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author | Bin Jin <bjin1990@gmail.com> | 2015-12-05 17:32:36 +0000 |
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committer | wm4 <wm4@nowhere> | 2015-12-07 23:48:12 +0100 |
commit | 18fe6e6dc8784348cf4f55b3a07c191a0ed8943d (patch) | |
tree | ac41f8b0e90c48174dfd95523d33f133b9b2858f /video/out | |
parent | aaa64b879e3e54ece97e9babdd7e13127974a449 (diff) | |
download | mpv-18fe6e6dc8784348cf4f55b3a07c191a0ed8943d.tar.bz2 mpv-18fe6e6dc8784348cf4f55b3a07c191a0ed8943d.tar.xz |
filter_kernels: add warnings for potential LUT sampling error
Diffstat (limited to 'video/out')
-rw-r--r-- | video/out/filter_kernels.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/video/out/filter_kernels.c b/video/out/filter_kernels.c index b826da5b45..d39e5ba4c5 100644 --- a/video/out/filter_kernels.c +++ b/video/out/filter_kernels.c @@ -139,6 +139,12 @@ static void mp_compute_weights(struct filter_kernel *filter, // Fill the given array with weights for the range [0.0, 1.0]. The array is // interpreted as rectangular array of count * filter->size items. +// +// There will be slight sampling error if these weights are used in a OpenGL +// texture as LUT directly. The sampling point of a texel is located at its +// center, so out_array[0] will end up at 0.5 / count instead of 0.0. +// Correct lookup requires a linear coordinate mapping from [0.0, 1.0] to +// [0.5 / count, 1.0 - 0.5 / count]. void mp_compute_lut(struct filter_kernel *filter, int count, float *out_array) { struct filter_window *window = &filter->w; |