GPUVideoDecoder.hpp

#pragma once
 
#include <Gfx/Graph/Node.hpp>
#include <Gfx/Graph/RenderList.hpp>
#include <Gfx/Graph/RenderState.hpp>
#include <Video/VideoInterface.hpp>
 
extern "C" {
#include <libavutil/pixdesc.h>
}
 
#define SCORE_GFX_VIDEO_UNIFORMS \
"layout(std140, binding = 0) uniform renderer_t {\n" \
"  mat4 clipSpaceCorrMatrix;\n" \
"  vec2 renderSize;\n" \
"} renderer;\n" \
"\n" \
"layout(std140, binding = 2) uniform material_t {\n" \
"  vec2 scale;\n" \
"  vec2 texSz;\n" \
"} mat;\n"
 
namespace score::gfx
{
// TODO the "model" nodes should have a first update step so that they
// can share data across all renderers during a tick
class VideoNode;
 
class GPUVideoDecoder
{
public:
  GPUVideoDecoder();
  virtual ~GPUVideoDecoder();
 
  [[nodiscard]] virtual std::pair<QShader, QShader> init(RenderList& r) = 0;
 
  virtual void exec(RenderList&, QRhiResourceUpdateBatch& res, AVFrame& frame) = 0;
 
  void release(RenderList&);
 
  static QRhiTextureSubresourceUploadDescription
  createTextureUpload(uint8_t* pixels, int w, int h, int bytesPerPixel, int stride);
 
  static QString vertexShader() noexcept;
 
  std::vector<Sampler> samplers;
};
 
struct EmptyDecoder : GPUVideoDecoder
{
  static const constexpr auto hashtag_no_filter = R"_(#version 450
    void main ()
    {
    }
  )_";
 
  explicit EmptyDecoder() { }
 
  std::pair<QShader, QShader> init(RenderList& r) override
  {
    return score::gfx::makeShaders(r.state, vertexShader(), hashtag_no_filter);
  }
 
  void exec(RenderList&, QRhiResourceUpdateBatch& res, AVFrame& frame) override { }
};
}