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