score::gfx::Y210Decoder Struct Reference

Decodes Y210 packed 4:2:2 10-bit videos. More...

Inheritance diagram for score::gfx::Y210Decoder:

Detailed Description

Decodes Y210 packed 4:2:2 10-bit videos.

Packed as Y0 Cb Y1 Cr, each a 16-bit little-endian word with the 10 bits of data in the high end. 8 bytes per macropixel (2 pixels), so 4 * width bytes per row.

QRhi has no four-channel 16-bit UNORM format, so the samples are uploaded into an RG16 texture at {w, h}: 4 bytes per texel is exactly one luma plus one chroma sample, and texel x holds (Y of pixel x, Cb on even columns / Cr on odd columns). The shader takes the luma of its own texel and the two chroma samples of the macropixel it belongs to.

Public Member Functions
	Y210Decoder (Video::ImageFormat &d)
std::pair< QShader, QShader >	init (RenderList &r) override
	Initialize a GPUVideoDecoder.
void	exec (RenderList &, QRhiResourceUpdateBatch &res, AVFrame &frame) override
	Decode and upload a video frame to the GPU.
Public Member Functions inherited from score::gfx::GPUVideoDecoder
virtual void	release (RenderList &)
	This method will release all the created samplers and textures.

Public Attributes
Video::ImageFormat &	decoder
Public Attributes inherited from score::gfx::GPUVideoDecoder
std::vector< Sampler >	samplers
bool	hasFrame {}
bool	failed {}
bool	formatChanged {}

Static Public Attributes
static const constexpr auto	frag

Additional Inherited Members
Static Public Member Functions inherited from score::gfx::GPUVideoDecoder
static QRhiTextureSubresourceUploadDescription	createTextureUpload (uint8_t *pixels, int w, int h, int bytesPerPixel, int stride)
	Utility method to create a QRhiTextureSubresourceUploadDescription.
static QString	vertexShader (bool invertY=false) noexcept

Member Function Documentation

exec()

void score::gfx::Y210Decoder::exec ( RenderList &  , QRhiResourceUpdateBatch &  res, AVFrame &  frame  )

inlineoverridevirtual

Decode and upload a video frame to the GPU.

Implements score::gfx::GPUVideoDecoder.

init()

std::pair< QShader, QShader > score::gfx::Y210Decoder::init ( RenderList &  r )

inlineoverridevirtual

Initialize a GPUVideoDecoder.

This method must :

• Create samplers and textures for the video format.
• Create shaders that will render the data put into these textures.

It returns a {vertex, fragment} shader pair.

Implements score::gfx::GPUVideoDecoder.

Member Data Documentation

frag

const constexpr auto score::gfx::Y210Decoder::frag

staticconstexpr

Initial value:

= R"_(#version 450
 
)_" SCORE_GFX_VIDEO_UNIFORMS R"_(
 
layout(binding=3) uniform sampler2D u_tex;
 
layout(location = 0) in vec2 v_texcoord;
layout(location = 0) out vec4 fragColor;
 
%2
 
vec4 processTexture(vec4 tex) {
  vec4 processed = convert_to_rgb(tex);
  { %1 }
  return processed;
}
 
void main()
{
  int x = int(floor(v_texcoord.x * mat.texSz.x));
  int y = int(floor(v_texcoord.y * mat.texSz.y));
  int cx = (x / 2) * 2;
 
  const float s = )_" SCORE_GFX_MSB_ALIGNED_SCALE R"_(;
  float luma = texelFetch(u_tex, ivec2(x, y), 0).r * s;
  float cb = texelFetch(u_tex, ivec2(cx, y), 0).g * s;
  float cr = texelFetch(u_tex, ivec2(cx + 1, y), 0).g * s;
 
  fragColor = processTexture(vec4(luma, cb, cr, 1.));
})_"

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

• Y210.hpp