diff options
Diffstat (limited to 'src/dsp/warp.h')
| -rw-r--r-- | src/dsp/warp.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/dsp/warp.h b/src/dsp/warp.h index 7367a9b..9c20f12 100644 --- a/src/dsp/warp.h +++ b/src/dsp/warp.h @@ -38,9 +38,39 @@ namespace libgav1 { namespace dsp { +// Section 7.11.3.5. +struct WarpFilterParams { + int64_t x4; + int64_t y4; + int ix4; + int iy4; +}; + // Initializes Dsp::warp. This function is not thread-safe. void WarpInit_C(); +// Section 7.11.3.5. +inline WarpFilterParams GetWarpFilterParams(int src_x, int src_y, + int subsampling_x, + int subsampling_y, + const int* warp_params) { + WarpFilterParams filter_params; + // warp_params[2]/[5] require 17 bits (the others 14). With large resolutions + // the result of the multiplication will require 33. + const int64_t dst_x = static_cast<int64_t>(src_x) * warp_params[2] + + src_y * warp_params[3] + warp_params[0]; + const int64_t dst_y = src_x * warp_params[4] + + static_cast<int64_t>(src_y) * warp_params[5] + + warp_params[1]; + filter_params.x4 = dst_x >> subsampling_x; + filter_params.y4 = dst_y >> subsampling_y; + filter_params.ix4 = + static_cast<int>(filter_params.x4 >> kWarpedModelPrecisionBits); + filter_params.iy4 = + static_cast<int>(filter_params.y4 >> kWarpedModelPrecisionBits); + return filter_params; +} + } // namespace dsp } // namespace libgav1 |