[libcamera-devel] [PATCH v4 0/3] qcam: NV family YUV format conversion by using OpenGL shader

[Laurent Pinchart]

Hi Show,

On Sat, Aug 22, 2020 at 12:15:59AM +0800, Show Liu wrote:
> Hi,
> 
> This is the version 4 patchset for qcam to accelerate the YUV format conversion
> by OpenGL shader. Most of the modifications are according to the comments
> and suggestions from V3. 
> And the big change is using the QOpenGLFramebufferObject with QOffscreenSurface
> instead of the QOpenGLWidget, the main reason that use dynamic_cast
> to get the viewfinder_ is really weird.
> In this version, OpenGL rendering enabled by --render=gles,
> and if any error occurs during OpenGL configuration, it will return to use QT rendering.
> But compared with the previous version, this version performance dropped a lot
> due to I using the toImage() function to get the image when rendering complete,
> it's really an inefficient operation. the framerate down to 16.x ~ 18.x fps(1280 x 800).
> I am still trying to improve this performance issue. Any suggestions are welcome.

Isn't it expected though if you render to an off-screen surface and then
convert it to a QImage ? What was the issue with rendering directly on
the screen with QOpenGLWidget ? Just the dynamic cast ?

> Show Liu (3):
>   qcam: add OpenGL shader code as QT resource
>   qcam: add OpenGL renderer
>   qcam: use the OpenGL renderer as NV family YUV format converter
> 
>  src/qcam/assets/shader/NV_2_planes_UV_f.glsl |  32 ++
>  src/qcam/assets/shader/NV_2_planes_VU_f.glsl |  32 ++
>  src/qcam/assets/shader/NV_3_planes_UV_f.glsl |  33 ++
>  src/qcam/assets/shader/NV_3_planes_VU_f.glsl |  33 ++
>  src/qcam/assets/shader/NV_vertex_shader.glsl |  16 +
>  src/qcam/assets/shader/shaders.qrc           |  10 +
>  src/qcam/main.cpp                            |   3 +
>  src/qcam/main_window.cpp                     |   2 +
>  src/qcam/main_window.h                       |   1 +
>  src/qcam/meson.build                         |   3 +
>  src/qcam/renderer.cpp                        | 346 +++++++++++++++++++
>  src/qcam/renderer.h                          |  81 +++++
>  src/qcam/viewfinder.cpp                      |  46 ++-
>  src/qcam/viewfinder.h                        |  10 +
>  14 files changed, 640 insertions(+), 8 deletions(-)
>  create mode 100644 src/qcam/assets/shader/NV_2_planes_UV_f.glsl
>  create mode 100644 src/qcam/assets/shader/NV_2_planes_VU_f.glsl
>  create mode 100644 src/qcam/assets/shader/NV_3_planes_UV_f.glsl
>  create mode 100644 src/qcam/assets/shader/NV_3_planes_VU_f.glsl
>  create mode 100644 src/qcam/assets/shader/NV_vertex_shader.glsl
>  create mode 100644 src/qcam/assets/shader/shaders.qrc
>  create mode 100644 src/qcam/renderer.cpp
>  create mode 100644 src/qcam/renderer.h

-- 
Regards,

Laurent Pinchart