libavcore/imgutils.c

   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 /**
  20  * @file
  21  * misc image utilities
  22  */
  23
  24 #include "imgutils.h"
  25 #include "libavutil/pixdesc.h"
  26
  27 int av_fill_image_linesizes(int linesize[4], enum PixelFormat pix_fmt, int width)
  28 {
  29     int i;
  30     const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[pix_fmt];
  31     int max_step     [4];       /* max pixel step for each plane */
  32     int max_step_comp[4];       /* the component for each plane which has the max pixel step */
  33
  34     memset(linesize, 0, 4*sizeof(linesize[0]));
  35
  36     if (desc->flags & PIX_FMT_HWACCEL)
  37         return AVERROR(EINVAL);
  38
  39     if (desc->flags & PIX_FMT_BITSTREAM) {
  40         linesize[0] = (width * (desc->comp[0].step_minus1+1) + 7) >> 3;
  41         return 0;
  42     }
  43
  44     memset(max_step     , 0, sizeof(max_step     ));
  45     memset(max_step_comp, 0, sizeof(max_step_comp));
  46     for (i = 0; i < 4; i++) {
  47         const AVComponentDescriptor *comp = &(desc->comp[i]);
  48         if ((comp->step_minus1+1) > max_step[comp->plane]) {
  49             max_step     [comp->plane] = comp->step_minus1+1;
  50             max_step_comp[comp->plane] = i;
  51         }
  52     }
  53
  54     for (i = 0; i < 4; i++) {
  55         int s = (max_step_comp[i] == 1 || max_step_comp[i] == 2) ? desc->log2_chroma_w : 0;
  56         linesize[i] = max_step[i] * (((width + (1 << s) - 1)) >> s);
  57     }
  58
  59     return 0;
  60 }
  61
  62 int av_fill_image_pointers(uint8_t *data[4], enum PixelFormat pix_fmt, int height,
  63                            uint8_t *ptr, const int linesizes[4])
  64 {
  65     int i, total_size, size[4], has_plane[4];
  66
  67     const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[pix_fmt];
  68     memset(data     , 0, sizeof(data[0])*4);
  69     memset(size     , 0, sizeof(size));
  70     memset(has_plane, 0, sizeof(has_plane));
  71
  72     if (desc->flags & PIX_FMT_HWACCEL)
  73         return AVERROR(EINVAL);
  74
  75     data[0] = ptr;
  76     size[0] = linesizes[0] * height;
  77
  78     if (desc->flags & PIX_FMT_PAL) {
  79         size[0] = (size[0] + 3) & ~3;
  80         data[1] = ptr + size[0]; /* palette is stored here as 256 32 bits words */
  81         return size[0] + 256 * 4;
  82     }
  83
  84     for (i = 0; i < 4; i++)
  85         has_plane[desc->comp[i].plane] = 1;
  86
  87     total_size = size[0];
  88     for (i = 1; has_plane[i] && i < 4; i++) {
  89         int h, s = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
  90         data[i] = data[i-1] + size[i-1];
  91         h = (height + (1 << s) - 1) >> s;
  92         size[i] = h * linesizes[i];
  93         total_size += size[i];
  94     }
  95
  96     return total_size;
  97 }