drivers: video: sw_isp: introduce a software-based ISP

This adds a driver that converts video frames submitted into a different
format, which supports bayer (RGGB8, BGGR8, GRBG8, GBRG8), RGB24,
RGB565, YUYV input format and can convert them to RGB24 RGB565, and YUYV.
Setting the video input and output formats will control the format
conversion done by this software device.

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

Author: josuah

drivers/video/CMakeLists.txt

@@ -7,6 +7,7 @@ zephyr_library_sources(video_common.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_MCUX_CSI	video_mcux_csi.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_MCUX_MIPI_CSI2RX video_mcux_mipi_csi2rx.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_SW_GENERATOR	video_sw_generator.c)
+zephyr_library_sources_ifdef(CONFIG_VIDEO_SW_ISP video_sw_isp.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_MT9M114	mt9m114.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_OV7725	ov7725.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_OV2640	ov2640.c)

drivers/video/Kconfig

@@ -58,6 +58,8 @@ source "drivers/video/Kconfig.mcux_mipi_csi2rx"
 
 source "drivers/video/Kconfig.sw_generator"
 
+source "drivers/video/Kconfig.sw_isp"
+
 source "drivers/video/Kconfig.mt9m114"
 
 source "drivers/video/Kconfig.ov7725"

drivers/video/Kconfig.sw_isp

@@ -0,0 +1,37 @@
+# Copyright (c) 2025 tinyVision.ai Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config VIDEO_SW_ISP
+	bool "Video Software Image Signal Processor (ISP)"
+	imply PIXEL
+	help
+	  Enable a software-based image processing pipeline, providing the essential components
+	  of an Image Signal Processsor (ISP) exposing the essential features of the "pixel"
+	  library as a native Video API.
+
+config VIDEO_SW_ISP_STACK_SIZE
+	int "Stack size for the thread executing the pipelne"
+	default 1024
+	help
+	  Stack size for the thread executing the pipeline. All of the processing elements are not
+	  allocated on the stack but use global variables instead. The default value is therefore
+	  planning only for the temporary variables.
+
+config VIDEO_SW_ISP_THREAD_PRIORITY
+	int "Stack size for the thread executing the pipelne"
+	default 5
+	help
+	  Priority for the thread executing the pipeline. The default value is an intermediate
+	  starting point to be tuned arbitrarily to fit the application.
+
+config VIDEO_SW_ISP_INPUT_WIDTH
+	int "Width of the input of the pipeline in pixels, used for buffer allocation purposees."
+	default 640
+	help
+	  The default value is VGA width, a widespread default resolution supported broadly.
+
+config VIDEO_SW_ISP_INPUT_HEIGHT
+	int "Height of the input of the pipeline in pixels, used for buffer allocation purposees."
+	default 480
+	help
+	  The default value is VGA height, a widespread default resolution supported broadly.