score::gfx::YUV420Decoder Struct Reference

Decodes YUV420 videos. More...

Inheritance diagram for score::gfx::YUV420Decoder:

Detailed Description

Decodes YUV420 videos.

Method was taken from https://www.roxlu.com/2014/039/decoding-h264-and-yuv420p-playback

Public Member Functions
	YUV420Decoder (Video::ImageFormat &d)
std::pair< QShader, QShader >	init (RenderList &r) override
	Initialize a GPUVideoDecoder. More...
void	exec (RenderList &, QRhiResourceUpdateBatch &res, AVFrame &frame) override
	Decode and upload a video frame to the GPU.
void	setYPixels (QRhiResourceUpdateBatch &res, uint8_t *pixels, int stride) const noexcept
void	setUPixels (QRhiResourceUpdateBatch &res, uint8_t *pixels, int stride) const noexcept
void	setVPixels (QRhiResourceUpdateBatch &res, uint8_t *pixels, int stride) const noexcept
Public Member Functions inherited from score::gfx::GPUVideoDecoder
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

Static Public Attributes
static constexpr const auto	yuv420_filter

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. More...
static QString	vertexShader () noexcept

Member Function Documentation

init()

std::pair<QShader, QShader> score::gfx::YUV420Decoder::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

yuv420_filter

constexpr const auto score::gfx::YUV420Decoder::yuv420_filter

staticconstexpr

Initial value:

= R"_(#version 450
 
)_" SCORE_GFX_VIDEO_UNIFORMS R"_(
 
  layout(binding=3) uniform sampler2D y_tex;
  layout(binding=4) uniform sampler2D u_tex;
  layout(binding=5) uniform sampler2D v_tex;
 
  layout(location = 0) in vec2 v_texcoord;
  layout(location = 0) out vec4 fragColor;
 
  const vec3 R_cf = vec3(1.164383,  0.000000,  1.596027);
  const vec3 G_cf = vec3(1.164383, -0.391762, -0.812968);
  const vec3 B_cf = vec3(1.164383,  2.017232,  0.000000);
  const vec3 offset = vec3(-0.0625, -0.5, -0.5);
 
  void main ()
  {
    float y = texture(y_tex, v_texcoord).r;
    float u = texture(u_tex, v_texcoord).r;
    float v = texture(v_tex, v_texcoord).r;
    vec3 yuv = vec3(y,u,v);
    yuv += offset;
    fragColor = vec4(0.0, 0.0, 0.0, 1.0);
    fragColor.r = dot(yuv, R_cf);
    fragColor.g = dot(yuv, G_cf);
    fragColor.b = dot(yuv, B_cf);
  })_"

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

• YUV420.hpp