score::gfx::P010Encoder Struct Reference

GPU RGBA -> p010le encoder (semi-planar 4:2:0, 10-bit). More...

Inheritance diagram for score::gfx::P010Encoder:

Detailed Description

GPU RGBA -> p010le encoder (semi-planar 4:2:0, 10-bit).

Each 10-bit sample (0..1023) sits in the high 10 bits of its 16-bit word (low 6 bits zero), matching AV_PIX_FMT_P010LE / GStreamer P010_10LE. Two planes: Y full-res, interleaved UV half-res. Feed a >8-bit source texture (RGBA16F) for real 10-bit precision.

Two implementations selected at compile time (see YUV422P10Encoder for the full rationale and the qtbase commit reference):

• Qt >= 6.10: native R16 (Y) / RG16 (UV) targets; QRhi reads them back tightly. Bilinear sampling averages the 2x2 chroma block.
• Qt < 6.10: the GL backend reads 16-bit single/dual-channel textures back as 8-bit RGBA, so we pack the bytes into RGBA8 ourselves.

Both paths expose the same readback byte layout (Y = 2w bytes/row over h rows, UV = 2w bytes/row over h/2 rows, U then V interleaved per site), so consumers are agnostic. Requires width % 2 == 0.

Public Member Functions
void	setupPlane (QRhi &rhi, const RenderState &state, QRhiTexture *inputRGBA, QRhiTexture::Format fmt, int w, int h, const char *frag, const QString &colorConversion, QRhiTexture *&tex, QRhiTextureRenderTarget *&rt, QRhiRenderPassDescriptor *&rp, QRhiShaderResourceBindings *&srb, QRhiGraphicsPipeline *&pipeline)
void	init (QRhi &rhi, const RenderState &state, QRhiTexture *inputRGBA, int width, int height, const QString &colorConversion=colorMatrixOut()) override
void	exec (QRhi &rhi, QRhiCommandBuffer &cb) override
int	planeCount () const override
	Number of readback planes (1 for UYVY, 2 for NV12, 3 for I420).
const QRhiReadbackResult &	readback (int plane) const override
	Get the readback result for a given plane. Valid after endOffscreenFrame.
void	release () override
	Release all GPU resources.
Public Member Functions inherited from score::gfx::GPUVideoEncoder
virtual QRhiTexture *	outputTexture () const noexcept
virtual void	setReadbackEnabled (bool) noexcept

Public Attributes
QRhiTexture *	m_yTexture {}
QRhiTextureRenderTarget *	m_yRT {}
QRhiRenderPassDescriptor *	m_yRP {}
QRhiShaderResourceBindings *	m_ySRB {}
QRhiGraphicsPipeline *	m_yPipeline {}
QRhiReadbackResult	m_yReadback {}
QRhiTexture *	m_uvTexture {}
QRhiTextureRenderTarget *	m_uvRT {}
QRhiRenderPassDescriptor *	m_uvRP {}
QRhiShaderResourceBindings *	m_uvSRB {}
QRhiGraphicsPipeline *	m_uvPipeline {}
QRhiReadbackResult	m_uvReadback {}
QRhiSampler *	m_sampler {}
int	m_width {}
int	m_height {}

Static Public Attributes
static constexpr const char *	pack_fn
static constexpr const char *	y_frag
static constexpr const char *	uv_frag
Static Public Attributes inherited from score::gfx::GPUVideoEncoder
static constexpr const char *	vertex_shader
static constexpr const char *	rgb_to_yuv_glsl
static constexpr const char *	y_flip_glsl
	Fragment shader Y-flip: on GL, flip v_texcoord.y. On Metal/HLSL, no flip.

Member Function Documentation

exec()

void score::gfx::P010Encoder::exec ( QRhi &  rhi, QRhiCommandBuffer &  cb  )

inlineoverridevirtual

Execute the conversion pass. Call inside beginOffscreenFrame/endOffscreenFrame. Renders the conversion shader and schedules GPU->CPU readback(s).

Implements score::gfx::GPUVideoEncoder.

init()

void score::gfx::P010Encoder::init ( QRhi &  rhi, const RenderState &  state, QRhiTexture *  inputRGBA, int  width, int  height, const QString &  colorConversion = colorMatrixOut()  )

inlineoverridevirtual

Create render targets, textures, samplers, and the graphics pipeline.

Parameters

rhi	The QRhi instance.
state	The render state (for shader compilation).
inputRGBA	The scene RGBA texture to read from.
width	Source width in pixels.
height	Source height in pixels.
colorConversion	GLSL code from colorMatrixOut() defining convert_from_rgb(). If empty, defaults to BT.709 full range.

Implements score::gfx::GPUVideoEncoder.

planeCount()

int score::gfx::P010Encoder::planeCount ( ) const

inlineoverridevirtual

Number of readback planes (1 for UYVY, 2 for NV12, 3 for I420).

Implements score::gfx::GPUVideoEncoder.

readback()

const QRhiReadbackResult & score::gfx::P010Encoder::readback ( int  plane ) const

inlineoverridevirtual

Get the readback result for a given plane. Valid after endOffscreenFrame.

Implements score::gfx::GPUVideoEncoder.

release()

void score::gfx::P010Encoder::release ( )

inlineoverridevirtual

Release all GPU resources.

Implements score::gfx::GPUVideoEncoder.

Member Data Documentation

pack_fn

constexpr const char* score::gfx::P010Encoder::pack_fn

staticconstexpr

Initial value:

= R"_(
    // 10-bit value -> high 10 bits of a 16-bit UNORM word (low 6 bits zero).
    float pack10hi(float v) {
      return round(clamp(v, 0.0, 1.0) * 1023.0) * 64.0 / 65535.0;
    }
  )_"

uv_frag

constexpr const char* score::gfx::P010Encoder::uv_frag

staticconstexpr

Initial value:

= R"_(#version 450
    layout(location = 0) in vec2 v_texcoord;
    layout(location = 0) out vec4 fragColor;
    layout(binding = 3) uniform sampler2D src_tex;
    )_" "%1" R"_(
    )_" "%2" R"_(
    vec2 flip_y(vec2 tc) {
    // Only OpenGL. The rest of the engine puts its geometry through
    // renderer.clipSpaceCorrMatrix, which negates Y on Vulkan; this pass draws
    // a hardcoded triangle in raw NDC and does not, so the correction it needs
    // is not the same one. Flipping on Vulkan as well handed libav, GStreamer,
    // NDI and every other consumer an upside-down picture.
      return tc;
      return vec2(tc.x, 1.0 - tc.y);
    }
    void main() {
      vec3 rgb = texture(src_tex, flip_y(v_texcoord)).rgb;
      vec3 yuv = convert_from_rgb(rgb);
      fragColor = vec4(pack10hi(yuv.y), pack10hi(yuv.z), 0.0, 1.0);
    }
  )_"

y_frag

constexpr const char* score::gfx::P010Encoder::y_frag

staticconstexpr

Initial value:

= R"_(#version 450
    layout(location = 0) in vec2 v_texcoord;
    layout(location = 0) out vec4 fragColor;
    layout(binding = 3) uniform sampler2D src_tex;
    )_" "%1" R"_(
    )_" "%2" R"_(
    vec2 flip_y(vec2 tc) {
    // Only OpenGL. The rest of the engine puts its geometry through
    // renderer.clipSpaceCorrMatrix, which negates Y on Vulkan; this pass draws
    // a hardcoded triangle in raw NDC and does not, so the correction it needs
    // is not the same one. Flipping on Vulkan as well handed libav, GStreamer,
    // NDI and every other consumer an upside-down picture.
      return tc;
      return vec2(tc.x, 1.0 - tc.y);
    }
    void main() {
      vec3 rgb = texture(src_tex, flip_y(v_texcoord)).rgb;
      vec3 yuv = convert_from_rgb(rgb);
      fragColor = vec4(pack10hi(yuv.x), 0.0, 0.0, 1.0);
    }
  )_"

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The documentation for this struct was generated from the following file:

• encoders/P010.hpp