On Mon, Jan 1, 2024 at 10:50 PM Lynne <d...@lynne.ee> wrote: > Jan 1, 2024, 15:16 by nuomi2...@gmail.com: > > > + */ > > +void ff_vvc_inv_dct2_4(int *coeffs, const ptrdiff_t stride, const > size_t nz) > > +{ > > + const int a = 64, b = 83, c = 36; > > + const int x0 = coeffs[0 * stride], x1 = coeffs[1 * stride]; > > + const int x2 = coeffs[2 * stride], x3 = coeffs[3 * stride]; > > + const int E[2] = { > > + a * (x0 + G2(+x2)), > > + a * (x0 + G2(-x2)), > > + }; > > + const int O[2] = { > > + b * x1 + G2(+c * x3), > > + c * x1 + G2(-b * x3), > > + }; > > + > > + coeffs[0 * stride] = E[0] + O[0]; > > + coeffs[1 * stride] = E[1] + O[1]; > > + coeffs[2 * stride] = E[1] - O[1]; > > + coeffs[3 * stride] = E[0] - O[0]; > > +} > > > > Is that how the transforms are specified (matrices)? > Yes, a, b, c are matrix coeffs.
> Also, why are you not adding the transformed residual *directly* to the > input. > This is how all our other decoders do this, because it skips a copy. This > isn't > something you can quite optimize later on. > It is possible, but it's a bit more complicated than other codecs. For chroma, we need to perform lmcs_scale_chroma before adding it to the residual. Let's track it with https://github.com/ffvvc/FFmpeg/issues/177, and fix it later. > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".