mirror of
https://github.com/torvalds/linux.git
synced 2024-09-20 06:53:04 +00:00
b5bad839c0
Export reference quantization and huffman tables as provided in ITU-T.81 so that they can be re-used by other JPEG drivers. These are example tables provided in ITU-T.81 as reference tables and the JPEG encoders are free to use either these or their own proprietary tables. Also add necessary prefixes to be used for huffman tables in global header file. Signed-off-by: Devarsh Thakkar <devarsht@ti.com> Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Sebastian Fricke <sebastian.fricke@collabora.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
190 lines
6.4 KiB
C
190 lines
6.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* V4L2 JPEG helpers header
|
|
*
|
|
* Copyright (C) 2019 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
|
|
*
|
|
* For reference, see JPEG ITU-T.81 (ISO/IEC 10918-1)
|
|
*/
|
|
|
|
#ifndef _V4L2_JPEG_H
|
|
#define _V4L2_JPEG_H
|
|
|
|
#include <linux/v4l2-controls.h>
|
|
|
|
#define V4L2_JPEG_MAX_COMPONENTS 4
|
|
#define V4L2_JPEG_MAX_TABLES 4
|
|
/*
|
|
* Prefixes used to generate huffman table class and destination identifiers as
|
|
* described below:
|
|
*
|
|
* V4L2_JPEG_LUM_HT | V4L2_JPEG_DC_HT : Prefix for Luma DC coefficients
|
|
* huffman table
|
|
* V4L2_JPEG_LUM_HT | V4L2_JPEG_AC_HT : Prefix for Luma AC coefficients
|
|
* huffman table
|
|
* V4L2_JPEG_CHR_HT | V4L2_JPEG_DC_HT : Prefix for Chroma DC coefficients
|
|
* huffman table
|
|
* V4L2_JPEG_CHR_HT | V4L2_JPEG_AC_HT : Prefix for Chroma AC coefficients
|
|
* huffman table
|
|
*/
|
|
#define V4L2_JPEG_LUM_HT 0x00
|
|
#define V4L2_JPEG_CHR_HT 0x01
|
|
#define V4L2_JPEG_DC_HT 0x00
|
|
#define V4L2_JPEG_AC_HT 0x10
|
|
|
|
/* Length of reference huffman tables as provided in Table K.3 of ITU-T.81 */
|
|
#define V4L2_JPEG_REF_HT_AC_LEN 178
|
|
#define V4L2_JPEG_REF_HT_DC_LEN 28
|
|
|
|
/* Array size for 8x8 block of samples or DCT coefficient */
|
|
#define V4L2_JPEG_PIXELS_IN_BLOCK 64
|
|
|
|
/**
|
|
* struct v4l2_jpeg_reference - reference into the JPEG buffer
|
|
* @start: pointer to the start of the referenced segment or table
|
|
* @length: size of the referenced segment or table
|
|
*
|
|
* Wnen referencing marker segments, start points right after the marker code,
|
|
* and length is the size of the segment parameters, excluding the marker code.
|
|
*/
|
|
struct v4l2_jpeg_reference {
|
|
u8 *start;
|
|
size_t length;
|
|
};
|
|
|
|
/* B.2.2 Frame header syntax */
|
|
|
|
/**
|
|
* struct v4l2_jpeg_frame_component_spec - frame component-specification
|
|
* @component_identifier: C[i]
|
|
* @horizontal_sampling_factor: H[i]
|
|
* @vertical_sampling_factor: V[i]
|
|
* @quantization_table_selector: quantization table destination selector Tq[i]
|
|
*/
|
|
struct v4l2_jpeg_frame_component_spec {
|
|
u8 component_identifier;
|
|
u8 horizontal_sampling_factor;
|
|
u8 vertical_sampling_factor;
|
|
u8 quantization_table_selector;
|
|
};
|
|
|
|
/**
|
|
* struct v4l2_jpeg_frame_header - JPEG frame header
|
|
* @height: Y
|
|
* @width: X
|
|
* @precision: P
|
|
* @num_components: Nf
|
|
* @component: component-specification, see v4l2_jpeg_frame_component_spec
|
|
* @subsampling: decoded subsampling from component-specification
|
|
*/
|
|
struct v4l2_jpeg_frame_header {
|
|
u16 height;
|
|
u16 width;
|
|
u8 precision;
|
|
u8 num_components;
|
|
struct v4l2_jpeg_frame_component_spec component[V4L2_JPEG_MAX_COMPONENTS];
|
|
enum v4l2_jpeg_chroma_subsampling subsampling;
|
|
};
|
|
|
|
/* B.2.3 Scan header syntax */
|
|
|
|
/**
|
|
* struct v4l2_jpeg_scan_component_spec - scan component-specification
|
|
* @component_selector: Cs[j]
|
|
* @dc_entropy_coding_table_selector: Td[j]
|
|
* @ac_entropy_coding_table_selector: Ta[j]
|
|
*/
|
|
struct v4l2_jpeg_scan_component_spec {
|
|
u8 component_selector;
|
|
u8 dc_entropy_coding_table_selector;
|
|
u8 ac_entropy_coding_table_selector;
|
|
};
|
|
|
|
/**
|
|
* struct v4l2_jpeg_scan_header - JPEG scan header
|
|
* @num_components: Ns
|
|
* @component: component-specification, see v4l2_jpeg_scan_component_spec
|
|
*/
|
|
struct v4l2_jpeg_scan_header {
|
|
u8 num_components; /* Ns */
|
|
struct v4l2_jpeg_scan_component_spec component[V4L2_JPEG_MAX_COMPONENTS];
|
|
/* Ss, Se, Ah, and Al are not used by any driver */
|
|
};
|
|
|
|
/**
|
|
* enum v4l2_jpeg_app14_tf - APP14 transform flag
|
|
* According to Rec. ITU-T T.872 (06/2012) 6.5.3
|
|
* APP14 segment is for color encoding, it contains a transform flag,
|
|
* which may have values of 0, 1 and 2 and are interpreted as follows:
|
|
* @V4L2_JPEG_APP14_TF_CMYK_RGB: CMYK for images encoded with four components
|
|
* RGB for images encoded with three components
|
|
* @V4L2_JPEG_APP14_TF_YCBCR: an image encoded with three components using YCbCr
|
|
* @V4L2_JPEG_APP14_TF_YCCK: an image encoded with four components using YCCK
|
|
* @V4L2_JPEG_APP14_TF_UNKNOWN: indicate app14 is not present
|
|
*/
|
|
enum v4l2_jpeg_app14_tf {
|
|
V4L2_JPEG_APP14_TF_CMYK_RGB = 0,
|
|
V4L2_JPEG_APP14_TF_YCBCR = 1,
|
|
V4L2_JPEG_APP14_TF_YCCK = 2,
|
|
V4L2_JPEG_APP14_TF_UNKNOWN = -1,
|
|
};
|
|
|
|
/**
|
|
* struct v4l2_jpeg_header - parsed JPEG header
|
|
* @sof: pointer to frame header and size
|
|
* @sos: pointer to scan header and size
|
|
* @num_dht: number of entries in @dht
|
|
* @dht: pointers to huffman tables and sizes
|
|
* @num_dqt: number of entries in @dqt
|
|
* @dqt: pointers to quantization tables and sizes
|
|
* @frame: parsed frame header
|
|
* @scan: pointer to parsed scan header, optional
|
|
* @quantization_tables: references to four quantization tables, optional
|
|
* @huffman_tables: references to four Huffman tables in DC0, DC1, AC0, AC1
|
|
* order, optional
|
|
* @restart_interval: number of MCU per restart interval, Ri
|
|
* @ecs_offset: buffer offset in bytes to the entropy coded segment
|
|
* @app14_tf: transform flag from app14 data
|
|
*
|
|
* When this structure is passed to v4l2_jpeg_parse_header, the optional scan,
|
|
* quantization_tables, and huffman_tables pointers must be initialized to NULL
|
|
* or point at valid memory.
|
|
*/
|
|
struct v4l2_jpeg_header {
|
|
struct v4l2_jpeg_reference sof;
|
|
struct v4l2_jpeg_reference sos;
|
|
unsigned int num_dht;
|
|
struct v4l2_jpeg_reference dht[V4L2_JPEG_MAX_TABLES];
|
|
unsigned int num_dqt;
|
|
struct v4l2_jpeg_reference dqt[V4L2_JPEG_MAX_TABLES];
|
|
|
|
struct v4l2_jpeg_frame_header frame;
|
|
struct v4l2_jpeg_scan_header *scan;
|
|
struct v4l2_jpeg_reference *quantization_tables;
|
|
struct v4l2_jpeg_reference *huffman_tables;
|
|
u16 restart_interval;
|
|
size_t ecs_offset;
|
|
enum v4l2_jpeg_app14_tf app14_tf;
|
|
};
|
|
|
|
int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out);
|
|
|
|
int v4l2_jpeg_parse_frame_header(void *buf, size_t len,
|
|
struct v4l2_jpeg_frame_header *frame_header);
|
|
int v4l2_jpeg_parse_scan_header(void *buf, size_t len,
|
|
struct v4l2_jpeg_scan_header *scan_header);
|
|
int v4l2_jpeg_parse_quantization_tables(void *buf, size_t len, u8 precision,
|
|
struct v4l2_jpeg_reference *q_tables);
|
|
int v4l2_jpeg_parse_huffman_tables(void *buf, size_t len,
|
|
struct v4l2_jpeg_reference *huffman_tables);
|
|
|
|
extern const u8 v4l2_jpeg_zigzag_scan_index[V4L2_JPEG_PIXELS_IN_BLOCK];
|
|
extern const u8 v4l2_jpeg_ref_table_luma_qt[V4L2_JPEG_PIXELS_IN_BLOCK];
|
|
extern const u8 v4l2_jpeg_ref_table_chroma_qt[V4L2_JPEG_PIXELS_IN_BLOCK];
|
|
extern const u8 v4l2_jpeg_ref_table_luma_dc_ht[V4L2_JPEG_REF_HT_DC_LEN];
|
|
extern const u8 v4l2_jpeg_ref_table_luma_ac_ht[V4L2_JPEG_REF_HT_AC_LEN];
|
|
extern const u8 v4l2_jpeg_ref_table_chroma_dc_ht[V4L2_JPEG_REF_HT_DC_LEN];
|
|
extern const u8 v4l2_jpeg_ref_table_chroma_ac_ht[V4L2_JPEG_REF_HT_AC_LEN];
|
|
|
|
#endif
|