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Diffstat (limited to '')
-rw-r--r-- | third_party/aom/aom_dsp/recenter.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/third_party/aom/aom_dsp/recenter.h b/third_party/aom/aom_dsp/recenter.h new file mode 100644 index 0000000000..b3fd412907 --- /dev/null +++ b/third_party/aom/aom_dsp/recenter.h @@ -0,0 +1,61 @@ +/* + * Copyright (c) 2018, Alliance for Open Media. All rights reserved + * + * This source code is subject to the terms of the BSD 2 Clause License and + * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License + * was not distributed with this source code in the LICENSE file, you can + * obtain it at www.aomedia.org/license/software. If the Alliance for Open + * Media Patent License 1.0 was not distributed with this source code in the + * PATENTS file, you can obtain it at www.aomedia.org/license/patent. + */ + +#ifndef AOM_AOM_DSP_RECENTER_H_ +#define AOM_AOM_DSP_RECENTER_H_ + +#include "config/aom_config.h" + +#include "aom/aom_integer.h" + +// Inverse recenters a non-negative literal v around a reference r +static INLINE uint16_t inv_recenter_nonneg(uint16_t r, uint16_t v) { + if (v > (r << 1)) + return v; + else if ((v & 1) == 0) + return (v >> 1) + r; + else + return r - ((v + 1) >> 1); +} + +// Inverse recenters a non-negative literal v in [0, n-1] around a +// reference r also in [0, n-1] +static INLINE uint16_t inv_recenter_finite_nonneg(uint16_t n, uint16_t r, + uint16_t v) { + if ((r << 1) <= n) { + return inv_recenter_nonneg(r, v); + } else { + return n - 1 - inv_recenter_nonneg(n - 1 - r, v); + } +} + +// Recenters a non-negative literal v around a reference r +static INLINE uint16_t recenter_nonneg(uint16_t r, uint16_t v) { + if (v > (r << 1)) + return v; + else if (v >= r) + return ((v - r) << 1); + else + return ((r - v) << 1) - 1; +} + +// Recenters a non-negative literal v in [0, n-1] around a +// reference r also in [0, n-1] +static INLINE uint16_t recenter_finite_nonneg(uint16_t n, uint16_t r, + uint16_t v) { + if ((r << 1) <= n) { + return recenter_nonneg(r, v); + } else { + return recenter_nonneg(n - 1 - r, n - 1 - v); + } +} + +#endif // AOM_AOM_DSP_RECENTER_H_ |