Re: [PATCH 2/3] gpu: ipu-v3: ipu-ic: Add support for BT.709 encoding

On Sun, Feb 3, 2019 at 11:48 AM Steve Longerbeam slongerbeam@gmail.com wrote:

Pass v4l2 encoding enum to the ipu_ic task init functions, and add support for the BT.709 encoding and inverse encoding matrices.

Reported-by: Tim Harvey tharvey@gateworks.com Signed-off-by: Steve Longerbeam slongerbeam@gmail.com

---

drivers/gpu/ipu-v3/ipu-ic.c | 67 ++++++++++++++++++--- drivers/gpu/ipu-v3/ipu-image-convert.c | 1 + drivers/staging/media/imx/imx-ic-prpencvf.c | 4 +- include/video/imx-ipu-v3.h | 5 +- 4 files changed, 67 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/ipu-v3/ipu-ic.c b/drivers/gpu/ipu-v3/ipu-ic.c index 35ae86ff0585..63362b4fff81 100644 --- a/drivers/gpu/ipu-v3/ipu-ic.c +++ b/drivers/gpu/ipu-v3/ipu-ic.c @@ -199,6 +199,23 @@ static const struct ic_csc_params ic_csc_rgb2ycbcr_bt601 = { .scale = 1, };

+/*

• • BT.709 encoding from RGB full range to YUV limited range:
• • Y = R * .2126 + G * .7152 + B * .0722;
• • U = R * -.1146 + G * -.3854 + B * .5000 + 128.;
• • V = R * .5000 + G * -.4542 + B * -.0458 + 128.;
• */

+static const struct ic_csc_params ic_csc_rgb2ycbcr_bt709 = {

•   .coeff = {
  

•           { 54, 183, 18 },
  

•           { 483, 413, 128 },
  

•           { 128, 396, 500 },
  

•   },
  

•   .offset = { 0, 512, 512 },
  

•   .scale = 1,
  

+};

/* transparent RGB->RGB matrix for graphics combining */ static const struct ic_csc_params ic_csc_rgb2rgb = { .coeff = { @@ -226,12 +243,31 @@ static const struct ic_csc_params ic_csc_ycbcr2rgb_bt601 = { .scale = 2, };

+/*

• • Inverse BT.709 encoding from YUV limited range to RGB full range:
• • R = (1. * (Y - 16)) + (1.5748 * (Cr - 128));
• • G = (1. * (Y - 16)) - (0.1873 * (Cb - 128)) - (0.4681 * (Cr - 128));
• • B = (1. * (Y - 16)) + (1.8556 * (Cb - 128);
• */

+static const struct ic_csc_params ic_csc_ycbcr2rgb_bt709 = {

•   .coeff = {
  

•           { 128, 0, 202 },
  

•           { 128, 488, 452 },
  

•           { 128, 238, 0 },
  

•   },
  

•   .offset = { -435, 136, -507 },
  

•   .scale = 2,
  

+};

static int init_csc(struct ipu_ic *ic, enum ipu_color_space inf, enum ipu_color_space outf,

•               enum v4l2_ycbcr_encoding encoding,
                int csc_index)
  

{ struct ipu_ic_priv *priv = ic->priv;

•   const struct ic_csc_params *params_rgb2yuv, *params_yuv2rgb;
    const struct ic_csc_params *params;
    u32 __iomem *base;
    const u16 (*c)[3];
  

@@ -241,10 +277,24 @@ static int init_csc(struct ipu_ic *ic, base = (u32 __iomem *) (priv->tpmem_base + ic->reg->tpmem_csc[csc_index]);

•   switch (encoding) {
  

•   case V4L2_YCBCR_ENC_601:
  

•           params_rgb2yuv =  &ic_csc_rgb2ycbcr_bt601;
  

•           params_yuv2rgb = &ic_csc_ycbcr2rgb_bt601;
  

•           break;
  

•   case V4L2_YCBCR_ENC_709:
  

•           params_rgb2yuv =  &ic_csc_rgb2ycbcr_bt709;
  

•           params_yuv2rgb = &ic_csc_ycbcr2rgb_bt709;
  

•           break;
  

•   default:
  

•           dev_err(priv->ipu->dev, "Unsupported YCbCr encoding\n");
  

•           return -EINVAL;
  

•   }
  

Steve,

This will fail for RGB to RGB with 'Unsupported YCbCr encoding. We need to account for the RGB->RGB case.

How about something like:

static int init_csc(struct ipu_ic *ic, enum ipu_color_space inf, enum ipu_color_space outf, + enum v4l2_ycbcr_encoding encoding, int csc_index) { struct ipu_ic_priv *priv = ic->priv; - const struct ic_csc_params *params; + const struct ic_csc_params *params = NULL; u32 __iomem *base; const u16 (*c)[3]; const u16 *a; @@ -241,13 +276,18 @@ static int init_csc(struct ipu_ic *ic, base = (u32 __iomem *) (priv->tpmem_base + ic->reg->tpmem_csc[csc_index]);

- if (inf == IPUV3_COLORSPACE_YUV && outf == IPUV3_COLORSPACE_RGB) - params = &ic_csc_ycbcr2rgb_bt601; - else if (inf == IPUV3_COLORSPACE_RGB && outf == IPUV3_COLORSPACE_YUV) - params = &ic_csc_rgb2ycbcr_bt601; + if (inf == IPUV3_COLORSPACE_YUV && outf == IPUV3_COLORSPACE_RGB) { + params = (encoding == V4L2_YCBCR_ENC_601) ? + &ic_csc_ycbcr2rgb_bt601 : &ic_csc_ycbcr2rgb_bt709; + } + else if (inf == IPUV3_COLORSPACE_RGB && outf == IPUV3_COLORSPACE_YUV) { + params = (encoding == V4L2_YCBCR_ENC_601) ? + &ic_csc_rgb2ycbcr_bt601 : &ic_csc_rgb2ycbcr_bt709; + } else if (inf == IPUV3_COLORSPACE_RGB && outf == IPUV3_COLORSPACE_RGB) params = &ic_csc_rgb2rgb; - else { + + if (!params) { dev_err(priv->ipu->dev, "Unsupported color space conversion\n"); return -EINVAL; }

Tim