ref: b178fe7bfb96379d6dda6351b5739378d5c9f4d2
dir: /vpx_scale/generic/gen_scalers.c/
/*
* 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.
*/
#include "vpx_scale/vpxscale.h"
#include "vpx_mem/vpx_mem.h"
/****************************************************************************
* Imports
****************************************************************************/
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_4_5_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 4 to 5.
*
* SPECIAL NOTES : None.
*
****************************************************************************/
void vp8_horizontal_line_4_5_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned i;
unsigned int a, b, c;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width - 4; i += 4)
{
a = src[0];
b = src[1];
des [0] = (unsigned char) a;
des [1] = (unsigned char)((a * 51 + 205 * b + 128) >> 8);
c = src[2] * 154;
a = src[3];
des [2] = (unsigned char)((b * 102 + c + 128) >> 8);
des [3] = (unsigned char)((c + 102 * a + 128) >> 8);
b = src[4];
des [4] = (unsigned char)((a * 205 + 51 * b + 128) >> 8);
src += 4;
des += 5;
}
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 51 + 205 * b + 128) >> 8);
c = src[2] * 154;
a = src[3];
des [2] = (unsigned char)((b * 102 + c + 128) >> 8);
des [3] = (unsigned char)((c + 102 * a + 128) >> 8);
des [4] = (unsigned char)(a);
}
/****************************************************************************
*
* ROUTINE : vp8_vertical_band_4_5_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales vertical band of pixels by scale 4 to 5. The
* height of the band scaled is 4-pixels.
*
* SPECIAL NOTES : The routine uses the first line of the band below
* the current band.
*
****************************************************************************/
void vp8_vertical_band_4_5_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c, d;
unsigned char *des = dest;
for (i = 0; i < dest_width; i++)
{
a = des [0];
b = des [dest_pitch];
des[dest_pitch] = (unsigned char)((a * 51 + 205 * b + 128) >> 8);
c = des[dest_pitch*2] * 154;
d = des[dest_pitch*3];
des [dest_pitch*2] = (unsigned char)((b * 102 + c + 128) >> 8);
des [dest_pitch*3] = (unsigned char)((c + 102 * d + 128) >> 8);
/* First line in next band */
a = des [dest_pitch * 5];
des [dest_pitch * 4] = (unsigned char)((d * 205 + 51 * a + 128) >> 8);
des ++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_last_vertical_band_4_5_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales last vertical band of pixels by scale 4 to 5. The
* height of the band scaled is 4-pixels.
*
* SPECIAL NOTES : The routine does not have available the first line of
* the band below the current band, since this is the
* last band.
*
****************************************************************************/
void vp8_last_vertical_band_4_5_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c, d;
unsigned char *des = dest;
for (i = 0; i < dest_width; ++i)
{
a = des[0];
b = des[dest_pitch];
des[dest_pitch] = (unsigned char)((a * 51 + 205 * b + 128) >> 8);
c = des[dest_pitch*2] * 154;
d = des[dest_pitch*3];
des [dest_pitch*2] = (unsigned char)((b * 102 + c + 128) >> 8);
des [dest_pitch*3] = (unsigned char)((c + 102 * d + 128) >> 8);
/* No other line for interplation of this line, so .. */
des[dest_pitch*4] = (unsigned char) d;
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_2_3_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 2 to 3.
*
* SPECIAL NOTES : None.
*
*
****************************************************************************/
void vp8_horizontal_line_2_3_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width - 2; i += 2)
{
a = src[0];
b = src[1];
c = src[2];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 85 + 171 * b + 128) >> 8);
des [2] = (unsigned char)((b * 171 + 85 * c + 128) >> 8);
src += 2;
des += 3;
}
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 85 + 171 * b + 128) >> 8);
des [2] = (unsigned char)(b);
}
/****************************************************************************
*
* ROUTINE : vp8_vertical_band_2_3_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales vertical band of pixels by scale 2 to 3. The
* height of the band scaled is 2-pixels.
*
* SPECIAL NOTES : The routine uses the first line of the band below
* the current band.
*
****************************************************************************/
void vp8_vertical_band_2_3_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
for (i = 0; i < dest_width; i++)
{
a = des [0];
b = des [dest_pitch];
c = des[dest_pitch*3];
des [dest_pitch ] = (unsigned char)((a * 85 + 171 * b + 128) >> 8);
des [dest_pitch*2] = (unsigned char)((b * 171 + 85 * c + 128) >> 8);
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_last_vertical_band_2_3_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales last vertical band of pixels by scale 2 to 3. The
* height of the band scaled is 2-pixels.
*
* SPECIAL NOTES : The routine does not have available the first line of
* the band below the current band, since this is the
* last band.
*
****************************************************************************/
void vp8_last_vertical_band_2_3_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b;
unsigned char *des = dest;
for (i = 0; i < dest_width; ++i)
{
a = des [0];
b = des [dest_pitch];
des [dest_pitch ] = (unsigned char)((a * 85 + 171 * b + 128) >> 8);
des [dest_pitch*2] = (unsigned char)(b);
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_3_5_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 3 to 5.
*
* SPECIAL NOTES : None.
*
*
****************************************************************************/
void vp8_horizontal_line_3_5_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width - 3; i += 3)
{
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 102 + 154 * b + 128) >> 8);
c = src[2] ;
des [2] = (unsigned char)((b * 205 + c * 51 + 128) >> 8);
des [3] = (unsigned char)((b * 51 + c * 205 + 128) >> 8);
a = src[3];
des [4] = (unsigned char)((c * 154 + a * 102 + 128) >> 8);
src += 3;
des += 5;
}
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 102 + 154 * b + 128) >> 8);
c = src[2] ;
des [2] = (unsigned char)((b * 205 + c * 51 + 128) >> 8);
des [3] = (unsigned char)((b * 51 + c * 205 + 128) >> 8);
des [4] = (unsigned char)(c);
}
/****************************************************************************
*
* ROUTINE : vp8_vertical_band_3_5_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales vertical band of pixels by scale 3 to 5. The
* height of the band scaled is 3-pixels.
*
* SPECIAL NOTES : The routine uses the first line of the band below
* the current band.
*
****************************************************************************/
void vp8_vertical_band_3_5_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
for (i = 0; i < dest_width; i++)
{
a = des [0];
b = des [dest_pitch];
des [dest_pitch] = (unsigned char)((a * 102 + 154 * b + 128) >> 8);
c = des[dest_pitch*2];
des [dest_pitch*2] = (unsigned char)((b * 205 + c * 51 + 128) >> 8);
des [dest_pitch*3] = (unsigned char)((b * 51 + c * 205 + 128) >> 8);
/* First line in next band... */
a = des [dest_pitch * 5];
des [dest_pitch * 4] = (unsigned char)((c * 154 + a * 102 + 128) >> 8);
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_last_vertical_band_3_5_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales last vertical band of pixels by scale 3 to 5. The
* height of the band scaled is 3-pixels.
*
* SPECIAL NOTES : The routine does not have available the first line of
* the band below the current band, since this is the
* last band.
*
****************************************************************************/
void vp8_last_vertical_band_3_5_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
for (i = 0; i < dest_width; ++i)
{
a = des [0];
b = des [dest_pitch];
des [ dest_pitch ] = (unsigned char)((a * 102 + 154 * b + 128) >> 8);
c = des[dest_pitch*2];
des [dest_pitch*2] = (unsigned char)((b * 205 + c * 51 + 128) >> 8);
des [dest_pitch*3] = (unsigned char)((b * 51 + c * 205 + 128) >> 8);
/* No other line for interplation of this line, so .. */
des [ dest_pitch * 4 ] = (unsigned char)(c) ;
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_3_4_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 3 to 4.
*
* SPECIAL NOTES : None.
*
*
****************************************************************************/
void vp8_horizontal_line_3_4_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width - 3; i += 3)
{
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 64 + b * 192 + 128) >> 8);
c = src[2];
des [2] = (unsigned char)((b + c + 1) >> 1);
a = src[3];
des [3] = (unsigned char)((c * 192 + a * 64 + 128) >> 8);
src += 3;
des += 4;
}
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a * 64 + b * 192 + 128) >> 8);
c = src[2] ;
des [2] = (unsigned char)((b + c + 1) >> 1);
des [3] = (unsigned char)(c);
}
/****************************************************************************
*
* ROUTINE : vp8_vertical_band_3_4_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales vertical band of pixels by scale 3 to 4. The
* height of the band scaled is 3-pixels.
*
* SPECIAL NOTES : The routine uses the first line of the band below
* the current band.
*
****************************************************************************/
void vp8_vertical_band_3_4_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
for (i = 0; i < dest_width; i++)
{
a = des [0];
b = des [dest_pitch];
des [dest_pitch] = (unsigned char)((a * 64 + b * 192 + 128) >> 8);
c = des[dest_pitch*2];
des [dest_pitch*2] = (unsigned char)((b + c + 1) >> 1);
/* First line in next band... */
a = des [dest_pitch*4];
des [dest_pitch*3] = (unsigned char)((c * 192 + a * 64 + 128) >> 8);
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_last_vertical_band_3_4_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales last vertical band of pixels by scale 3 to 4. The
* height of the band scaled is 3-pixels.
*
* SPECIAL NOTES : The routine does not have available the first line of
* the band below the current band, since this is the
* last band.
*
****************************************************************************/
void vp8_last_vertical_band_3_4_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c;
unsigned char *des = dest;
for (i = 0; i < dest_width; ++i)
{
a = des [0];
b = des [dest_pitch];
des [dest_pitch] = (unsigned char)((a * 64 + b * 192 + 128) >> 8);
c = des[dest_pitch*2];
des [dest_pitch*2] = (unsigned char)((b + c + 1) >> 1);
/* No other line for interplation of this line, so .. */
des [dest_pitch*3] = (unsigned char)(c);
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_1_2_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 1 to 2.
*
* SPECIAL NOTES : None.
*
****************************************************************************/
void vp8_horizontal_line_1_2_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned int i;
unsigned int a, b;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width - 1; i += 1)
{
a = src[0];
b = src[1];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)((a + b + 1) >> 1);
src += 1;
des += 2;
}
a = src[0];
des [0] = (unsigned char)(a);
des [1] = (unsigned char)(a);
}
/****************************************************************************
*
* ROUTINE : vp8_vertical_band_1_2_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales vertical band of pixels by scale 1 to 2. The
* height of the band scaled is 1-pixel.
*
* SPECIAL NOTES : The routine uses the first line of the band below
* the current band.
*
****************************************************************************/
void vp8_vertical_band_1_2_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b;
unsigned char *des = dest;
for (i = 0; i < dest_width; i++)
{
a = des [0];
b = des [dest_pitch * 2];
des[dest_pitch] = (unsigned char)((a + b + 1) >> 1);
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_last_vertical_band_1_2_scale_c
*
* INPUTS : unsigned char *dest : Pointer to destination data.
* unsigned int dest_pitch : Stride of destination data.
* unsigned int dest_width : Width of destination data.
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Scales last vertical band of pixels by scale 1 to 2. The
* height of the band scaled is 1-pixel.
*
* SPECIAL NOTES : The routine does not have available the first line of
* the band below the current band, since this is the
* last band.
*
****************************************************************************/
void vp8_last_vertical_band_1_2_scale_c(unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned char *des = dest;
for (i = 0; i < dest_width; ++i)
{
des[dest_pitch] = des[0];
des++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_4_5_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 4 to 5.
*
* SPECIAL NOTES : None.
*
****************************************************************************/
void vp8_horizontal_line_5_4_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width; i += 5)
{
a = src[0];
b = src[1];
c = src[2];
d = src[3];
e = src[4];
des[0] = (unsigned char) a;
des[1] = (unsigned char)((b * 192 + c * 64 + 128) >> 8);
des[2] = (unsigned char)((c * 128 + d * 128 + 128) >> 8);
des[3] = (unsigned char)((d * 64 + e * 192 + 128) >> 8);
src += 5;
des += 4;
}
}
void vp8_vertical_band_5_4_scale_c(unsigned char *source, unsigned int src_pitch, unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
unsigned char *src = source;
for (i = 0; i < dest_width; i++)
{
a = src[0 * src_pitch];
b = src[1 * src_pitch];
c = src[2 * src_pitch];
d = src[3 * src_pitch];
e = src[4 * src_pitch];
des[0 * dest_pitch] = (unsigned char) a;
des[1 * dest_pitch] = (unsigned char)((b * 192 + c * 64 + 128) >> 8);
des[2 * dest_pitch] = (unsigned char)((c * 128 + d * 128 + 128) >> 8);
des[3 * dest_pitch] = (unsigned char)((d * 64 + e * 192 + 128) >> 8);
src ++;
des ++;
}
}
/*7***************************************************************************
*
* ROUTINE : vp8_horizontal_line_3_5_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 3 to 5.
*
* SPECIAL NOTES : None.
*
*
****************************************************************************/
void vp8_horizontal_line_5_3_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned int i;
unsigned int a, b, c, d , e;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width; i += 5)
{
a = src[0];
b = src[1];
c = src[2];
d = src[3];
e = src[4];
des[0] = (unsigned char) a;
des[1] = (unsigned char)((b * 85 + c * 171 + 128) >> 8);
des[2] = (unsigned char)((d * 171 + e * 85 + 128) >> 8);
src += 5;
des += 3;
}
}
void vp8_vertical_band_5_3_scale_c(unsigned char *source, unsigned int src_pitch, unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
unsigned int i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
unsigned char *src = source;
for (i = 0; i < dest_width; i++)
{
a = src[0 * src_pitch];
b = src[1 * src_pitch];
c = src[2 * src_pitch];
d = src[3 * src_pitch];
e = src[4 * src_pitch];
des[0 * dest_pitch] = (unsigned char) a;
des[1 * dest_pitch] = (unsigned char)((b * 85 + c * 171 + 128) >> 8);
des[2 * dest_pitch] = (unsigned char)((d * 171 + e * 85 + 128) >> 8);
src ++;
des ++;
}
}
/****************************************************************************
*
* ROUTINE : vp8_horizontal_line_1_2_scale_c
*
* INPUTS : const unsigned char *source : Pointer to source data.
* unsigned int source_width : Stride of source.
* unsigned char *dest : Pointer to destination data.
* unsigned int dest_width : Stride of destination (NOT USED).
*
* OUTPUTS : None.
*
* RETURNS : void
*
* FUNCTION : Copies horizontal line of pixels from source to
* destination scaling up by 1 to 2.
*
* SPECIAL NOTES : None.
*
****************************************************************************/
void vp8_horizontal_line_2_1_scale_c
(
const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width
)
{
unsigned int i;
unsigned int a;
unsigned char *des = dest;
const unsigned char *src = source;
(void) dest_width;
for (i = 0; i < source_width; i += 2)
{
a = src[0];
des [0] = (unsigned char)(a);
src += 2;
des += 1;
}
}
void vp8_vertical_band_2_1_scale_c(unsigned char *source, unsigned int src_pitch, unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
(void) dest_pitch;
(void) src_pitch;
vpx_memcpy(dest, source, dest_width);
}
void vp8_vertical_band_2_1_scale_i_c(unsigned char *source, unsigned int src_pitch, unsigned char *dest, unsigned int dest_pitch, unsigned int dest_width)
{
int i;
int temp;
int width = dest_width;
(void) dest_pitch;
for (i = 0; i < width; i++)
{
temp = 8;
temp += source[i-(int)src_pitch] * 3;
temp += source[i] * 10;
temp += source[i+src_pitch] * 3;
temp >>= 4 ;
dest[i] = (unsigned char)(temp);
}
}