ref: 397aad3ec28020a9b766e362e061701783c9633e
dir: /vp8/common/filter_c.c/
/*
* Copyright (c) 2010 The VP8 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.
*/
#include <stdlib.h>
#define BLOCK_HEIGHT_WIDTH 4
#define VP8_FILTER_WEIGHT 128
#define VP8_FILTER_SHIFT 7
static const int bilinear_filters[8][2] =
{
{ 128, 0 },
{ 112, 16 },
{ 96, 32 },
{ 80, 48 },
{ 64, 64 },
{ 48, 80 },
{ 32, 96 },
{ 16, 112 }
};
static const short sub_pel_filters[8][6] =
{
{ 0, 0, 128, 0, 0, 0 }, // note that 1/8 pel positions are just as per alpha -0.5 bicubic
{ 0, -6, 123, 12, -1, 0 },
{ 2, -11, 108, 36, -8, 1 }, // New 1/4 pel 6 tap filter
{ 0, -9, 93, 50, -6, 0 },
{ 3, -16, 77, 77, -16, 3 }, // New 1/2 pel 6 tap filter
{ 0, -6, 50, 93, -9, 0 },
{ 1, -8, 36, 108, -11, 2 }, // New 1/4 pel 6 tap filter
{ 0, -1, 12, 123, -6, 0 },
};
void vp8_filter_block2d_first_pass
(
unsigned char *src_ptr,
int *output_ptr,
unsigned int src_pixels_per_line,
unsigned int pixel_step,
unsigned int output_height,
unsigned int output_width,
const short *vp8_filter
)
{
unsigned int i, j;
int Temp;
for (i = 0; i < output_height; i++)
{
for (j = 0; j < output_width; j++)
{
Temp = ((int)src_ptr[-2 * (int)pixel_step] * vp8_filter[0]) +
((int)src_ptr[-1 * (int)pixel_step] * vp8_filter[1]) +
((int)src_ptr[0] * vp8_filter[2]) +
((int)src_ptr[pixel_step] * vp8_filter[3]) +
((int)src_ptr[2*pixel_step] * vp8_filter[4]) +
((int)src_ptr[3*pixel_step] * vp8_filter[5]) +
(VP8_FILTER_WEIGHT >> 1); // Rounding
// Normalize back to 0-255
Temp = Temp >> VP8_FILTER_SHIFT;
if (Temp < 0)
Temp = 0;
else if (Temp > 255)
Temp = 255;
output_ptr[j] = Temp;
src_ptr++;
}
// Next row...
src_ptr += src_pixels_per_line - output_width;
output_ptr += output_width;
}
}
void vp8_filter_block2d_second_pass
(
int *src_ptr,
unsigned char *output_ptr,
int output_pitch,
unsigned int src_pixels_per_line,
unsigned int pixel_step,
unsigned int output_height,
unsigned int output_width,
const short *vp8_filter
)
{
unsigned int i, j;
int Temp;
for (i = 0; i < output_height; i++)
{
for (j = 0; j < output_width; j++)
{
// Apply filter
Temp = ((int)src_ptr[-2 * (int)pixel_step] * vp8_filter[0]) +
((int)src_ptr[-1 * (int)pixel_step] * vp8_filter[1]) +
((int)src_ptr[0] * vp8_filter[2]) +
((int)src_ptr[pixel_step] * vp8_filter[3]) +
((int)src_ptr[2*pixel_step] * vp8_filter[4]) +
((int)src_ptr[3*pixel_step] * vp8_filter[5]) +
(VP8_FILTER_WEIGHT >> 1); // Rounding
// Normalize back to 0-255
Temp = Temp >> VP8_FILTER_SHIFT;
if (Temp < 0)
Temp = 0;
else if (Temp > 255)
Temp = 255;
output_ptr[j] = (unsigned char)Temp;
src_ptr++;
}
// Start next row
src_ptr += src_pixels_per_line - output_width;
output_ptr += output_pitch;
}
}
void vp8_filter_block2d
(
unsigned char *src_ptr,
unsigned char *output_ptr,
unsigned int src_pixels_per_line,
int output_pitch,
const short *HFilter,
const short *VFilter
)
{
int FData[9*4]; // Temp data bufffer used in filtering
// First filter 1-D horizontally...
vp8_filter_block2d_first_pass(src_ptr - (2 * src_pixels_per_line), FData, src_pixels_per_line, 1, 9, 4, HFilter);
// then filter verticaly...
vp8_filter_block2d_second_pass(FData + 8, output_ptr, output_pitch, 4, 4, 4, 4, VFilter);
}
void vp8_block_variation_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int *HVar,
int *VVar
)
{
int i, j;
unsigned char *Ptr = src_ptr;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
*HVar += abs((int)Ptr[j] - (int)Ptr[j+1]);
*VVar += abs((int)Ptr[j] - (int)Ptr[j+src_pixels_per_line]);
}
Ptr += src_pixels_per_line;
}
}
void vp8_sixtap_predict_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const short *HFilter;
const short *VFilter;
HFilter = sub_pel_filters[xoffset]; // 6 tap
VFilter = sub_pel_filters[yoffset]; // 6 tap
vp8_filter_block2d(src_ptr, dst_ptr, src_pixels_per_line, dst_pitch, HFilter, VFilter);
}
void vp8_sixtap_predict8x8_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const short *HFilter;
const short *VFilter;
int FData[13*16]; // Temp data bufffer used in filtering
HFilter = sub_pel_filters[xoffset]; // 6 tap
VFilter = sub_pel_filters[yoffset]; // 6 tap
// First filter 1-D horizontally...
vp8_filter_block2d_first_pass(src_ptr - (2 * src_pixels_per_line), FData, src_pixels_per_line, 1, 13, 8, HFilter);
// then filter verticaly...
vp8_filter_block2d_second_pass(FData + 16, dst_ptr, dst_pitch, 8, 8, 8, 8, VFilter);
}
void vp8_sixtap_predict8x4_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const short *HFilter;
const short *VFilter;
int FData[13*16]; // Temp data bufffer used in filtering
HFilter = sub_pel_filters[xoffset]; // 6 tap
VFilter = sub_pel_filters[yoffset]; // 6 tap
// First filter 1-D horizontally...
vp8_filter_block2d_first_pass(src_ptr - (2 * src_pixels_per_line), FData, src_pixels_per_line, 1, 9, 8, HFilter);
// then filter verticaly...
vp8_filter_block2d_second_pass(FData + 16, dst_ptr, dst_pitch, 8, 8, 4, 8, VFilter);
}
void vp8_sixtap_predict16x16_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const short *HFilter;
const short *VFilter;
int FData[21*24]; // Temp data bufffer used in filtering
HFilter = sub_pel_filters[xoffset]; // 6 tap
VFilter = sub_pel_filters[yoffset]; // 6 tap
// First filter 1-D horizontally...
vp8_filter_block2d_first_pass(src_ptr - (2 * src_pixels_per_line), FData, src_pixels_per_line, 1, 21, 16, HFilter);
// then filter verticaly...
vp8_filter_block2d_second_pass(FData + 32, dst_ptr, dst_pitch, 16, 16, 16, 16, VFilter);
}
/****************************************************************************
*
* ROUTINE : filter_block2d_bil_first_pass
*
* INPUTS : UINT8 *src_ptr : Pointer to source block.
* UINT32 src_pixels_per_line : Stride of input block.
* UINT32 pixel_step : Offset between filter input samples (see notes).
* UINT32 output_height : Input block height.
* UINT32 output_width : Input block width.
* INT32 *vp8_filter : Array of 2 bi-linear filter taps.
*
* OUTPUTS : INT32 *output_ptr : Pointer to filtered block.
*
* RETURNS : void
*
* FUNCTION : Applies a 1-D 2-tap bi-linear filter to the source block in
* either horizontal or vertical direction to produce the
* filtered output block. Used to implement first-pass
* of 2-D separable filter.
*
* SPECIAL NOTES : Produces INT32 output to retain precision for next pass.
* Two filter taps should sum to VP8_FILTER_WEIGHT.
* pixel_step defines whether the filter is applied
* horizontally (pixel_step=1) or vertically (pixel_step=stride).
* It defines the offset required to move from one input
* to the next.
*
****************************************************************************/
void vp8_filter_block2d_bil_first_pass
(
unsigned char *src_ptr,
unsigned short *output_ptr,
unsigned int src_pixels_per_line,
int pixel_step,
unsigned int output_height,
unsigned int output_width,
const int *vp8_filter
)
{
unsigned int i, j;
for (i = 0; i < output_height; i++)
{
for (j = 0; j < output_width; j++)
{
// Apply bilinear filter
output_ptr[j] = (((int)src_ptr[0] * vp8_filter[0]) +
((int)src_ptr[pixel_step] * vp8_filter[1]) +
(VP8_FILTER_WEIGHT / 2)) >> VP8_FILTER_SHIFT;
src_ptr++;
}
// Next row...
src_ptr += src_pixels_per_line - output_width;
output_ptr += output_width;
}
}
/****************************************************************************
*
* ROUTINE : filter_block2d_bil_second_pass
*
* INPUTS : INT32 *src_ptr : Pointer to source block.
* UINT32 src_pixels_per_line : Stride of input block.
* UINT32 pixel_step : Offset between filter input samples (see notes).
* UINT32 output_height : Input block height.
* UINT32 output_width : Input block width.
* INT32 *vp8_filter : Array of 2 bi-linear filter taps.
*
* OUTPUTS : UINT16 *output_ptr : Pointer to filtered block.
*
* RETURNS : void
*
* FUNCTION : Applies a 1-D 2-tap bi-linear filter to the source block in
* either horizontal or vertical direction to produce the
* filtered output block. Used to implement second-pass
* of 2-D separable filter.
*
* SPECIAL NOTES : Requires 32-bit input as produced by filter_block2d_bil_first_pass.
* Two filter taps should sum to VP8_FILTER_WEIGHT.
* pixel_step defines whether the filter is applied
* horizontally (pixel_step=1) or vertically (pixel_step=stride).
* It defines the offset required to move from one input
* to the next.
*
****************************************************************************/
void vp8_filter_block2d_bil_second_pass
(
unsigned short *src_ptr,
unsigned char *output_ptr,
int output_pitch,
unsigned int src_pixels_per_line,
unsigned int pixel_step,
unsigned int output_height,
unsigned int output_width,
const int *vp8_filter
)
{
unsigned int i, j;
int Temp;
for (i = 0; i < output_height; i++)
{
for (j = 0; j < output_width; j++)
{
// Apply filter
Temp = ((int)src_ptr[0] * vp8_filter[0]) +
((int)src_ptr[pixel_step] * vp8_filter[1]) +
(VP8_FILTER_WEIGHT / 2);
output_ptr[j] = (unsigned int)(Temp >> VP8_FILTER_SHIFT);
src_ptr++;
}
// Next row...
src_ptr += src_pixels_per_line - output_width;
output_ptr += output_pitch;
}
}
/****************************************************************************
*
* ROUTINE : filter_block2d_bil
*
* INPUTS : UINT8 *src_ptr : Pointer to source block.
* UINT32 src_pixels_per_line : Stride of input block.
* INT32 *HFilter : Array of 2 horizontal filter taps.
* INT32 *VFilter : Array of 2 vertical filter taps.
*
* OUTPUTS : UINT16 *output_ptr : Pointer to filtered block.
*
* RETURNS : void
*
* FUNCTION : 2-D filters an input block by applying a 2-tap
* bi-linear filter horizontally followed by a 2-tap
* bi-linear filter vertically on the result.
*
* SPECIAL NOTES : The largest block size can be handled here is 16x16
*
****************************************************************************/
void vp8_filter_block2d_bil
(
unsigned char *src_ptr,
unsigned char *output_ptr,
unsigned int src_pixels_per_line,
unsigned int dst_pitch,
const int *HFilter,
const int *VFilter,
int Width,
int Height
)
{
unsigned short FData[17*16]; // Temp data bufffer used in filtering
// First filter 1-D horizontally...
vp8_filter_block2d_bil_first_pass(src_ptr, FData, src_pixels_per_line, 1, Height + 1, Width, HFilter);
// then 1-D vertically...
vp8_filter_block2d_bil_second_pass(FData, output_ptr, dst_pitch, Width, Width, Height, Width, VFilter);
}
void vp8_bilinear_predict4x4_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const int *HFilter;
const int *VFilter;
HFilter = bilinear_filters[xoffset];
VFilter = bilinear_filters[yoffset];
#if 0
{
int i;
unsigned char temp1[16];
unsigned char temp2[16];
bilinear_predict4x4_mmx(src_ptr, src_pixels_per_line, xoffset, yoffset, temp1, 4);
vp8_filter_block2d_bil(src_ptr, temp2, src_pixels_per_line, 4, HFilter, VFilter, 4, 4);
for (i = 0; i < 16; i++)
{
if (temp1[i] != temp2[i])
{
bilinear_predict4x4_mmx(src_ptr, src_pixels_per_line, xoffset, yoffset, temp1, 4);
vp8_filter_block2d_bil(src_ptr, temp2, src_pixels_per_line, 4, HFilter, VFilter, 4, 4);
}
}
}
#endif
vp8_filter_block2d_bil(src_ptr, dst_ptr, src_pixels_per_line, dst_pitch, HFilter, VFilter, 4, 4);
}
void vp8_bilinear_predict8x8_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const int *HFilter;
const int *VFilter;
HFilter = bilinear_filters[xoffset];
VFilter = bilinear_filters[yoffset];
vp8_filter_block2d_bil(src_ptr, dst_ptr, src_pixels_per_line, dst_pitch, HFilter, VFilter, 8, 8);
}
void vp8_bilinear_predict8x4_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const int *HFilter;
const int *VFilter;
HFilter = bilinear_filters[xoffset];
VFilter = bilinear_filters[yoffset];
vp8_filter_block2d_bil(src_ptr, dst_ptr, src_pixels_per_line, dst_pitch, HFilter, VFilter, 8, 4);
}
void vp8_bilinear_predict16x16_c
(
unsigned char *src_ptr,
int src_pixels_per_line,
int xoffset,
int yoffset,
unsigned char *dst_ptr,
int dst_pitch
)
{
const int *HFilter;
const int *VFilter;
HFilter = bilinear_filters[xoffset];
VFilter = bilinear_filters[yoffset];
vp8_filter_block2d_bil(src_ptr, dst_ptr, src_pixels_per_line, dst_pitch, HFilter, VFilter, 16, 16);
}