/src/libvpx/vpx_scale/generic/vpx_scale.c

Source (jump to first uncovered line)
/*
 *  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.
 */

/****************************************************************************
 *
 *   Module Title :     scale.c
 *
 *   Description  :     Image scaling functions.
 *
 ***************************************************************************/

/****************************************************************************
 *  Header Files
 ****************************************************************************/
#include <assert.h>

#include "./vpx_scale_rtcd.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_scale/vpx_scale.h"
#include "vpx_scale/yv12config.h"

typedef struct {
  int expanded_frame_width;
  int expanded_frame_height;

  int HScale;
  int HRatio;
  int VScale;
  int VRatio;

  YV12_BUFFER_CONFIG *src_yuv_config;
  YV12_BUFFER_CONFIG *dst_yuv_config;

} SCALE_VARS;

/****************************************************************************
 *
 *  ROUTINE       : scale1d_2t1_i
 *
 *  INPUTS        : const unsigned char *source : Pointer to data to be scaled.
 *                  int source_step             : Number of pixels to step on in
 *                                                source.
 *                  unsigned int source_scale   : Scale for source (UNUSED).
 *                  unsigned int source_length  : Length of source (UNUSED).
 *                  unsigned char *dest         : Pointer to output data array.
 *                  int dest_step               : Number of pixels to step on in
 *                                                destination.
 *                  unsigned int dest_scale     : Scale for destination
 *                                                (UNUSED).
 *                  unsigned int dest_length    : Length of destination.
 *
 *  OUTPUTS       : None.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Performs 2-to-1 interpolated scaling.
 *
 *  SPECIAL NOTES : None.
 *
 ****************************************************************************/
static void scale1d_2t1_i(const unsigned char *source, int source_step,
                          unsigned int source_scale, unsigned int source_length,
                          unsigned char *dest, int dest_step,
                          unsigned int dest_scale, unsigned int dest_length) {
  unsigned int i, j;
  unsigned int temp;
  int source_pitch = source_step;
  (void)source_length;
  (void)source_scale;
  (void)dest_scale;

  source_step *= 2;
  dest[0] = source[0];

  for (i = dest_step, j = source_step; i < dest_length * dest_step;
       i += dest_step, j += source_step) {
    temp = 8;
    temp += 3 * source[j - source_pitch];
    temp += 10 * source[j];
    temp += 3 * source[j + source_pitch];
    temp >>= 4;
    dest[i] = (char)(temp);
  }
}

/****************************************************************************
 *
 *  ROUTINE       : scale1d_2t1_ps
 *
 *  INPUTS        : const unsigned char *source : Pointer to data to be scaled.
 *                  int source_step             : Number of pixels to step on in
 *                                                source.
 *                  unsigned int source_scale   : Scale for source (UNUSED).
 *                  unsigned int source_length  : Length of source (UNUSED).
 *                  unsigned char *dest         : Pointer to output data array.
 *                  int dest_step               : Number of pixels to step on in
 *                                                destination.
 *                  unsigned int dest_scale     : Scale for destination
 *                                                (UNUSED).
 *                  unsigned int dest_length    : Length of destination.
 *
 *  OUTPUTS       : None.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Performs 2-to-1 point subsampled scaling.
 *
 *  SPECIAL NOTES : None.
 *
 ****************************************************************************/
static void scale1d_2t1_ps(const unsigned char *source, int source_step,
                           unsigned int source_scale,
                           unsigned int source_length, unsigned char *dest,
                           int dest_step, unsigned int dest_scale,
                           unsigned int dest_length) {
  unsigned int i, j;

  (void)source_length;
  (void)source_scale;
  (void)dest_scale;

  source_step *= 2;
  j = 0;

  for (i = 0; i < dest_length * dest_step; i += dest_step, j += source_step)
    dest[i] = source[j];
}
/****************************************************************************
 *
 *  ROUTINE       : scale1d_c
 *
 *  INPUTS        : const unsigned char *source : Pointer to data to be scaled.
 *                  int source_step             : Number of pixels to step on in
 *                                                source.
 *                  unsigned int source_scale   : Scale for source.
 *                  unsigned int source_length  : Length of source (UNUSED).
 *                  unsigned char *dest         : Pointer to output data array.
 *                  int dest_step               : Number of pixels to step on in
 *                                                destination.
 *                  unsigned int dest_scale     : Scale for destination.
 *                  unsigned int dest_length    : Length of destination.
 *
 *  OUTPUTS       : None.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Performs linear interpolation in one dimension.
 *
 *  SPECIAL NOTES : None.
 *
 ****************************************************************************/
static void scale1d_c(const unsigned char *source, int source_step,
                      unsigned int source_scale, unsigned int source_length,
                      unsigned char *dest, int dest_step,
                      unsigned int dest_scale, unsigned int dest_length) {
  unsigned int i;
  unsigned int round_value = dest_scale / 2;
  unsigned int left_modifier = dest_scale;
  unsigned int right_modifier = 0;
  unsigned char left_pixel = *source;
  unsigned char right_pixel = *(source + source_step);

  (void)source_length;

  /* These asserts are needed if there are boundary issues... */
  /*assert ( dest_scale > source_scale );*/
  /*assert ( (source_length-1) * dest_scale >= (dest_length-1) * source_scale
   * );*/

  assert(dest_scale != 0);
  for (i = 0; i < dest_length * dest_step; i += dest_step) {
    dest[i] = (char)((left_modifier * left_pixel +
                      right_modifier * right_pixel + round_value) /
                     dest_scale);

    right_modifier += source_scale;

    while (right_modifier > dest_scale) {
      right_modifier -= dest_scale;
      source += source_step;
      left_pixel = *source;
      right_pixel = *(source + source_step);
    }

    left_modifier = dest_scale - right_modifier;
  }
}

/****************************************************************************
 *
 *  ROUTINE       : Scale2D
 *
 *  INPUTS        : const unsigned char *source    : Pointer to data to be
 *                                                   scaled.
 *                  int source_pitch               : Stride of source image.
 *                  unsigned int source_width      : Width of input image.
 *                  unsigned int source_height     : Height of input image.
 *                  unsigned char *dest            : Pointer to output data
 *                                                   array.
 *                  int dest_pitch                 : Stride of destination
 *                                                   image.
 *                  unsigned int dest_width        : Width of destination image.
 *                  unsigned int dest_height       : Height of destination
 *                                                   image.
 *                  unsigned char *temp_area       : Pointer to temp work area.
 *                  unsigned char temp_area_height : Height of temp work area.
 *                  unsigned int hscale            : Horizontal scale factor
 *                                                   numerator.
 *                  unsigned int hratio            : Horizontal scale factor
 *                                                   denominator.
 *                  unsigned int vscale            : Vertical scale factor
 *                                                   numerator.
 *                  unsigned int vratio            : Vertical scale factor
 *                                                   denominator.
 *                  unsigned int interlaced        : Interlace flag.
 *
 *  OUTPUTS       : None.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Performs 2-tap linear interpolation in two dimensions.
 *
 *  SPECIAL NOTES : Expansion is performed one band at a time to help with
 *                  caching.
 *
 ****************************************************************************/
static void Scale2D(
    /*const*/
    unsigned char *source, int source_pitch, unsigned int source_width,
    unsigned int source_height, unsigned char *dest, int dest_pitch,
    unsigned int dest_width, unsigned int dest_height, unsigned char *temp_area,
    unsigned char temp_area_height, unsigned int hscale, unsigned int hratio,
    unsigned int vscale, unsigned int vratio, unsigned int interlaced) {
  /*unsigned*/
  int i, j, k;
  int bands;
  int dest_band_height;
  int source_band_height;

  typedef void (*Scale1D)(const unsigned char *source, int source_step,
                          unsigned int source_scale, unsigned int source_length,
                          unsigned char *dest, int dest_step,
                          unsigned int dest_scale, unsigned int dest_length);

  Scale1D Scale1Dv = scale1d_c;
  Scale1D Scale1Dh = scale1d_c;

  void (*horiz_line_scale)(const unsigned char *, unsigned int, unsigned char *,
                           unsigned int) = NULL;
  void (*vert_band_scale)(unsigned char *, unsigned int, unsigned char *,
                          unsigned int, unsigned int) = NULL;

  int ratio_scalable = 1;
  int interpolation = 0;

  unsigned char *source_base;
  unsigned char *line_src;

  source_base = (unsigned char *)source;

  if (source_pitch < 0) {
    int offset;

    offset = (source_height - 1);
    offset *= source_pitch;

    source_base += offset;
  }

  /* find out the ratio for each direction */
  switch (hratio * 10 / hscale) {
    case 8:
      /* 4-5 Scale in Width direction */
      horiz_line_scale = vp8_horizontal_line_5_4_scale;
      break;
    case 6:
      /* 3-5 Scale in Width direction */
      horiz_line_scale = vp8_horizontal_line_5_3_scale;
      break;
    case 5:
      /* 1-2 Scale in Width direction */
      horiz_line_scale = vp8_horizontal_line_2_1_scale;
      break;
    default:
      /* The ratio is not acceptable now */
      /* throw("The ratio is not acceptable for now!"); */
      ratio_scalable = 0;
      break;
  }

  switch (vratio * 10 / vscale) {
    case 8:
      /* 4-5 Scale in vertical direction */
      vert_band_scale = vp8_vertical_band_5_4_scale;
      source_band_height = 5;
      dest_band_height = 4;
      break;
    case 6:
      /* 3-5 Scale in vertical direction */
      vert_band_scale = vp8_vertical_band_5_3_scale;
      source_band_height = 5;
      dest_band_height = 3;
      break;
    case 5:
      /* 1-2 Scale in vertical direction */

      if (interlaced) {
        /* if the content is interlaced, point sampling is used */
        vert_band_scale = vp8_vertical_band_2_1_scale;
      } else {
        interpolation = 1;
        /* if the content is progressive, interplo */
        vert_band_scale = vp8_vertical_band_2_1_scale_i;
      }

      source_band_height = 2;
      dest_band_height = 1;
      break;
    default:
      /* The ratio is not acceptable now */
      /* throw("The ratio is not acceptable for now!"); */
      ratio_scalable = 0;
      break;
  }

  if (ratio_scalable) {
    if (source_height == dest_height) {
      /* for each band of the image */
      for (k = 0; k < (int)dest_height; k++) {
        horiz_line_scale(source, source_width, dest, dest_width);
        source += source_pitch;
        dest += dest_pitch;
      }

      return;
    }

    if (interpolation) {
      if (source < source_base) source = source_base;

      horiz_line_scale(source, source_width, temp_area, dest_width);
    }

    for (k = 0;
         k < (int)(dest_height + dest_band_height - 1) / dest_band_height;
         k++) {
      /* scale one band horizontally */
      for (i = 0; i < source_band_height; i++) {
        /* Trap case where we could read off the base of the source buffer */

        line_src = (unsigned char *)source + i * source_pitch;

        if (line_src < source_base) line_src = source_base;

        horiz_line_scale(line_src, source_width,
                         temp_area + (i + 1) * dest_pitch, dest_width);
      }

      /* Vertical scaling is in place */
      vert_band_scale(temp_area + dest_pitch, dest_pitch, dest, dest_pitch,
                      dest_width);

      if (interpolation)
        memcpy(temp_area, temp_area + source_band_height * dest_pitch,
               dest_width);

      /* Next band... */
      source += (unsigned long)source_band_height * source_pitch;
      dest += (unsigned long)dest_band_height * dest_pitch;
    }

    return;
  }

  if (hscale == 2 && hratio == 1) Scale1Dh = scale1d_2t1_ps;

  if (vscale == 2 && vratio == 1) {
    if (interlaced)
      Scale1Dv = scale1d_2t1_ps;
    else
      Scale1Dv = scale1d_2t1_i;
  }

  if (source_height == dest_height) {
    /* for each band of the image */
    for (k = 0; k < (int)dest_height; k++) {
      Scale1Dh(source, 1, hscale, source_width + 1, dest, 1, hratio,
               dest_width);
      source += source_pitch;
      dest += dest_pitch;
    }

    return;
  }

  if (dest_height > source_height) {
    dest_band_height = temp_area_height - 1;
    source_band_height = dest_band_height * source_height / dest_height;
  } else {
    source_band_height = temp_area_height - 1;
    dest_band_height = source_band_height * vratio / vscale;
  }

  /* first row needs to be done so that we can stay one row ahead for vertical
   * zoom */
  Scale1Dh(source, 1, hscale, source_width + 1, temp_area, 1, hratio,
           dest_width);

  /* for each band of the image */
  bands = (dest_height + dest_band_height - 1) / dest_band_height;

  for (k = 0; k < bands; k++) {
    /* scale one band horizontally */
    for (i = 1; i < source_band_height + 1; i++) {
      if (k * source_band_height + i < (int)source_height) {
        Scale1Dh(source + i * source_pitch, 1, hscale, source_width + 1,
                 temp_area + i * dest_pitch, 1, hratio, dest_width);
      } else { /*  Duplicate the last row */
        /* copy temp_area row 0 over from last row in the past */
        memcpy(temp_area + i * dest_pitch, temp_area + (i - 1) * dest_pitch,
               dest_pitch);
      }
    }

    /* scale one band vertically */
    for (j = 0; j < (int)dest_width; j++) {
      Scale1Dv(&temp_area[j], dest_pitch, vscale, source_band_height + 1,
               &dest[j], dest_pitch, vratio, dest_band_height);
    }

    /* copy temp_area row 0 over from last row in the past */
    memcpy(temp_area, temp_area + source_band_height * dest_pitch, dest_pitch);

    /* move to the next band */
    source += source_band_height * source_pitch;
    dest += dest_band_height * dest_pitch;
  }
}

/****************************************************************************
 *
 *  ROUTINE       : vpx_scale_frame
 *
 *  INPUTS        : YV12_BUFFER_CONFIG *src        : Pointer to frame to be
 *                                                   scaled.
 *                  YV12_BUFFER_CONFIG *dst        : Pointer to buffer to hold
 *                                                   scaled frame.
 *                  unsigned char *temp_area       : Pointer to temp work area.
 *                  unsigned char temp_area_height : Height of temp work area.
 *                  unsigned int hscale            : Horizontal scale factor
 *                                                   numerator.
 *                  unsigned int hratio            : Horizontal scale factor
 *                                                   denominator.
 *                  unsigned int vscale            : Vertical scale factor
 *                                                   numerator.
 *                  unsigned int vratio            : Vertical scale factor
 *                                                   denominator.
 *                  unsigned int interlaced        : Interlace flag.
 *
 *  OUTPUTS       : None.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Performs 2-tap linear interpolation in two dimensions.
 *
 *  SPECIAL NOTES : Expansion is performed one band at a time to help with
 *                  caching.
 *
 ****************************************************************************/
void vpx_scale_frame(YV12_BUFFER_CONFIG *src, YV12_BUFFER_CONFIG *dst,
                     unsigned char *temp_area, unsigned char temp_height,
                     unsigned int hscale, unsigned int hratio,
                     unsigned int vscale, unsigned int vratio,
                     unsigned int interlaced) {
  int i;
  int dw = (hscale - 1 + src->y_width * hratio) / hscale;
  int dh = (vscale - 1 + src->y_height * vratio) / vscale;

  /* call our internal scaling routines!! */
  Scale2D((unsigned char *)src->y_buffer, src->y_stride, src->y_width,
          src->y_height, (unsigned char *)dst->y_buffer, dst->y_stride, dw, dh,
          temp_area, temp_height, hscale, hratio, vscale, vratio, interlaced);

  if (dw < (int)dst->y_width)
    for (i = 0; i < dh; i++)
      memset(dst->y_buffer + i * dst->y_stride + dw - 1,
             dst->y_buffer[i * dst->y_stride + dw - 2], dst->y_width - dw + 1);

  if (dh < (int)dst->y_height)
    for (i = dh - 1; i < (int)dst->y_height; i++)
      memcpy(dst->y_buffer + i * dst->y_stride,
             dst->y_buffer + (dh - 2) * dst->y_stride, dst->y_width + 1);

  Scale2D((unsigned char *)src->u_buffer, src->uv_stride, src->uv_width,
          src->uv_height, (unsigned char *)dst->u_buffer, dst->uv_stride,
          dw / 2, dh / 2, temp_area, temp_height, hscale, hratio, vscale,
          vratio, interlaced);

  if (dw / 2 < (int)dst->uv_width)
    for (i = 0; i < dst->uv_height; i++)
      memset(dst->u_buffer + i * dst->uv_stride + dw / 2 - 1,
             dst->u_buffer[i * dst->uv_stride + dw / 2 - 2],
             dst->uv_width - dw / 2 + 1);

  if (dh / 2 < (int)dst->uv_height)
    for (i = dh / 2 - 1; i < (int)dst->y_height / 2; i++)
      memcpy(dst->u_buffer + i * dst->uv_stride,
             dst->u_buffer + (dh / 2 - 2) * dst->uv_stride, dst->uv_width);

  Scale2D((unsigned char *)src->v_buffer, src->uv_stride, src->uv_width,
          src->uv_height, (unsigned char *)dst->v_buffer, dst->uv_stride,
          dw / 2, dh / 2, temp_area, temp_height, hscale, hratio, vscale,
          vratio, interlaced);

  if (dw / 2 < (int)dst->uv_width)
    for (i = 0; i < dst->uv_height; i++)
      memset(dst->v_buffer + i * dst->uv_stride + dw / 2 - 1,
             dst->v_buffer[i * dst->uv_stride + dw / 2 - 2],
             dst->uv_width - dw / 2 + 1);

  if (dh / 2 < (int)dst->uv_height)
    for (i = dh / 2 - 1; i < (int)dst->y_height / 2; i++)
      memcpy(dst->v_buffer + i * dst->uv_stride,
             dst->v_buffer + (dh / 2 - 2) * dst->uv_stride, dst->uv_width);
}

Coverage Report

Created: 2024-09-06 07:53

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3		*
4		* Use of this source code is governed by a BSD-style license
5		* that can be found in the LICENSE file in the root of the source
6		* tree. An additional intellectual property rights grant can be found
7		* in the file PATENTS. All contributing project authors may
8		* be found in the AUTHORS file in the root of the source tree.
9		*/
10
11		/****************************************************************************
12		*
13		* Module Title : scale.c
14		*
15		* Description : Image scaling functions.
16		*
17		***************************************************************************/
18
19		/****************************************************************************
20		* Header Files
21		****************************************************************************/
22		#include <assert.h>
23
24		#include "./vpx_scale_rtcd.h"
25		#include "vpx_mem/vpx_mem.h"
26		#include "vpx_scale/vpx_scale.h"
27		#include "vpx_scale/yv12config.h"
28
29		typedef struct {
30		int expanded_frame_width;
31		int expanded_frame_height;
32
33		int HScale;
34		int HRatio;
35		int VScale;
36		int VRatio;
37
38		YV12_BUFFER_CONFIG *src_yuv_config;
39		YV12_BUFFER_CONFIG *dst_yuv_config;
40
41		} SCALE_VARS;
42
43		/****************************************************************************
44		*
45		* ROUTINE : scale1d_2t1_i
46		*
47		* INPUTS : const unsigned char *source : Pointer to data to be scaled.
48		* int source_step : Number of pixels to step on in
49		* source.
50		* unsigned int source_scale : Scale for source (UNUSED).
51		* unsigned int source_length : Length of source (UNUSED).
52		* unsigned char *dest : Pointer to output data array.
53		* int dest_step : Number of pixels to step on in
54		* destination.
55		* unsigned int dest_scale : Scale for destination
56		* (UNUSED).
57		* unsigned int dest_length : Length of destination.
58		*
59		* OUTPUTS : None.
60		*
61		* RETURNS : void
62		*
63		* FUNCTION : Performs 2-to-1 interpolated scaling.
64		*
65		* SPECIAL NOTES : None.
66		*
67		****************************************************************************/
68		static void scale1d_2t1_i(const unsigned char *source, int source_step,
69		unsigned int source_scale, unsigned int source_length,
70		unsigned char *dest, int dest_step,
71	0	unsigned int dest_scale, unsigned int dest_length) {
72	0	unsigned int i, j;
73	0	unsigned int temp;
74	0	int source_pitch = source_step;
75	0	(void)source_length;
76	0	(void)source_scale;
77	0	(void)dest_scale;
78
79	0	source_step *= 2;
80	0	dest[0] = source[0];
81
82	0	for (i = dest_step, j = source_step; i < dest_length * dest_step;
83	0	i += dest_step, j += source_step) {
84	0	temp = 8;
85	0	temp += 3 * source[j - source_pitch];
86	0	temp += 10 * source[j];
87	0	temp += 3 * source[j + source_pitch];
88	0	temp >>= 4;
89	0	dest[i] = (char)(temp);
90	0	}
91	0	}
92
93		/****************************************************************************
94		*
95		* ROUTINE : scale1d_2t1_ps
96		*
97		* INPUTS : const unsigned char *source : Pointer to data to be scaled.
98		* int source_step : Number of pixels to step on in
99		* source.
100		* unsigned int source_scale : Scale for source (UNUSED).
101		* unsigned int source_length : Length of source (UNUSED).
102		* unsigned char *dest : Pointer to output data array.
103		* int dest_step : Number of pixels to step on in
104		* destination.
105		* unsigned int dest_scale : Scale for destination
106		* (UNUSED).
107		* unsigned int dest_length : Length of destination.
108		*
109		* OUTPUTS : None.
110		*
111		* RETURNS : void
112		*
113		* FUNCTION : Performs 2-to-1 point subsampled scaling.
114		*
115		* SPECIAL NOTES : None.
116		*
117		****************************************************************************/
118		static void scale1d_2t1_ps(const unsigned char *source, int source_step,
119		unsigned int source_scale,
120		unsigned int source_length, unsigned char *dest,
121		int dest_step, unsigned int dest_scale,
122	0	unsigned int dest_length) {
123	0	unsigned int i, j;
124
125	0	(void)source_length;
126	0	(void)source_scale;
127	0	(void)dest_scale;
128
129	0	source_step *= 2;
130	0	j = 0;
131
132	0	for (i = 0; i < dest_length * dest_step; i += dest_step, j += source_step)
133	0	dest[i] = source[j];
134	0	}
135		/****************************************************************************
136		*
137		* ROUTINE : scale1d_c
138		*
139		* INPUTS : const unsigned char *source : Pointer to data to be scaled.
140		* int source_step : Number of pixels to step on in
141		* source.
142		* unsigned int source_scale : Scale for source.
143		* unsigned int source_length : Length of source (UNUSED).
144		* unsigned char *dest : Pointer to output data array.
145		* int dest_step : Number of pixels to step on in
146		* destination.
147		* unsigned int dest_scale : Scale for destination.
148		* unsigned int dest_length : Length of destination.
149		*
150		* OUTPUTS : None.
151		*
152		* RETURNS : void
153		*
154		* FUNCTION : Performs linear interpolation in one dimension.
155		*
156		* SPECIAL NOTES : None.
157		*
158		****************************************************************************/
159		static void scale1d_c(const unsigned char *source, int source_step,
160		unsigned int source_scale, unsigned int source_length,
161		unsigned char *dest, int dest_step,
162	0	unsigned int dest_scale, unsigned int dest_length) {
163	0	unsigned int i;
164	0	unsigned int round_value = dest_scale / 2;
165	0	unsigned int left_modifier = dest_scale;
166	0	unsigned int right_modifier = 0;
167	0	unsigned char left_pixel = *source;
168	0	unsigned char right_pixel = *(source + source_step);
169
170	0	(void)source_length;
171
172		/* These asserts are needed if there are boundary issues... */
173		/assert ( dest_scale > source_scale );/
174		/assert ( (source_length-1) dest_scale >= (dest_length-1) * source_scale
175		* );*/
176
177	0	assert(dest_scale != 0);
178	0	for (i = 0; i < dest_length * dest_step; i += dest_step) {
179	0	dest[i] = (char)((left_modifier * left_pixel +
180	0	right_modifier * right_pixel + round_value) /
181	0	dest_scale);
182
183	0	right_modifier += source_scale;
184
185	0	while (right_modifier > dest_scale) {
186	0	right_modifier -= dest_scale;
187	0	source += source_step;
188	0	left_pixel = *source;
189	0	right_pixel = *(source + source_step);
190	0	}
191
192	0	left_modifier = dest_scale - right_modifier;
193	0	}
194	0	}
195
196		/****************************************************************************
197		*
198		* ROUTINE : Scale2D
199		*
200		* INPUTS : const unsigned char *source : Pointer to data to be
201		* scaled.
202		* int source_pitch : Stride of source image.
203		* unsigned int source_width : Width of input image.
204		* unsigned int source_height : Height of input image.
205		* unsigned char *dest : Pointer to output data
206		* array.
207		* int dest_pitch : Stride of destination
208		* image.
209		* unsigned int dest_width : Width of destination image.
210		* unsigned int dest_height : Height of destination
211		* image.
212		* unsigned char *temp_area : Pointer to temp work area.
213		* unsigned char temp_area_height : Height of temp work area.
214		* unsigned int hscale : Horizontal scale factor
215		* numerator.
216		* unsigned int hratio : Horizontal scale factor
217		* denominator.
218		* unsigned int vscale : Vertical scale factor
219		* numerator.
220		* unsigned int vratio : Vertical scale factor
221		* denominator.
222		* unsigned int interlaced : Interlace flag.
223		*
224		* OUTPUTS : None.
225		*
226		* RETURNS : void
227		*
228		* FUNCTION : Performs 2-tap linear interpolation in two dimensions.
229		*
230		* SPECIAL NOTES : Expansion is performed one band at a time to help with
231		* caching.
232		*
233		****************************************************************************/
234		static void Scale2D(
235		/const/
236		unsigned char *source, int source_pitch, unsigned int source_width,
237		unsigned int source_height, unsigned char *dest, int dest_pitch,
238		unsigned int dest_width, unsigned int dest_height, unsigned char *temp_area,
239		unsigned char temp_area_height, unsigned int hscale, unsigned int hratio,
240	0	unsigned int vscale, unsigned int vratio, unsigned int interlaced) {
241		/unsigned/
242	0	int i, j, k;
243	0	int bands;
244	0	int dest_band_height;
245	0	int source_band_height;
246
247	0	typedef void (Scale1D)(const unsigned char source, int source_step,
248	0	unsigned int source_scale, unsigned int source_length,
249	0	unsigned char *dest, int dest_step,
250	0	unsigned int dest_scale, unsigned int dest_length);
251
252	0	Scale1D Scale1Dv = scale1d_c;
253	0	Scale1D Scale1Dh = scale1d_c;
254
255	0	void (horiz_line_scale)(const unsigned char , unsigned int, unsigned char *,
256	0	unsigned int) = NULL;
257	0	void (vert_band_scale)(unsigned char , unsigned int, unsigned char *,
258	0	unsigned int, unsigned int) = NULL;
259
260	0	int ratio_scalable = 1;
261	0	int interpolation = 0;
262
263	0	unsigned char *source_base;
264	0	unsigned char *line_src;
265
266	0	source_base = (unsigned char *)source;
267
268	0	if (source_pitch < 0) {
269	0	int offset;
270
271	0	offset = (source_height - 1);
272	0	offset *= source_pitch;
273
274	0	source_base += offset;
275	0	}
276
277		/* find out the ratio for each direction */
278	0	switch (hratio * 10 / hscale) {
279	0	case 8:
280		/* 4-5 Scale in Width direction */
281	0	horiz_line_scale = vp8_horizontal_line_5_4_scale;
282	0	break;
283	0	case 6:
284		/* 3-5 Scale in Width direction */
285	0	horiz_line_scale = vp8_horizontal_line_5_3_scale;
286	0	break;
287	0	case 5:
288		/* 1-2 Scale in Width direction */
289	0	horiz_line_scale = vp8_horizontal_line_2_1_scale;
290	0	break;
291	0	default:
292		/* The ratio is not acceptable now */
293		/* throw("The ratio is not acceptable for now!"); */
294	0	ratio_scalable = 0;
295	0	break;
296	0	}
297
298	0	switch (vratio * 10 / vscale) {
299	0	case 8:
300		/* 4-5 Scale in vertical direction */
301	0	vert_band_scale = vp8_vertical_band_5_4_scale;
302	0	source_band_height = 5;
303	0	dest_band_height = 4;
304	0	break;
305	0	case 6:
306		/* 3-5 Scale in vertical direction */
307	0	vert_band_scale = vp8_vertical_band_5_3_scale;
308	0	source_band_height = 5;
309	0	dest_band_height = 3;
310	0	break;
311	0	case 5:
312		/* 1-2 Scale in vertical direction */
313
314	0	if (interlaced) {
315		/* if the content is interlaced, point sampling is used */
316	0	vert_band_scale = vp8_vertical_band_2_1_scale;
317	0	} else {
318	0	interpolation = 1;
319		/* if the content is progressive, interplo */
320	0	vert_band_scale = vp8_vertical_band_2_1_scale_i;
321	0	}
322
323	0	source_band_height = 2;
324	0	dest_band_height = 1;
325	0	break;
326	0	default:
327		/* The ratio is not acceptable now */
328		/* throw("The ratio is not acceptable for now!"); */
329	0	ratio_scalable = 0;
330	0	break;
331	0	}
332
333	0	if (ratio_scalable) {
334	0	if (source_height == dest_height) {
335		/* for each band of the image */
336	0	for (k = 0; k < (int)dest_height; k++) {
337	0	horiz_line_scale(source, source_width, dest, dest_width);
338	0	source += source_pitch;
339	0	dest += dest_pitch;
340	0	}
341
342	0	return;
343	0	}
344
345	0	if (interpolation) {
346	0	if (source < source_base) source = source_base;
347
348	0	horiz_line_scale(source, source_width, temp_area, dest_width);
349	0	}
350
351	0	for (k = 0;
352	0	k < (int)(dest_height + dest_band_height - 1) / dest_band_height;
353	0	k++) {
354		/* scale one band horizontally */
355	0	for (i = 0; i < source_band_height; i++) {
356		/* Trap case where we could read off the base of the source buffer */
357
358	0	line_src = (unsigned char )source + i source_pitch;
359
360	0	if (line_src < source_base) line_src = source_base;
361
362	0	horiz_line_scale(line_src, source_width,
363	0	temp_area + (i + 1) * dest_pitch, dest_width);
364	0	}
365
366		/* Vertical scaling is in place */
367	0	vert_band_scale(temp_area + dest_pitch, dest_pitch, dest, dest_pitch,
368	0	dest_width);
369
370	0	if (interpolation)
371	0	memcpy(temp_area, temp_area + source_band_height * dest_pitch,
372	0	dest_width);
373
374		/* Next band... */
375	0	source += (unsigned long)source_band_height * source_pitch;
376	0	dest += (unsigned long)dest_band_height * dest_pitch;
377	0	}
378
379	0	return;
380	0	}
381
382	0	if (hscale == 2 && hratio == 1) Scale1Dh = scale1d_2t1_ps;
383
384	0	if (vscale == 2 && vratio == 1) {
385	0	if (interlaced)
386	0	Scale1Dv = scale1d_2t1_ps;
387	0	else
388	0	Scale1Dv = scale1d_2t1_i;
389	0	}
390
391	0	if (source_height == dest_height) {
392		/* for each band of the image */
393	0	for (k = 0; k < (int)dest_height; k++) {
394	0	Scale1Dh(source, 1, hscale, source_width + 1, dest, 1, hratio,
395	0	dest_width);
396	0	source += source_pitch;
397	0	dest += dest_pitch;
398	0	}
399
400	0	return;
401	0	}
402
403	0	if (dest_height > source_height) {
404	0	dest_band_height = temp_area_height - 1;
405	0	source_band_height = dest_band_height * source_height / dest_height;
406	0	} else {
407	0	source_band_height = temp_area_height - 1;
408	0	dest_band_height = source_band_height * vratio / vscale;
409	0	}
410
411		/* first row needs to be done so that we can stay one row ahead for vertical
412		* zoom */
413	0	Scale1Dh(source, 1, hscale, source_width + 1, temp_area, 1, hratio,
414	0	dest_width);
415
416		/* for each band of the image */
417	0	bands = (dest_height + dest_band_height - 1) / dest_band_height;
418
419	0	for (k = 0; k < bands; k++) {
420		/* scale one band horizontally */
421	0	for (i = 1; i < source_band_height + 1; i++) {
422	0	if (k * source_band_height + i < (int)source_height) {
423	0	Scale1Dh(source + i * source_pitch, 1, hscale, source_width + 1,
424	0	temp_area + i * dest_pitch, 1, hratio, dest_width);
425	0	} else { /* Duplicate the last row */
426		/* copy temp_area row 0 over from last row in the past */
427	0	memcpy(temp_area + i * dest_pitch, temp_area + (i - 1) * dest_pitch,
428	0	dest_pitch);
429	0	}
430	0	}
431
432		/* scale one band vertically */
433	0	for (j = 0; j < (int)dest_width; j++) {
434	0	Scale1Dv(&temp_area[j], dest_pitch, vscale, source_band_height + 1,
435	0	&dest[j], dest_pitch, vratio, dest_band_height);
436	0	}
437
438		/* copy temp_area row 0 over from last row in the past */
439	0	memcpy(temp_area, temp_area + source_band_height * dest_pitch, dest_pitch);
440
441		/* move to the next band */
442	0	source += source_band_height * source_pitch;
443	0	dest += dest_band_height * dest_pitch;
444	0	}
445	0	}
446
447		/****************************************************************************
448		*
449		* ROUTINE : vpx_scale_frame
450		*
451		* INPUTS : YV12_BUFFER_CONFIG *src : Pointer to frame to be
452		* scaled.
453		* YV12_BUFFER_CONFIG *dst : Pointer to buffer to hold
454		* scaled frame.
455		* unsigned char *temp_area : Pointer to temp work area.
456		* unsigned char temp_area_height : Height of temp work area.
457		* unsigned int hscale : Horizontal scale factor
458		* numerator.
459		* unsigned int hratio : Horizontal scale factor
460		* denominator.
461		* unsigned int vscale : Vertical scale factor
462		* numerator.
463		* unsigned int vratio : Vertical scale factor
464		* denominator.
465		* unsigned int interlaced : Interlace flag.
466		*
467		* OUTPUTS : None.
468		*
469		* RETURNS : void
470		*
471		* FUNCTION : Performs 2-tap linear interpolation in two dimensions.
472		*
473		* SPECIAL NOTES : Expansion is performed one band at a time to help with
474		* caching.
475		*
476		****************************************************************************/
477		void vpx_scale_frame(YV12_BUFFER_CONFIG src, YV12_BUFFER_CONFIG dst,
478		unsigned char *temp_area, unsigned char temp_height,
479		unsigned int hscale, unsigned int hratio,
480		unsigned int vscale, unsigned int vratio,
481	0	unsigned int interlaced) {
482	0	int i;
483	0	int dw = (hscale - 1 + src->y_width * hratio) / hscale;
484	0	int dh = (vscale - 1 + src->y_height * vratio) / vscale;
485
486		/* call our internal scaling routines!! */
487	0	Scale2D((unsigned char *)src->y_buffer, src->y_stride, src->y_width,
488	0	src->y_height, (unsigned char *)dst->y_buffer, dst->y_stride, dw, dh,
489	0	temp_area, temp_height, hscale, hratio, vscale, vratio, interlaced);
490
491	0	if (dw < (int)dst->y_width)
492	0	for (i = 0; i < dh; i++)
493	0	memset(dst->y_buffer + i * dst->y_stride + dw - 1,
494	0	dst->y_buffer[i * dst->y_stride + dw - 2], dst->y_width - dw + 1);
495
496	0	if (dh < (int)dst->y_height)
497	0	for (i = dh - 1; i < (int)dst->y_height; i++)
498	0	memcpy(dst->y_buffer + i * dst->y_stride,
499	0	dst->y_buffer + (dh - 2) * dst->y_stride, dst->y_width + 1);
500
501	0	Scale2D((unsigned char *)src->u_buffer, src->uv_stride, src->uv_width,
502	0	src->uv_height, (unsigned char *)dst->u_buffer, dst->uv_stride,
503	0	dw / 2, dh / 2, temp_area, temp_height, hscale, hratio, vscale,
504	0	vratio, interlaced);
505
506	0	if (dw / 2 < (int)dst->uv_width)
507	0	for (i = 0; i < dst->uv_height; i++)
508	0	memset(dst->u_buffer + i * dst->uv_stride + dw / 2 - 1,
509	0	dst->u_buffer[i * dst->uv_stride + dw / 2 - 2],
510	0	dst->uv_width - dw / 2 + 1);
511
512	0	if (dh / 2 < (int)dst->uv_height)
513	0	for (i = dh / 2 - 1; i < (int)dst->y_height / 2; i++)
514	0	memcpy(dst->u_buffer + i * dst->uv_stride,
515	0	dst->u_buffer + (dh / 2 - 2) * dst->uv_stride, dst->uv_width);
516
517	0	Scale2D((unsigned char *)src->v_buffer, src->uv_stride, src->uv_width,
518	0	src->uv_height, (unsigned char *)dst->v_buffer, dst->uv_stride,
519	0	dw / 2, dh / 2, temp_area, temp_height, hscale, hratio, vscale,
520	0	vratio, interlaced);
521
522	0	if (dw / 2 < (int)dst->uv_width)
523	0	for (i = 0; i < dst->uv_height; i++)
524	0	memset(dst->v_buffer + i * dst->uv_stride + dw / 2 - 1,
525	0	dst->v_buffer[i * dst->uv_stride + dw / 2 - 2],
526	0	dst->uv_width - dw / 2 + 1);
527
528	0	if (dh / 2 < (int)dst->uv_height)
529	0	for (i = dh / 2 - 1; i < (int)dst->y_height / 2; i++)
530	0	memcpy(dst->v_buffer + i * dst->uv_stride,
531	0	dst->v_buffer + (dh / 2 - 2) * dst->uv_stride, dst->uv_width);
532	0	}