On 7/5/2023 10:45 AM, Suraj Kandpal wrote:
Some rc_range_parameter calculations were missed for YCbCr420,
add them to calculate_rc_param()
--v2
-take into account the new formula to get bpp_i
--v4
-Fix range_bpg_offset formula for YCbCr420 bpp <= 16 [Ankit]
Cc: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx>
Cc: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
Cc: Uma Shankar <uma.shankar@xxxxxxxxx>
Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_vdsc.c | 144 ++++++++++++++++------
1 file changed, 106 insertions(+), 38 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index cfcd463f66bb..8f0dac908e61 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -52,23 +52,36 @@ static bool is_pipe_dsc(struct intel_crtc *crtc, enum transcoder cpu_transcoder)
return true;
}
+static void
+intel_vdsc_set_min_max_qp(struct drm_dsc_config *vdsc_cfg, int buf,
+ int bpp)
+{
+ int bpc = vdsc_cfg->bits_per_component;
+
+ /* Read range_minqp and range_max_qp from qp tables */
+ vdsc_cfg->rc_range_params[buf].range_min_qp =
+ intel_lookup_range_min_qp(bpc, buf, bpp, vdsc_cfg->native_420);
+ vdsc_cfg->rc_range_params[buf].range_max_qp =
+ intel_lookup_range_max_qp(bpc, buf, bpp, vdsc_cfg->native_420);
+}
+
+/*
+ * Calculate RC Params using the below two methods:
+ * 1. DSCParameterValuesVESA V1-2 spreadsheet
+ * 2. VESA DSC 1.2a DSC Tools Application.
+ * Note:
+ * Above two methods use a common formula to derive values for any combination of DSC
+ * variables. The formula approach may yield slight differences in the derived PPS
+ * parameters from the original parameter sets. These differences are not consequential
+ * to the coding performance because all parameter sets have been shown to produce
+ * visually lossless quality (provides the same PPS values as
+ * DSCParameterValuesVESA V1-2 spreadsheet)
+ */
As I understand we are using the values of rc parameters from the tables
given for DSC tools application from C-model for different
bits_per_pixel and bpcs.
It would be good to mention the C-model used for these values.
static void
calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
{
int bpc = vdsc_cfg->bits_per_component;
int bpp = vdsc_cfg->bits_per_pixel >> 4;
- static const s8 ofs_und6[] = {
- 0, -2, -2, -4, -6, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
- };
- static const s8 ofs_und8[] = {
- 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12
- };
- static const s8 ofs_und12[] = {
- 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12
- };
- static const s8 ofs_und15[] = {
- 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -10, -12, -12, -12
- };
int qp_bpc_modifier = (bpc - 8) * 2;
u32 res, buf_i, bpp_i;
@@ -119,33 +132,88 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
vdsc_cfg->rc_quant_incr_limit0 = 11 + qp_bpc_modifier;
vdsc_cfg->rc_quant_incr_limit1 = 11 + qp_bpc_modifier;
- bpp_i = (2 * (bpp - 6));
- for (buf_i = 0; buf_i < DSC_NUM_BUF_RANGES; buf_i++) {
- u8 range_bpg_offset;
-
- /* Read range_minqp and range_max_qp from qp tables */
- vdsc_cfg->rc_range_params[buf_i].range_min_qp =
- intel_lookup_range_min_qp(bpc, buf_i, bpp_i, vdsc_cfg->native_420);
- vdsc_cfg->rc_range_params[buf_i].range_max_qp =
- intel_lookup_range_max_qp(bpc, buf_i, bpp_i, vdsc_cfg->native_420);
-
- /* Calculate range_bpg_offset */
- if (bpp <= 6) {
- range_bpg_offset = ofs_und6[buf_i];
- } else if (bpp <= 8) {
- res = DIV_ROUND_UP(((bpp - 6) * (ofs_und8[buf_i] - ofs_und6[buf_i])), 2);
- range_bpg_offset = ofs_und6[buf_i] + res;
- } else if (bpp <= 12) {
- range_bpg_offset = ofs_und8[buf_i];
- } else if (bpp <= 15) {
- res = DIV_ROUND_UP(((bpp - 12) * (ofs_und15[buf_i] - ofs_und12[buf_i])), 3);
- range_bpg_offset = ofs_und12[buf_i] + res;
- } else {
- range_bpg_offset = ofs_und15[buf_i];
+ if (vdsc_cfg->native_420) {
+ static const s8 ofs_und4[] = {
+ 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
+ };
+ static const s8 ofs_und5[] = {
+ 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12
+ };
+ static const s8 ofs_und6[] = {
+ 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12
+ };
+ static const s8 ofs_und8[] = {
+ 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -10, -12, -12, -12
+ };
+
+ bpp_i = bpp - 8;
+ for (buf_i = 0; buf_i < DSC_NUM_BUF_RANGES; buf_i++) {
+ u8 range_bpg_offset;
+
+ intel_vdsc_set_min_max_qp(vdsc_cfg, buf_i, bpp_i);
+
+ /* Calculate range_bpg_offset */
+ if (bpp <= 8) {
+ range_bpg_offset = ofs_und4[buf_i];
+ } else if (bpp <= 10) {
+ res = DIV_ROUND_UP(((bpp - 8) *
+ (ofs_und5[buf_i] - ofs_und4[buf_i])), 2);
+ range_bpg_offset = ofs_und4[buf_i] + res;
We can have a macro for this, as essentially we are using linear
interpolation to get these values for a bpp from the table of nearby bpps.
But that perhaps would be a separate patch.
With the suggested changes in note, this is:
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
Regards,
Ankit
+ } else if (bpp <= 12) {
+ res = DIV_ROUND_UP(((bpp - 10) *
+ (ofs_und6[buf_i] - ofs_und5[buf_i])), 2);
+ range_bpg_offset = ofs_und5[buf_i] + res;
+ } else if (bpp <= 16) {
+ res = DIV_ROUND_UP(((bpp - 12) *
+ (ofs_und8[buf_i] - ofs_und6[buf_i])), 4);
+ range_bpg_offset = ofs_und6[buf_i] + res;
+ } else {
+ range_bpg_offset = ofs_und8[buf_i];
+ }
+
+ vdsc_cfg->rc_range_params[buf_i].range_bpg_offset =
+ range_bpg_offset & DSC_RANGE_BPG_OFFSET_MASK;
+ }
+ } else {
+ static const s8 ofs_und6[] = {
+ 0, -2, -2, -4, -6, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
+ };
+ static const s8 ofs_und8[] = {
+ 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12
+ };
+ static const s8 ofs_und12[] = {
+ 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12
+ };
+ static const s8 ofs_und15[] = {
+ 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -10, -12, -12, -12
+ };
+
+ bpp_i = (2 * (bpp - 6));
+ for (buf_i = 0; buf_i < DSC_NUM_BUF_RANGES; buf_i++) {
+ u8 range_bpg_offset;
+
+ intel_vdsc_set_min_max_qp(vdsc_cfg, buf_i, bpp_i);
+
+ /* Calculate range_bpg_offset */
+ if (bpp <= 6) {
+ range_bpg_offset = ofs_und6[buf_i];
+ } else if (bpp <= 8) {
+ res = DIV_ROUND_UP(((bpp - 6) *
+ (ofs_und8[buf_i] - ofs_und6[buf_i])), 2);
+ range_bpg_offset = ofs_und6[buf_i] + res;
+ } else if (bpp <= 12) {
+ range_bpg_offset = ofs_und8[buf_i];
+ } else if (bpp <= 15) {
+ res = DIV_ROUND_UP(((bpp - 12) *
+ (ofs_und15[buf_i] - ofs_und12[buf_i])), 3);
+ range_bpg_offset = ofs_und12[buf_i] + res;
+ } else {
+ range_bpg_offset = ofs_und15[buf_i];
+ }
+
+ vdsc_cfg->rc_range_params[buf_i].range_bpg_offset =
+ range_bpg_offset & DSC_RANGE_BPG_OFFSET_MASK;
}
-
- vdsc_cfg->rc_range_params[buf_i].range_bpg_offset =
- range_bpg_offset & DSC_RANGE_BPG_OFFSET_MASK;
}
}
