This is the GitHub repo for ld-decode-GPU. This adds modifications to the ld-chroma-decoder part of the project to add GPU support of decoding analogue video.
Currently very much a work in progress.
UPDATE:
Should have done this eariler. Both decoders work on the GPU. I have not tried it with audio but there is no reason why it should not work. The PAL decoder is about 30%ish faster than its CPU counterpart, but the NTSC GPU decoder is about 16% slower on my system. Though, I think it should be fairly straightforward for the GPU and CPU to work together. Note that this only supports the 2D decoder. Having the 3D decoders on the GPU will need a lot of work.