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Subject[PATCH RFT 4/7] media: hantro: jpeg: Add JFIF APP0 segment to JPEG encoder output
Date
While the V4L2_PIX_FMT_JPEG format doesn't specify any requirements for
the APP0 or APP1 segments, it would be nice if the output is JFIF
compliant. While some programs can read JPEG streams that aren't, some
guess work is involved.

Add the standard JFIF APP0 segment to the JPEG header, so that the JPEG
encoder output is JFIF compliant.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
drivers/staging/media/hantro/hantro_jpeg.c | 21 +++++++++++++--------
drivers/staging/media/hantro/hantro_jpeg.h | 2 +-
2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/media/hantro/hantro_jpeg.c b/drivers/staging/media/hantro/hantro_jpeg.c
index df62fbdff7c9..7d4018bd6876 100644
--- a/drivers/staging/media/hantro/hantro_jpeg.c
+++ b/drivers/staging/media/hantro/hantro_jpeg.c
@@ -12,15 +12,15 @@
#include "hantro_jpeg.h"
#include "hantro.h"

-#define LUMA_QUANT_OFF 7
-#define CHROMA_QUANT_OFF 72
-#define HEIGHT_OFF 141
-#define WIDTH_OFF 143
+#define LUMA_QUANT_OFF 25
+#define CHROMA_QUANT_OFF 90
+#define HEIGHT_OFF 159
+#define WIDTH_OFF 161

-#define HUFF_LUMA_DC_OFF 160
-#define HUFF_LUMA_AC_OFF 193
-#define HUFF_CHROMA_DC_OFF 376
-#define HUFF_CHROMA_AC_OFF 409
+#define HUFF_LUMA_DC_OFF 178
+#define HUFF_LUMA_AC_OFF 211
+#define HUFF_CHROMA_DC_OFF 394
+#define HUFF_CHROMA_AC_OFF 427

/* Default tables from JPEG ITU-T.81
* (ISO/IEC 10918-1) Annex K, tables K.1 and K.2
@@ -144,6 +144,11 @@ static const unsigned char hantro_jpeg_header[JPEG_HEADER_SIZE] = {
/* SOI */
0xff, 0xd8,

+ /* JFIF-APP0 */
+ 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46,
+ 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x00, 0x01,
+ 0x00, 0x00,
+
/* DQT */
0xff, 0xdb, 0x00, 0x84,

diff --git a/drivers/staging/media/hantro/hantro_jpeg.h b/drivers/staging/media/hantro/hantro_jpeg.h
index 035ab25b803f..f33c492134e4 100644
--- a/drivers/staging/media/hantro/hantro_jpeg.h
+++ b/drivers/staging/media/hantro/hantro_jpeg.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0+ */

-#define JPEG_HEADER_SIZE 601
+#define JPEG_HEADER_SIZE 619
#define JPEG_QUANT_SIZE 64

struct hantro_jpeg_ctx {
--
2.34.1.448.ga2b2bfdf31-goog
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