drivers: video: common: Add utilities to seek frmival/caps structures

Introduce a video_get_format_index() utility to help finding a caps
entry out of a given format. Introduce several utilities to seek and
apply frame intervals.

Signed-off-by: Josuah Demangeon <me@josuah.net>

tests/drivers/video/api/CMakeLists.txt

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(integration)
+
+target_sources(app PRIVATE src/video_common.c)

tests/drivers/video/api/prj.conf

@@ -0,0 +1,5 @@
+CONFIG_ZTEST=y
+CONFIG_VIDEO=y
+CONFIG_VIDEO_BUFFER_POOL_SZ_MAX=16384
+CONFIG_VIDEO_BUFFER_POOL_NUM_MAX=1
+CONFIG_VIDEO_LOG_LEVEL_DBG=y

tests/drivers/video/api/src/video_common.c

@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2024 tinyVision.ai Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+#include <zephyr/drivers/video.h>
+
+enum {
+	RGB565,
+	YUYV_A,
+	YUYV_B,
+};
+
+static const struct video_format_cap fmts[] = {
+	[RGB565] = {.pixelformat = VIDEO_PIX_FMT_RGB565,
+		    .width_min  = 1280, .width_max  = 1280, .width_step  = 50,
+		    .height_min = 720,  .height_max = 720,  .height_step = 50},
+	[YUYV_A] = {.pixelformat = VIDEO_PIX_FMT_YUYV,
+		    .width_min  = 100,  .width_max  = 1000, .width_step  = 50,
+		    .height_min = 100,  .height_max = 1000, .height_step = 50},
+	[YUYV_B] = {.pixelformat = VIDEO_PIX_FMT_YUYV,
+		    .width_min  = 1920, .width_max  = 1920, .width_step  = 0,
+		    .height_min = 1080, .height_max = 1080, .height_step = 0},
+	{0},
+};
+
+ZTEST(video_common, test_video_format_caps_index)
+{
+	struct video_format fmt = {0};
+	size_t idx;
+	int ret;
+
+	fmt.pixelformat = VIDEO_PIX_FMT_YUYV;
+
+	fmt.width = 100;
+	fmt.height = 100;
+	fmt.pitch = 100 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_ok(ret, "expecting minimum value to match");
+	zassert_equal(idx, YUYV_A);
+
+	fmt.width = 1000;
+	fmt.height = 1000;
+	fmt.pitch = 1000 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_ok(ret, "expecting maximum value to match");
+	zassert_equal(idx, YUYV_A);
+
+	fmt.width = 1920;
+	fmt.height = 1080;
+	fmt.pitch = 1920 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_ok(ret, "expecting exact match to work");
+	zassert_equal(idx, YUYV_B);
+
+	fmt.width = 1001;
+	fmt.height = 1000;
+	fmt.pitch = 1001 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_not_ok(ret, "expecting 1 above maximum width to mismatch");
+
+	fmt.width = 1000;
+	fmt.height = 1001;
+	fmt.pitch = 1000 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_not_ok(ret, "expecting 1 above maximum height to mismatch");
+
+	fmt.width = 1280;
+	fmt.height = 720;
+	fmt.pitch = 1280 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_not_ok(ret);
+	zassert_not_ok(ret, "expecting wrong format to mismatch");
+
+	fmt.pixelformat = VIDEO_PIX_FMT_RGB565;
+
+	fmt.width = 1000;
+	fmt.height = 1000;
+	fmt.pitch = 1000 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_not_ok(ret, "expecting wrong format to mismatch");
+
+	fmt.width = 1280;
+	fmt.height = 720;
+	fmt.pitch = 1280 * 2;
+	ret = video_format_caps_index(fmts, &fmt, &idx);
+	zassert_ok(ret, "expecting exact match to work");
+	zassert_equal(idx, RGB565);
+}
+
+ZTEST(video_common, test_video_frmival_nsec)
+{
+	zassert_equal(
+		video_frmival_nsec(&(struct video_frmival){.numerator = 1, .denominator = 15}),
+		66666666);
+
+	zassert_equal(
+		video_frmival_nsec(&(struct video_frmival){.numerator = 1, .denominator = 30}),
+		33333333);
+
+	zassert_equal(
+		video_frmival_nsec(&(struct video_frmival){.numerator = 5, .denominator = 1}),
+		5000000000);
+
+	zassert_equal(
+		video_frmival_nsec(&(struct video_frmival){.numerator = 1, .denominator = 1750000}),
+		571);
+}
+
+ZTEST(video_common, test_video_closest_frmival_stepwise)
+{
+	struct video_frmival_stepwise stepwise;
+	struct video_frmival desired;
+	struct video_frmival expected;
+	struct video_frmival match;
+
+	stepwise.min.numerator = 1;
+	stepwise.min.denominator = 30;
+	stepwise.max.numerator = 30;
+	stepwise.max.denominator = 30;
+	stepwise.step.numerator = 1;
+	stepwise.step.denominator = 30;
+
+	desired.numerator = 1;
+	desired.denominator = 1;
+	video_closest_frmival_stepwise(&stepwise, &desired, &match);
+	zassert_equal(video_frmival_nsec(&match), video_frmival_nsec(&desired), "1 / 1");
+
+	desired.numerator = 3;
+	desired.denominator = 30;
+	video_closest_frmival_stepwise(&stepwise, &desired, &match);
+	zassert_equal(video_frmival_nsec(&match), video_frmival_nsec(&desired), "3 / 30");
+
+	desired.numerator = 7;
+	desired.denominator = 80;
+	expected.numerator = 3;
+	expected.denominator = 30;
+	video_closest_frmival_stepwise(&stepwise, &desired, &match);
+	zassert_equal(video_frmival_nsec(&match), video_frmival_nsec(&expected), "7 / 80");
+
+	desired.numerator = 1;
+	desired.denominator = 120;
+	video_closest_frmival_stepwise(&stepwise, &desired, &match);
+	zassert_equal(video_frmival_nsec(&match), video_frmival_nsec(&stepwise.min), "1 / 120");
+
+	desired.numerator = 100;
+	desired.denominator = 1;
+	video_closest_frmival_stepwise(&stepwise, &desired, &match);
+	zassert_equal(video_frmival_nsec(&match), video_frmival_nsec(&stepwise.max), "100 / 1");
+}
+
+ZTEST_SUITE(video_common, NULL, NULL, NULL, NULL, NULL);

tests/drivers/video/api/testcase.yaml

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+# Copyright (c) 2024 tinyVision.ai Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+tests:
+  drivers.video.api:
+    tags:
+      - drivers
+      - video
+    platform_allow: native_sim