[Intel-gfx] [PATCH i-g-t] chamelium: Add support for VGA frame comparison testing

Paul Kocialkowski paul.kocialkowski at linux.intel.com
Thu Jul 6 13:26:14 UTC 2017


This adds support for VGA frame comparison check. Since VGA uses a
DAC-ADC chain, its data cannot be expected to be pixel perfect. Thus, it
is impossible to uses a CRC check and full frames have to be analyzed
instead. Such an analysis is implemented, based on both an absolute
error threshold and a correlation with the expected error trend for
a DAC-ADC chain. It was tested with a couple encoders and provides
reliable error detection with few false positives.

In case the frame does not match, it is dumped to a file in a similar
fashion as CRC tests.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski at linux.intel.com>
---
 configure.ac        |   5 +-
 lib/Makefile.am     |   2 +
 lib/igt_chamelium.c | 235 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 lib/igt_chamelium.h |   6 +-
 tests/chamelium.c   |  82 ++++++++++++++++++
 5 files changed, 325 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index 0418e605..e7c3603b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -182,8 +182,9 @@ PKG_CHECK_MODULES(GLIB, glib-2.0)
 # for chamelium
 PKG_CHECK_MODULES(XMLRPC, xmlrpc_client, [xmlrpc=yes], [xmlrpc=no])
 PKG_CHECK_MODULES(PIXMAN, pixman-1, [pixman=yes], [pixman=no])
-AM_CONDITIONAL(HAVE_CHAMELIUM, [test "x$xmlrpc$pixman" = xyesyes])
-if test x"$xmlrpc$pixman" = xyesyes; then
+PKG_CHECK_MODULES(GSL, gsl, [gsl=yes], [gsl=no])
+AM_CONDITIONAL(HAVE_CHAMELIUM, [test "x$xmlrpc$pixman$gsl" = xyesyesyes])
+if test x"$xmlrpc$pixman$gsl" = xyesyesyes; then
 	AC_DEFINE(HAVE_CHAMELIUM, 1, [Enable Chamelium support])
 fi
 
diff --git a/lib/Makefile.am b/lib/Makefile.am
index d4f41128..fb922ced 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -35,6 +35,7 @@ AM_CFLAGS = \
 	    $(DRM_CFLAGS) \
 	    $(PCIACCESS_CFLAGS) \
 	    $(LIBUNWIND_CFLAGS) \
+	    $(GSL_CFLAGS) \
 	    $(KMOD_CFLAGS) \
 	    $(PROCPS_CFLAGS) \
 	    $(DEBUG_CFLAGS) \
@@ -54,6 +55,7 @@ libintel_tools_la_LIBADD = \
 	$(DRM_LIBS) \
 	$(PCIACCESS_LIBS) \
 	$(PROCPS_LIBS) \
+	$(GSL_LIBS) \
 	$(KMOD_LIBS) \
 	$(CAIRO_LIBS) \
 	$(LIBUDEV_LIBS) \
diff --git a/lib/igt_chamelium.c b/lib/igt_chamelium.c
index 9aca6842..79ea8b4f 100644
--- a/lib/igt_chamelium.c
+++ b/lib/igt_chamelium.c
@@ -34,6 +34,8 @@
 #include <glib.h>
 #include <pixman.h>
 #include <cairo.h>
+#include <gsl/gsl_statistics_double.h>
+#include <gsl/gsl_fit.h>
 
 #include "igt.h"
 
@@ -1035,6 +1037,235 @@ void chamelium_write_frame_to_png(const struct chamelium *chamelium,
 }
 
 /**
+ * chamelium_analogue_frame_crop:
+ * @chamelium: The Chamelium instance to use
+ * @dump: The chamelium frame dump to crop
+ * @width: The cropped frame width
+ * @height: The cropped frame height
+ *
+ * Detects the corners of a chamelium frame and crops it to the requested
+ * width/height. This is useful for VGA frame dumps that also contain the
+ * pixels dumped during the blanking intervals.
+ *
+ * The detection is done on a brightness-threshold-basis, that is adapted
+ * to the reference frame used by i-g-t. It may not be as relevant for other
+ * frames.
+ */
+void chamelium_crop_analogue_frame(struct chamelium_frame_dump *dump, int width,
+				   int height)
+{
+	unsigned char *bgr;
+	unsigned char *p;
+	unsigned char *q;
+	int top, left;
+	int x, y, xx, yy;
+	int score;
+
+	if (dump->width == width && dump->height == height)
+		return;
+
+	/* Start with the most bottom-right position. */
+	top = dump->height - height;
+	left = dump->width - width;
+
+	igt_assert(top >= 0 && left >= 0);
+
+	igt_debug("Cropping analogue frame from %dx%d to %dx%d\n", dump->width,
+		  dump->height, width, height);
+
+	/* Detect the top-left corner of the frame. */
+	for (x = 0; x < dump->width; x++) {
+		for (y = 0; y < dump->height; y++) {
+			p = &dump->bgr[(x + y * dump->width) * 3];
+
+			/* Detect significantly bright pixels. */
+			if (p[0] < 50 && p[1] < 50 && p[2] < 50)
+				continue;
+
+			/*
+			 * Make sure close-by pixels are also significantly
+			 * bright.
+			 */
+			score = 0;
+			for (xx = x; xx < x + 10; xx++) {
+				for (yy = y; yy < y + 10; yy++) {
+					p = &dump->bgr[(xx + yy * dump->width) * 3];
+
+					if (p[0] > 50 && p[1] > 50 && p[2] > 50)
+						score++;
+				}
+			}
+
+			/* Not enough pixels are significantly bright. */
+			if (score < 25)
+				continue;
+
+			if (x < left)
+				left = x;
+
+			if (y < top)
+				top = y;
+
+			if (left == x || top == y)
+				continue;
+		}
+	}
+
+	igt_debug("Detected analogue frame edges at %dx%d\n", left, top);
+
+	/* Crop the frame given the detected top-left corner. */
+	bgr = malloc(width * height * 3);
+
+	for (y = 0; y < height; y++) {
+		p = &dump->bgr[(left + (top + y) * dump->width) * 3];
+		q = &bgr[(y * width) * 3];
+		memcpy(q, p, width * 3);
+	}
+
+	free(dump->bgr);
+	dump->width = width;
+	dump->height = height;
+	dump->bgr = bgr;
+}
+
+/**
+ * chamelium_check_analogue_frame_eq:
+ * @chamelium: The Chamelium instance to use
+ * @dump: The chamelium frame dump to check
+ * @fb: The framebuffer to check against
+ *
+ * Checks that the analogue image contained in the chamelium frame dump matches
+ * the given framebuffer.
+ *
+ * In order to determine whether the frame matches the reference, the following
+ * reasoning is implemented:
+ * 1. The absolute error for each color value of the reference is collected.
+ * 2. The average absolute error is calculated for each color value of the
+ *    reference and must not go above 60 (23.5 % of the total range).
+ * 3. A linear fit for the average absolute error from the pixel value is
+ *    calculated, as a DAC-ADC chain is expected to have a linear error curve.
+ * 4. The linear fit is correlated with the actual average absolute error for
+ *    the frame and the correlation coefficient is checked to be > 0.985,
+ *    indicating a match with the expected error trend.
+ *
+ * Most errors (e.g. due to scaling, rotation, color space, etc) can be
+ * reliably detected this way, with a minimized number of false-positives.
+ * However, the brightest values (250 and up) are ignored as the error trend
+ * is often not linear there in practice due to clamping.
+ *
+ * Returns: a boolean indicating whether the frames match
+ */
+bool chamelium_check_analogue_frame_match(const struct chamelium *chamelium,
+					  const struct chamelium_frame_dump *dump,
+					  struct igt_fb *fb)
+{
+	cairo_t *cr;
+	cairo_surface_t *fb_surface;
+	pixman_image_t *reference_src, *reference_bgr;
+	int w = dump->width, h = dump->height;
+	int error_count[3][256][2] = { 0 };
+	double error_average[4][250];
+	double error_trend[250];
+	double c0, c1, cov00, cov01, cov11, sumsq;
+	double correlation;
+	unsigned char *bgr;
+	unsigned char *p;
+	unsigned char *q;
+	bool match = true;
+	int diff;
+	int x, y;
+	int i, j;
+
+	/* Get the cairo surface for the framebuffer */
+	cr = igt_get_cairo_ctx(chamelium->drm_fd, fb);
+	fb_surface = cairo_get_target(cr);
+	cairo_surface_reference(fb_surface);
+	cairo_destroy(cr);
+
+	/*
+	 * Convert the reference image into the same format as the chamelium
+	 * image
+	 */
+	reference_src = pixman_image_create_bits(
+	    PIXMAN_x8r8g8b8, w, h,
+	    (void*)cairo_image_surface_get_data(fb_surface),
+	    cairo_image_surface_get_stride(fb_surface));
+	reference_bgr = convert_frame_format(reference_src, PIXMAN_b8g8r8);
+	pixman_image_unref(reference_src);
+
+	bgr = (unsigned char *) pixman_image_get_data(reference_bgr);
+
+	/* Collect the absolute error for each color value */
+	for (x = 0; x < w; x++) {
+		for (y = 0; y < h; y++) {
+			p = &dump->bgr[(x + y * w) * 3];
+			q = &bgr[(x + y * w) * 3];
+
+			for (i = 0; i < 3; i++) {
+				diff = (int) p[i] - q[i];
+				if (diff < 0)
+					diff = -diff;
+
+				error_count[i][q[i]][0] += diff;
+				error_count[i][q[i]][1]++;
+			}
+		}
+	}
+
+	/* Calculate the average absolute error for each color value */
+	for (i = 0; i < 250; i++) {
+		error_average[0][i] = i;
+
+		for (j = 1; j < 4; j++) {
+			error_average[j][i] = (double) error_count[j-1][i][0] /
+					      error_count[j-1][i][1];
+
+			if (error_average[j][i] > 60) {
+				igt_warn("Error average too high (%f)\n",
+					 error_average[j][i]);
+
+				match = false;
+				goto complete;
+			}
+		}
+	}
+
+	/*
+	 * Calculate error trend from linear fit.
+	 * A DAC-ADC chain is expected to have a linear absolute error on
+	 * most of its range
+	 */
+	for (i = 1; i < 4; i++) {
+		gsl_fit_linear((const double *) &error_average[0], 1,
+			       (const double *) &error_average[i], 1, 250,
+			       &c0, &c1, &cov00, &cov01, &cov11, &sumsq);
+
+		for (j = 0; j < 250; j++)
+			error_trend[j] = c0 + j * c1;
+
+		correlation = gsl_stats_correlation((const double *) &error_trend,
+						    1,
+						    (const double *) &error_average[i],
+						    1, 250);
+
+		if (correlation < 0.985) {
+			igt_warn("Error with reference not correlated (%f)\n",
+				 correlation);
+
+			match = false;
+			goto complete;
+		}
+	}
+
+complete:
+
+	pixman_image_unref(reference_bgr);
+	cairo_surface_destroy(fb_surface);
+
+	return match;
+}
+
+/**
  * chamelium_get_frame_limit:
  * @chamelium: The Chamelium instance to use
  * @port: The port to check the frame limit on
@@ -1482,7 +1713,7 @@ igt_constructor {
 	/* Frame dumps can be large, so we need to be able to handle very large
 	 * responses
 	 *
-	 * Limit here is 10MB
+	 * Limit here is 15MB
 	 */
-	xmlrpc_limit_set(XMLRPC_XML_SIZE_LIMIT_ID, 10485760);
+	xmlrpc_limit_set(XMLRPC_XML_SIZE_LIMIT_ID, 15728640);
 }
diff --git a/lib/igt_chamelium.h b/lib/igt_chamelium.h
index aa881971..df1ebd12 100644
--- a/lib/igt_chamelium.h
+++ b/lib/igt_chamelium.h
@@ -102,13 +102,17 @@ int chamelium_get_captured_frame_count(struct chamelium *chamelium);
 int chamelium_get_frame_limit(struct chamelium *chamelium,
 			      struct chamelium_port *port,
 			      int w, int h);
-
 void chamelium_assert_frame_eq(const struct chamelium *chamelium,
 			       const struct chamelium_frame_dump *dump,
 			       struct igt_fb *fb);
 void chamelium_write_frame_to_png(const struct chamelium *chamelium,
 				  const struct chamelium_frame_dump *dump,
 				  const char *filename);
+void chamelium_crop_analogue_frame(struct chamelium_frame_dump *dump, int width,
+				   int height);
+bool chamelium_check_analogue_frame_match(const struct chamelium *chamelium,
+					  const struct chamelium_frame_dump *dump,
+					  struct igt_fb *fb);
 void chamelium_destroy_frame_dump(struct chamelium_frame_dump *dump);
 
 #endif /* IGT_CHAMELIUM_H */
diff --git a/tests/chamelium.c b/tests/chamelium.c
index 3d95c05c..5ccdee7c 100644
--- a/tests/chamelium.c
+++ b/tests/chamelium.c
@@ -360,6 +360,10 @@ enable_output(data_t *data,
 					    BROADCAST_RGB_FULL);
 
 	igt_display_commit(display);
+
+	if (chamelium_port_get_type(port) == DRM_MODE_CONNECTOR_VGA)
+		usleep(250000);
+
 	chamelium_port_wait_video_input_stable(data->chamelium, port,
 					       HOTPLUG_TIMEOUT);
 
@@ -470,6 +474,81 @@ test_display_crc(data_t *data, struct chamelium_port *port, int count)
 }
 
 static void
+test_analogue_frame_dump(data_t *data, struct chamelium_port *port)
+{
+	igt_display_t display;
+	igt_output_t *output;
+	igt_plane_t *primary;
+	struct igt_fb fb;
+	struct chamelium_frame_dump *frame;
+	drmModeModeInfo *mode;
+	drmModeConnector *connector;
+	int fb_id, i;
+	const char *connector_name;
+	char *frame_dump_path;
+	char path[PATH_MAX];
+	bool eq;
+
+	output = prepare_output(data, &display, port);
+	connector = chamelium_port_get_connector(data->chamelium, port, false);
+	primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
+	igt_assert(primary);
+
+	connector_name = kmstest_connector_type_str(connector->connector_type);
+	frame_dump_path = chamelium_get_frame_dump_path(data->chamelium);
+
+	for (i = 0; i < connector->count_modes; i++) {
+		mode = &connector->modes[i];
+
+		fb_id = igt_create_color_pattern_fb(data->drm_fd,
+						    mode->hdisplay, mode->vdisplay,
+						    DRM_FORMAT_XRGB8888,
+						    LOCAL_DRM_FORMAT_MOD_NONE,
+						    0, 0, 0, &fb);
+		igt_assert(fb_id > 0);
+
+		enable_output(data, port, output, mode, &fb);
+
+		igt_debug("Reading frame dumps from Chamelium...\n");
+
+		frame = chamelium_port_dump_pixels(data->chamelium, port, 0, 0,
+						   0, 0);
+
+		chamelium_crop_analogue_frame(frame, mode->hdisplay,
+					      mode->vdisplay);
+
+		eq = chamelium_check_analogue_frame_match(data->chamelium,
+							  frame, &fb);
+		if (!eq && frame_dump_path) {
+			igt_debug("Dumping reference and chamelium frames to %s...\n",
+				  frame_dump_path);
+
+			snprintf(path, PATH_MAX, "%s/frame-reference-%s.png",
+				 frame_dump_path, connector_name);
+			igt_write_fb_to_png(data->drm_fd, &fb, path);
+
+			snprintf(path, PATH_MAX, "%s/frame-chamelium-%s.png",
+				 frame_dump_path, connector_name);
+			chamelium_write_frame_to_png(data->chamelium,
+							     frame, path);
+
+			chamelium_destroy_frame_dump(frame);
+		}
+
+		igt_fail_on_f(!eq,
+			      "Chamelium analogue frame mismatch with reference\n");
+
+		chamelium_destroy_frame_dump(frame);
+
+		disable_output(data, port, output);
+		igt_remove_fb(data->drm_fd, &fb);
+	}
+
+	drmModeFreeConnector(connector);
+	igt_display_fini(&display);
+}
+
+static void
 test_hpd_without_ddc(data_t *data, struct chamelium_port *port)
 {
 	struct udev_monitor *mon = igt_watch_hotplug();
@@ -706,6 +785,9 @@ igt_main
 
 		connector_subtest("vga-hpd-without-ddc", VGA)
 			test_hpd_without_ddc(&data, port);
+
+		connector_subtest("vga-frame-dump", VGA)
+			test_analogue_frame_dump(&data, port);
 	}
 
 	igt_subtest_group {
-- 
2.13.2



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