i.MX ProcessorsのトピックRe: YUV to RGB conversion

YUV to RGB conversion

richard_rojfors — Thu, 19 Jan 2017 13:57:10 GMT

Hi,

I would like to know which colorspace that are assumed by the different GPU's when using YUV textures on the imx6q.

I have tried to find this in the TRM and has found:

GPU2D support both BT.601 and B709 buffers.

But what about the GPU3D, when using YUV textures via the vivante extensions, which conversion is used to RGB?

Thanks in advance

Re: YUV to RGB conversion

richard_rojfors — Thu, 19 Jan 2017 15:11:03 GMT

Btw I also hit an issue when I try to set the conversion mode used by G2D. I do this in weston, in which I have implemented support for shm-buffers YUV-encoded.

I try to use gco2D_SetYUVColorMode, but it returns -13:

gcvSTATUS_NOT_SUPPORTED = -13,

Re: YUV to RGB conversion

Bio_TICFSL — Thu, 19 Jan 2017 17:32:12 GMT

Hi Richar,

Please check sect.2.4.1 Color space conversion from YUV to RGB in your i.MX_6_Graphics_User's_Guide.pdf and sect.7.3.15 Video conversion Linux Guide of the Linux user bsp guide:

https://community.nxp.com/servlet/JiveServlet/download/833793-1-393243/i.MX_6_Graphics_User's_Guide.pdf

https://community.nxp.com/servlet/JiveServlet/download/833793-1-393244/i.MX_Linux_User's_Guide.pdf

Regards

Re: YUV to RGB conversion

richard_rojfors — Fri, 20 Jan 2017 08:39:15 GMT

Hi,

This is not an answer to my question.

I'm already doing colorspace conversion using G2D and GPU3D, but I'm asking which conversion methods that are used and how to change them. At least for G2D its possible to change according to the TRM.

GPU2D:

I'm asking how to use the BT.709 or BT.601 converstion method. Which is used by default and how to change to the other? According to the TRM 31.4.1.3:

GPU supports BT.601 and BT.709 YUV to RGB color conversion standards.

In the documents you provided I see no reference to where you change conversion mode in those documents. They only show YUV->RGB conversion. To change mode I tried gco2D_SetYUVColorMode but it returns -13.

How do I change conversion mode?

GPU3D:

Which conversion method is used from YUV to RGB by GPU3D when mapping up texures as for instance GL_VIV_UYVY?