get_property = gst_bayer2rgb_get_property;
190 GST_BASE_TRANSFORM_CLASS (klass)->transform_caps =
191 GST_DEBUG_FUNCPTR (gst_bayer2rgb_transform_caps);
192 GST_BASE_TRANSFORM_CLASS (klass)->get_unit_size =
193 GST_DEBUG_FUNCPTR (gst_bayer2rgb_get_unit_size);
194 GST_BASE_TRANSFORM_CLASS (klass)->set_caps =
195 GST_DEBUG_FUNCPTR (gst_bayer2rgb_set_caps);
196 GST_BASE_TRANSFORM_CLASS (klass)->transform =
197 GST_DEBUG_FUNCPTR (gst_bayer2rgb_transform);
201 gst_bayer2rgb_init (GstBayer2RGB * filter, GstBayer2RGBClass * klass)
203 gst_bayer2rgb_reset (filter);
204 gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);
207 /* No properties are implemented, so only a warning is produced */
209 gst_bayer2rgb_set_property (GObject * object, guint prop_id,
210 const GValue * value, GParamSpec * pspec)
215 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
221 gst_bayer2rgb_get_property (GObject * object, guint prop_id,
222 GValue * value, GParamSpec * pspec)
227 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
232 /* Routine to convert colormask value into relative byte offset */
234 get_pix_offset (int mask, int bpp)
236 int bpp32 = (bpp / 8) - 3;
248 GST_ERROR ("Invalid color mask 0x%08x", mask);
254 gst_bayer2rgb_set_caps (GstBaseTransform * base, GstCaps * incaps,
257 GstBayer2RGB *filter = GST_BAYER2RGB (base);
258 GstStructure *structure;
261 GST_DEBUG ("in caps %" GST_PTR_FORMAT " out caps %" GST_PTR_FORMAT, incaps,
264 structure = gst_caps_get_structure (incaps, 0);
266 gst_structure_get_int (structure, "width", &filter->width);
267 gst_structure_get_int (structure, "height", &filter->height);
268 filter->stride = GST_ROUND_UP_4 (filter->width);
270 /* To cater for different RGB formats, we need to set params for later */
271 structure = gst_caps_get_structure (outcaps, 0);
272 gst_structure_get_int (structure, "bpp", &bpp);
273 filter->pixsize = bpp / 8;
274 gst_structure_get_int (structure, "red_mask", &val);
275 filter->r_off = get_pix_offset (val, bpp);
276 gst_structure_get_int (structure, "green_mask", &val);
277 filter->g_off = get_pix_offset (val, bpp);
278 gst_structure_get_int (structure, "blue_mask", &val);
279 filter->b_off = get_pix_offset (val, bpp);
285 gst_bayer2rgb_reset (GstBayer2RGB * filter)
297 gst_bayer2rgb_transform_caps (GstBaseTransform * base,
298 GstPadDirection direction, GstCaps * caps)
300 GstStructure *structure;
302 GstStructure *newstruct;
304 GST_DEBUG_OBJECT (caps, "transforming caps (from)");
306 structure = gst_caps_get_structure (caps, 0);
308 if (direction == GST_PAD_SRC) {
309 newcaps = gst_caps_new_simple ("video/x-raw-bayer", NULL);
311 newcaps = gst_caps_new_simple ("video/x-raw-rgb", NULL);
313 newstruct = gst_caps_get_structure (newcaps, 0);
315 gst_structure_set_value (newstruct, "width",
316 gst_structure_get_value (structure, "width"));
317 gst_structure_set_value (newstruct, "height",
318 gst_structure_get_value (structure, "height"));
319 gst_structure_set_value (newstruct, "framerate",
320 gst_structure_get_value (structure, "framerate"));
322 GST_DEBUG_OBJECT (newcaps, "transforming caps (into)");
328 gst_bayer2rgb_get_unit_size (GstBaseTransform * base, GstCaps * caps,
331 GstStructure *structure;
337 structure = gst_caps_get_structure (caps, 0);
339 if (gst_structure_get_int (structure, "width", &width) &&
340 gst_structure_get_int (structure, "height", &height)) {
341 name = gst_structure_get_name (structure);
342 /* Our name must be either video/x-raw-bayer video/x-raw-rgb */
343 if (strcmp (name, "video/x-raw-rgb")) {
344 /* For bayer, we handle only BA81 (BGGR), which is BPP=24 */
345 *size = GST_ROUND_UP_4 (width) * height;
348 /* For output, calculate according to format */
349 if (gst_structure_get_int (structure, "bpp", &pixsize)) {
350 *size = width * height * (pixsize / 8);
356 GST_ELEMENT_ERROR (base, CORE, NEGOTIATION, (NULL),
357 ("Incomplete caps, some required field missing"));
362 * We define values for the colors, just to make the code more readable.
364 #define RED 0 /* Pure red element */
365 #define GREENB 1 /* Green element which is on a blue line */
366 #define BLUE 2 /* Pure blue element */
367 #define GREENR 3 /* Green element which is on a red line */
369 /* Routine to generate the top and bottom edges (not including corners) */
371 hborder (uint8_t * input, uint8_t * output, int bot_top,
372 int typ, GstBayer2RGB * filter)
374 uint8_t *op; /* output pointer */
375 uint8_t *ip; /* input pointer */
376 uint8_t *nx; /* next line pointer */
377 int ix; /* loop index */
379 op = output + (bot_top * filter->width * (filter->height - 1) + 1) *
381 ip = input + bot_top * filter->stride * (filter->height - 1);
382 /* calculate minus or plus one line, depending upon bot_top flag */
383 nx = ip + (1 - 2 * bot_top) * filter->stride;
384 /* Stepping horizontally */
385 for (ix = 1; ix < filter->width - 1; ix++, op += filter->pixsize) {
388 op[filter->r_off] = ip[ix];
389 op[filter->g_off] = (ip[ix + 1] + ip[ix - 1] + nx[ix] + 1) / 3;
390 op[filter->b_off] = (nx[ix + 1] + nx[ix - 1] + 1) / 2;
394 op[filter->r_off] = (ip[ix + 1] + ip[ix - 1] + 1) / 2;
395 op[filter->g_off] = ip[ix];
396 op[filter->b_off] = nx[ix];
400 op[filter->r_off] = nx[ix];
401 op[filter->g_off] = ip[ix];
402 op[filter->b_off] = (ip[ix + 1] + ip[ix - 1] + 1) / 2;
406 op[filter->r_off] = (nx[ix + 1] + nx[ix - 1] + 1) / 2;
407 op[filter->g_off] = (ip[ix + 1] + ip[ix - 1] + nx[ix] + 1) / 3;
408 op[filter->b_off] = ip[ix];
415 /* Routine to generate the left and right edges, not including corners */
417 vborder (uint8_t * input, uint8_t * output, int right_left,
418 int typ, GstBayer2RGB * filter)
420 uint8_t *op; /* output pointer */
421 uint8_t *ip; /* input pointer */
422 uint8_t *la; /* line above pointer */
423 uint8_t *lb; /* line below pointer */
424 int ix; /* loop index */
425 int lr; /* 'left-right' flag - +1 is right, -1 is left */
427 lr = (1 - 2 * right_left);
428 /* stepping vertically */
429 for (ix = 1; ix < filter->height - 1; ix++) {
430 ip = input + right_left * (filter->width - 1) + ix * filter->stride;
431 op = output + (right_left * (filter->width - 1) + ix * filter->width) *
433 la = ip + filter->stride;
434 lb = ip - filter->stride;
437 op[filter->r_off] = ip[0];
438 op[filter->g_off] = (la[0] + ip[lr] + lb[0] + 1) / 3;
439 op[filter->b_off] = (la[lr] + lb[lr] + 1) / 2;
443 op[filter->r_off] = ip[lr];
444 op[filter->g_off] = ip[0];
445 op[filter->b_off] = (la[lr] + lb[lr] + 1) / 2;
449 op[filter->r_off] = (la[lr] + lb[lr] + 1) / 2;
450 op[filter->g_off] = ip[0];
451 op[filter->b_off] = ip[lr];
455 op[filter->r_off] = (la[lr] + lb[lr] + 1) / 2;
456 op[filter->g_off] = (la[0] + ip[lr] + lb[0] + 1) / 3;
457 op[filter->b_off] = ip[0];
464 /* Produce the four (top, bottom, left, right) edges */
466 do_row0_col0 (uint8_t * input, uint8_t * output, GstBayer2RGB * filter)
470 /* Horizontal edges */
471 hborder (input, output, 0, GREENB, filter);
472 if (filter->height & 1)
473 type = GREENB; /* odd # rows, "bottom" edge same as top */
475 type = RED; /* even #, bottom side different */
476 hborder (input, output, 1, type, filter);
479 vborder (input, output, 0, GREENR, filter);
480 if (filter->width & 1)
481 type = GREENR; /* odd # cols, "right" edge same as left */
483 type = RED; /* even #, right side different */
484 vborder (input, output, 1, type, filter);
488 corner (uint8_t * input, uint8_t * output, int x, int y,
489 int xd, int yd, int typ, GstBayer2RGB * filter)
491 uint8_t *ip; /* input pointer */
492 uint8_t *op; /* output pointer */
493 uint8_t *nx; /* adjacent line */
495 op = output + y * filter->width * filter->pixsize + x * filter->pixsize;
496 ip = input + y * filter->stride + x;
497 nx = ip + yd * filter->stride;
500 op[filter->r_off] = ip[0];
501 op[filter->g_off] = (nx[0] + ip[xd] + 1) / 2;
502 op[filter->b_off] = nx[xd];
505 op[filter->r_off] = ip[xd];
506 op[filter->g_off] = ip[0];
507 op[filter->b_off] = nx[0];
510 op[filter->r_off] = nx[0];
511 op[filter->g_off] = ip[0];
512 op[filter->b_off] = ip[xd];
515 op[filter->r_off] = nx[xd];
516 op[filter->g_off] = (nx[0] + ip[xd] + 1) / 2;
517 op[filter->b_off] = ip[0];
523 do_corners (uint8_t * input, uint8_t * output, GstBayer2RGB * filter)
528 corner (input, output, 0, 0, 1, 1, BLUE, filter);
530 corner (input, output, 0, filter->height - 1, 1, -1,
531 (filter->height & 1) ? BLUE : GREENR, filter);
533 corner (input, output, filter->width - 1, 0, -1, 0,
534 (filter->width & 1) ? BLUE : GREENB, filter);
536 if (filter->width & 1) /* if odd # cols, B or GB */
539 typ = GREENB; /* if even # cols, B or GR */
540 typ |= (filter->height & 1); /* if odd # rows, GB or GR */
541 corner (input, output, filter->width - 1, filter->height - 1, -1, -1,
546 do_body (uint8_t * input, uint8_t * output, GstBayer2RGB * filter)
548 int ip, op; /* input and output pointers */
549 int w, h; /* loop indices */
550 int type; /* calculated colour of current element */
555 * We are processing row (line) by row, starting with the second
556 * row and continuing through the next to last. Each row is processed
557 * column by column, starting with the second and continuing through
558 * to the next to last.
560 for (h = 1; h < filter->height - 1; h++) {
562 * Remember we are processing "row by row". For each row, we need
563 * to set the type of the first element to be processed. Since we
564 * have already processed the edges, the "first element" will be
565 * the pixel at position (1,1). Assuming BG format, this should
566 * be RED for odd-numbered rows and GREENB for even rows.
572 /* Calculate the starting position for the row */
573 op = h * filter->width * filter->pixsize; /* output (converted) pos */
574 ip = h * filter->stride; /* input (bayer data) pos */
575 for (w = 1; w < filter->width - 1; w++) {
576 op += filter->pixsize; /* we are processing "horizontally" */
580 output[op + filter->r_off] = input[ip];
581 output[op + filter->b_off] = (input[ip - filter->stride - 1] +
582 input[ip - filter->stride + 1] +
583 input[ip + filter->stride - 1] +
584 input[ip + filter->stride + 1] + 2) / 4;
585 v1 = input[ip + filter->stride];
586 v2 = input[ip - filter->stride];
592 output[op + filter->g_off] = (v1 + v2 + 1) / 2;
594 output[op + filter->g_off] = (h1 + h2 + 1) / 2;
596 output[op + filter->g_off] = (v1 + h1 + v2 + h2 + 2) / 4;
600 output[op + filter->r_off] = (input[ip + 1] + input[ip - 1] + 1) / 2;
601 output[op + filter->g_off] = input[ip];
602 output[op + filter->b_off] = (input[ip - filter->stride] +
603 input[ip + filter->stride] + 1) / 2;
607 output[op + filter->r_off] = (input[ip - filter->stride] +
608 input[ip + filter->stride] + 1) / 2;
609 output[op + filter->g_off] = input[ip];
610 output[op + filter->b_off] = (input[ip + 1] + input[ip - 1] + 1) / 2;
614 output[op + filter->r_off] = (input[ip - filter->stride - 1] +
615 input[ip - filter->stride + 1] +
616 input[ip + filter->stride - 1] +
617 input[ip + filter->stride + 1] + 2) / 4;
618 output[op + filter->b_off] = input[ip];
619 v1 = input[ip + filter->stride];
620 v2 = input[ip - filter->stride];
626 output[op + filter->g_off] = (v1 + v2 + 1) / 2;
628 output[op + filter->g_off] = (h1 + h2 + 1) / 2;
630 output[op + filter->g_off] = (v1 + h1 + v2 + h2 + 2) / 4;
639 gst_bayer2rgb_transform (GstBaseTransform * base, GstBuffer * inbuf,
642 GstBayer2RGB *filter = GST_BAYER2RGB (base);
643 uint8_t *input, *output;
646 * We need to lock our filter params to prevent changing
647 * caps in the middle of a transformation (nice way to get
650 GST_OBJECT_LOCK (filter);
652 GST_DEBUG ("transforming buffer");
653 input = (uint8_t *) GST_BUFFER_DATA (inbuf);
654 output = (uint8_t *) GST_BUFFER_DATA (outbuf);
655 do_corners (input, output, filter);
656 do_row0_col0 (input, output, filter);
657 do_body (input, output, filter);
659 GST_OBJECT_UNLOCK (filter);