Decode (corpus) vs Microsoft DirectXTex

Primary decode baseline: ambientCG proxy corpus (~1024^2), not synthetic X-grid.
Same DDS bytes for both peers (encoded by rusty_dds from corpus PNGs).
Roles: albedo / normal / mask. ratio < 1 => rusty_dds faster.
DirectXTex decode included

Summary

{
  "cases": 24,
  "vs_directxtex": {
    "ahead": 24,
    "behind": 0,
    "peer_ok_cases": 24
  }
}

Case	Content	Role	rusty_dds (ns)	DirectXTex (ns)	Ratio (rusty/dx)
Bricks097_Color__bc1	bc1	albedo	1013820	10071200	0.101
Bricks097_Color__bc7	bc7	albedo	2278395	19496200	0.117
Bricks097_NormalGL__bc5u	bc5u	normal	1071070	14582700	0.073
Bricks097_NormalGL__bc5s	bc5s	normal	1275190	14620800	0.087
Bricks097_Roughness__bc4u	bc4u	mask	887465	11738400	0.076
Bricks097_Roughness__bc4s	bc4s	mask	884600	12786400	0.069
Metal063_Color__bc1	bc1	albedo	1826735	21306300	0.086
Metal063_Color__bc7	bc7	albedo	10180710	36122900	0.282
Metal063_NormalGL__bc5u	bc5u	normal	3384275	23923300	0.141
Metal063_NormalGL__bc5s	bc5s	normal	2736780	19490600	0.140
Metal063_Roughness__bc4u	bc4u	mask	2027090	18916600	0.107
Metal063_Roughness__bc4s	bc4s	mask	3782770	19694200	0.192
Rock064_Color__bc1	bc1	albedo	2360695	20610600	0.115
Rock064_Color__bc7	bc7	albedo	7984340	53302200	0.150
Rock064_NormalGL__bc5u	bc5u	normal	2960400	28322400	0.105
Rock064_NormalGL__bc5s	bc5s	normal	4707135	29696800	0.159
Rock064_Roughness__bc4u	bc4u	mask	2960840	22514500	0.132
Rock064_Roughness__bc4s	bc4s	mask	3595255	24037900	0.150
Wood095_Color__bc1	bc1	albedo	1194975	9983600	0.120
Wood095_Color__bc7	bc7	albedo	8611040	23267400	0.370
Wood095_NormalGL__bc5u	bc5u	normal	1273780	16979100	0.075
Wood095_NormalGL__bc5s	bc5s	normal	1750775	14773200	0.119
Wood095_Roughness__bc4u	bc4u	mask	1144665	11915500	0.096
Wood095_Roughness__bc4s	bc4s	mask	1240700	14784200	0.084