From e842972404fa3a4a3571e64864be1e311a0ba4c9 Mon Sep 17 00:00:00 2001 From: triple-groove Date: Sun, 22 Feb 2026 16:07:56 -0800 Subject: [PATCH 3/5] fix(dsc): correct RC parameter tables to match VESA DSC 1.1 standard The minqp444_8b, maxqp444_8b, and ofs_und8 tables in nvt_dsc_pps.c contain non-standard values for the 8bpc / 8.0 bpp operating point (column index 4). Ranges 9-14 have more constrained max_qp values than the VESA DSC 1.1 specification (Table E-5), and range 11 has an incorrect bpg_offset. These deviations prevent the DSC encoder from quantizing aggressively enough when the RC buffer approaches overflow on complex content, causing visible block/tile "rainbow static" artifacts on sinks that implement strict VESA-compliant DSC decompression. Corrected values (all at column index 4 = 8.0 bpp): minqp444_8b range 9: 4 -> 3 minqp444_8b range 13: 8 -> 7 minqp444_8b range 14: 12 -> 13 maxqp444_8b range 10: 10 -> 11 maxqp444_8b range 11: 11 -> 12 maxqp444_8b range 12: 11 -> 13 maxqp444_8b range 13: 12 -> 13 maxqp444_8b range 14: 13 -> 15 ofs_und8 range 11: -10 -> -12 Tested on RTX 5090 with Bigscreen Beyond VR headset (DSC 1.1, 8bpc, 8.0 bpp, RGB 4:4:4, 3840x1920@90Hz). Artifacts completely eliminated. Signed-off-by: triple-groove --- src/common/modeset/timing/nvt_dsc_pps.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/src/common/modeset/timing/nvt_dsc_pps.c b/src/common/modeset/timing/nvt_dsc_pps.c index ce6d6a795470..d100c57d9351 100644 --- a/src/common/modeset/timing/nvt_dsc_pps.c +++ b/src/common/modeset/timing/nvt_dsc_pps.c @@ -187,12 +187,12 @@ static const NvU8 minqp444_8b[15][37]={ ,{ 5, 5, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0} ,{ 5, 5, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0} ,{ 5, 5, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 0, 0, 0} - ,{ 6, 5, 5, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 1, 1, 1, 1, 1, 1, 0, 0, 0} + ,{ 6, 5, 5, 4, 3, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 1, 1, 1, 1, 1, 1, 0, 0, 0} // [9] col4: 4->3 (VESA DSC 1.1) ,{ 6, 6, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 0} ,{ 6, 6, 6, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 0} ,{ 6, 6, 6, 6, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 0} - ,{ 9, 9, 9, 9, 8, 8, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 3, 3, 3, 3, 2, 2, 1, 1, 1} - ,{14,14,13,13,12,12,12,12,11,11,10,10,10,10, 9, 9, 9, 8, 8, 8, 7, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 3, 3, 3, 3} + ,{ 9, 9, 9, 9, 7, 8, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 3, 3, 3, 3, 2, 2, 1, 1, 1} // [13] col4: 8->7 (VESA DSC 1.1) + ,{14,14,13,13,13,12,12,12,11,11,10,10,10,10, 9, 9, 9, 8, 8, 8, 7, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 3, 3, 3, 3} // [14] col4: 12->13 (VESA DSC 1.1) }; static const NvU8 maxqp444_8b[15][37]={ @@ -206,11 +206,11 @@ static const NvU8 maxqp444_8b[15][37]={ ,{10,10, 9, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 7, 6, 5, 5, 4, 4, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1} ,{11,11,10,10, 9, 9, 9, 9, 9, 9, 8, 8, 8, 7, 7, 6, 6, 5, 5, 5, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1} ,{12,11,11,10,10,10, 9, 9, 9, 9, 9, 9, 9, 8, 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1} - ,{12,12,11,11,10,10,10,10,10,10, 9, 9, 9, 8, 8, 7, 7, 6, 6, 6, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 1} - ,{12,12,12,11,11,11,10,10,10,10, 9, 9, 9, 9, 8, 8, 8, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 1} - ,{12,12,12,12,11,11,11,11,11,10,10, 9, 9, 9, 8, 8, 8, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 1} - ,{13,13,13,13,12,12,11,11,11,11,10,10,10,10, 9, 9, 8, 8, 8, 8, 7, 7, 6, 6, 6, 6, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2} - ,{15,15,14,14,13,13,13,13,12,12,11,11,11,11,10,10,10, 9, 9, 9, 8, 8, 8, 8, 7, 7, 6, 6, 6, 6, 5, 5, 5, 4, 4, 4, 4} + ,{12,12,11,11,11,10,10,10,10,10, 9, 9, 9, 8, 8, 7, 7, 6, 6, 6, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 1} // [10] col4: 10->11 (VESA DSC 1.1) + ,{12,12,12,11,12,11,10,10,10,10, 9, 9, 9, 9, 8, 8, 8, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 1} // [11] col4: 11->12 (VESA DSC 1.1) + ,{12,12,12,12,13,11,11,11,11,10,10, 9, 9, 9, 8, 8, 8, 7, 7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 1} // [12] col4: 11->13 (VESA DSC 1.1) + ,{13,13,13,13,13,12,11,11,11,11,10,10,10,10, 9, 9, 8, 8, 8, 8, 7, 7, 6, 6, 6, 6, 5, 5, 4, 4, 4, 4, 3, 3, 2, 2, 2} // [13] col4: 12->13 (VESA DSC 1.1) + ,{15,15,14,14,15,13,13,13,12,12,11,11,11,11,10,10,10, 9, 9, 9, 8, 8, 8, 8, 7, 7, 6, 6, 6, 6, 5, 5, 5, 4, 4, 4, 4} // [14] col4: 13->15 (VESA DSC 1.1) }; static const NvU8 minqp444_10b[15][49]={ @@ -934,7 +934,7 @@ DSC_PpsCalcRcParam //else { const NvU32 ofs_und6[] = { 0, -2, -2, -4, -6, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12 }; - const NvU32 ofs_und8[] = { 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12 }; + const NvU32 ofs_und8[] = { 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12 }; // [11]: -10->-12 (VESA DSC 1.1) const NvU32 ofs_und12[] = { 2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -10, -12, -12, -12 }; const NvU32 ofs_und15[] = { 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -10, -12, -12, -12 }; -- 2.53.0