ra8_jpeg_sw adapter for the generic camera codec facade. More...

#include "ra8_camera_codec_jpeg_sw.h"
#include <stddef.h>
#include <stdint.h>
#include "ra8_attributes.h"
#include "ra8_camera_internal.h"
#include "ra8_err.h"
#include "ra8_jpeg_sw.h"

Include dependency graph for ra8_camera_codec_jpeg_sw.c:

Enumerations
enum	camera_jpeg_color_t : int32_t { k_camera_jpeg_luma_black = 16 , k_camera_jpeg_chroma_mid = 128 , k_camera_jpeg_luma_scale = 298 , k_camera_jpeg_red_cr = 409 , k_camera_jpeg_green_cb = 100 , k_camera_jpeg_green_cr = 208 , k_camera_jpeg_blue_cb = 516 , k_camera_jpeg_rounding = 128 , k_camera_jpeg_shift = 8 , k_camera_jpeg_u8_max = 255 }
	BT.601 limited-range fixed-point conversion constants. More...

Functions
static uint8_t	internal_jpeg_sw_clamp (int32_t component)
	Clamp a signed RGB component to one byte.
static void	internal_jpeg_sw_ycbcr_to_rgb (uint8_t y, uint8_t cb, uint8_t cr, uint8_t *output)
	Convert one limited-range YCbCr pixel to packed RGB888.
static void	internal_jpeg_sw_read_rgb (const ra8_camera_frame_t input, uint32_t x, uint32_t y, uint8_t output)
	Read one source pixel as RGB888.
static void	internal_jpeg_sw_prepare_rgb (const ra8_camera_codec_jpeg_sw_state_t state, const ra8_camera_frame_t input)
	Nearest-neighbour sample input into the configured RGB workspace.
static ra8_err_t	internal_jpeg_sw_encode (void ctx, const ra8_camera_frame_t input, const ra8_camera_buffer_t output_buffer, ra8_camera_frame_t out_frame)
	Convert and encode one raw frame with ra8_jpeg_sw.
ra8_err_t	ra8_camera_codec_jpeg_sw_init (ra8_camera_codec_t codec, ra8_camera_codec_jpeg_sw_state_t state, const ra8_camera_codec_jpeg_sw_cfg_t *cfg)
	Bind the software baseline-JPEG encoder backend.

Variables
static const ra8_camera_codec_iface_t	s_jpeg_sw_codec_iface
	Software JPEG codec vtable.

Detailed Description

ra8_jpeg_sw adapter for the generic camera codec facade.

Tag: [Ring 4 / Service] {World: NS}

Samples RGB888 or UYVY422 into the configured packed-RGB workspace, delegates baseline-JPEG encoding, and translates the produced byte count into a generic JPEG frame view.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file ra8_camera_codec_jpeg_sw.c.

Enumeration Type Documentation

◆ camera_jpeg_color_t

enum camera_jpeg_color_t : int32_t

BT.601 limited-range fixed-point conversion constants.

Enumerator
k_camera_jpeg_luma_black	Limited-range black level.
k_camera_jpeg_chroma_mid	Neutral chroma level.
k_camera_jpeg_luma_scale	Fixed-point luma scale.
k_camera_jpeg_red_cr	Cr contribution to red.
k_camera_jpeg_green_cb	Cb subtraction from green.
k_camera_jpeg_green_cr	Cr subtraction from green.
k_camera_jpeg_blue_cb	Cb contribution to blue.
k_camera_jpeg_rounding	Fixed-point rounding bias.
k_camera_jpeg_shift	Fixed-point fractional-bit count.
k_camera_jpeg_u8_max	Maximum packed RGB channel value.

Definition at line 29 of file ra8_camera_codec_jpeg_sw.c.

Function Documentation

◆ internal_jpeg_sw_clamp()

uint8_t internal_jpeg_sw_clamp ( int32_t component )

static

Clamp a signed RGB component to one byte.

Saturates a fixed-point conversion result into packed RGB range.

Parameters

[in] component Signed channel value.

Returns: Clamped channel byte.

Return values

0	Component was below the packed range.
255	Component was above the packed range.

Precondition: component is a completed fixed-point channel calculation.; No global state is required.

Postcondition: The result is in the inclusive range 0..255.; No state is modified.

Note: Thread-safe and deterministic.

Since: 0.1.0

Definition at line 57 of file ra8_camera_codec_jpeg_sw.c.

References k_camera_jpeg_u8_max, and RA8_INTERNAL.

Referenced by internal_jpeg_sw_ycbcr_to_rgb().

◆ internal_jpeg_sw_encode()

ra8_err_t internal_jpeg_sw_encode	(	void *	ctx,
		const ra8_camera_frame_t *	input,
		const ra8_camera_buffer_t *	output_buffer,
		ra8_camera_frame_t *	out_frame )

static

Convert and encode one raw frame with ra8_jpeg_sw.

Converts or samples the input into caller-owned RGB workspace, then writes a baseline JPEG into the per-call output buffer.

Parameters

[in]	ctx	Bound software-JPEG state.
[in]	input	Valid RGB888 or UYVY422 frame.
[in]	output_buffer	Caller-owned JPEG destination.
[out]	out_frame	Receives the encoded JPEG view.

Returns: ra8_err_t Error code.

Return values

k_ra8_ok	JPEG encoded.
k_ra8_err_null_ptr	Required state, frame, or buffer pointer is NULL.
k_ra8_err_not_supported	Input format is not raw RGB888 or UYVY422.
other	Forwarded from ra8_jpeg_sw_encode.

Precondition: Input passes generic frame validation.; Workspace and output buffer do not overlap readable input storage.

Postcondition: On success out_frame->data == output_buffer->data.; On success the returned dimensions match configured output geometry.

Note: Not thread-safe with respect to state workspace or output buffer.

Since: 0.1.0

Definition at line 193 of file ra8_camera_codec_jpeg_sw.c.

References ra8_camera_buffer_t::capacity, ra8_camera_codec_jpeg_sw_state_t::cfg, ra8_camera_buffer_t::data, ra8_camera_frame_t::format, internal_jpeg_sw_prepare_rgb(), k_ra8_camera_format_jpeg, k_ra8_camera_format_rgb888, k_ra8_camera_format_uyvy422, k_ra8_err_not_supported, k_ra8_err_null_ptr, k_ra8_ok, ra8_camera_codec_jpeg_sw_cfg_t::output_height, ra8_camera_codec_jpeg_sw_cfg_t::output_width, ra8_camera_codec_jpeg_sw_cfg_t::quality, RA8_INTERNAL, ra8_jpeg_sw_encode(), and ra8_camera_codec_jpeg_sw_cfg_t::rgb_workspace.

◆ internal_jpeg_sw_prepare_rgb()

void internal_jpeg_sw_prepare_rgb	(	const ra8_camera_codec_jpeg_sw_state_t *	state,
		const ra8_camera_frame_t *	input )

static

Nearest-neighbour sample input into the configured RGB workspace.

Maps each configured output coordinate into the source frame and materializes a tightly packed RGB image for the JPEG encoder.

Parameters

[in]	state	Backend state holding output geometry and workspace.
[in]	input	Valid RGB888 or UYVY422 input frame.

Precondition: State configuration passed backend initialization.; Input storage remains readable throughout conversion.

Postcondition: The complete configured RGB workspace prefix is initialized.; Input storage and backend configuration are unchanged.

Note: Not thread-safe with respect to the shared workspace.

Since: 0.1.0

Definition at line 155 of file ra8_camera_codec_jpeg_sw.c.

References ra8_camera_codec_jpeg_sw_state_t::cfg, ra8_camera_frame_t::height, internal_jpeg_sw_read_rgb(), ra8_camera_codec_jpeg_sw_cfg_t::output_height, ra8_camera_codec_jpeg_sw_cfg_t::output_width, RA8_INTERNAL, ra8_camera_codec_jpeg_sw_cfg_t::rgb_workspace, and ra8_camera_frame_t::width.

Referenced by internal_jpeg_sw_encode().

◆ internal_jpeg_sw_read_rgb()

void internal_jpeg_sw_read_rgb	(	const ra8_camera_frame_t *	input,
		uint32_t	x,
		uint32_t	y,
		uint8_t *	output )

static

Read one source pixel as RGB888.

Copies RGB input directly or decodes the selected pixel from its shared UYVY chroma pair.

Parameters

[in]	input	Valid RGB888 or UYVY422 frame.
[in]	x	Source column.
[in]	y	Source row.
[out]	output	Receives packed red, green, and blue bytes.

Precondition: x < input->width and y < input->height.; output addresses at least three writable bytes.

Postcondition: Exactly three output bytes are written.; Input bytes are unchanged.

Note: Thread-safe with respect to immutable input storage.

Since: 0.1.0

Definition at line 123 of file ra8_camera_codec_jpeg_sw.c.

References ra8_camera_frame_t::data, ra8_camera_frame_t::format, internal_jpeg_sw_ycbcr_to_rgb(), k_ra8_camera_format_rgb888, and ra8_camera_frame_t::stride_bytes.

Referenced by internal_jpeg_sw_prepare_rgb().

◆ internal_jpeg_sw_ycbcr_to_rgb()

void internal_jpeg_sw_ycbcr_to_rgb	(	uint8_t	y,
		uint8_t	cb,
		uint8_t	cr,
		uint8_t *	output )

static

Convert one limited-range YCbCr pixel to packed RGB888.

Applies the integer BT.601 limited-range transform and saturation.

Parameters

[in]	y	Luma sample.
[in]	cb	Blue-difference chroma sample.
[in]	cr	Red-difference chroma sample.
[out]	output	Receives packed red, green, and blue bytes.

Precondition: output addresses at least three writable bytes.; Input samples are complete unsigned bytes.

Postcondition: Exactly three output bytes are written.; Every output channel is in the inclusive range 0..255.

Note: Thread-safe; uses no mutable shared state.

Since: 0.1.0

Definition at line 84 of file ra8_camera_codec_jpeg_sw.c.

References internal_jpeg_sw_clamp(), k_camera_jpeg_blue_cb, k_camera_jpeg_chroma_mid, k_camera_jpeg_green_cb, k_camera_jpeg_green_cr, k_camera_jpeg_luma_black, k_camera_jpeg_luma_scale, k_camera_jpeg_red_cr, k_camera_jpeg_rounding, and k_camera_jpeg_shift.

Referenced by internal_jpeg_sw_read_rgb().

◆ ra8_camera_codec_jpeg_sw_init()

ra8_err_t ra8_camera_codec_jpeg_sw_init	(	ra8_camera_codec_t *	codec,
		ra8_camera_codec_jpeg_sw_state_t *	state,
		const ra8_camera_codec_jpeg_sw_cfg_t *	cfg )

nodiscard

Bind the software baseline-JPEG encoder backend.

Parameters

[out]	codec	Caller-owned codec handle to bind.
[out]	state	Caller-owned backend state to populate.
[in]	cfg	Output geometry, quality, and RGB workspace.

Returns: ra8_err_t Error code.

Return values

k_ra8_ok	Codec bound.
k_ra8_err_null_ptr	An argument or cfg->rgb_workspace was NULL.
k_ra8_err_invalid_arg	Quality or output geometry was invalid.
k_ra8_err_invalid_size	RGB workspace was too small.

Precondition: codec and state out-live every codec operation.; No other call mutates them while encoding.

Postcondition: On success RGB888 and UYVY422 inputs can be encoded as JPEG.; On error codec and state are unchanged.

Note: Independent state objects are thread-safe; ra8_jpeg_sw_encode is re-entrant.

Since: 0.1.0

Definition at line 250 of file ra8_camera_codec_jpeg_sw.c.

References ra8_camera_codec_jpeg_sw_state_t::cfg, ra8_camera_codec_t::ctx, ra8_camera_codec_t::iface, k_ra8_err_invalid_arg, k_ra8_err_invalid_size, k_ra8_err_null_ptr, k_ra8_jpeg_sw_quality_max, k_ra8_jpeg_sw_quality_min, k_ra8_ok, ra8_camera_codec_jpeg_sw_cfg_t::output_height, ra8_camera_codec_jpeg_sw_cfg_t::output_width, ra8_camera_codec_jpeg_sw_cfg_t::quality, ra8_camera_codec_jpeg_sw_cfg_t::rgb_workspace, ra8_camera_codec_jpeg_sw_cfg_t::rgb_workspace_capacity, and s_jpeg_sw_codec_iface.

Referenced by c6_cam_camera_init().

Variable Documentation

◆ s_jpeg_sw_codec_iface

const ra8_camera_codec_iface_t s_jpeg_sw_codec_iface

static

Initial value:

                                                            = {
  .encode = internal_jpeg_sw_encode,
}

Software JPEG codec vtable.

Definition at line 246 of file ra8_camera_codec_jpeg_sw.c.

Referenced by ra8_camera_codec_jpeg_sw_init().

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ camera_jpeg_color_t

Function Documentation

◆ internal_jpeg_sw_clamp()

◆ internal_jpeg_sw_encode()

◆ internal_jpeg_sw_prepare_rgb()

◆ internal_jpeg_sw_read_rgb()

◆ internal_jpeg_sw_ycbcr_to_rgb()

◆ ra8_camera_codec_jpeg_sw_init()

Variable Documentation

◆ s_jpeg_sw_codec_iface