diff --git a/Cargo.lock b/Cargo.lock
index 95b68a1..178c669 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -71,9 +71,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.49"
+version = "1.2.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90583009037521a116abf44494efecd645ba48b6622457080f080b85544e2215"
+checksum = "aebf35691d1bfb0ac386a69bac2fde4dd276fb618cf8bf4f5318fe285e821bb2"
 dependencies = [
  "find-msvc-tools",
  "shlex",
@@ -87,9 +87,9 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "cmake"
-version = "0.1.56"
+version = "0.1.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b042e5d8a74ae91bb0961acd039822472ec99f8ab0948cbf6d1369588f8be586"
+checksum = "75443c44cd6b379beb8c5b45d85d0773baf31cce901fe7bb252f4eff3008ef7d"
 dependencies = [
  "cc",
 ]
@@ -102,9 +102,9 @@ checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
 [[package]]
 name = "env_filter"
-version = "0.1.4"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1bf3c259d255ca70051b30e2e95b5446cdb8949ac4cd22c0d7fd634d89f568e2"
+checksum = "7a1c3cc8e57274ec99de65301228b537f1e4eedc1b8e0f9411c6caac8ae7308f"
 dependencies = [
  "log",
  "regex",
@@ -112,9 +112,9 @@ dependencies = [
 
 [[package]]
 name = "env_logger"
-version = "0.11.8"
+version = "0.11.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13c863f0904021b108aa8b2f55046443e6b1ebde8fd4a15c399893aae4fa069f"
+checksum = "b2daee4ea451f429a58296525ddf28b45a3b64f1acf6587e2067437bb11e218d"
 dependencies = [
  "anstream",
  "anstyle",
@@ -125,9 +125,9 @@ dependencies = [
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.5"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a3076410a55c90011c298b04d0cfa770b00fa04e1e3c97d3f6c9de105a03844"
+checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 
 [[package]]
 name = "is_terminal_polyfill"
@@ -137,9 +137,9 @@ checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
 
 [[package]]
 name = "jiff"
-version = "0.2.16"
+version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49cce2b81f2098e7e3efc35bc2e0a6b7abec9d34128283d7a26fa8f32a6dbb35"
+checksum = "1a3546dc96b6d42c5f24902af9e2538e82e39ad350b0c766eb3fbf2d8f3d8359"
 dependencies = [
  "jiff-static",
  "log",
@@ -150,9 +150,9 @@ dependencies = [
 
 [[package]]
 name = "jiff-static"
-version = "0.2.16"
+version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "980af8b43c3ad5d8d349ace167ec8170839f753a42d233ba19e08afe1850fa69"
+checksum = "2a8c8b344124222efd714b73bb41f8b5120b27a7cc1c75593a6ff768d9d05aa4"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -167,9 +167,9 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
-version = "0.2.178"
+version = "0.2.183"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37c93d8daa9d8a012fd8ab92f088405fb202ea0b6ab73ee2482ae66af4f42091"
+checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
 
 [[package]]
 name = "libloading"
@@ -198,9 +198,9 @@ dependencies = [
 
 [[package]]
 name = "memchr"
-version = "2.7.6"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "nu-ansi-term"
@@ -225,9 +225,9 @@ checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.16"
+version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b3cff922bd51709b605d9ead9aa71031d81447142d828eb4a6eba76fe619f9b"
+checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 
 [[package]]
 name = "pixelforge"
@@ -243,42 +243,42 @@ dependencies = [
 
 [[package]]
 name = "portable-atomic"
-version = "1.11.1"
+version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
+checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
 
 [[package]]
 name = "portable-atomic-util"
-version = "0.2.4"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8a2f0d8d040d7848a709caf78912debcc3f33ee4b3cac47d73d1e1069e83507"
+checksum = "7a9db96d7fa8782dd8c15ce32ffe8680bbd1e978a43bf51a34d39483540495f5"
 dependencies = [
  "portable-atomic",
 ]
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.103"
+version = "1.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.42"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a338cc41d27e6cc6dce6cefc13a0729dfbb81c262b1f519331575dd80ef3067f"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "regex"
-version = "1.12.2"
+version = "1.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
+checksum = "e10754a14b9137dd7b1e3e5b0493cc9171fdd105e0ab477f51b72e7f3ac0e276"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -288,9 +288,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
+checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -299,9 +299,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.8"
+version = "0.8.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
+checksum = "dc897dd8d9e8bd1ed8cdad82b5966c3e0ecae09fb1907d58efaa013543185d0a"
 
 [[package]]
 name = "roxmltree"
@@ -376,9 +376,9 @@ checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
 [[package]]
 name = "syn"
-version = "2.0.111"
+version = "2.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -416,9 +416,9 @@ dependencies = [
 
 [[package]]
 name = "tracing"
-version = "0.1.43"
+version = "0.1.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d15d90a0b5c19378952d479dc858407149d7bb45a14de0142f6c534b16fc647"
+checksum = "63e71662fa4b2a2c3a26f570f037eb95bb1f85397f3cd8076caed2f026a6d100"
 dependencies = [
  "pin-project-lite",
  "tracing-attributes",
@@ -438,9 +438,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-core"
-version = "0.1.35"
+version = "0.1.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a04e24fab5c89c6a36eb8558c9656f30d81de51dfa4d3b45f26b21d61fa0a6c"
+checksum = "db97caf9d906fbde555dd62fa95ddba9eecfd14cb388e4f491a66d74cd5fb79a"
 dependencies = [
  "once_cell",
  "valuable",
@@ -477,9 +477,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.22"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
 [[package]]
 name = "utf8parse"
diff --git a/src/converter/mod.rs b/src/converter/mod.rs
index b0d6b8f..53f4bd4 100644
--- a/src/converter/mod.rs
+++ b/src/converter/mod.rs
@@ -22,6 +22,10 @@ pub enum ColorSpace {
     Bt709,
     /// BT.2020 (HDR / wide color gamut).
     Bt2020,
+    /// sRGB input converted to BT.2020 + PQ output.
+    /// Used for SDR content during HDR streaming sessions.
+    /// Applies: inverse sRGB EOTF → BT.709→BT.2020 gamut mapping → PQ OETF.
+    SrgbToBt2020Pq,
 }
 
 /// Supported input pixel formats for color conversion.
@@ -42,8 +46,11 @@ pub enum InputFormat {
     /// RGBA16F (64-bit, 16-bit float per channel).
     /// Maps to DRM_FORMAT_ABGR16161616F / VK_FORMAT_R16G16B16A16_SFLOAT.
     ///
-    /// Expected input is linear-light scRGB where 1.0 = 80 nits.
-    /// The converter applies the PQ (ST 2084) transfer function internally.
+    /// The converter treats FP16 data the same as other formats: passthrough
+    /// for `ColorSpace::Bt709` / `Bt2020`, and sRGB→BT.2020+PQ conversion
+    /// for `ColorSpace::SrgbToBt2020Pq`. No linear→PQ transfer function is
+    /// applied automatically; if the source is PQ-encoded (e.g. via the
+    /// gamescope WSI layer), use `ColorSpace::Bt2020` for passthrough.
     RGBA16F,
 }
 
@@ -216,6 +223,14 @@ impl ColorConverter {
         self.output_buffer
     }
 
+    /// Set the color space for subsequent conversions.
+    ///
+    /// This takes effect on the next `convert()` call without recreating the pipeline,
+    /// since the color space is passed via push constants.
+    pub fn set_color_space(&mut self, color_space: ColorSpace) {
+        self.config.color_space = color_space;
+    }
+
     /// Build buffer-to-image copy regions for multi-planar YUV formats.
     ///
     /// For multi-planar formats like NV12, I420, and YUV444, we need separate.
@@ -874,6 +889,19 @@ mod tests {
         );
     }
 
+    // ========================
+    // ColorSpace tests.
+    // ========================
+
+    #[test]
+    fn test_color_space_enum_values() {
+        // Verify enum values match shader push constant expectations:
+        // 0=BT.709, 1=BT.2020, 2=sRGB→BT.2020+PQ.
+        assert_eq!(ColorSpace::Bt709 as u32, 0);
+        assert_eq!(ColorSpace::Bt2020 as u32, 1);
+        assert_eq!(ColorSpace::SrgbToBt2020Pq as u32, 2);
+    }
+
     // ========================
     // OutputFormat tests.
     // ========================
diff --git a/src/converter/shader.rs b/src/converter/shader.rs
index 0b9f3a4..2a7df19 100644
--- a/src/converter/shader.rs
+++ b/src/converter/shader.rs
@@ -40,7 +40,7 @@ layout(push_constant) uniform PushConstants {
     uint height;
     uint input_format;   // 0=BGRx, 1=RGBx, 2=BGRA, 3=RGBA, 4=ABGR2101010, 5=RGBA16F
     uint output_format;  // 0=NV12, 1=I420, 2=YUV444, 3=P010, 4=YUV444P10
-    uint color_space;    // 0=BT.709, 1=BT.2020
+    uint color_space;    // 0=BT.709, 1=BT.2020, 2=sRGB→BT.2020+PQ
     uint full_range;     // 0=limited/studio range, 1=full range
 } params;
 
@@ -89,19 +89,50 @@ vec3 linear_to_pq(vec3 L) {
     return N;
 }
 
+// Inverse sRGB EOTF: sRGB gamma-encoded [0,1] → linear light [0,1].
+// Uses the standard piecewise sRGB transfer function.
+vec3 srgb_to_linear(vec3 srgb) {
+    // Clamp to [0,1] to avoid NaN from pow() on negative/out-of-range FP16 inputs.
+    srgb = clamp(srgb, 0.0, 1.0);
+    // sRGB piecewise: linear below 0.04045, gamma above.
+    return mix(
+        pow((srgb + 0.055) / 1.055, vec3(2.4)),
+        srgb / 12.92,
+        lessThanEqual(srgb, vec3(0.04045))
+    );
+}
+
+// BT.709 to BT.2020 gamut mapping matrix (applied in linear light).
+// Derived from the BT.709 and BT.2020 primaries via the CIE XYZ intermediate.
+vec3 bt709_to_bt2020(vec3 rgb709) {
+    return vec3(
+        0.6274 * rgb709.r + 0.3293 * rgb709.g + 0.0433 * rgb709.b,
+        0.0691 * rgb709.r + 0.9195 * rgb709.g + 0.0114 * rgb709.b,
+        0.0164 * rgb709.r + 0.0880 * rgb709.g + 0.8956 * rgb709.b
+    );
+}
+
 // Read normalized RGB from source image via texelFetch.
-// Returns values in [0, 1] range for all formats.
-// For RGBA16F (HDR), applies PQ transfer function to map linear-light to [0, 1].
+// Returns values in [0, 1] range representing the final signal level for YUV conversion.
+//
+// The compositor (Smithay) does NOT perform color-managed compositing: it blits
+// client textures to the GBM output without applying any transfer function.
+// Therefore the GBM buffer preserves the source's encoding:
+//   - PQ surfaces → PQ-encoded values (even in FP16)
+//   - sRGB surfaces → sRGB gamma-encoded values (even in FP16)
+//
+// color_space 0 (BT.709) and 1 (BT.2020): passthrough — data is already encoded.
+// color_space 2 (sRGB→BT.2020+PQ): decode sRGB, convert gamut, apply PQ.
 vec3 read_rgb(ivec2 coord) {
     vec4 rgba = texelFetch(inputImage, coord, 0);
-    if (params.input_format == 5u) {
-        // RGBA16F: linear-light floats in scene-referred scRGB scale
-        // where 1.0 = 80 nits (the sRGB / scRGB reference white).
-        // PQ EOTF input must be absolute luminance normalized to [0, 1]
-        // where 1.0 = 10 000 nits, hence the factor 10000 / 80 = 125.
-        return linear_to_pq(rgba.rgb / 125.0);
+    if (params.color_space == 2u) {
+        // sRGB→BT.2020+PQ: decode sRGB gamma → linear BT.709 → BT.2020 gamut → PQ.
+        vec3 linear_709 = srgb_to_linear(rgba.rgb);
+        vec3 linear_2020 = bt709_to_bt2020(linear_709);
+        // SDR reference white at 203 nits (ITU-R BT.2408) → normalize to PQ's 10000 nit scale.
+        return linear_to_pq(linear_2020 * (203.0 / 10000.0));
     }
-    // UNORM formats (8-bit and 10-bit): texelFetch returns [0.0, 1.0].
+    // BT.709 or BT.2020 passthrough: values are already properly encoded.
     return rgba.rgb;
 }
 
@@ -109,8 +140,8 @@ vec3 read_rgb(ivec2 coord) {
 // Returns Y in [0, 1], U and V in [0, 1] centered at 0.5.
 vec3 rgb_to_yuv(vec3 rgb) {
     float yr, yg, yb, ur, ug, ub, vr, vg, vb;
-    if (params.color_space == 1u) {
-        // BT.2020
+    if (params.color_space >= 1u) {
+        // BT.2020 (also used for sRGB→BT.2020+PQ, since read_rgb already converted).
         yr = BT2020_Y_R; yg = BT2020_Y_G; yb = BT2020_Y_B;
         ur = BT2020_U_R; ug = BT2020_U_G; ub = BT2020_U_B;
         vr = BT2020_V_R; vg = BT2020_V_G; vb = BT2020_V_B;