X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=ycbcr.cpp;h=8c4f7801d33c2efb1ad6c43dac73f3d5d87a30d0;hp=eaa2ee8c3bb277903bef8ab7a8a33f6c137aecf1;hb=425d68dcbdd681ad3157000360521e8f36eb6c4c;hpb=25162b5457057af3ebcc1649571eeeb923e90098 diff --git a/ycbcr.cpp b/ycbcr.cpp index eaa2ee8..8c4f780 100644 --- a/ycbcr.cpp +++ b/ycbcr.cpp @@ -59,7 +59,7 @@ float compute_chroma_offset(float pos, unsigned subsampling_factor, unsigned res // Given , compute the values needed to turn Y'CbCr into R'G'B'; // first subtract the returned offset, then left-multiply the returned matrix // (the scaling is already folded into it). -void compute_ycbcr_matrix(YCbCrFormat ycbcr_format, float* offset, Matrix3d* ycbcr_to_rgb) +void compute_ycbcr_matrix(YCbCrFormat ycbcr_format, float* offset, Matrix3d* ycbcr_to_rgb, GLenum type, double *scale_factor) { double coeff[3], scale[3]; @@ -89,7 +89,11 @@ void compute_ycbcr_matrix(YCbCrFormat ycbcr_format, float* offset, Matrix3d* ycb assert(false); } - const int num_levels = ycbcr_format.num_levels; + int num_levels = ycbcr_format.num_levels; + if (num_levels == 0) { + // For the benefit of clients using old APIs, but still zeroing out the structure. + num_levels = 256; + } if (ycbcr_format.full_range) { offset[0] = 0.0 / (num_levels - 1); offset[1] = double(num_levels / 2) / (num_levels - 1); // E.g. 128/255. @@ -132,6 +136,24 @@ void compute_ycbcr_matrix(YCbCrFormat ycbcr_format, float* offset, Matrix3d* ycb // Fold in the scaling. *ycbcr_to_rgb *= Map(scale).asDiagonal(); + + if (type == GL_UNSIGNED_SHORT) { + // For 10-bit or 12-bit packed into 16-bit, we need to scale the values + // so that the max value goes from 1023 (or 4095) to 65535. We do this + // by folding the scaling into the conversion matrix, so it comes essentially + // for free. However, the offset is before the scaling (and thus assumes + // correctly scaled values), so we need to adjust that the other way. + double scale = 65535.0 / (ycbcr_format.num_levels - 1); + offset[0] /= scale; + offset[1] /= scale; + offset[2] /= scale; + *ycbcr_to_rgb *= scale; + if (scale_factor != NULL) { + *scale_factor = scale; + } + } else if (scale_factor != NULL) { + *scale_factor = 1.0; + } } } // namespace movit