/*
* i965_vpp_avs.c - Adaptive Video Scaler (AVS) block
*
* Copyright (C) 2014 Intel Corporation
* Author: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "sysdeps.h"
#include <math.h>
#include <va/va.h>
#include "i965_vpp_avs.h"
typedef void (*AVSGenCoeffsFunc)(float *coeffs, int num_coeffs, int phase,
int num_phases, float f);
/* Initializes all coefficients to zero */
static void
avs_init_coeffs(float *coeffs, int num_coeffs)
{
#if defined(__STDC_IEC_559__) && (__STDC_IEC_559__ > 0)
memset(coeffs
, 0, num_coeffs
* sizeof(*coeffs
)); #else
int i;
for (i = 0; i < num_coeffs; i++)
coeffs[i] = 0.0f;
#endif
}
/* Computes the sinc(x) function */
static float
avs_sinc(float x)
{
if (x == 0.0f)
return 1.0f;
return sin(x
* M_PI
) / (x
* M_PI
); }
/* Convolution kernel for linear interpolation */
static float
avs_kernel_linear(float x)
{
const float abs_x = fabsf(x);
return abs_x < 1.0f ? 1 - abs_x : 0.0f;
}
/* Convolution kernel for Lanczos-based interpolation */
static float
avs_kernel_lanczos(float x, float a)
{
const float abs_x = fabsf(x);
return abs_x < a ? avs_sinc(x) * avs_sinc(x / a) : 0.0f;
}
/* Truncates floating-point value towards an epsilon factor */
static inline float
avs_trunc_coeff(float x, float epsilon)
{
return rintf(x / epsilon) * epsilon;
}
/* Normalize coefficients for one sample/direction */
static void
avs_normalize_coeffs_1(float *coeffs, int num_coeffs, float epsilon)
{
float s, sum = 0.0;
int i, c, r, r1;
for (i = 0; i < num_coeffs; i++)
sum += coeffs[i];
if (sum < epsilon)
return;
s = 0.0;
for (i = 0; i < num_coeffs; i++)
s += (coeffs[i] = avs_trunc_coeff(coeffs[i] / sum, epsilon));
/* Distribute the remaining bits, while allocating more to the center */
c = num_coeffs/2;
c = c - (coeffs[c - 1] > coeffs[c]);
r = (1.0f - s) / epsilon;
r1 = r / 4;
if (coeffs[c + 1] == 0.0f)
coeffs[c] += r * epsilon;
else {
coeffs[c] += (r - 2*r1) * epsilon;
coeffs[c - 1] += r1 * epsilon;
coeffs[c + 1] += r1 * epsilon;
}
}
/* Normalize all coefficients so that their sum yields 1.0f */
static void
avs_normalize_coeffs(AVSCoeffs *coeffs, const AVSConfig *config)
{
avs_normalize_coeffs_1(coeffs->y_k_h, config->num_luma_coeffs,
config->coeff_epsilon);
avs_normalize_coeffs_1(coeffs->y_k_v, config->num_luma_coeffs,
config->coeff_epsilon);
avs_normalize_coeffs_1(coeffs->uv_k_h, config->num_chroma_coeffs,
config->coeff_epsilon);
avs_normalize_coeffs_1(coeffs->uv_k_v, config->num_chroma_coeffs,
config->coeff_epsilon);
}
/* Validate coefficients for one sample/direction */
static bool
avs_validate_coeffs_1(float *coeffs, int num_coeffs, const float *min_coeffs,
const float *max_coeffs)
{
int i;
for (i = 0; i < num_coeffs; i++) {
if (coeffs[i] < min_coeffs[i] || coeffs[i] > max_coeffs[i])
return false;
}
return true;
}
/* Validate coefficients wrt. the supplied range in config */
static bool
avs_validate_coeffs(AVSCoeffs *coeffs, const AVSConfig *config)
{
const AVSCoeffs * const min_coeffs = &config->coeff_range.lower_bound;
const AVSCoeffs * const max_coeffs = &config->coeff_range.upper_bound;
return avs_validate_coeffs_1(coeffs->y_k_h, config->num_luma_coeffs,
min_coeffs->y_k_h, max_coeffs->y_k_h) &&
avs_validate_coeffs_1(coeffs->y_k_v, config->num_luma_coeffs,
min_coeffs->y_k_v, max_coeffs->y_k_v) &&
avs_validate_coeffs_1(coeffs->uv_k_h, config->num_chroma_coeffs,
min_coeffs->uv_k_h, max_coeffs->uv_k_h) &&
avs_validate_coeffs_1(coeffs->uv_k_v, config->num_chroma_coeffs,
min_coeffs->uv_k_v, max_coeffs->uv_k_v);
}
/* Generate coefficients for default quality (bilinear) */
static void
avs_gen_coeffs_linear(float *coeffs, int num_coeffs, int phase, int num_phases,
float f)
{
const int c = num_coeffs/2 - 1;
const float p = (float)phase / (num_phases*2);
avs_init_coeffs(coeffs, num_coeffs);
coeffs[c] = avs_kernel_linear(p);
coeffs[c + 1] = avs_kernel_linear(p - 1);
}
/* Generate coefficients for high quality (lanczos) */
static void
avs_gen_coeffs_lanczos(float *coeffs, int num_coeffs, int phase, int num_phases,
float f)
{
const int c = num_coeffs/2 - 1;
const int l = num_coeffs > 4 ? 3 : 2;
const float p = (float)phase / (num_phases*2);
int i;
if (f > 1.0f)
f = 1.0f;
for (i = 0; i < num_coeffs; i++)
coeffs[i] = avs_kernel_lanczos((i - (c + p)) * f, l);
}
/* Generate coefficients with the supplied scaler */
static bool
avs_gen_coeffs(AVSState *avs, float sx, float sy, AVSGenCoeffsFunc gen_coeffs)
{
const AVSConfig * const config = avs->config;
int i;
for (i = 0; i <= config->num_phases; i++) {
AVSCoeffs * const coeffs = &avs->coeffs[i];
gen_coeffs(coeffs->y_k_h, config->num_luma_coeffs,
i, config->num_phases, sx);
gen_coeffs(coeffs->uv_k_h, config->num_chroma_coeffs,
i, config->num_phases, sx);
gen_coeffs(coeffs->y_k_v, config->num_luma_coeffs,
i, config->num_phases, sy);
gen_coeffs(coeffs->uv_k_v, config->num_chroma_coeffs,
i, config->num_phases, sy);
avs_normalize_coeffs(coeffs, config);
if (!avs_validate_coeffs(coeffs, config))
return false;
}
return true;
}
/* Initializes AVS state with the supplied configuration */
void
avs_init_state(AVSState *avs, const AVSConfig *config)
{
avs->config = config;
avs->flags = 0;
avs->scale_x = 0.0f;
avs->scale_y = 0.0f;
}
/* Checks whether the AVS scaling parameters changed */
static inline bool
avs_params_changed(AVSState *avs, float sx, float sy, uint32_t flags)
{
if (avs->flags != flags)
return true;
if (flags >= VA_FILTER_SCALING_HQ) {
if (avs->scale_x != sx || avs->scale_y != sy)
return true;
}
else {
if (avs->scale_x == 0.0f || avs->scale_y == 0.0f)
return true;
}
return false;
}
/* Updates AVS coefficients for the supplied factors and quality level */
bool
avs_update_coefficients(AVSState *avs, float sx, float sy, uint32_t flags)
{
AVSGenCoeffsFunc gen_coeffs;
flags &= VA_FILTER_SCALING_MASK;
if (!avs_params_changed(avs, sx, sy, flags))
return true;
switch (flags) {
case VA_FILTER_SCALING_HQ:
gen_coeffs = avs_gen_coeffs_lanczos;
break;
default:
gen_coeffs = avs_gen_coeffs_linear;
break;
}
if (!avs_gen_coeffs(avs, sx, sy, gen_coeffs)) {
assert(0 && "invalid set of coefficients generated"); return false;
}
avs->flags = flags;
avs->scale_x = sx;
avs->scale_y = sy;
return true;
}