ref: c7e9e486b8e0d1cdf5100c7d8a858b4d935910bb
dir: /vpx_dsp/inv_txfm.h/
/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef VPX_DSP_INV_TXFM_H_
#define VPX_DSP_INV_TXFM_H_
#include <assert.h>
#include "./vpx_config.h"
#include "vpx_dsp/txfm_common.h"
#include "vpx_ports/mem.h"
#ifdef __cplusplus
extern "C" {
#endif
static INLINE tran_low_t check_range(tran_high_t input) {
#if CONFIG_COEFFICIENT_RANGE_CHECKING
// For valid VP9 input streams, intermediate stage coefficients should always
// stay within the range of a signed 16 bit integer. Coefficients can go out
// of this range for invalid/corrupt VP9 streams. However, strictly checking
// this range for every intermediate coefficient can burdensome for a decoder,
// therefore the following assertion is only enabled when configured with
// --enable-coefficient-range-checking.
assert(INT16_MIN <= input);
assert(input <= INT16_MAX);
#endif // CONFIG_COEFFICIENT_RANGE_CHECKING
return (tran_low_t)input;
}
static INLINE tran_low_t dct_const_round_shift(tran_high_t input) {
tran_high_t rv = ROUND_POWER_OF_TWO(input, DCT_CONST_BITS);
return check_range(rv);
}
#if CONFIG_VP9_HIGHBITDEPTH
static INLINE tran_low_t highbd_check_range(tran_high_t input,
int bd) {
#if CONFIG_COEFFICIENT_RANGE_CHECKING
// For valid highbitdepth VP9 streams, intermediate stage coefficients will
// stay within the ranges:
// - 8 bit: signed 16 bit integer
// - 10 bit: signed 18 bit integer
// - 12 bit: signed 20 bit integer
const int32_t int_max = (1 << (7 + bd)) - 1;
const int32_t int_min = -int_max - 1;
assert(int_min <= input);
assert(input <= int_max);
(void) int_min;
#endif // CONFIG_COEFFICIENT_RANGE_CHECKING
(void) bd;
return (tran_low_t)input;
}
static INLINE tran_low_t highbd_dct_const_round_shift(tran_high_t input,
int bd) {
tran_high_t rv = ROUND_POWER_OF_TWO(input, DCT_CONST_BITS);
return highbd_check_range(rv, bd);
}
#endif // CONFIG_VP9_HIGHBITDEPTH
#if CONFIG_EMULATE_HARDWARE
// When CONFIG_EMULATE_HARDWARE is 1 the transform performs a
// non-normative method to handle overflows. A stream that causes
// overflows in the inverse transform is considered invalid in VP9,
// and a hardware implementer is free to choose any reasonable
// method to handle overflows. However to aid in hardware
// verification they can use a specific implementation of the
// WRAPLOW() macro below that is identical to their intended
// hardware implementation (and also use configure options to trigger
// the C-implementation of the transform).
//
// The particular WRAPLOW implementation below performs strict
// overflow wrapping to match common hardware implementations.
// bd of 8 uses trans_low with 16bits, need to remove 16bits
// bd of 10 uses trans_low with 18bits, need to remove 14bits
// bd of 12 uses trans_low with 20bits, need to remove 12bits
// bd of x uses trans_low with 8+x bits, need to remove 24-x bits
#define WRAPLOW(x, bd) ((((int32_t)(x)) << (24 - bd)) >> (24 - bd))
#else
#define WRAPLOW(x, bd) ((int32_t)(x))
#endif // CONFIG_EMULATE_HARDWARE
void idct4_c(const tran_low_t *input, tran_low_t *output);
void idct8_c(const tran_low_t *input, tran_low_t *output);
void idct16_c(const tran_low_t *input, tran_low_t *output);
void idct32_c(const tran_low_t *input, tran_low_t *output);
void iadst4_c(const tran_low_t *input, tran_low_t *output);
void iadst8_c(const tran_low_t *input, tran_low_t *output);
void iadst16_c(const tran_low_t *input, tran_low_t *output);
#if CONFIG_VP9_HIGHBITDEPTH
void vpx_highbd_idct4_c(const tran_low_t *input, tran_low_t *output, int bd);
void vpx_highbd_idct8_c(const tran_low_t *input, tran_low_t *output, int bd);
void vpx_highbd_idct16_c(const tran_low_t *input, tran_low_t *output, int bd);
void vpx_highbd_iadst4_c(const tran_low_t *input, tran_low_t *output, int bd);
void vpx_highbd_iadst8_c(const tran_low_t *input, tran_low_t *output, int bd);
void vpx_highbd_iadst16_c(const tran_low_t *input, tran_low_t *output, int bd);
static INLINE uint16_t highbd_clip_pixel_add(uint16_t dest, tran_high_t trans,
int bd) {
trans = WRAPLOW(trans, bd);
return clip_pixel_highbd(WRAPLOW(dest + trans, bd), bd);
}
#endif
static INLINE uint8_t clip_pixel_add(uint8_t dest, tran_high_t trans) {
trans = WRAPLOW(trans, 8);
return clip_pixel(WRAPLOW(dest + trans, 8));
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // VPX_DSP_INV_TXFM_H_