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-rw-r--r-- | third_party/aom/aom_dsp/prob.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/third_party/aom/aom_dsp/prob.h b/third_party/aom/aom_dsp/prob.h new file mode 100644 index 0000000000..5711a40a40 --- /dev/null +++ b/third_party/aom/aom_dsp/prob.h @@ -0,0 +1,144 @@ +/* + * Copyright (c) 2016, 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_PROB_H_ +#define AOM_AOM_DSP_PROB_H_ + +#include <assert.h> +#include <stdio.h> + +#include "config/aom_config.h" + +#include "aom_dsp/aom_dsp_common.h" +#include "aom_dsp/entcode.h" +#include "aom_ports/bitops.h" +#include "aom_ports/mem.h" + +#ifdef __cplusplus +extern "C" { +#endif + +typedef uint16_t aom_cdf_prob; + +#define CDF_SIZE(x) ((x) + 1) +#define CDF_PROB_BITS 15 +#define CDF_PROB_TOP (1 << CDF_PROB_BITS) +/*The value stored in an iCDF is CDF_PROB_TOP minus the actual cumulative + probability (an "inverse" CDF). + This function converts from one representation to the other (and is its own + inverse).*/ +#define AOM_ICDF(x) (CDF_PROB_TOP - (x)) + +#define AOM_CDF2(a0) AOM_ICDF(a0), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF3(a0, a1) AOM_ICDF(a0), AOM_ICDF(a1), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF4(a0, a1, a2) \ + AOM_ICDF(a0), AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF5(a0, a1, a2, a3) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF6(a0, a1, a2, a3, a4) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), \ + AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF7(a0, a1, a2, a3, a4, a5) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF8(a0, a1, a2, a3, a4, a5, a6) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF9(a0, a1, a2, a3, a4, a5, a6, a7) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF10(a0, a1, a2, a3, a4, a5, a6, a7, a8) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF11(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(a9), \ + AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF12(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(a9), AOM_ICDF(a10), \ + AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF13(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(a9), AOM_ICDF(a10), \ + AOM_ICDF(a11), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF14(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(a9), AOM_ICDF(a10), \ + AOM_ICDF(a11), AOM_ICDF(a12), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF15(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(a9), AOM_ICDF(a10), \ + AOM_ICDF(a11), AOM_ICDF(a12), AOM_ICDF(a13), AOM_ICDF(CDF_PROB_TOP), 0 +#define AOM_CDF16(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, \ + a14) \ + AOM_ICDF(a0) \ + , AOM_ICDF(a1), AOM_ICDF(a2), AOM_ICDF(a3), AOM_ICDF(a4), AOM_ICDF(a5), \ + AOM_ICDF(a6), AOM_ICDF(a7), AOM_ICDF(a8), AOM_ICDF(a9), AOM_ICDF(a10), \ + AOM_ICDF(a11), AOM_ICDF(a12), AOM_ICDF(a13), AOM_ICDF(a14), \ + AOM_ICDF(CDF_PROB_TOP), 0 + +static INLINE uint8_t get_prob(unsigned int num, unsigned int den) { + assert(den != 0); + { + const int p = (int)(((uint64_t)num * 256 + (den >> 1)) / den); + // (p > 255) ? 255 : (p < 1) ? 1 : p; + const int clipped_prob = p | ((255 - p) >> 23) | (p == 0); + return (uint8_t)clipped_prob; + } +} + +static INLINE void update_cdf(aom_cdf_prob *cdf, int8_t val, int nsymbs) { + assert(nsymbs < 17); + const int count = cdf[nsymbs]; + + // rate is computed in the spec as: + // 3 + ( cdf[N] > 15 ) + ( cdf[N] > 31 ) + Min(FloorLog2(N), 2) + // In this case cdf[N] is |count|. + // Min(FloorLog2(N), 2) is 1 for nsymbs == {2, 3} and 2 for all + // nsymbs > 3. So the equation becomes: + // 4 + (count > 15) + (count > 31) + (nsymbs > 3). + // Note that the largest value for count is 32 (it is not incremented beyond + // 32). So using that information: + // count >> 4 is 0 for count from 0 to 15. + // count >> 4 is 1 for count from 16 to 31. + // count >> 4 is 2 for count == 31. + // Now, the equation becomes: + // 4 + (count >> 4) + (nsymbs > 3). + const int rate = 4 + (count >> 4) + (nsymbs > 3); + + int i = 0; + do { + if (i < val) { + cdf[i] += (CDF_PROB_TOP - cdf[i]) >> rate; + } else { + cdf[i] -= cdf[i] >> rate; + } + } while (++i < nsymbs - 1); + cdf[nsymbs] += (count < 32); +} + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif // AOM_AOM_DSP_PROB_H_ |