libavcodec/imgconvert.c

   1 /*
   2  * Misc image conversion routines
   3  * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * misc image conversion routines
  25  */
  26
  27 /* TODO:
  28  * - write 'ffimg' program to test all the image related stuff
  29  * - move all api to slice based system
  30  * - integrate deinterlacing, postprocessing and scaling in the conversion process
  31  */
  32
  33 #include "avcodec.h"
  34 #include "imgconvert.h"
  35 #include "internal.h"
  36 #include "mathops.h"
  37 #include "libavutil/colorspace.h"
  38 #include "libavutil/common.h"
  39 #include "libavutil/pixdesc.h"
  40 #include "libavutil/internal.h"
  41 #include "libavutil/imgutils.h"
  42
  43 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift)
  44 {
  45     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
  46     *h_shift = desc->log2_chroma_w;
  47     *v_shift = desc->log2_chroma_h;
  48 }
  49
  50 static int is_gray(const AVPixFmtDescriptor *desc)
  51 {
  52     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;
  53 }
  54
  55 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt,
  56                              enum AVPixelFormat src_pix_fmt,
  57                              int has_alpha)
  58 {
  59     const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_pix_fmt);
  60     const AVPixFmtDescriptor *dst_desc = av_pix_fmt_desc_get(dst_pix_fmt);
  61     int loss, i, nb_components = FFMIN(src_desc->nb_components,
  62                                        dst_desc->nb_components);
  63
  64     /* compute loss */
  65     loss = 0;
  66
  67     if (dst_pix_fmt == src_pix_fmt)
  68         return 0;
  69
  70     for (i = 0; i < nb_components; i++)
  71         if (src_desc->comp[i].depth > dst_desc->comp[i].depth)
  72             loss |= FF_LOSS_DEPTH;
  73
  74     if (dst_desc->log2_chroma_w > src_desc->log2_chroma_w ||
  75         dst_desc->log2_chroma_h > src_desc->log2_chroma_h)
  76         loss |= FF_LOSS_RESOLUTION;
  77
  78     if ((src_desc->flags & AV_PIX_FMT_FLAG_RGB) != (dst_desc->flags & AV_PIX_FMT_FLAG_RGB))
  79         loss |= FF_LOSS_COLORSPACE;
  80
  81     if (has_alpha && !(dst_desc->flags & AV_PIX_FMT_FLAG_ALPHA) &&
  82          (src_desc->flags & AV_PIX_FMT_FLAG_ALPHA))
  83         loss |= FF_LOSS_ALPHA;
  84
  85     if (dst_pix_fmt == AV_PIX_FMT_PAL8 && !is_gray(src_desc))
  86         return loss | FF_LOSS_COLORQUANT;
  87
  88     if (src_desc->nb_components > dst_desc->nb_components)
  89         if (is_gray(dst_desc))
  90             loss |= FF_LOSS_CHROMA;
  91
  92     return loss;
  93 }
  94
  95 static enum AVPixelFormat avcodec_find_best_pix_fmt1(enum AVPixelFormat *pix_fmt_list,
  96                                       enum AVPixelFormat src_pix_fmt,
  97                                       int has_alpha,
  98                                       int loss_mask)
  99 {
 100     int dist, i, loss, min_dist;
 101     enum AVPixelFormat dst_pix_fmt;
 102
 103     /* find exact color match with smallest size */
 104     dst_pix_fmt = AV_PIX_FMT_NONE;
 105     min_dist = 0x7fffffff;
 106     i = 0;
 107     while (pix_fmt_list[i] != AV_PIX_FMT_NONE) {
 108         enum AVPixelFormat pix_fmt = pix_fmt_list[i];
 109
 110         if (i > AV_PIX_FMT_NB) {
 111             av_log(NULL, AV_LOG_ERROR, "Pixel format list longer than expected, "
 112                    "it is either not properly terminated or contains duplicates\n");
 113             return AV_PIX_FMT_NONE;
 114         }
 115
 116         loss = avcodec_get_pix_fmt_loss(pix_fmt, src_pix_fmt, has_alpha) & loss_mask;
 117         if (loss == 0) {
 118             dist = av_get_bits_per_pixel(av_pix_fmt_desc_get(pix_fmt));
 119             if (dist < min_dist) {
 120                 min_dist = dist;
 121                 dst_pix_fmt = pix_fmt;
 122             }
 123         }
 124         i++;
 125     }
 126     return dst_pix_fmt;
 127 }
 128
 129 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
 130                                             enum AVPixelFormat src_pix_fmt,
 131                                             int has_alpha, int *loss_ptr)
 132 {
 133     enum AVPixelFormat dst_pix_fmt;
 134     int loss_mask, i;
 135     static const int loss_mask_order[] = {
 136         ~0, /* no loss first */
 137         ~FF_LOSS_ALPHA,
 138         ~FF_LOSS_RESOLUTION,
 139         ~(FF_LOSS_COLORSPACE | FF_LOSS_RESOLUTION),
 140         ~FF_LOSS_COLORQUANT,
 141         ~FF_LOSS_DEPTH,
 142         0,
 143     };
 144
 145     /* try with successive loss */
 146     i = 0;
 147     for(;;) {
 148         loss_mask = loss_mask_order[i++];
 149         dst_pix_fmt = avcodec_find_best_pix_fmt1(pix_fmt_list, src_pix_fmt,
 150                                                  has_alpha, loss_mask);
 151         if (dst_pix_fmt >= 0)
 152             goto found;
 153         if (loss_mask == 0)
 154             break;
 155     }
 156     return AV_PIX_FMT_NONE;
 157  found:
 158     if (loss_ptr)
 159         *loss_ptr = avcodec_get_pix_fmt_loss(dst_pix_fmt, src_pix_fmt, has_alpha);
 160     return dst_pix_fmt;
 161 }
 162
 163 /* 2x2 -> 1x1 */
 164 void ff_shrink22(uint8_t *dst, int dst_wrap,
 165                      const uint8_t *src, int src_wrap,
 166                      int width, int height)
 167 {
 168     int w;
 169     const uint8_t *s1, *s2;
 170     uint8_t *d;
 171
 172     for(;height > 0; height--) {
 173         s1 = src;
 174         s2 = s1 + src_wrap;
 175         d = dst;
 176         for(w = width;w >= 4; w-=4) {
 177             d[0] = (s1[0] + s1[1] + s2[0] + s2[1] + 2) >> 2;
 178             d[1] = (s1[2] + s1[3] + s2[2] + s2[3] + 2) >> 2;
 179             d[2] = (s1[4] + s1[5] + s2[4] + s2[5] + 2) >> 2;
 180             d[3] = (s1[6] + s1[7] + s2[6] + s2[7] + 2) >> 2;
 181             s1 += 8;
 182             s2 += 8;
 183             d += 4;
 184         }
 185         for(;w > 0; w--) {
 186             d[0] = (s1[0] + s1[1] + s2[0] + s2[1] + 2) >> 2;
 187             s1 += 2;
 188             s2 += 2;
 189             d++;
 190         }
 191         src += 2 * src_wrap;
 192         dst += dst_wrap;
 193     }
 194 }
 195
 196 /* 4x4 -> 1x1 */
 197 void ff_shrink44(uint8_t *dst, int dst_wrap,
 198                      const uint8_t *src, int src_wrap,
 199                      int width, int height)
 200 {
 201     int w;
 202     const uint8_t *s1, *s2, *s3, *s4;
 203     uint8_t *d;
 204
 205     for(;height > 0; height--) {
 206         s1 = src;
 207         s2 = s1 + src_wrap;
 208         s3 = s2 + src_wrap;
 209         s4 = s3 + src_wrap;
 210         d = dst;
 211         for(w = width;w > 0; w--) {
 212             d[0] = (s1[0] + s1[1] + s1[2] + s1[3] +
 213                     s2[0] + s2[1] + s2[2] + s2[3] +
 214                     s3[0] + s3[1] + s3[2] + s3[3] +
 215                     s4[0] + s4[1] + s4[2] + s4[3] + 8) >> 4;
 216             s1 += 4;
 217             s2 += 4;
 218             s3 += 4;
 219             s4 += 4;
 220             d++;
 221         }
 222         src += 4 * src_wrap;
 223         dst += dst_wrap;
 224     }
 225 }
 226
 227 /* 8x8 -> 1x1 */
 228 void ff_shrink88(uint8_t *dst, int dst_wrap,
 229                      const uint8_t *src, int src_wrap,
 230                      int width, int height)
 231 {
 232     int w, i;
 233
 234     for(;height > 0; height--) {
 235         for(w = width;w > 0; w--) {
 236             int tmp=0;
 237             for(i=0; i<8; i++){
 238                 tmp += src[0] + src[1] + src[2] + src[3] + src[4] + src[5] + src[6] + src[7];
 239                 src += src_wrap;
 240             }
 241             *(dst++) = (tmp + 32)>>6;
 242             src += 8 - 8*src_wrap;
 243         }
 244         src += 8*src_wrap - 8*width;
 245         dst += dst_wrap - width;
 246     }
 247 }
 248
 249 /* return true if yuv planar */
 250 static inline int is_yuv_planar(const AVPixFmtDescriptor *desc)
 251 {
 252     return (!(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
 253              (desc->flags & AV_PIX_FMT_FLAG_PLANAR));
 254 }
 255
 256 #if FF_API_AVPICTURE
 257 FF_DISABLE_DEPRECATION_WARNINGS
 258
 259 int av_picture_crop(AVPicture *dst, const AVPicture *src,
 260                     enum AVPixelFormat pix_fmt, int top_band, int left_band)
 261 {
 262     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
 263     int y_shift;
 264     int x_shift;
 265
 266     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB || !is_yuv_planar(desc))
 267         return -1;
 268
 269     y_shift = desc->log2_chroma_h;
 270     x_shift = desc->log2_chroma_w;
 271
 272     dst->data[0] = src->data[0] + (top_band * src->linesize[0]) + left_band;
 273     dst->data[1] = src->data[1] + ((top_band >> y_shift) * src->linesize[1]) + (left_band >> x_shift);
 274     dst->data[2] = src->data[2] + ((top_band >> y_shift) * src->linesize[2]) + (left_band >> x_shift);
 275
 276     dst->linesize[0] = src->linesize[0];
 277     dst->linesize[1] = src->linesize[1];
 278     dst->linesize[2] = src->linesize[2];
 279     return 0;
 280 }
 281
 282 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width,
 283                    enum AVPixelFormat pix_fmt, int padtop, int padbottom, int padleft, int padright,
 284             int *color)
 285 {
 286     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
 287     uint8_t *optr;
 288     int y_shift;
 289     int x_shift;
 290     int yheight;
 291     int i, y;
 292
 293     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB ||
 294         !is_yuv_planar(desc)) return -1;
 295
 296     for (i = 0; i < 3; i++) {
 297         x_shift = i ? desc->log2_chroma_w : 0;
 298         y_shift = i ? desc->log2_chroma_h : 0;
 299
 300         if (padtop || padleft) {
 301             memset(dst->data[i], color[i],
 302                 dst->linesize[i] * (padtop >> y_shift) + (padleft >> x_shift));
 303         }
 304
 305         if (padleft || padright) {
 306             optr = dst->data[i] + dst->linesize[i] * (padtop >> y_shift) +
 307                 (dst->linesize[i] - (padright >> x_shift));
 308             yheight = (height - 1 - (padtop + padbottom)) >> y_shift;
 309             for (y = 0; y < yheight; y++) {
 310                 memset(optr, color[i], (padleft + padright) >> x_shift);
 311                 optr += dst->linesize[i];
 312             }
 313         }
 314
 315         if (src) { /* first line */
 316             uint8_t *iptr = src->data[i];
 317             optr = dst->data[i] + dst->linesize[i] * (padtop >> y_shift) +
 318                     (padleft >> x_shift);
 319             memcpy(optr, iptr, (width - padleft - padright) >> x_shift);
 320             iptr += src->linesize[i];
 321             optr = dst->data[i] + dst->linesize[i] * (padtop >> y_shift) +
 322                 (dst->linesize[i] - (padright >> x_shift));
 323             yheight = (height - 1 - (padtop + padbottom)) >> y_shift;
 324             for (y = 0; y < yheight; y++) {
 325                 memset(optr, color[i], (padleft + padright) >> x_shift);
 326                 memcpy(optr + ((padleft + padright) >> x_shift), iptr,
 327                        (width - padleft - padright) >> x_shift);
 328                 iptr += src->linesize[i];
 329                 optr += dst->linesize[i];
 330             }
 331         }
 332
 333         if (padbottom || padright) {
 334             optr = dst->data[i] + dst->linesize[i] *
 335                 ((height - padbottom) >> y_shift) - (padright >> x_shift);
 336             memset(optr, color[i],dst->linesize[i] *
 337                 (padbottom >> y_shift) + (padright >> x_shift));
 338         }
 339     }
 340     return 0;
 341 }
 342
 343 FF_DISABLE_DEPRECATION_WARNINGS
 344 #endif /* FF_API_AVPICTURE */