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| author | Devarsh Thakkar <devarsht@ti.com> | 2024-06-19 01:06:48 +0530 |
|---|---|---|
| committer | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2024-06-24 11:05:06 +0200 |
| commit | b5bad839c01e3a2a41056ac0bc07e7b1ea0ba412 (patch) | |
| tree | 4416f533b8e7c99251d52f8d3032d813fd5ccd58 /include/media | |
| parent | a1e2940458853d00c178c842c889e4ae3ef5eaec (diff) | |
| download | lwn-b5bad839c01e3a2a41056ac0bc07e7b1ea0ba412.tar.gz lwn-b5bad839c01e3a2a41056ac0bc07e7b1ea0ba412.zip | |
media: v4l2-jpeg: Export reference quantization and huffman tables
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>
Diffstat (limited to 'include/media')
| -rw-r--r-- | include/media/v4l2-jpeg.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/media/v4l2-jpeg.h b/include/media/v4l2-jpeg.h index 2dba843ce3bd..b65658a02e3c 100644 --- a/include/media/v4l2-jpeg.h +++ b/include/media/v4l2-jpeg.h @@ -14,6 +14,30 @@ #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 @@ -154,4 +178,12 @@ int v4l2_jpeg_parse_quantization_tables(void *buf, size_t len, u8 precision, 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 |