Re: [PATCH v2] media: aspeed: Use full swing as JFIF to fix incorrect color

From: Paul Menzel
Date: Wed Feb 09 2022 - 04:49:45 EST


Dear Jammy,


Am 09.02.22 um 09:42 schrieb Jammy Huang:
Current settings for video capture rgb-2-yuv is BT.601(studio swing),
but JFIF uses BT.601(full swing) to deocde. This mismatch will lead
to incorrect color. For example, input RGB value, (0, 0, 255), will
become (16, 16, 235) after jpg decoded.

Add an enum, aspeed_video_capture_format, to define VR008[7:6]
capture format and correct default settings for video capture to fix
the problem.

Maybe quote the datasheet:

VR008[7:6] will decide the data format for video capture:
00: CCIR601 studio swing compliant YUV format
01: CCIR601 full swing compliant YUV format
10: RGB format
11: Gray color mode

Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx>
---
v2:
- update subject from 'media: aspeed: Fix-incorrect-color' to
'media: aspeed: Use full swing as JFIF to fix incorrect'
- update commit message
- add enum, aspeed_video_capture_format, to define VR008[7:6]
---
drivers/media/platform/aspeed-video.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index eb9c17ac0e14..5bcf60b4628b 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -86,8 +86,6 @@
#define VE_CTRL_SOURCE BIT(2)
#define VE_CTRL_INT_DE BIT(4)
#define VE_CTRL_DIRECT_FETCH BIT(5)
-#define VE_CTRL_YUV BIT(6)
-#define VE_CTRL_RGB BIT(7)
#define VE_CTRL_CAPTURE_FMT GENMASK(7, 6)
#define VE_CTRL_AUTO_OR_CURSOR BIT(8)
#define VE_CTRL_CLK_INVERSE BIT(11)
@@ -202,6 +200,15 @@ enum {
VIDEO_CLOCKS_ON,
};
+// for VE_CTRL_CAPTURE_FMT
+enum aspeed_video_capture_format {
+ VIDEO_CAP_FMT_YUV_STUDIO = 0,

Maybe also append `_SWING`?

+ VIDEO_CAP_FMT_YUV_FULL,
+ VIDEO_CAP_FMT_RGB,
+ VIDEO_CAP_FMT_GRAY,
+ VIDEO_CAP_FMT_MAX
+};
+
struct aspeed_video_addr {
unsigned int size;
dma_addr_t dma;
@@ -1089,7 +1096,8 @@ static void aspeed_video_init_regs(struct aspeed_video *video)
u32 comp_ctrl = VE_COMP_CTRL_RSVD |
FIELD_PREP(VE_COMP_CTRL_DCT_LUM, video->jpeg_quality) |
FIELD_PREP(VE_COMP_CTRL_DCT_CHR, video->jpeg_quality | 0x10);
- u32 ctrl = VE_CTRL_AUTO_OR_CURSOR;
+ u32 ctrl = VE_CTRL_AUTO_OR_CURSOR |
+ FIELD_PREP(VE_CTRL_CAPTURE_FMT, VIDEO_CAP_FMT_YUV_FULL);
u32 seq_ctrl = video->jpeg_mode;
if (video->frame_rate)

Reviewed-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>


Kind regards,

Paul