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VPAC LDC mesh_img

lawrence

Prodigy 100 points

I want to use VPAC LDC function to rectify the pictures. I can sue openvx api tivxVpacLdcNode by supply the para mesh_img. Can you tell me what is the content in the mesh_img and how to generate it if the tivx_vapc_ldc_mesh_params_t.subsample_factor = 2 ?

over 5 years ago

0 Gang Hua over 5 years ago

TI__Guru 52385 points

Hi Lawrence,

TDA4 TRM on ti.com has no details about VPAC yet (still under development).

The mesh table of TDA4 LDC is the same as that of TDA3 LDC.
For mesh generation, you may refer to this post: https://e2e.ti.com/support/processors/f/791/p/662696/2435557?tisearch=e2e-sitesearch&keymatch=LDC (TDA3 TRM: http://www.ti.com/lit/ug/spruie7d/spruie7d.pdf ).

Once you get the text file according to the post link above, the mesh LUT in H/W memory (i.e., openvx mesh image) must follow the H/W format:

– One 32-bit word for each entry (little endian)

• 16 LSBs: vertical offset

• 16 MSBs: horizontal offset

– Mesh LUT row alignment: 16-Byte alignment (add 0 padding as needed)

Best,

Gang